Search

Background: The Committee on Standardization of Laboratory Testing Related to Diabetes Mellitus of the Japan Diabetes Society (JDS) previously recommended use of the primary calibrator (JDS Lot 1) prepared by the former Committee for Standardization of Glycohemoglobin for standardizing the measurement of haemoglobin A1c (HbA1c). Owing to the depletion of vials of Lot 1 in March 2001, the present committee certified a new reference material, Lot 2, now distributed by the Health Care Technology Foundation (HECTEF). The standardization programme for HbA1c measurement in Japan is currently based on Lot 2, which has values assigned from within Lot 1; the Lot 1 values were consensus values based on assays by laboratories in the Japanese national quality control programme. In this study, for the purpose of international comparison and standardization, Lot 2 was assayed by the JDS reference laboratories, the National Glycoprotein Standardization Program (NGSP) in the USA, and by reference laboratories approved by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). Method: The HbA1c values of JDS Lot 2 were transferred from those assigned to Lot 1 using KO500, a high-resolution HPLC method, at three laboratories approved by the JDS committee. Subsequently, vials of JDS Lot 2 were shipped to and assayed by the NGSP in the USA and 10 IFCC reference laboratories. Result: The JDS-assigned HbA1c values (from Lot 1) are 4.04 for Level 1, 5.38 for Level 2, 7.32 for Level 3, 9.88 for Level 4, and 12.63 for Level 5, all expressed as a percentage of total haemoglobin. The values obtained by NGSP and the IFCC laboratories gave the following formulas: NGSP value (%) = JDS value (%) + 0.3%; IFCC value (%) = 1.068 × JDS value (%) -1.741%. Conclusion: Although the values obtained by the IFCC laboratories are significantly lower than the values assigned to Lot 2 by the JDS, the relationship is linear. In addition, standardization of HbA1c based on JDS Lot 2 is currently at a satisfactory level in Japan. As a result, the reassignment of values for Lot 2 to agree with the IFCC values should be relatively easy and will be done after all relevant parties agree to the change. [ABSTRACT FROM AUTHOR]

Background: In 2001, the Committee on Standardization of Laboratory Testing Related to Diabetes Mellitus of the Japan Diabetes Society (JDS) prepared and certified a new reference material for haemoglobin A1c (HbA1c), Lot 2. The standardization programme for HbA1c measurement in Japan is currently based on Lot 2, although some laboratories still use the previous material (Lot 1). The values assigned to Lot 2 were based on the consensus values for Lot 1 and should give the same results. Therefore, there should be no difference in the measured values no matter which calibrators are used. The Committee conducted a domestic survey in order to confirm this relationship. Method: In November 2002, four samples for HbA1c assay were sent to 795 laboratories as part of a national survey in Japan. Assays were performed using the laboratories' routine clinical methods. The coefficients of variation (CVs) of the reported values from all laboratories for the samples were calculated in order to determine the current level of standardization in Japan. Results: The overall CVs in the measured values for the four samples ranged from 2.7% to 4.0%. Values from laboratories using calibrators based on Lots 1 and 2 were similar. Conclusion: The present state of standardization for the routine measurement of HbA1c in Japan, as indicated by the 2002 survey, is excellent. This should aid in the eventual conversion of Lot 2 to IFCC-based values from the results of the 2002 national HbA1c survey. [ABSTRACT FROM AUTHOR]

To clarify heterogeneity in Japanese adult-onset type 1 diabetes, we analyzed the HLA-DR and -DQ haplotypes, depending on the clinical phenotype, and compared them with those in childhood-onset type 1 diabetes (CO). The patients in a previously reported Ehime Study were divided into subgroups by the mode of onset of diabetes: 68 acute-onset type 1 diabetic patients (AO) and 28 slowly progressive type 1 diabetic patients (SO). HLA haplotypes were compared with those of 80 CO patients and 190 control subjects. Two major susceptible HLA haplotypes in the Japanese, DRB1*0405-DQB1*0401 (DR4) and DRB1*0901-DQB1*0303 (DR9), were significantly increased in the AO and CO groups, but only DR9 was increased in the SO group. AO subjects had a higher frequency of DR9 than CO subjects. Accordingly, the DR9:DR4 frequency increased with increasing age of onset. Another susceptible haplotype, DRB1*0802-DQB1*0302 (DR8), was involved only in the CO group. Analysis of haplotype combinations revealed that DR4 and DR9 had significant dosage effects on the AO and CO groups (P < 0.0001), but only DR9 had such an effect in the SO group (P < 0.03). These results suggest differences in the contribution of HLA class II haplotypes to susceptibility of type 1 diabetes depending on the clinical phenotype and also indicate that HLA class II haplotypes may be associated with the onset age of type 1 diabetes. [ABSTRACT FROM AUTHOR]

OBJECTIVE -- To examine the contribution of the CTLA4 gene in the susceptibility to fulminant type 1 diabetes and compare it with classic type 1A diabetes. RESEARCH DESIGN AND METHODS --We genotyped the +49G>A and CT60G>A variants of the CTLA4 gene in fulminant type 1 diabetic patients (n = 55), classic type 1A diabetic patients (n = 91), and healthy control subjects (n = 369). We also assessed serum levels of the soluble form of CTLA4 (sCTLA4). RESULTS -- The +49GG and CT60GG genotypes were associated with type 1A diabetes (P < 0.001). In contrast, the CT60AA genotype, but not the + 49G>A variation, was associated with fulminant type 1 diabetes (P < 0.05), especially in patients carrying HLA-DR4 (P < 0.01). Serum levels of sCTLA4 were significantly decreased in patients with fulminant type 1 diabetes (P < 0.05). CONCLUSIONS -- These results suggest that CTLA4 CT60 affects the genetic susceptibility to fulminant type 1 diabetes. Furthermore, the contribution of CTLA4 to disease susceptibility is distinct between fulminant type 1 diabetes and classic type 1A diabetes. [ABSTRACT FROM AUTHOR]

Aim/Introduction: Insulin administration was found to trigger type 1 diabetes in six Japanese type 2 diabetes patients with type 1 diabetes high‐risk human leukocyte antigen class II and the class I allele of the insulin gene variable number tandem repeat genotype. The objective of the present study was to assess the contribution of non‐human leukocyte antigen single‐nucleotide polymorphisms (SNPs) to the risk of developing insulin‐triggered type 1 diabetes. Materials and Methods: We genotyped 13 type 1 diabetes susceptible SNPs in six patients and compared them with those in Japanese controls (Hap Map3‐JPT). The SNPs that showed statistically significant results were further analyzed using non‐diabetic control participants and participants with type 2 diabetes at the Ehime University Hospital. Results: The risk allele frequency of BACH2 rs3757247 in the six patients was significantly more frequent than that in 86 Japanese controls (P = 0.038). No significant difference in the allele frequency was observed in the other SNPs. This result was confirmed by the findings that the risk allele frequency of BACH2 in the six patients was significantly higher than that in the non‐diabetic control participants (n = 179) and type 2 diabetes with or without insulin treatment (n = 154 or n = 152; P = 0.035, 0.034 or 0.037, respectively). Despite being statistically not significant, the six patients were all homozygous for the CLEC16A rs12708716 risk allele and five were homozygous for the CLEC16A rs2903692 risk allele. Conclusions: In addition to type 1 diabetes high‐risk human leukocyte antigen class II and the class I allele of the insulin gene variable number tandem repeat genotype, the possibility that the risk variants of BACH2 and CLEC16A could contribute to the development of insulin‐triggered type 1 diabetes cannot be excluded. [ABSTRACT FROM AUTHOR]

Presents a response to a letter to the editor of "Diabetes Care" regarding the results of a study on the clinical heterogeneity of patients with adult-onset diabetes and GAD autoantibodies.

