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Background Type 2 diabetes is an important health concern worldwide. The disease etiology may depend on multiple environmental and genetic factors that cause insulin resistance, including dysregulation of iron storage. The goal of this study was to examine the relationship of the serum ferritin concentration with onset of diabetes over a long period. Methods Correlations of serum ferritin and metabolic markers with onset of diabetes mellitus were examined over 15 years in 150 males participating in a health screening program. Results HOMA-β showed a gradual significant decrease in the first 4 years in subjects with ferritin > 190 ng/mL (group H) compared to those with ferritin ≤ 190 ng/mL, but there was no difference in HOMA-R between these groups. A significant number of cases with onset of diabetes was observed over 15 years (hazard ratio (HR): 3.97), and obesity, fasting blood glucose level, hemoglobin A1c (HbA1c), HOMA-R, fasting immunoreactive insulin (IRI) and C-peptide immunoreactivity (CPR) were all significant in univariate comparison between non-diabetes and diabetes-onset groups. In multivariate analysis, ferritin in group H (HR: 3.25), fatty liver (HR: 3.38), estimated glomerular filtration rate (eGFR) < 70 mL/min/1.73 m2 (HR: 3.48) and high-density lipoprotein (HDL) < 40 mg/dL (HR: 2.61) were significant predictive factors for onset of type 2 diabetes mellitus. Conclusions These results suggest that the serum ferritin level is an important index for priority intervention in preventive medicine for reduction of onset of diabetes.

The increase in the number of patients with type 2 diabetes mellitus is an important concern worldwide. The goal of this study was to investigate factors involved in the onset of type 2 diabetes mellitus, and sex differences in long-term follow up of people with normal glucose tolerance.Of 1,309 individuals who underwent screening at our facility in 2004, 748 individuals without diabetes were enrolled. Correlations of metabolic markers including serum adiponectin (APN) with onset of type 2 diabetes mellitus were examined over 15 years in these individuals.The Kaplan-Meier curve for onset of type 2 diabetes mellitus for 15 years in the decreased APN group was examined. Hazard ratios for the APN concentration for onset of diabetes were 1.78 (95% confidence interval [CI] 1.20-2.63, P = 0.004) in all participants, 1.48 (95% CI 0.96-2.29, P = 0.078) for men and 3.01 (95% CI 1.37-6.59, P = 0.006) for women. During the follow-up period of 15 years, body mass index, estimated glomerular filtration rate, fatty liver, C-reactive protein and alanine aminotransferase in men were significant in univariate analysis, but only estimated glomerular filtration rate and fatty liver were significantly related to onset of type 2 diabetes mellitus in multivariate analysis. In women, body mass index, systolic blood pressure, triglyceride, fatty liver and APN were significant in univariate analysis, and APN was the only significant risk factor in multivariate analysis (P 0.05).There are differences between men and women with regard to targets for intervention to prevent the onset of type 2 diabetes mellitus. Individuals requiring intensive intervention should be selected with this finding to maximize the use of limited social and economic resources.

A prospective, multicentre, open‐label, blinded‐endpoint, randomized controlled study was conducted to evaluate the efficacy of treatment with ipragliflozin (sodium‐dependent glucose transporter‐2 inhibitor) versus metformin for visceral fat reduction and glycaemic control among Japanese patients with type 2 diabetes treated with sitagliptin, HbA1c levels of 7%‐10%, and body mass index (BMI) ≥ 22 kg/m2. Patients were randomly assigned (1:1) to receive ipragliflozin 50 mg or metformin 1000‐1500 mg daily. The primary outcome was change in visceral fat area as measured by computed tomography after 24 weeks of therapy. The secondary outcomes were effects on glucose metabolism and lipid metabolism. Mean percentage reduction in visceral fat area was significantly greater in the ipragliflozin group than in the metformin group (−12.06% vs. −3.65%, P = 0.040). Ipragliflozin also significantly reduced BMI, subcutaneous fat area, waist circumference, fasting insulin, and homeostatic model assessment (HOMA)‐resistance, and increased HDL‐cholesterol levels. Metformin significantly reduced HbA1c and LDL‐cholesterol levels and increased HOMA‐beta. There were no severe adverse events. The use of ipragliflozin or metformin in combination with dipeptidyl peptidase‐4 inhibitors, widely used in Japan, may have beneficial effects in ameliorating multiple cardiovascular risk factors.

BACKGROUND AND AIM To elucidate features of nonobese non-alcoholic fatty liver disease (NAFLD), we assessed Japanese patients with NAFLD stratified by body mass index (BMI) and by sex. METHODS Biopsy-proven 762 NAFLD patients (404 men) were classified into three groups by the Japanese criteria: nonobese group (BMI

Objective: This study was to investigate the relationship between the progression of Diabetic nephropathy (DN) and Coronary artery calcification score (CACS) in Japanese patients with Type 2 Diabetes mellitus (T2DM) at baseline and over 5 years of follow-up. Methods: A total of 107 patients with T2DM who underwent coronary computed tomography (CT) angiography using multidetector CT and were assessed for DN each year were studied. Patients were divided into two groups based on the median CACS derived from the Agatston score. Kaplan-Meier analyses were performed to examine whether the relationship between CACS and DN progression was different between the sexes. Results: Over a 5-year follow-up, men in the high CACS group demonstrated more DN progression compared with those in the low CACS group. In male patients without diabetic retinopathy (DR), those in the high CACS group also had significantly higher DN progression than those in the low CACS group. Patients with DR in the high and low CACS groups did not have a significantly different rate of DN progression. In women, DN progression was not significantly different between the high and low CACS groups. Conclusions: In men with T2DM, CACS is a good predictor of DN progression. Overall, DN progression was not related to the presence of DR, suggesting that the progression of DN in men may be affected by atherosclerotic factors more than in women