Type 1 diabetes is a disease characterized by destruction of pancreatic β-cells, which leads to absolute deficiency of insulin secretion. Depending on the manner of onset and progression, it is classified as fulminant, acute-onset or slowly progressive type 1 diabetes. Here, we propose the diagnostic criteria for acute-onset type 1 diabetes mellitus. Among the patients who develop ketosis or diabetic ketoacidosis within 3 months after the onset of hyperglycemic symptoms and require insulin treatment continuously after the diagnosis of diabetes, those with anti-islet autoantibodies are diagnosed with 'acute-onset type 1 diabetes mellitus (autoimmune)'. In contrast, those whose endogenous insulin secretion is exhausted (fasting serum C-peptide immunoreactivity <0.6 ng/mL) without verifiable anti-islet autoantibodies are diagnosed simply with 'acute-onset type 1 diabetes mellitus'. Patients should be reevaluated after certain periods in case their statuses of anti-islet autoantibodies and/or endogenous insulin secretory capacity are unknown. [ABSTRACT FROM AUTHOR]

We have revised a part of the diagnostic criteria for fulminant type 1 diabetes. The new criteria were set both to express the essence of this disease of rapid increase of patients' blood glucose and to be highly sensitive to reduce the misdiagnosis. After analyzing the data of 382 patients with newly-diagnosed fulminant type 1 diabetes, we adopted the glycated hemoglobin (HbA1c) level of 8.7% (National Glycohemoglobin Standardization Program [ NGSP] value). The new criterion indicates 100% of sensitivity and the best value by receiver operating characteristic curve analysis. In addition, we added a comment that 'This value (HbA1c <8.7% in NGSP) is not applicable for patients with previously diagnosed glucose intolerance' in the new criteria and also a comment that 'Association with human leukocyte antigen DRB1*04:05- DQB1*04:01 is reported' as a related finding. We did not revise the screening criteria and the other part of the diagnostic criteria, because they are still reliable. [ABSTRACT FROM AUTHOR]

OBJECTIVE--Interferon therapy can trigger induction of several autoimmune diseases, including type 1 diabetes. To assess the clinical, immunologic, and genetic characteristics of type 1 diabetes induced by interferon therapy, we conducted a nationwide cross-sectional survey. RESEARCH DESIGN AND METHODS--Clinical characteristics, anti-islet autoantibodies, and HLA-DR typing were examined in 91 patients for whom type 1 diabetes developed during or shortly after interferon therapy. RESULTS--Median age at the onset of type I diabetes was 56 (interquartile range 48-63) years and mean ± SD BMI was 20.8 ± 2.7 kg/m². The time period from the imitation of interferon therapy to type 1 diabetes onset in patients receiving pegylated interferon and ribavirin was significantly shorter than that in patients with nonpegylated interferon single therapy (P < 0.05). Anti-islet autoantibodies were detected in 94.5% of patients at diabetes onset. Type 1 diabetes susceptibility HLA-DRs in the Japanese population, DR4 and DRg, were also associated with interferon treatment-related type 1 diabetes. Furthermore, the prevalence of HLA-DR13 was significantly higher in interferon treatment-related type 1 diabetes than in healthy control subjects (odds ratio 3.80 [95% CI 2.20-7.551; P < 0.0001) and classical type 1 diabetes (2.15 [1.17-3.93]; P < 0.05). CONCLUSIONS--Anti-islet autoantibodies should be investigated before and during interferon therapy to identify subjects at high risk of type 1 diabetes. Stronger antiviral treatment may induce earlier development of type 1 diabetes. Furthermore, patients who develop interferon-induced type 1 diabetes are genetically susceptible. [ABSTRACT FROM AUTHOR]

Background. The purpose of this study is to investigate the relationship between serum resistin levels and chronic kidney disease (CKD).Methods. A total of 3192 community-dwelling subjects (1377 men, 1815 women), aged ≥40 years and without renal failure, were divided into four groups according to quartiles of serum resistin concentrations: ≤7.1, 7.2–9.9, 10.0–14.7 and ≥14.8 ng/mL. The associations of resistin levels with renal function status were examined cross-sectionally. The estimated glomerular filtration rate (eGFR) was calculated using the equation from the Modification of Diet in Renal Disease Study, and CKD was defined as an eGFR of <60 mL/min/1.73 m2.Results. The age- and sex-adjusted mean values of eGFR decreased significantly with elevating quartiles of resistin (P for trend <0.001). The age- and sex-adjusted odds ratios (ORs) for the presence of CKD increased progressively with higher quartiles of resistin. This trend remained robust even after controlling for age, sex, body mass index, diabetes, homeostasis model assessment of insulin resistance (HOMA-IR), high-sensitivity C-reactive protein (hs-CRP), triglycerides, high-density lipoprotein and total cholesterol, hypertension, current smoking, current drinking, and regular exercise [second quartile: OR 1.44, 95% confidence interval (CI) 1.05–1.99; third quartile: OR 2.15, 95% CI 1.58–2.92; fourth quartile: OR 2.32, 95% CI 1.71–3.16; P for trend <0.001]. In stratified analyses, high resistin level (≥7.2 ng/mL) was a significant relevant factor in CKD, independent of HOMA-IR or hs-CRP level.Conclusion. Our findings suggest that elevated resistin level is significantly associated with the likelihood of CKD in the general Japanese population. [ABSTRACT FROM AUTHOR]

It was recently reported that GCKR rs780094 was associated with fasting plasma glucose (FPG) and triglyceride (TG) levels in various ethnic populations (A allele for low FPG and high TG). An association between GCKR rs780094 and type 2 diabetes mellitus (T2DM) (A allele for low risk) has also been reported. We examined the association between GCKR rs780094 and T2DM in Japanese subjects by analyzing 488 cases and 398 controls. A meta-analysis was performed involving two previous association studies. We also analyzed the association between the single-nucleotide polymorphism and clinical parameters in the general Japanese population (n=1854). In the case-control study, the A allele of GCKR rs780094 was associated with a reduced risk of T2DM (odds ratio=0.711 (95% confidence interval=0.589-0.859), P=4.2 × 10−4). A meta-analysis confirmed the association of GCKR rs780094 with T2DM susceptibility. In the general Japanese population, subjects with the A/A genotype had lower levels of FPG, fasting plasma insulin and homeostasis model assessment of insulin resistance than those with the G/G genotype. Conversely, subjects with the A/A genotype had higher levels of TG than those with the G/G genotype. We replicated GCKR rs780094 as a marker of T2DM susceptibility in Japanese subjects. This suggests that GCKR rs780094 is a common variant for T2DM susceptibility in various ethnic groups. [ABSTRACT FROM AUTHOR]

Insulin resistance is a feature of type 2 diabetes. Resistin, secreted from adipocytes, causes insulin resistance in mice. We previously reported that the G/G genotype of single nucleotide polymorphism (SNP) at 2420 (rs1862513) in the human resistin gene (RETN) increased susceptibility to type 2 diabetes by enhancing its promoter activity. Plasma resistin was highest in Japanese subjects with G/G genotype, followed by C/G, and C/C. In this study, we cross-sectionally analyzed plasma resistin and SNPs in the RETN region in 2,019 community-dwelling Japanese subjects. Plasma resistin was associated with SNP-638 (rs34861192), SNP-537 (rs34124816), SNP-420, SNP-358 (rs3219175), SNP+299 (rs3745367), and SNP+1263 (rs3745369) (P<10-13 in all cases). SNP-638, SNP -420, SNP-358, and SNP+157 were in the same linkage disequilibrium (LD) block. SNP-358 and SNP-638 were nearly in complete LD (r² = 0.98), and were tightly correlated with SNP-420 (r² = 0.50, and 0.51, respectively). The correlation between either SNP-358 (or SNP-638) or SNP-420 and plasma resistin appeared to be strong (risk alleles for high plasma resistin; A at SNP-358, r² = 0.5224, P = 4.94 × 10-324; G at SNP-420, r² = 0.2616, P = 1.71 × 10-133). In haplotypes determined by SNP-420 and SNP-358, the estimated frequencies for C-G, G-A, and G-G were 0.6700, 0.2005, and 0.1284, respectively, and C-A was rare (0.0011), suggesting that subjects with A at 2358, generally had G at 2420. This G-A haplotype conferred the highest plasma resistin (8.24 ng/ml difference/allele compared to C-G, P,0.0001). In THP-1 cells, the RETN promoter with the G-A haplotype showed the highest activity. Nuclear proteins specifically recognized one base difference at SNP-358, but not at SNP-638. Therefore, A at -358 is required for G at 2420 to confer the highest plasma resistin in the general Japanese population. In Caucasians, the association between SNP-420 and plasma resistin is not strong, and A at 2358 may not exist, suggesting that SNP-358 could explain this ethnic difference. [ABSTRACT FROM AUTHOR]

Objective The Ala allele of the Pro12Ala polymorphism (rs1801282) of peroxisome proliferator-activated receptor γ (PPARγ) is protective against type 2 diabetes (T2DM). Resistin, secreted from adipocytes, causes insulin resistance in rodents. Resistin gene expression is reduced by the PPARγ ligand. We previously reported that subjects with the G/G genotype of a resistin gene single nucleotide polymorphism (SNP) at –420 (rs1862513) had the highest circulating resistin levels, followed by C/G and C/C. The aim of this study was to determine the relationship among PPARγ Pro12Ala polymorphism, resistin SNP-420, and plasma resistin. Design, patients and measurements We cross-sectionally analysed 2077 community-dwelling subjects attending an annual medical check-up. Genotypes were determined by TaqMan analysis. Fasting plasma resistin was measured using ELISA. Results Plasma resistin appeared to be higher in subjects with the Pro/Pro genotype of PPARγ than those with Pro/Ala and Ala/Ala genotypes (mean ± SE, 11·6 ± 0·2 vs. 10·4 ± 0·5 μg/l). Multiple regression analysis, adjusted for age, gender, BMI, and resistin SNP-420, revealed that the Pro/Pro genotype was a positive predictor of plasma resistin (PPARγ ,  Pro/Pro vs. Pro/Ala + Ala/Ala, unstandardized regression coefficient (β) = 1·03, P = 0·0384). The effects of the Pro/Pro genotype of PPARγ (Pro/Pro vs. Pro/Ala + Ala/Ala) and the G/G genotype of resistin SNP-420 (G/G vs. C/C) on plasma resistin were synergistic (β = 4·76, P = 0·011). Conclusions The PPARγ Pro12Ala Pro/Pro and resistin SNP-420 G/G genotypes were synergistically associated with plasma resistin, when adjusted for age, gender, and BMI, in the Japanese general population. [ABSTRACT FROM AUTHOR]

OBJECTIVE--The present study was conducted to confirm possible associations between candidate genes from genome-wide association studies and type 2 diabetes in Japanese diabetic patients and a community-based general population. A total of 11 previously reported single-nucleotide polymorphisms (SNPs) from the TCF7L2, CDKAL1, HHEX, IGF2BP2, CDKN2A/B, SLC30A8, and KCNJ11 genes were analyzed. RESEARCH DESIGN AND METHODS--Candidate SNPs were genotyped in 506 type 2 diabetic patients and 402 control subjects and meta-analyzed with six previous association studies in Japanese patients. Associations with fasting plasma insulin levels were investigated in a general population sample (n = 1,963, 61 ± 13 years). RESULTS--In our case-control subjects, susceptibility to type 2 diabetes was replicated in TCF7L2 (rs12255372), CDKAL1 (rs7756992, rs7754840), HHEX (rs7923837), IGF2BP2 (rs4402960 and rs1470579), CDKN2A/B (rs10811661), and SLC30A8 (rs13266634). In addition to these polymorphisms, meta-analysis confirmed the association of type 2 diabetes susceptibility with KCNJ11 rs5219, TCF7L2 rs7903146, and HHEX rs1111875. The TCF7L2 rs12255372 polymorphism showed the highest odds ratio (OR) for type 2 diabetes (OR 1.714 [1.298-2.263]). Odds ratio of other polymorphisms ranged from 1.13 to 1.41. The risk allele of CDKAL1 rs7756992 was significantly associated with lower insulin levels in type 2 diabetic patients after adjustment for other confounding factors. CONCLUSIONS--Type 2 diabetes susceptibility of seven candidate genes was confirmed in Japanese. Conservation of susceptible loci for type 2 diabetes was independent of ethnic background. Diabetes 58:493-498, 2009 [ABSTRACT FROM AUTHOR]

Abstract: To clarify the detailed clinical features and HLA subtype in the patients with fulminant type 1 diabetes, we investigated consecutive 250 case records registered to the committee of the Japan Diabetes Society between 2000/7/15 and 2006/6/30. After the classification with age at onset or gender, clinical data and HLA DR were evaluated. As a result, the prevalence of male patients, BMI, HbA1c and ALT levels at the onset increased significantly according to the elder quartile, but no other data showed any significant difference. Only age at onset and blood glucose level were significantly higher in male patients than in female patients without pregnancy by multivariate analysis. The distribution of HLA DR was not different in any subtype by gender or age at onset. Our present study revealed common feature in clinical and HLA-DR status regardless of age and gender within fulminant type 1 diabetes except pregnant women. [Copyright &y& Elsevier]