Aims/Introduction Hemoglobin A1c (HbA1c) levels in patients with type 2 diabetes mellitus fluctuate throughout the year. However, there are few studies that have evaluated the therapeutic effect of hypoglycemic agents while considering such fluctuations. In a multicenter study (Januvia Multicenter Prospective Trial in Type 2 Diabetes Study), pretreatment patients with type 2 diabetes mellitus were divided into seven groups and given sitagliptin for 1 year. The aim of the present study was to evaluate the differences in the therapeutic effect, and the efficacy of sitagliptin in patients with type 2 diabetes mellitus based on the month the administration of the drug began as a subanalysis of the Januvia Multicenter Prospective Trial in Type 2 Diabetes Study. Materials and Methods Patients with type 2 diabetes mellitus were divided into four groups according to the month of initiation of sitagliptin. Changes in HbA1c in each group were compared at 3 and 12 months after administration of sitagliptin. As a negative correlation has been reported between baseline HbA1c and the degree of change after administration of sitagliptin, an analysis using the residual error from the approximate line was carried out. Results In the analysis of the degree of change in HbA1c, patients in the group in which administration of sitagliptin was started between August and October had the lowest degree of improvement at 3 months after starting sitagliptin. However, there was no significant intergroup difference in improvement at 12 months after the start of sitagliptin. The same result was also obtained in residual analysis. Conclusions The present study suggested that the season of administration of sitagliptin influenced the subsequent hypoglycemic effect even after analysis excluding the influence of HbA1c value at the start of treatment. This study provides possibility, showing that seasonal fluctuations have an effect on the efficacy of antidiabetic drugs.

Aims/Introduction Recent randomized clinical trials have suggested that sodium–glucose cotransporter 2 inhibitors might reduce cardiovascular events and heart failure, and have renal protective effects. Despite these remarkable benefits, the effects of sodium–glucose cotransporter 2 inhibitors on bone and muscle are unclear. Materials and Methods A subanalysis of a randomized controlled study was carried out to evaluate the effects of the sodium–glucose cotransporter 2 inhibitor, ipragliflozin, versus metformin on bone and muscle in Japanese patients with type 2 diabetes mellitus (baseline body mass index ≥22 kg/m2 and hemoglobin A1c 7–10%) who were already receiving sitagliptin. These patients were randomly administered ipragliflozin 50 mg or metformin 1,000–1,500 mg daily. The effects of these medications on the bone formation marker, bone alkali phosphatase; the bone resorption marker, tartrate‐resistant acid phosphatase 5b (TRACP‐5b); handgrip strength; abdominal cross‐sectional muscle area; and bone density of the fourth lumbar vertebra were evaluated. Results After 24 weeks of treatment, the changes in bone density of the fourth lumbar vertebra, handgrip strength and abdominal cross‐sectional muscle area were not significantly different between the two groups. However, TRACP‐5b levels increased in patients treated with ipragliflozin compared with patients treated with metformin (median 11.94 vs −10.30%, P, Ipragliflozin in combination with sitagliptin did not affect bones or muscles adversely compared to metformin. However, ipragliflozin increased the levels of the bone resorption marker, tartrate‐resistant acid phosphatase 5b.

[This corrects the article DOI: 10.1007/s13340-017-0330-2.].

To elucidate features of nonobese non-alcoholic fatty liver disease (NAFLD), we assessed Japanese patients with NAFLD stratified by body mass index (BMI) and by sex.Biopsy-proven 762 NAFLD patients (404 men) were classified into three groups by the Japanese criteria: nonobese group (BMI 25 kg/mOver 25% of men and almost 40% of women were nonobese, but most of them had visceral fat obesity and/or insulin resistance. The median age (years) of the nonobese, obese, and severely obese men was 49.9, 46.8, and 40.5 (P 0.01), respectively, while those of women was 60.2, 59.6, and 48.5 (P 0.01), respectively. The prevalence of metabolic comorbidities and PNPLA3 risk alleles did not differ among these groups in both sexes. Also, the prevalence of non-alcoholic steatohepatitis was not significantly different in both sexes, although nonobese patients had a higher prevalence of mild steatosis. Advanced fibrosis showed a marked difference between men and women. Advanced fibrosis was significantly more frequent among severely obese men (nonobese: 31.0%, obese: 41.6%, severely obese: 60.9%; P 0.01), but it was lower among severely obese women (51.4%, 62.9%, 33.7%; P 0.01). Skeletal muscle mass was significantly lower in nonobese patients.Non-alcoholic fatty liver disease was not milder in nonobese patients. Histological steatosis was associated with BMI, but advanced fibrosis was not and showed a significant sex difference.

The fasting blood glucose concentration in type 1 diabetes may vary without being much affected by diet and exercise. This study aimed to identify association of morning fasting blood glucose concentration variability with insulin antibodies and clinical factors. The subjects in this study were 54 patients with type 1 diabetes who had high variation of fasting blood glucose. The insulin antibody level was measured, and correlations of glycemic variability with antibody levels, binding rates, and other clinical factors were investigated. The standard deviation (SD) of the 30-day morning self-monitored fasting blood glucose concentration (FBG SD) was evaluated as an index of glycemic variability. The mean glucose level was 159.8±42.1 mg/dL and the FBG SD was 47.5±22.0 mg/dL. Glycemic variability (FBG SD) was positively correlated with insulin antibody level, but not with insulin antibody binding rate, and had a negative correlation with C-peptide immunoreactivity/plasma glucose (CPR/PG) and positive correlations with diabetes duration, basal insulin dose and bolus insulin dose. Glycemic variability was not correlated with BMI, HbA1c or age. In multiple regression analysis of glycemic variability, CPR/PG was the only significant related factor. The results showed that glycemic variability was mainly influenced by endogenous insulin secretion capacity and was high in patients with high insulin antibody levels. In some patients with a high insulin antibody titer, the antibody may have an effect on the variability of the fasting glucose concentration in type 1 diabetes.