Objective The c-Jun N-terminal kinase 1 (JNK1, mitogen-activated kinase 8; MAPK8) phosphorylates insulin receptor substrate-1 (IRS-1) at serine 307, which induces insulin resistance. MAPK8 activity is increased in obese insulin-resistant mice, whereas mapk8 (–/–) mice show decreased adiposity and improved insulin sensitivity. The aim of this study was to determine the relationship between single nucleotide polymorphisms (SNPs) of MAPK8 and type 2 diabetes (T2DM). Design, patients and measurements Approximately 2 kb of 5′ flanking and the coding regions were initially sequenced in 24 Japanese T2DM subjects. Identified SNPs were genotyped in 204 T2DM cases and 201 nondiabetic controls. The function of promoter SNP–1066 (g.–1066G > A, rs10857561) was analysed by electrophoretic mobility shift assay (EMSA) and luciferase assay. SNP–1066 was further genotyped in a total of 498 cases and 407 controls, and in 2075 subjects in the general population. Results In 204 cases and 201 controls, 11 identified SNPs were not associated with T2DM. These SNPs were in the same linkage disequilibrium (LD) block. The tag SNP–1066 was not associated with T2DM in a total of 498 cases and 407 controls with the power > 80% when the relative risk is > 1·31. Functionally, transcription factor AP2α specifically recognized G but not A at –1066. MAPK8 promoter activity was unchanged between G and A. In 2075 subjects, neither body mass index (BMI), fasting plasma glucose (FPG), homeostasis model assessment insulin resistance index (HOMA-IR), nor β cell function index (HOMA-β) was associated with SNP–1066. Conclusions The G/G genotype of MAPK8 SNP–1066 did not affect T2DM susceptibility despite specific binding of AP2α. [ABSTRACT FROM AUTHOR]

Objective Resistin, secreted from adipocytes, causes insulin resistance in rodents. We reported that the G/G genotype of a resistin gene promoter single nucleotide polymorphism (SNP) at −420 increases type 2 diabetes (T2DM) susceptibility by enhancing promoter activity. We also showed that serum resistin was positively correlated with G at SNP-420, the duration of T2DM, and HbA1c in T2DM. The aim of this study was to determine the relation between serum resistin and factors related to the metabolic syndrome (MetS) in T2DM. Design, patients and measurements We analysed 238 Japanese T2DM subjects (124 males and 114 females, age 60·2 ± 11·3 years, body mass index (BMI) 24·1 ± 3·9) whose overnight fasting sera were available. Serum resistin was measured using ELISA. Results Serum resistin was higher in subjects with either obesity ( P = 0·041), low HDL ( P = 0·004), high triglycerides (TG) ( P = 0·019), hypertension (HT) ( P = 0·001) or atherosclerosis ( P = 0·012). Simple regression analysis revealed that serum resistin was correlated with lower HDL, TG and high-sensitivity C-reactive protein (hsCRP). Multiple regression analysis (or logistic regression analysis for HT), adjusted for age, gender, BMI and the duration of T2DM, revealed that serum resistin was correlated with lower HDL ( P = 0·008), TG ( P = 0·041), HT ( P = 0·031) and hsCRP ( P = 0·004). Serum resistin was positively correlated with the number of MetS factors, independent of age, gender and the duration of T2DM ( P < 0·001). Adjustment by either thiazolidinedione (TZD) treatment or hsCRP had no effects on these findings. Conclusions Serum resistin was positively correlated with the accumulation of MetS factors in T2DM. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To clarify the natural course and factors involved in beta cell failure in Japanese latent autoimmune diabetes in adults (LADA) patients. Research design and methods: Insulin secretion in 57 LADA patients identified from among 4980 adult-onset diabetic patients in a hospital-based Ehime study were examined over a 5-year period. Postprandial serum C-peptide levels below 0.33nmol/l were defined as beta cell failure. The involvement of clinical and immunological factors in the progression to beta cell failure were evaluated. Results: Forty-two of the fifty-seven LADA patients completed the 5-year follow-up. Eleven (26.2%) required insulin treatment and five (11.9%) progressed to beta cell failure. A Cox regression analysis revealed that positive anti-thyroid peroxidase antibody (TPOAb) and insulinoma-associated protein 2 (IA-2Ab) were associated with the need for insulin treatment (p <0.05 and p <0.01, respectively). Positive TPOAb, anti-thyroglobulin antibody (TGAb), IA-2 antibody (p <0.01 for each), and lower serum fasting C-peptide levels (p <0.05) were contributors to the progression to beta cell failure. Involvement of type 1 diabetes susceptible HLA class II genes was not evident. Conclusions: Japanese LADA patients are a heterogeneous population. In addition to IA-2 antibody, presence of TPOAb and fasting C-peptide level could indicate an oncoming deterioration of beta cell function. [Copyright &y& Elsevier]

Objective Adiponectin is secreted specifically from adipocytes, and improves insulin sensitivity. Of its isoforms, the high molecular weight (HMW) complex is thought to be the most active. The aim of this study was to determine the relationship between serum total or HMW adiponectin and diabetic microangiopathy. Design, patients and measurements We analysed 198 Japanese patients with type 2 diabetes mellitus (T2DM) whose fasting serum samples were available. Serum total adiponectin and HMW adiponectin were measured using an enzyme-linked immunosorbent assay (ELISA). Results Serum total adiponectin was found to have increased in the advanced stages of diabetic retinopathy (mean ± SE, none, 6·9 ± 0·3; simple, 8·3 ± 1·0; preproliferative, 8·4 ± 0·8; proliferative, 12 ± 1·1 mg/l;anova P = 0·0004) and nephropathy (stage I, 7·0 ± 0·3; II, 7·7 ± 0·5; III, 9·5 ± 0·9; IV, 16 ± 4·5 mg/l, P < 0·0001). Similarly, serum HMW adiponectin had increased in the advanced stages of retinopathy (3·7 ± 0·2, 4·6 ± 0·5, 4·6 ± 0·6 and 6·9 ± 0·8 mg/l, respectively, P = 0·0005) and nephropathy (3·7 ± 0·2, 4·3 ± 0·4, 5·3 ± 0·7 and 7·9 ± 2·2 mg/l, respectively, P = 0·0007). Neither serum total nor HMW adiponectin was correlated with neuropathy. The HMW/total adiponectin ratio was not correlated with microangiopathy. Multiple regression analysis revealed that serum total and HMW adiponectin were independent factors for retinopathy stage ( P = 0·0055 and P = 0·0027, respectively) and nephropathy stage ( P = 0·0003 and P = 0·0018, respectively), when adjusted for age, gender, body mass index (BMI) and the duration of T2DM. This correlation remained significant when serum creatinine (or estimated glomerular filtration rate) and hypertension were added as independent variables. Treatment with thiazolidinediones (TZDs) did not affect these findings. Conclusions Serum total adiponectin and HMW adiponectin were found to be positively correlated with the severity of retinopathy and nephropathy but not with neuropathy in T2DM. [ABSTRACT FROM AUTHOR]

Abstract: Insulin administration causes various types of immune response to insulin. However, there have been no reports that insulin administration triggers pancreatic β-cell destruction in diabetic patients. We evaluated three patients who had suffered from type 2 diabetes or impaired glucose tolerance for 5–30 years. After an episode of diabetic mononeuropathy or poor glycemic control, they started human insulin therapy. All the patients’ serum or urinary C-peptide levels were preserved before insulin therapy, whereas within a few months they rapidly declined to below detection limits. A high titer of insulin antibody was detected at or after the development of insulin deficiency. Shortly after the initiation of insulin therapy, two of the patients developed an insulin allergy. Autoantibodies to GAD65 or IA-2 were negative throughout the clinical course in two cases, but transiently positive in one case. In a histological examination of pancreas tissue obtained by a pancreatic biopsy in one case, mononuclear cell infiltration into the islets was observed. They all had a type 1 diabetes high-risk HLA class II haplotype in Japanese, and class I alleles of the insulin gene VNTR. The above findings suggest that insulin administration may have triggered pancreatic β-cell destruction in these patients. [Copyright &y& Elsevier]

Transcription factor 7-like 2 ( TCF7L2) has been shown to be associated with type 2 diabetes mellitus in multiple ethnic groups. Regarding the Asian population, Horikoshi et al. (Diabetologia 50:747–751, 2007) and Hayashi et al. (Diabetologia 50:980–984, 2007) reported that single nucleotide polymorphisms (SNPs) in TCF7L2 were associated with type 2 diabetes in the Japanese population, while contradictory results were reported for Han Chinese populations. The aim of this study was to investigate the associations of the TCF7L2 gene with type 2 diabetes using a relatively large sample size: 2,214 Japanese individuals with type 2 diabetes and 1,873 normal controls. The minor alleles of rs7903146, rs11196205, and rs12255372 showed significant associations with type 2 diabetes (OR = 1.48, P = 2.7 × 10−4; OR = 1.39, P = 4.6 × 10−4; OR = 1.70, P = 9.8 × 10−5, respectively) in the combined sample sets. However, neither rs11196218 nor rs290487 showed a significant association. These results indicate that TCF7L2 is an important susceptibility gene for type 2 diabetes in the Japanese population. [ABSTRACT FROM AUTHOR]

OBJECTIVE--Resistin is an adipocyte-secreted cytokine associated with insulin resistance in mice. We previously reported that the G/G genotype of a resistin single nucleotide polymorphism (SNP) at -420 increases type 2 diabetes susceptibility by enhancing its promoter activity. The aim of the present study was to determine the relevance of SNP -120 in a large number of subjects. RESEARCH DESIGN AND METHODS--We examined 2,610 type 2 diabetic case and 2,502 control subjects. The relation between SNP -420 and the age of type 2 diabetes onset was further analyzed by adding 237 type 2 diabetic subjects with age of onset ≤40 years. RESULTS--When analyzed without considering subject age, the SNP -420 genotype was not associated with type 2 diabetes. Since we reported that the onset of type 2 diabetes was earlier in G/G genotype, we analyzed the data using a trend test for age intervals of 10 years. The frequency of G/G genotype differed among age grades in type 2 diabetes (P = 0.037) and appeared to be higher in younger grades. In type 2 diabetes, G/G genotype was more frequent in subjects aged <40 years than in those aged ≥40 years (G/G vs. C/C, P = 0.003). In a total of 2,430 type 2 diabetic subjects with age of onset <60 years, the trend test showed that the G/G genotype had an increasing linear trend as the age grade of type 2 diabetes onset became younger (P = 0.0379). In control subjects, the frequency of C/G genotype showed an increasing linear trend with increasing age (P = 0.010). CONCLUSIONS--The G/G genotype frequency of resistin SNP -420 appears to be increased in younger-onset type 2 diabetic subjects. Diabetes 56:2834-2838, 2007 [ABSTRACT FROM AUTHOR]

OBJECTIVE -- Resistin, secreted from adipocytes, causes insulin resistance in rodents. We previously reported that the G/G genotype of a resistin gene promoter single nucleotide polymorphism (SNP) at -420 increases type 2 diabetes susceptibility by enhancing promoter activity. We report here on the relation between plasma resistin and either SNP -420 genotype or factors related to insulin resistance. RESEARCH DESIGN AND METHODS -- We cross-sectionally analyzed 2,078 community-dwelling Japanese subjects attending a yearly medical checkup. The SNP -420 genotype was determined by TaqMan analysis. Fasting plasma resistin was measured using an enzyme-linked immunosorbent assay kit. RESULTS -- Plasma resistin was associated with the SNP -420 genotype (P < 0.0001), which was highest in G/G followed by C/G and C/C. Plasma resistin was higher in elderly individuals, female subjects, nondrinkers, and subjects with high blood pressure (P < 0.001, 0.003, <0.001, and 0.001, respectively). Simple regression analysis revealed that age, female sex, homeostasis model assessment of insulin resistance (HOMA-IR) index, systolic blood pressure, low HDL cholesterol, and high-sensitivity C-reactive protein (hs-CRP) were positively correlated with plasma resistin (P <0.001, 0.003, <0.001, 0.004, <0.001, and 0.003, respectively). Multiple regression analysis adjusted for age, sex, and BMI revealed that plasma resistin was an independent factor for HOMA-IR, low HDL cholesterol, and hs-CRP (P = 0.001, <0.001, and 0.006, respectively). CONCLUSIONS -- Plasma resistin was associated with SNP -420 and was correlated with insulin resistance, low serum HDL cholesterol, and high hs-CRP in the Japanese general population. [ABSTRACT FROM AUTHOR]

Abstract: Resistin, secreted from adipocytes, causes insulin resistance and diabetes in rodents. To determine the relation between serum resistin and diabetic microangiopathies in humans, we analyzed 238 Japanese T2DM subjects. Mean serum resistin was higher in subjects with either advanced retinopathy (preproliferative or proliferative) (P =0.0130), advanced nephropathy (stage III or IV) (P =0.0151), or neuropathy (P =0.0013). Simple regression analysis showed that serum resistin was positively correlated with retinopathy stage (P =0.0212), nephropathy stage (P =0.0052), and neuropathy (P =0.0013). Multiple regression analysis adjusted for age, gender, and BMI, revealed that serum resistin was correlated with retinopathy stage (P =0.0144), nephropathy stage (P =0.0111), and neuropathy (P =0.0053). Serum resistin was positively correlated with the number of advanced microangiopathies, independent of age, gender, BMI, and either the duration of T2DM (P =0.0318) or serum creatinine (P =0.0092). Therefore, serum resistin was positively correlated with the severity of microangiopathies in T2DM. [Copyright &y& Elsevier]

Abstract: Phosphodiesterase 3B (PDE3B), a major PDE isoform in adipocytes, plays a pivotal role in the anti-lipolytic action of insulin. Insulin phosphorylates and activates PDE3B in a phosphatidylinositol 3-kinase-dependent manner. We identified a new 50kDa protein that is phosphorylated by insulin and is co-immunoprecipitated with PDE3B by anti-PDE3B antibodies in rat adipocytes. The insulin-induced phosphorylation of the 50kDa protein was also detected in a cell free system against the N-terminal and the catalytic regions, which are more than 700 amino acids apart recognize the 50kDa protein, suggesting that it is not a proteolytic product, but an associated protein with PDE3B. Phosphoamino acid analysis indicated that both serine and threonine residues in the 50kDa protein were phosphorylated, but only serine residues in PDE3B were phosphorylated. Therefore, it appears likely that this is a new protein which is associated with PDE3B. [Copyright &y& Elsevier]

Abstract: Resistin, secreted from adipocytes, causes insulin resistance in rodents. Its roles and main source in humans remain unknown. The G/G genotype of resistin single nucleotide polymorphism, SNP-420, induces type 2 diabetes mellitus (T2DM) by increasing promoter activity. We elucidated factors correlated with serum resistin and effects of SNP-420 on monocyte resistin mRNA. In 198 T2DM and 157 controls, fasting serum resistin was higher in T2DM. Multiple regression analysis revealed that SNP-420 genotype was the strongest determinant of serum resistin. In T2DM, 1-year duration of T2DM and 1% HbA1c was also correlated with 0.19 and 0.54ng/ml serum resistin, respectively. Logistic regression analysis revealed that serum resistin was an independent factor for T2DM. In 23 healthy volunteers, monocyte resistin mRNA was positively correlated with its simultaneous serum levels and was higher in G/G genotype. Thus, SNP-420 determines monocyte mRNA and serum levels of resistin, which could induce T2DM. [Copyright &y& Elsevier]