Background: Visceral fat accumulation is associated with insulin resistance and various metabolic complications. We aimed to determine the effect of ipragliflozin (sodium-dependent glucose transporter-2 inhibitor) versus metformin with a dipeptidyl peptidase-4 (DPP-4) inhibitor (sitagliptin) in reducing visceral fat in Asian patients with insufficiently controlled type 2 diabetes. Methods: A prospective, multicenter, blinded-endpoint, randomized controlled study was conducted to evaluate the efficacy of treatment with either ipragliflozin or metformin combined with sitagliptin on visceral fat reduction and glycemic control among Japanese patients with type 2 diabetes, HbA1c 7-10%, and BMI ≥22 kg/m2. Patients who met the eligibility criteria were randomly assigned (1:1) to receive ipragliflozin 50 mg (n=51) or metformin 1000-1500 mg daily (n=52). The primary outcome was rate change in visceral fat area measured by computed tomography at 24 weeks of therapy. Two radiologists, blinded to patients' clinical information and randomized treatment assignment, analyzed the images. Secondary outcomes included effects on blood glucose, fasting insulin level, and lipids. The full analysis set was used for analysis. Findings: Mean percent reduction in visceral fat area was significantly greater in the ipragliflozin group than in the metformin group (-12·06% vs. -3·65%, group difference [95% CI] -8·40%; [-16·4 to -3·38], P=0·040). The ipragliflozin group also showed significant lowering of fasting insulin (-20·73% vs. 0·85%, group difference [95% CI] -21·58%, [2·80 to 34·20], P=0·018), while HbA1c decreased in the metformin group compared with ipragliflozin group. Interpretation: Ipragliflozin significantly reduced the visceral fat area compared with metformin, as the secondary agent used in combination with DPP-4 inhibitor. Since the fasting insulin level decreased, the reduction in visceral fat associated with ipragliflozin administration might have contributed to the improvement in insulin resistance. Trial Registration Number: Trial registration: UMIN 000015170. Funding Statement: To conduct this study, an agreement was signed between Chiba University and Astellas Pharma Inc. (Tokyo, Japan). Astellas Pharma Inc. funded this work. Declaration of Interests: KY received research grants from Astellas Pharma Inc. and MSD K.K. (Tokyo, Japan), and received a lecture fee from Astellas Pharma Inc. and Sumitomo Dainippon Pharma (Tokyo, Japan). No conflicts of interest are declared for other authors. Ethics Approval Statement: The study protocol was approved by the Institutional Review Boards (IRBs), Ethics Review Committees, or Ethics Committees of the following institutions: Chiba University Hospital (ID number: G26009), Asahi General Hospital (ID number: 2014091602), National Hospital Organization Chiba Medical Center, Seirei Sakura Citizen Hospital, Chiba Rosai Hospital (ID number: 26-21), Toho University Sakura Medical Center (ID number: 2014-077), Tokyo Women’s Medical University Yachiyo Medical Center (ID number: 150303), Chiba Aoba Municipal Hospital, Kimitsu Chuo Hospital, Funabashi Central Hospital (ID number: H27-1), and Chiba Kaihin Municipal Hospital. In other facilities, approval was provided at Chiba University Hospital (which had the centralized IRB).

As a subanalysis of the Januvia Multicenter Prospective Trial in Type 2 Diabetes (JAMP study), we examined factors that decreased blood glucose control effect of sitagliptin after 3 months and patients requiring an addition or increase of diabetes treatment. We selected patients in whom glycated hemoglobin (HbA1c) levels decreased by month 3 after initiation of sitagliptin treatment and conducted two analyses: (1) in patients who did not change drugs until month 12, we compared changes in HbA1c levels between concomitant drugs and examined factors that decreased blood glucose control effect of sitagliptin; (2) compared changes in HbA1c levels and backgrounds between patients who did and did not require an addition to or increased dose of the antidiabetic agent. Four hundred and ninety-eight patients were chosen. In 369 patients without drug change until month 12, changes in HbA1c levels during months 3–12 were not significantly different among concomitant drugs; factors causing rebound HbA1c were smoking and weight gain. Patient characteristics were compared between those who did and did not require an additional drug or a dose increase (n = 114) (n = 384). Drug changes were associated with longer disease duration, younger age, higher rate of smoking, and higher degree of insulin resistance but not with concomitantly administered drugs. Smoking and weight gain were factors that decreased the effect of sitagliptin on reducing blood glucose levels. Differences in concomitant drugs did not affect sitagliptin’s effects on glycemic control. A dose increase or the addition of the antidiabetic drug was not associated with concomitant drugs.

Background: The aim of the study was to determine the effects of sitagliptin on renal function in a diabetic population including patients with normal renal function. Methods: We analyzed the association between 12-month, 50 mg/day sitagliptin and renal function in outpatients with type 2 diabetes mellitus and poor blood glucose control in a subset of patients in the larger Januvia Multicenter Prospective Trial in Type 2 Diabetes observational study. Stratified analyses of changes in estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR) were performed. Factors associated with changes in eGFR at 3 months were examined by multivariate regression analysis. Results: Of the 779 patients enrolled, 585 were followed up for 12 months. eGFR decreased significantly from baseline at 3 and 12 months in patients with a baseline eGFR of ≥ 90 mL/min/1.73 m 2 and in those with a baseline eGFR of ≥ 60 to < 90 mL/min/1.73 m 2 . Conversely, eGFR tended to increase at 3 and 12 months in patients with a baseline eGFR of ≥ 45 to < 60 mL/min/1.73 m 2 and in those with a baseline eGFR of ≥ 30 to < 45 mL/min/1.73 m 2 . UACR decreased significantly (-21.6 (-46.8, 7.8)) at 3 months in patients with a baseline UACR of ≥ 30 mg/g Cre. Multivariate regression analysis of factors associated with changes in eGFR at 3 months revealed that higher baseline eGFR and greater decline in UACR were associated with more conspicuous decreases in eGFR. Conclusions: In this group of diabetic patients receiving sitagliptin, eGFR declined in patients with high baseline eGFR, but not in those with a low baseline eGFR. J Clin Med Res. 2018;10(1):32-40 doi: https://doi.org/10.14740/jocmr3225w