Insulin resistance is a major cause of type 2 diabetes mellitus (T2DM). Resistin, an adipocyte-secreted hormone, antagonizes insulin. Transgenic mice that overexpress the resistin gene (Rem) in adipose tissue are insulin-resistant, whereas Rem (-/-) mice show lower fasting blood glucose, suggesting that the altered Retn promoter function could cause diabetes. To determine the role of RETN in human T2DM, we analyzed polymorphisms in its 5' flanking region. We found that the - 420G/G genotype was associated with T2DM (397 cases and 406 controls) (P = .008; adjusted odds ratio = 1.97 [by logistic regression analysis]) and could accelerate the onset of disease by 4.9 years (P = .006 [by multiple regression analysis]). Meta-analysis of 1,888 cases and 1,648 controls confirmed this association (P = .013). Linkage disequilibrium analysis revealed that the - 420G/G genotype itself was a primary variant determining T2DM susceptibility. Functionally, Sp1 and Sp3 transcription factors bound specifically to the susceptible DNA element that included -420G. Overexpression of Sp1 or Sp3 enhanced RETN promoter activity with - 420G in Drosophila Schneider line 2 cells that lacked endogenous Sp family members. Consistent with these findings, fasting serum resistin levels were higher in subjects with T2DM who carried the - 420G/G genotype. Therefore, the specific recognition of - 420G by Sp⅓ increases RETN promoter activity, leading to enhanced serum resistin levels, thereby inducing human T2DM. [ABSTRACT FROM AUTHOR]

Resistin, specifically secreted from adipocytes, antagonizes insulin and represents a promising candidate gene for type 2 diabetes. We reported that a frequent single nucleotide polymorphism (SNP) +299G>A in this gene is not associated with type 2 diabetes. To determine whether this SNP affects insulin resistance syndrome associated with type 2 diabetes, we examined its effects on susceptibility to obesity, hyperlipidemia and hypertension in type 2 diabetic subjects and on susceptibility to type 2 diabetes by interaction with other frequent genes involved in lipid metabolism, namely, β3-adrenergic receptor (b3AR) Trp64Arg, phosphodiesterase 3B (PDE3B) c.1389G>A or lysosomal acid lipase (LAL) Thr-6Pro. The 99 type 2 diabetic and 99 control subjects were typed by PCR direct sequencing or PCR-RFLP. No differences in frequencies of obesity, hyperlipidemia and hypertension were found between the type 2 diabetic subjects with G/G and those with G/A or A/A genotypes of the resistin SNP. When the combination of the resistin SNP with each of b3AR, PDE3B and LAL SNPs was assessed, no association with type 2 diabetes was evident. Therefore, the frequent SNP +299G>A in the resistin gene is unlikely to have major effects on susceptibility to insulin resistance syndrome associated with type 2 diabetes in Japanese subjects. [Copyright &y& Elsevier]

Objective: To describe the clinical and immunologic characteristics of fulminant type 1 diabetes, a novel subtype of type 1 diabetes, we conducted a nationwide survey.Research Design and Methods: History and laboratory data, including islet-related autoantibodies, were examined in 222 patients with fulminant and nonfulminant type 1 diabetes in our hospitals in addition to another 118 patients with fulminant type 1 diabetes located outside our hospitals in Japan.Results: In our hospitals, of the 222 patients studied, 43 (19.4%) were diagnosed with fulminant type 1 diabetes, 137 (61.7%) were classified as having autoimmune type 1 diabetes, and 42 were type 1 diabetic subjects who were not fulminant and did not have anti-islet antibodies. An additional 118 fulminant patients outside our hospitals were enrolled, making a total of 161 fulminant type 1 diabetic subjects (83 male and 78 female subjects; 14 children/adolescents and 147 adults) identified from all over Japan. (In 2000, the average incidence was three cases per month.) Flu-like symptoms and pregnancy were more frequently observed in the fulminant than in the autoimmune group (P < 0.001). In the fulminant patients, 4.8% were positive for anti-GAD antibodies and none were positive for anti-islet antigen 2 antibodies.Conclusions: Fulminant type 1 diabetes is a distinct subtype and accounts for approximately 20% of the ketosis-onset type 1 diabetes cases in Japan. Flu-like symptoms are characteristic of disease onset. Metabolic derangement is more severe in this subtype than in autoimmune type 1 diabetes. [ABSTRACT FROM AUTHOR]

OBJECTIVE — To describe the clinical and immunologic characteristics of fulminant type 1 diabetes, a novel subtype of type 1 diabetes, we conducted a nationwide survey. RESEARCH DESIGN AND METHODS — History and laboratory data, including isletrelated autoantibodies, were examined in 222 patients with fulminant and nonfulminant type 1 diabetes in our hospitals in addition to another 118 patients with fulminant type 1 diabetes located outside our hospitals in Japan. RESULTS — In our hospitals, of the 222 patients studied, 43 (19.4%) were diagnosed with fulminant type 1 diabetes, 137 (61.7%) were classified as having autoimmune type 1 diabetes, and 42 were type 1 diabetic subjects who were not fulminant and did not have anti-islet antibodies. An additional 118 fulminant patients outside our hospitals were enrolled, making a total of 161 fulminant type 1 diabetic subjects (83 male and 78 female subjects; 14 children/ adolescents and 147 adults) identified from all over Japan. (In 2000, the average incidence was three cases per month.) Flu-like symptoms and pregnancy were more frequently observed in the fulminant than in the autoimmune group (P < 0.001). In the fulminant patients, 4.8% were positive for anti-GAD antibodies and none were positive for anti-islet antigen 2 antibodies. CONCLUSIONS — Fulminant type 1 diabetes is a distinct subtype and accounts for ∼20% of the ketosis-onset type 1 diabetes cases in Japan. Flu-like symptoms are characteristic of disease onset. Metabolic derangement is more severe in this subtype than in autoimmune type 1 diabetes. [ABSTRACT FROM AUTHOR]

Phosphodiesterase 3B (PDE3B) gene expression is generally reduced in large adipocytes of obese, insulin-resistant mice. This reduced gene expression is restored by peroxisome proliferator-activated receptor (PPAR) γ ligands accompanied by a reduced fat cell size. To determine whether PDE3B gene expression is regulated by PPARγ itself, we analyzed lean PPARγ (+/−) mice with adipocyte size comparable to control PPARγ (+/+) mice. In adipocytes of PPARγ (+/−) mice, PDE3B mRNA and protein were both reduced to 63% of wild-type levels. Basal PDE activity tended to be decreased to 70% of wild-type levels, and, similarly, insulin-induced PDE activity was significantly decreased to 70%. Thus, PPARγ is required for PDE3B gene expression independent of adipocyte size. [Copyright &y& Elsevier]

The activation of phosphodiesterase 3B (PDE3B) reduces free fatty acid output from adipocytes. A reduced PDE3B gene expression could lead to insulin resistance. To determine whether there are polymorphisms associated with type 2 diabetes in PDE3B gene promoter, this 5′ flanking region was isolated. The transcription initiation site was located 206 bp upstream from the translation start site. Sequences of 2 kb of the 5′ flanking region for 24 type 2 diabetic Japanese subjects were initially analyzed using PCR direct sequencing, and the regions including the identified polymorphisms were then examined. In 98 controls and 98 type 2 diabetic subjects, −1947T > C, −567G > A, −465G > T, −458T > C, and −1727_−1726insTCAATT were found. Only −465G > T and this insertion had more than 5% frequencies. Since a complete linkage disequilibrium existed between them, −465G > T was further analyzed, along with a previously identified +1389G > A in the coding region, in a total of 200 controls and 207 type 2 diabetic subjects. These allele frequencies were not significantly different between these two groups (controls vs. cases; −465G > T, 12.0% vs. 10.1%, P=0.435; +1389G > A, 30.3% vs. 33.3%, P=0.408). These genotype distributions were not significantly different between these two groups. The T/T genotype at −465 was rare although this frequency could be higher in type 2 diabetes (4/207 subjects) than controls (0/200 subjects). The linkage disequilibrium existed between −465G > T and +1389G > A, and the estimated haplotype frequencies defined by these SNPs were not significantly different between the cases and controls. Thus, the identified polymorphisms are unlikely to have major effects on susceptibility to Japanese type 2 diabetes. [Copyright &y& Elsevier]

FOXC2, a forkhead/winged helix transcription factor, represents a promising candidate gene for type 2 diabetes since transgenic mice that specifically overexpress this gene in adipocytes are lean and insulin sensitive. To determine whether there are single nucleotide polymorphisms (SNPs) in this gene that are associated with type 2 diabetes, sequences of the coding and approximately 1 kb of 5' flanking regions in 24 Japanese type 2 diabetic subjects were initially analyzed using PCR direct sequencing, and the regions containing the identified polymorphisms were then examined. In 200 control subjects, three frequent SNPs were found (g. -512C>T [32.3%] and -350G>T [13.0%] in the 5' flanking region and +1548C>T [10.0%] in the 3' flanking region). Linkage disequilibria were found between all three pairs of these SNPs. Of the eight possible haplotypes defined by these SNPs, only four were found. When the frequencies of these SNPs and the four common haplotypes between 195 type 2 diabetic and 200 control subjects were compared, no association was evident. The +898C>T (Pro300Ser), +907C>A (Leu303Met), 1167_1169delCCA (389delHis), and +1251C>A (Ala417Ala) identified in the coding region were rare, although +907C>A could be higher in type 2 diabetic subjects (1.5%) than in control subjects (0.3%). Thus, the SNPs identified in the FOXC2 gene are unlikely to have major effects on susceptibility to Japanese type 2 diabetes. [ABSTRACT FROM AUTHOR]

Phosphodiesterase (PDE)-3B, a major PDE isoform in adipocytes, plays a pivotal role in the antilipolytic action of insulin. Insulin-induced phosphorylation and activation of PDE3B is phosphatidylinositol 3-kinase (PI3-K) and Akt dependent, but the precise mechanism of PDE3B activation is not fully understood. We have identified 14-3-3 beta, a critical scaffolding molecule in signal transduction, as a protein that interacts with PDE3B using the yeast two-hybrid system. The interaction between PDE3B and 14-3-3 beta was then confirmed in vitro. The glutathione S-transferase (GST)-tagged 14-3-3 beta interacts with endogenous PDE3B of rat adipocytes, and this interaction is enhanced when adipocytes are treated with insulin. Coimmunoprecipitation experiments reveal that endogenous PDE3B also associates with endogenous 14-3-3 beta in rat adipocytes, and this interaction is enhanced by insulin. Two different PI3-K inhibitors, wortmannin and Ly294002, block this induction, suggesting that PI3-K is required. Synthetic 15 amino acid peptides of rat PDE3B containing phosphorylated Ser-279 or -302 inhibit this interaction, indicating that the insulin-regulated phosphorylation of these serine residues is involved. Because insulin receptor substrate-1 also associates with 14-3-3, the dimeric 14-3-3 beta could function as a scaffolding protein in the activation of PDE3B by insulin. [ABSTRACT FROM AUTHOR]

Phosphodiesterase (PDE) 3B, a major isoform of PDE in adipocytes, mediates the antilipolytic action of insulin. PDE3B gene expression is generally reduced in adipocytes of either monogenic or polygenic rodent models of obese, insulin-resistance. An increased fat cell size, a common feature of obesity, could account for this reduction. Insulin receptor substrate-1 (IRS-1) (−/−) mice are lean with a reduced fat cell size and have insulin resistance due to a primary defect of insulin signaling. To determine whether the regulation of PDE3B gene expression is correlated with fat cell size, we examined this gene expression in adipose tissues of IRS-1 (−/−) mice. In IRS-1 (−/−) mice, PDE3B mRNA and protein levels were increased 1.24- and 1.35-fold those in C57BL/6J control mice, respectively. Independently, the fold induction of PDE activity by insulin (insulin-induced/basal) was 1.7-fold in control mice, but was reduced to 1.35-fold in IRS-1 (−/−) mice. Thus, PDE3B gene expression may be inversely correlated with a fat cell size, whereas insulin-induced PDE3B activation is mediated through IRS-1. [Copyright &y& Elsevier]

Objective: To characterize the clinical, autoimmune, and genetic features in Japanese adult-onset diabetic patients with GAD autoantibodies.Research Design and Methods: GAD autoantibodies (GADab) were screened in 4,980 diabetic patients with age of onset >20 years in the hospital-based Ehime Study, and the GADab-positive (GADab(+)) patients were then divided into two groups according to their insulin secretion and compared with nondiabetic subjects. The insulin-deficient state was defined as <0.33 nmol/l serum C-peptide (CPR) at 2 h postprandial or 6 min after a 1-mg glucagon load.Results: GADab was detected in 188 (3.8%) of the 4,980 diabetic patients tested. Of these patients, 72 (38.3%) were classified as insulin deficient, 97 (51.6%) were classified as non-insulin deficient, and 19 (10.1%) were unclassified. The GADab(+) insulin-deficient patients were characterized by young age at onset of diabetes, low BMI, low maximum BMI, and high levels of HbA(1c). The prevalence of IA-2 autoantibodies and thyrogastric autoantibodies in the GADab(+) insulin-deficient patients were significantly higher than those in the GADab(+) non-insulin-deficient patients (P < 0.05). GADab(+) patients with insulin deficiency had increased frequencies of HLA DRB1*0405-DQB1*0401, *0802-*0302, and *0901-*0303 haplotypes, whereas the frequency of only HLA DRB1*0405-DQB1*0401 was increased in the case of GADab(+) non-insulin-deficient patients. Of note is the fact that the GADab(+) non-insulin-deficient group did not differ from healthy control subjects with respect to type 1 diabetes protective haplotype HLA DRB1*1502-DQB1*0601. A total of 13% of the GADab(+) patients with diabetes had genotypes comprising the DRB1*1501-DQB1*0602 or *1502-*0601 and were characterized by old age at onset of diabetes, high BMI, resistance to the insulin-deficient state, low titer of GADab, and low frequency of other organ-specific autoantibodies.Conclusions: We conclude that GADab(+) non-insulin-deficient patients differ from GADab(+) patients with insulin deficiency with respect to clinical characteristics, humoral autoimmunity to other organ-specific autoantibodies, as well as HLA class II genes. [ABSTRACT FROM AUTHOR]