Summary Background Limited evidence suggests that multifactorial interventions for control of glucose, blood pressure, and lipids reduce macrovascular complications and mortality in patients with type 2 diabetes. However, safe and effective treatment targets for these risk factors have not been determined for such interventions. Methods In this multicentre, open-label, randomised, parallel-group trial, undertaken at 81 clinical sites in Japan, we randomly assigned (1:1) patients with type 2 diabetes aged 45–69 years with hypertension, dyslipidaemia, or both, and an HbA 1c of 6·9% (52·0 mmol/mol) or higher, to receive conventional therapy for glucose, blood pressure, and lipid control (targets: HbA 1c 1c 1c , and history of cardiovascular disease. Neither patients nor investigators were masked to group assignment. The primary outcome was occurrence of any of a composite of myocardial infarction, stroke, revascularisation (coronary artery bypass surgery, percutaneous transluminal coronary angioplasty, carotid endarterectomy, percutaneous transluminal cerebral angioplasty, and carotid artery stenting), and all-cause mortality. The primary analysis was done in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT00300976. Findings Between June 16, 2006, and March 31, 2009, 2542 eligible patients were randomly assigned to intensive therapy or conventional therapy (1271 in each group) and followed up for a median of 8·5 years (IQR 7·3–9·0). Two patients in the intensive therapy group were found to be ineligible after randomisation and were excluded from the analyses. During the intervention period, mean HbA 1c , systolic blood pressure, diastolic blood pressure, and LDL cholesterol concentrations were significantly lower in the intensive therapy group than in the conventional therapy group (6·8% [51·0 mmol/mol] vs 7·2% [55·2 mmol/mol]; 123 mm Hg vs 129 mm Hg; 71 mm Hg vs 74 mm Hg; and 85 mg/dL vs 104 mg/dL, respectively; all p vs 283 [22%] in the conventional therapy group, p vs 129 [10%], p=0·0001), the frequencies of major adverse events did not differ between groups. Interpretation Our results do not fully support the efficacy of further intensified multifactorial intervention compared with current standard care for the prevention of a composite of coronary events, cerebrovascular events, and all-cause mortality. Nevertheless, our findings suggest a potential benefit of an intensified intervention for the prevention of cerebrovascular events in patients with type 2 diabetes. Funding Ministry of Health, Labour and Welfare of Japan, Asahi Kasei Pharma, Astellas Pharma, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi Sankyo, Eli Lilly, GlaxoSmithKline, Kissei Pharmaceutical, Kowa Pharmaceutical, Mitsubishi Tanabe Pharma, Mochida Pharmaceutical, MSD, Novartis Pharma, Novo Nordisk, Ono Pharmaceutical, Pfizer, Sanwa Kagaku Kenkyusho, Shionogi, Sumitomo Dainippon Pharma, Taisho Toyama Pharmaceutical, and Takeda.

To determine the efficacy and safety of sitagliptin when used with some therapeutic drugs to treat elderly patients. Sitagliptin (50 mg/day) was added to the pre-existing therapy for type 2 diabetes. Changes in the glycated hemoglobin (HbA1c) level after 3 months of treatment were compared with the baseline, and exploratory analysis was performed. These analyses were conducted as subanalyses of the JAMP study, which was an open-label observational study. For patients who were ≥65 years of age, the change in HbA1c level from baseline ranged from −0.50 to −0.87% at 3 months after starting treatment. There was no significant difference in the change in HbA1c level between the patients treated with different concomitant drugs. No significant difference in HbA1c variations at 3 and 12 months from baseline was noted among the three age groups (≥75, 65–74, and

Aims/Introduction To assess the efficacy and safety of sitagliptin compared with α-glucosidase inhibitors in Japanese patients with type 2 diabetes inadequately controlled by metformin or pioglitazone alone. Materials and Methods In the present multicenter, randomized, open-label, parallel-group, active-controlled, non-inferiority trial, 119 patients aged 20–79 years with type 2 diabetes who had glycated hemoglobin 6.9–8.8% on stable metformin (500–1,500 mg/day) or pioglitazone (15–30 mg/day) alone were randomly assigned (1:1) to receive the addition of sitagliptin (50 mg/day) or an α-glucosidase inhibitor (0.6 mg/day voglibose or 150 mg/day miglitol) for 24 weeks. The primary end-point was change in glycated hemoglobin from baseline to week 12. All data were analyzed according to the intention-to-treat principle. Results After 12 weeks, reductions in adjusted mean glycated hemoglobin from baseline were −0.70% in sitagliptin and −0.21% in the α-glucosidase inhibitor groups respectively; between-group difference was −0.49% (95% confidence interval −0.66 to −0.32, P

Nonalcoholic fatty liver disease (NAFLD) is associated with insulin resistance, metabolic syndrome and cardiovascular disease. The purpose of this study was to evaluate the phenotype of Japanese type 1 diabetes with NAFLD. The study population consisted of patients with type 1 diabetes with (n = 25) and without (n = 119) NAFLD who underwent an examination with hepatic ultrasonography. The duration of diabetes, HbA1c, body mass index, basal and bolus insulin doses, urinary albumin excretion, prevalence of carotid artery plaques, and incidence of retinopathy in patients with NAFLD were all significantly higher than in those without NAFLD. Dyslipidemia and hypertension also occurred more frequently in the NAFLD group. Logistic analysis showed that age (P < 0.05), gender (P < 0.05), duration of diabetes (P < 0.05), dyslipidemia (P < 0.05), and the presence of NAFLD (P < 0.05) were independent risk factors for the presence of carotid artery plaque. Multiple regression analysis showed that the rate of urinary albumin excretion was significantly associated with age (P < 0.01), systolic blood pressure (P < 0.05), and the presence of NAFLD (P < 0.01). Our results suggest that the presence of NAFLD in type 1 diabetes may be strongly associated with the progression of diabetic nephropathy and macroangiopathy.

〔目的〕2型糖尿病患者の運動習慣の有無が日常生活活動パターンやその行動の選択にどのような影響を与えるのかについて調査を実施した。〔対象〕外来通院をする2型糖尿病患者48症例。〔方法〕身体活動量質問紙票からは日常生活の活動時間数を，歩数計からは総エネルギー消費量，歩数量，活動時間数，歩行時間数，強度の強い運動時間数を算出し，その調査から運動習慣の関連する因子を抽出した。〔結果〕運動習慣に影響を与える促進因子は，日常の3 METs以下の身体活動時間，歩数量，意図的に実施した運動時間の3因子に関連が見られた。〔結語〕2型糖尿病患者が運動習慣を有することは，平地歩行などの低強度な運動を日常から行う機会により与えられ，2型糖尿病罹患者の合併症を併発しうる脂質因子に影響を及ぼすことが示唆された。

To evaluate the clinical role of subcutaneous fat accumulation in subclinical arteriosclerosis, using computed tomography (CT), we measured the subcutaneous fat area (SFA), the visceral fat area (VFA) and the VFA/SFA ratio and compared these with the calcium score of the whole aorta (CSWA) in asymptomatic subjects who were undergoing general health screening.122 consecutive asymptomatic subjects (40 female, mean age 56.2+/-8.4 years) were analyzed. Whole-body low-dose CT scan (mAs=50, slice thickness=5 mm) was performed. The SFA and VFA were measured at the umbilical level. Calcification of whole aorta was defined as an area with90 HU and 1 mm(2), and CSWA was calculated using the modified Agatston method.Mean+/-SD of SFA, VFA and log CSWA were 158+/-67.1 cm(2), 94.0+/-44.8 cm(2), and 7.93+/-1.08, respectively. SFA was significantly and inversely correlated with log CSWA (r=-0.219, P=0.015) but VFA was not (r=0.105, P=0.250) and as a result, the VFA/SFA ratio was significantly and positively correlated with log CSWA (r=0.221, P=0.015). Subsequently, all predictor variables were used in a stepwise multiple regression model with log CSWA as dependent variable, and age, SFA and fasting plasma glucose significantly influenced log CSWA (P0.001) by the multiple regression formula Y=0.046X1***-0.005X2**+0.015X3*+4.426, (***P0.001, **P0.01, and *P0.05) where Y=log CSWA, X1=age, X2=SFA, and X3=fasting plasma glucose).SFA was significantly and inversely associated with log CSWA, in an independent fashion. These results suggest that subcutaneous fat accumulation might have a protective role against atherosclerosis in asymptomatic subjects.

Tyrosine phosphorylation of the insulin receptor is the initial event following receptor binding to insulin, and it induces further tyrosine phosphorylation of various intracellular molecules. This signaling is countered by protein tyrosine phosphatases (PTPases), which reportedly are associated with insulin resistance that can be reduced by regulation of PTPases. Protein tyrosine phosphatase 1B (PTP1B) and leukocyte antigen-related PTPase (LAR) are the PTPases implicated most frequently in insulin resistance and diabetes mellitus. Here, we show that PTP1B and LAR are expressed in human fibroblasts, and we examine the regulation of PTPase activity in fibroblasts from patients with an insulin receptor gene mutation as an in vitro model of insulin resistance. Total PTPase activity was significantly lower in the cytosolic and membrane fractions of fibroblasts with mutations compared with controls (p

Advanced glycation end products (AGEs), among the most important causes of atherosclerosis in diabetes mellitus, stimulate the proliferation of smooth muscle cells (SMCs). Smooth muscle cells are central in the formation of atherosclerotic lesions, where they show both increased migration and accelerated proliferation. In investigating how AGEs stimulate SMC proliferation, we focused on protein tyrosine phosphatase, especially Src homology 2-containing protein tyrosine phosphatase (SHP2), which is considered important in regulating cell proliferation. Advanced glycation end products increased activity of SHP2 in the membrane fraction of rat aortic SMCs compared with control bovine serum albumin (P < .05). Upon characterizing the genomic and promoter structure of SHP2, we detected nuclear factor-kappaB (NF-kappaB) binding sites in the promoter area. Advanced glycation end product stimulation increased luciferase activity in cells transfected with SHP2 promoter region including NF-kappaB binding sites (P < .05) and increased SHP2 expression (P < .05). These data indicate that AGE stimulation appears to activate NF-kappaB. Activated NF-kappaB binds to sites on the SHP2 promoter, resulting in increased SHP2 expression, SHP2 activity, and, ultimately, SMC proliferation. It suggests that AGE stimulation induces SMC proliferation via SHP2, underscoring the importance of control of AGE for suppressing macroangiopathy in diabetes mellitus.

This study was performed in order to establish a mouse model that represents the non-obese type 2 diabetes reflecting a majority of diabetic patients among Asian races and to show its pathophysiological profiles. Streptozotocin (STZ) was administered to C57BL/6J mice with or without nicotinamide (120 or 240 mg/kg, STZ/NA120 or STZ/NA240), twice with an interval of 2 d, and plasma glucose concentration, body weight, water intake, insulin contents and insulin signal-related proteins were monitored. STZ-induced hyperglycemia (fasting and non-fasting), body weight loss and polyposia were significantly depressed by NA dose-dependently. In STZ/NA120 and STZ/NA240 mice, pancreatic insulin content was retained by 28 and 43% of normal control (10.5+/-0.93 microU/ml), respectively, and histological damage of pancreatic beta cells was also less severe than that observed in STZ mice. When given the calorie-controlled high fat diet, the STZ/NA mice caused hyperlipidemia, and significantly increased insulin resistance. These observations suggest that the combined administration of STZ and NA causes partial depletion of pancreatic insulin and that the high fat constituents lead to insulin resistance in this model. The present mouse model, therefore, well exhibits the recent diabetic pathophysiological characteristics of a majority of Asian patients.

Peroxisome proliferator-activated receptors (PPARs) regulate the vascular cell functions as well as systemic lipid and glucose metabolism. Here, we studied the effect of TAK-559, a newly developed potent activator both for PPARalpha and gamma, on the vascular cell recruitment. TNF-alpha- or interleukin-1beta (IL-1beta)-induced THP-1 cell attachment to cultured endothelial cells was significantly reduced in the presence of 10 microM TAK-559 (P0.05). The secretion of monocyte chemoattractant protein-1 (MCP-1) from endothelial cells is reduced by 36% in the presence of 10 microM TAK-559, accompanied with the decreased mRNA expression in the cells. The proliferation and migration of cultured smooth muscle cells (SMCs) were significantly decreased in the presence of TAK-559 (P0.05). TAK-559-treated hypercholesterolemic rabbits showed the significant reduction of intimal thickning after balloon catheterization by 51% compared with control (P0.05), although the plasma lipid and glucose level was not changed between them. The numbers of macrophage and SMCs were decreased to 34% and 49% in the hyperplastic intima of arteries from TAK-559-treated rabbits compared to those from control, respectively. These results suggest that the PPARalpha and gamma activator inhibits the recruitment of macrophages and SMCs in intima, possibly leading to the reduction of intimal hyperplasia in hypercholesterolemia.

Recently, environmental chemicals have appeared in daily human life, and these chemicals have been incidentally taken in by humans. The serum concentrations of some of these chemicals have been found to be associated with the onset and incidence rate of diabetes mellitus. It has been suggested that one of the environmental chemicals, bisphenol A (BPA), has hormone-like activity. It has also been demonstrated that some hormones affect insulin resistance and fat distribution in the body. To study the effects of these environmental chemicals on glucose metabolism, the effect of BPA on glucose transport in mouse 3T3-F442A adipocytes was investigated. The 3T3-F442A adipocytes were incubated with various concentrations of BPA in a medium. Deoxyglucose uptake assay was performed with and without insulin. Immunoblot analysis was performed with a glucose transporter (GLUT) 4-specific antibody and antiphosphotyrosine antibody. The BPA treatment enhanced basal and insulin-stimulated glucose uptake, and caused an increased amount of GLUT4 protein. Thus, the enhanced glucose uptake resulting from the BPA treatment was at least partially due to the increased amount of GLUT4. Tyrosine phosphorylation of insulin receptor substrate-1 with insulin stimulation was not significantly affected. In conclusion, it was demonstrated that BPA, one of the chemicals that we intake incidentally, affects the glucose transport in adipocytes, and also that the environmental chemicals may be identified as one of the environmental factors that affect diabetes and obesity.