Resistin is a novel polypeptide specifically secreted from adipocytes, and its serum levels are increased in obese diabetic mice. Resistin antagonizes insulin and could account for insulin resistance. To determine whether there are single nucleotide polymorphisms (SNPs) in the resistin gene associated with type 2 diabetes, sequences for 24 Japanese type 2 diabetic patients were initially analyzed using PCR direct sequencing. Three SNPs were found in the introns, but none were present in the coding regions. The allele frequencies of genomic -167C>T, +157C>T, and +299G>A in 99 Japanese control subjects were determined to be 3.5, 6.6, and 39.4%, respectively. In each pair of these SNPs, linkage disequilibria were found between either -167C>T and +299G>A or +157C>T and +299G>A. A linkage disequilibrium was also detected among -167C>T, +157C>T, and +299G>A, and only four of the eight possible haplotypes defined by these SNPs were found. A comparison of the frequencies of these SNPs and haplotypes between 99 type 2 diabetes and 99 control subjects revealed no evidence for any association. These identified SNPs, which were in linkage disequilibrium, represent potentially useful tools for searching for their association with specific phenotypes of diabetes. [ABSTRACT FROM AUTHOR]

Phosphodiesterase (PDE) 3B is a key enzyme in the mediation of the antilipolytic action of insulin in adipocytes, and activation of this molecule results in a reduced output of free fatty acids (FFAs). An elevation of serum FFAs is known to cause insulin resistance in skeletal muscle and liver, which could be the primary cause of type 2 diabetes. To elucidate whether PDE3B is involved in this disease, we examined the PDE3B gene expression in epididymal fat tissues of obese insulin-resistant diabetic KKAy mice. We also examined the effect of an insulin-sensitizing drug, pioglitazone, on this gene expression. In adipose tissue of KKAy mice, PDE3B mRNA and its corresponding protein were reduced to 48 and 43% of those in C57BL/6J control mice. Basal and insulin-stimulated membrane-bound PDE activities were also decreased to 50 and 36% of those in the controls, respectively. Pioglitazone increased both PDE3B mRNA and protein levels by 1.8-fold of those in untreated KKAy mice. Basal and insulin-induced membrane-bound PDE activities were also increased by 1.6- and 2.0-fold, respectively. Pioglitazone reduced the elevated levels of serum insulin, glucose, FFAs, and triglyceride in KKAy mice. Thus, the reduced PDE3B gene expression in adipose tissues could be the primary event in the development of insulin resistance in KKAy mice, which was improved by pioglitazone possibly because of the restoration of the reduced PDE3B gene expression. [ABSTRACT FROM AUTHOR]

Coagulation factor XIII consists of two A- and two B-subunits, and either gene mutation can cause a complete deficiency. In a newborn patient with persistent bleeding from the umbilical cord stump, the plasma A-subunit protein was not detectable. Direct PCR sequencing revealed an nt 389 (ins G) frameshift mutation in exon 4 resulting in a new stop codon and a Ser 413 Leu missense mutation in exon 10 in either allele. His mother and father were heterozygous for the nt 389 (ins G) and the Ser 413 Leu, respectively, with about 50% reduction of the plasma A-subunit proteins. In all family members examined only those with either mutation showed the reduced subunit A protein levels. Thus, this complete deficiency of factor XIII was due to a novel compound heterozygous mutation in the A-subunit gene. [ABSTRACT FROM AUTHOR]

Background: A convenient method for the measurement of sialic acid in plasma apoB-containing lipoproteins is described. Methods: Dextran sulphate-Mg2+ precipitation and enzymatic sialic acid assay were combined and applied to analysis of plasma from 96 healthy controls and 136 hyperlipidaemic subjects of types IIa (n=46), IIb (n=43), and IV (n=47). Results: The sialic acid concentrations (mean±SD) in plasma apoB-containing lipoproteins were 19.4±5.9, 24.3±4.7 (P<0.0001 versus normal), 23.0±4.7 (P<0.0001), 27.9±5.2 (P<0.0001), and 22.3±3.4 mg/L (P<0.002), for normal, all types of hyperlipidaemia, types IIa, IIb, and IV, respectively. The contents of sialic acid in apoB were 2.03±0.41%, 2.09±0.35% (no significance versus normal), 1.86±0.27% (P<0.0001), 1.97±0.26% (P<0.02), and 2.28±0.41% (P<0.002), for normal, all types of hyperlipidaemia, types IIa, IIb, and IV, respectively. Conclusion: The content of sialic acid in apoB decreased significantly in type IIa but increased in type IV hyperlipidaemia, which may reflect the presence of sialic acid in very low-density lipoprotein apolipoproteins other than apoB. This simple precipitation method will be useful to evaluate the sialic acid content in low-density lipoprotein in hyperlipidaemic subjects, especially of type IIa. [ABSTRACT FROM AUTHOR]

Resistin, secreted from adipocytes, causes insulin resistance in rodents. We reported that the G/G genotype of a resistin gene promoter single nucleotide polymorphism (SNP) at -420 increases type 2 diabetes (T2DM) susceptibility by enhancing its promoter activity. We also showed that serum resistin was positively correlated with G at SNP-420, the duration of T2DM, and HbA1c in T2DM. To determine the relation between serum resistin and factors related to metabolic syndrome (MetS) in T2DM, we analyzed 238 Japanese T2DM patients. Fasting serum resistin was measured using ELISA. Serum resistin was higher in subjects with either obesity (P=0.041), past history of obesity (P-M).019), low HDL (P=0.004), high triglycerides (TG) (P=0.019), hypertension (HT) (P=0.001), or atherosclerosis (P=0.012). Simple regression analysis involving serum resistin (ng/ml) as a dependent variable revealed that serum resistin was correlated with max BMI (unstandardized coefficient (β)=0.383, P=0.025), HDL (mg/dl) (β=-0.142,P=0.003), TG (mg/dl) (β=0.013,P=0.042), HT (with= 1 or without=0) (β=5.044, P=0.001), high-sensitivity C-reactive protein (hsCRP) (mg/dl) (β=2.813, P=0.006), and atherosclerosis (with=1 or without=0) (β=4.157, P=0.012). Multiple regression analysis (or logistic regression analysis for HT) involving serum resistin as an independent variable, adjusted for age, gender, BMI (except analysis for max BMI), and the duration of T2DM, revealed that serum resistin was correlated with max BMI (P=0.026), HDL (P=0.008), TG (P=0.041), HT (P=0.031), and hsCRP (P=0.004). We then assessed the relation between serum resistin and the accumulation of each factor involved in MetS, namely, obesity, low HDL, high TG, and HT. Serum resistin was significantly different among the number of factors (ANOVA, P<0.001), and appears to be increased as the number was increased. Simple regression analysis involving the number of MetS factors as a dependent variable revealed that serum resistin was positively correlated with the number of MetS factors (β0.033, P<0.001). Multiple regression analysis showed that serum resistin was also positively correlated with the number of MetS factors, independent of age, gender, and the duration of T2DM (P<0.001). Therefore, serum resistin was associated with multiple factors related to MetS in T2DM. [ABSTRACT FROM AUTHOR]