Visceral fat accumulation is accompanied by several metabolic disorders. Here, we investigate the improvement of visceral fat accumulation in the early phase of diet. Hyperlipidemic obese patients received a low-calorie diet (1000 kcal/day) for 14 days. Visceral and subcutaneous fat accumulation was analyzed using ultrasonography. After 14 days of the diet, the average visceral fat of obese patients obviously decreased (P < 0.05), as well as the visceral fat-related secreted proteins, whereas subcutaneous fat did not decrease in these patients. These results show that visceral fat is reduced significantly in the early phase of diet therapy in humans. Therefore, to clarify its mechanism, we analyzed the expression of lipid metabolism-related genes in visceral and subcutaneous fat using obese rats. The Long-Evans Tokushima Otsuka (LETO) rats, as an obese model, were divided into two groups: fasting and non-fasting. The gene expressions in visceral and subcutaneous fat were measured by reverse transcriptase-polymerase chain reaction (RT-PCR). The expression of beta(3)-adrenergic receptor (AR), hormone sensitive lipase (HSL), peroxisome proliferator-activated receptor (PPAR)-gamma, and uncoupling protein (UCP)-2 genes increased by 3.2-, 2.3-, 2.2-, and 2-fold in visceral fat (P < 0.01), but remained almost unchanged in subcutaneous fat. Taken together, the responsiveness of lipid metabolism-related genes to fasting is more sensitive in visceral fat than in subcutaneous fat in rats, suggesting that the different responsiveness to calorie restriction in fat tissues is due to the different induction of metabolism-related gene expression.

Objective — Src homology 2–containing phosphotyrosine phosphatase 2 (SHP2) is ubiquitously expressed and believed to function as part of a positive signaling pathway mediating growth factor–induced protein tyrosine phosphorylation. Proliferation of aortic vascular smooth muscle cells (SMCs) is an important contributor to atherosclerosis. We examined the effect of SHP2 expression on SMC proliferative activity. Methods and Results — SHP2 was abundant in cultured aortic SMCs, and SHP2 staining was markedly increased in the thickened aortic intima in rats with balloon-induced injury. We obtained several SMC clones by using geneticin screening. Endogenous SHP2 expression varied among individual clones. Significant positive relationships were observed between SHP2 expression and bromodeoxyuridine uptake in SMCs stimulated by FBS, platelet-derived growth factor, or insulin-like growth factor-1. In SMCs transiently transfected with SHP2, FBS stimulation significantly increased bromodeoxyuridine uptake beyond the uptake by control SMCs. Conclusions — Increased SHP2 expression in SMCs may accelerate aortic atherosclerosis by increasing cell growth.

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 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 HbA1c. 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.

Introduction In Japan, dipeptidyl peptidase-4 (DPP-4) inhibitors are frequently used as the treatment of choice for patients with type 2 diabetes. In some cases, however, poor glycaemic and body weight control issues persist despite treatment with DPP-4 inhibitors. Previous researchers have revealed that sodium-dependent glucose transporter-2 (SGLT-2) inhibitors reduce both plasma glucose levels and body weight in patients with type 2 diabetes. However, further investigation regarding the effects of SGLT-2 inhibitors on body composition, especially in the Asian population who tends to have relatively low-to-moderate body mass indices, is required. Therefore, we aim to determine the effects of treatment with SGLT-2 inhibitors or metformin for reducing visceral fat in 106 Asian patients with type 2 diabetes who were undergoing treatment with the DPP-4 inhibitor sitagliptin (50 mg daily) for poor glycaemic control. Methods and analysis A prospective, multicentre, blinded-endpoint phase IV randomised controlled study will be conducted to evaluate the safety and efficacy of a 24-week treatment with either an SGLT-2 inhibitor (ipragliflozin) or metformin for reducing visceral fat and plasma glucose levels in patients with type 2 diabetes. Patients who satisfy the eligibility criteria will be randomised (1:1) to receive ipragliflozin (50 mg daily) or metformin (1000 mg daily). The primary outcome is the rate of change in the total area of visceral fat for patients in both treatment groups, measured using CT, after 24 weeks of therapy. Two radiologists, blinded to the clinical information, will perform centralised analysis of the images in a unified measurement condition. Ethics and dissemination The protocol was approved by the institutional review board of each hospital. This study is ongoing and due to finish in April 2017. The findings of this study will be disseminated via peer-reviewed publications and conference presentations, and will also be disseminated to participants. Trial registration number UMIN000015170, R000016861 (https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000016861); Pre-results

We tried to characterize the clinical features associated with glucose metabolism in the development of diabetes. Study subjects were glucose-tolerant subjects without a family history of diabetes (normal glucose tolerance [NGT]1 group, n = 15) and with a first-degree diabetes relative (NGT2, n = 9), 12 subjects with impaired glucose tolerance (IGT), and 13 subjects with type 2 diabetes mellitus (DM). The first phase C-peptide secretion (CS1), insulin sensitivity (Si), and glucose effectiveness (Sg) were assessed by the combination of C-peptide 2-compartment model and minimal model analyses. Using these parameters, each group was characterized: CS1 was decreased in NGT2 and IGT compared with NGT1 and further decreased in DM; Si was not different among NGT1, NGT2, and IGT, whereas Si was decreased in DM; CS1 x Si value was decreased in NGT2 compared with NGT1 and decreased in IGT, DM, progressively; Sg was decreased in IGT and DM compared with NGT1 and NGT2. CS1 x Si and Sg values could segregate each group distinctively, although it had a large variety of phenotypes. CS1 x Si value and Sg are assumed to represent the contributions of insulin-dependent and independent mechanisms to glucose tolerance, respectively, and thus, both mechanisms should play an important role in the characterization of pathophysiologic phenotypes of the subjects with various degrees of glucose tolerance.

Type 1 diabetic patients who have endured their condition for prolonged periods are not uncommon, but there are few well-documented cases of type 2 diabetic patients with duration of over fifty years. In the present case study, we analyzed the history of a diabetic patient whose duration was 53 years. Her case was consequently diagnosed not as the common type 2 diabetes, but as the slowly progressive type 1 diabetes (SPIDDM) identified by Japanese medical researchers. The patient, now 73 years old, was first diagnosed with diabetes in 1953 when she was 17 years of age and started insulin injections. In 1962 she was referred to our hospital, and two years later she vaginally delivered a healthy baby (birth weight 3100 g) at the 40(th) week of gestation. She was the first case of a diabetic mother delivering an infant treated at Tokyo Women's Medical College Hospital. Her data shows that her C-peptide responses by meal tolerance test in 1978 was at least partly preserved though it decreased year by year. Her anti-GAD antibody was found to be positive in 2000 and remained so in 2009. This leads us to conclude that the etiology of her SPIDDM was most likely has insulin secretion exhaustion.

Mutations of the hepatocyte nuclear factor 4 alpha (HNF-4alpha) gene have been demonstrated in maturity-onset diabetes of the young (MODY) 1 families. To investigate the possibility that the HNF-4alpha gene contributes to the onset of non-insulin-dependent diabetes mellitus (NIDDM) in Japanese patients, we screened all exons and flanking introns of this gene for mutations in 100 patients with NIDDM diagnosed after 25 years of age. We identified two missense mutations: M49V in exon 1c and T1301 in exon 4; and two nucleotide substitutions in introns: cytosine to thymidine at -5 nt in intron 1b and adenine to thymidine at -21 nt in intron 5. We screened an additional 220 diabetic subjects for the polymorphism in intron 1b. The c/t substitution in intron 1b was associated with NIDDM. This substitution in the polypyrimidine tract, an important cis-acting element directing intron removal, is likely to influence pre-mRNA splicing of this gene. T1301 in exon 4 was observed in only two diabetic subjects. This mutation could influence the conformation of this peptide, resulting in changes in ligand binding domain function. M49V in exon 1c was found in both diabetic and non-diabetic subjects; isoforms HNF-4alpha 4, 5, and 6 with this mutation may impair glucose metabolism in tissue. In contrast to the primary cause of nonsense and missense mutations of the HNF-4alpha gene in MODY1, the nucleotide substitution in intron 1b may partially contribute to development of NIDDM in combination with other genetic and environmental factors.

Cytokines induce apoptosis in pancreatic beta cells, but the exact mechanisms and sequence of events are not clear. Here, we investigate a role for tumor necrosis factor alpha (TNF-alpha) in the apoptosis of beta cells. Using the ribonuclease (RNase) protection assay and the reverse transcriptase-polymerase chain reaction (RT-PCR) method, we confirmed that TNF receptor 1 (TNFR1), TNFR1-associated death domain protein (TRADD), Fas receptor-associated intracellular protein with death domain (FADD), and FADD-like interleukin-1beta-converting enzyme (FLICE) were expressed in the pancreatic beta cell line, MIN6 cells. Fluorescent microscopic examination using Hoechst 33342 dye (Sigma, St Louis, MO) demonstrated that TNF-alpha induced time- and dose-dependent apoptotic nuclear changes in these beta cells. In situ end-labeling (ISEL) DNA analysis revealed that 10 nmol/L TNF-alpha generated new 3'-OH DNA strand breaks. Moreover, qualitative assessment of the induced DNA damage on agarose gels showed that 10 nmol/L TNF-alpha produced characteristic apoptotic patterns of DNA fragments formed by internucleosomal hydrolysis of static chromatin. In addition, C2-ceramides and natural ceramides dispersed in a solvent mixture of ethanol and dodecane induced characteristic features of apoptosis in MIN6 cells, mimicking TNF-induced DNA damage. We also determined endosomal ceramide production after TNF-alpha (10 nmol/L) treatment in MIN6 cells using the diacylglycerol kinase assay. These results suggest that TNF-alpha can cause apoptosis in pancreatic beta cells through TNFR1-linked apoptotic factors, TRADD, FADD, and FLICE, and TNF-induced ceramide production may be involved in the pathways.

The ras-mitogen-activated protein kinase (MAPK) cascade plays an important role not only in the mitogenic signal transduction pathway but also in the development of cancer, and it is believed to be one of the important regulators in normal hepatocytes and hepatocellular carcinoma. The aim of this study was to determine the role of insulin receptor substrate-1 and the MAPK cascade in rats with hepatocellular carcinoma induced by 3'-methyl-4-dimethylamino-azobenzene (3'-MeDAB).Liver cancer was induced in rats by feeding 3'-MeDAB, and the changes in expression of IRS-1 and MAPK were analyzed in tumorous, non-tumorous and control liver.Expression of insulin receptor substrate-1 (IRS-1) showed a 1.4-fold increase at protein level in the tumors (p0.01), but the tyrosine phosphorylation of IRS-1 did not differ between the tumor and control liver. Expression of MAPK and its activity were elevated 4.5-7.5-fold (p0.01) and 4.6-fold (p0.01) in the tumor compared with control liver. In non-tumorous lesions from rats fed with 3'-MeDAB, expression of MAPK, but not IRS-1, increased significantly (p0.01). Between tumorous and adjacent non-tumorous lesions, there was a significant difference in MAPK expression (p0.05) and activities (p0.05).The increased expression of MAPK may play an important role in the progression or initiation of HCC in this rat model.

Werner syndrome is a premature aging disease characterized by genomic instability and increased cancer risk. Here, we report a 45-year-old diabetic man as the first Werner syndrome patient found to have an adiponectin gene mutation. Showing graying and loss of hair, skin atrophy, and juvenile cataract, he was diagnosed with Werner syndrome type 4 by molecular analysis. His serum adiponectin concentration was low. In the globular domain of the adiponectin gene, I164T in exon 3 was detected. When we examined effects of pioglitazone (15 mg/day) on serum adiponectin multimer and monomer concentrations using selective assays, the patient's relative percentage increased in adiponectin concentration was almost same as that in the 18 diabetic patients without an adiponectin mutation, but the absolute adiponectin concentration was half of those seen in diabetic patients treated with the same pioglitazone dose who had no adiponectin mutation. The response suggested that pioglitazone treatment might help to prevent future Werner syndrome-related acceleration of atherosclerosis. Present and further clinical relevant to atherosclerosis in this patient should be imformative concerning the pathogenesis and treatment of atherosclerosis in the presence of hypoadiponectinemia and insulin resistance.

Cyclic adenosine 5′diphosphate-ribose (cADPR) is thought to have a second messenger role in insulin secretion through mobilisation of Ca2 +. As human lymphocyte antigen CD38 has both ADP-ribosyl cyclase and cADPR hydrolase activity, it may be important in glucose-induced insulin secretion in islets. Thirty one randomly selected Japanese patients with Type II diabetes mellitus who had first-degree and/or second-degree relative(s) with Type II diabetes mellitus were screened for mutations of this gene using single-stranded conformation polymorphism. Two variant patterns in exon 3 and exon 4 of the CD38 gene were identified. The variant in exon 3 resulted in an amino acid substitution from Arg140 (CGG) to Trp (TGG). The Arg140Trp mutation was observed in 4 of 31 patients, and allele frequencies were significantly different in patients and the control subjects (p = 0.004). One patient with this mutation has two missense mutations on beta cell/liver glucose transporter (GLUT2) gene; her mother, who has impaired glucose tolerance, also has this mutation on the CD38 gene and one missense mutation on the GLUT2 gene. Enzyme activity studies using COS-7 cells expressing the Arg140Trp mutation showed a reduction in ADP-ribosyl cyclase and cADPR hydrolase activity of around 50 %. The Arg140Trp mutation on CD38 thus appears to contribute to the development of Type II diabetes mellitus via the impairment of glucose-induced insulin secretion in the presence of other genetic defects. [Diabetologia (1998) 41: 1024–1028]

An 88-year-old male patient with macroglobulinemia was admitted to our hospital because of severe hyponatremia and unconsciousness. Laboratory findings showed decreased inhibition of antidiuretic hormone (ADH) and he was diagnosed with syndrome of inappropriate secretion of ADH (SIADH). Hyponatremia improved with only limitation of water intake and the patient was followed up on a continuing outpatient basis. However, soon after discharge from hospital, his legs started swelling with edema and hyponatremia worsened. He was re-admitted due to a fall at home. Hyponatremia was observed at re-admission. A CRH challenge test showed partial dysfunction of ACTH secretion. Corticosteroid therapy was performed, but the patient subsequently died from pneumonia. Pathological findings at autopsy revealed invasion of plasma cells and amyloid depositions in multiple organs, including the pituitary, adrenal cortex, heart, liver, kidney, lymph nodes and bone marrow. Consistent with these results, fibrosis was observed in the anterior lobe of the pituitary, suggesting that the autopsy findings were related to the clinical observations and diagnosis. This is the first reported case of macroglobulinemia complicated with multiple hormone dysfunction.

Pituitary apoplexy is a rare but potentially life-threatening condition caused by the sudden enlargement of a pituitary adenoma secondary to infarction and hemorrhage. Surgical stress is 1 cause of pituitary apoplexy, but asymptomatic pituitary adenomas are difficult to diagnose preoperatively. Here we report a case of a 78-year-old male who had postoperative pituitary apoplexy after surgery for lung cancer. He underwent right upper and middle lobectomy and lymph node dissection for squamous cell carcinoma with obstructive pneumonia. On the sixth postoperative day he developed sudden-onset fever, respiratory distress, and polyuria. Brain magnetic resonance imaging revealed an enlarged, hemorrhagic pituitary gland. He was treated with steroid hormone replacement. Subsequent endocrine hormone stress tests revealed recovery of his pituitary function. Based on his clinical course, the patient was diagnosed with acute adrenal insufficiency and diabetes insipidus due to pituitary apoplexy.

To examine the prevalence of abnormalities in the insulin receptor structure gene in Japanese Patients with non-insulin-dependent diabetes mellitus (NIDDM), a population of 51 patients with NIDDM was screened for mutations in this gene. Patient genomic DNAs of both alleles corresponding to 22 exons of the gene were amplified by polymerase chain reaction (PCR). The PCR products on pUC19 were sequenced. Three patients with heterozygous missense mutation Thr831→Ala831 in exon 13 and one patient with heterozygous missense mutation Tyr1334→Cys1334 in exon 22 of the ²-subunits were identified. Linkage analysis of one of the families plus statistical studies showed that the mutation Thr831→Ala831 is possibly responsible for the onset of NIDDM. In COS cells transiently expressing both mutant receptor cDNAs and a cDNA of a Mr 85,000 regulatory subunit of phosphatidylinositol 3-kinase (PI 3-kinase), the mutation Tyr1334→Cys1334 impaired binding of the receptor with the Mr 85,000 subunit of PI 3-kinase, but linkage analysis of the family showed that the mutation did not cosegregate with NIDDM in the pedigree. Therefore, one missense mutation (Thr831→Ala831) in the insulin receptor, as found in three patients, is possibly involved in the etiology of a subset of the 51 NIDDM patients.

Mutations in the insulin receptor gene may lead to insulin resistance and diabetes mellitus in some patients. We have studied an insulin-resistant patient with leprechaunism. Insulin binding to the patient's fibroblasts was markedly decreased. Determination of the nucleotide sequence of the patient's insulin receptor gene revealed heterozygosity for a 2-basepair deletion in exon 15. If the premessenger ribonucleic acid (pre-mRNA) is spliced normally, it causes a replacement of codon 970 in the beta-subunit with a premature chain termination codon, thereby deleting most of the intracellular domain of the receptor. The mRNA transcribed from the allele with a 2-base-pair deletion is likely to be unstable because mRNA transcripts from this allele could not be detected by complementary DNA sequencing. Northern blot analysis showed that the patient's insulin receptor mRNA was decreased by 90% compared with that of a control subject, thus suggesting that the patient is a compound heterozygote for two mutations that decrease levels of insulin receptor mRNA. This deletion mutation in exon 15 seems to be a de novo mutation, because it was not detected in either parent. Investigation of the inheritance of a silent sequence polymorphism in exon 17 provided that the deletion occurred in the maternal allele. Furthermore, linkage analysis suggests that the second mutation is derived from the patient's father, although we could not directly identify it by sequencing the coding region of the insulin receptor gene. Therefore, it is possible that this mutation is present in a regulatory domain of the insulin receptor gene, acting in cis-dominant fashion to reduce the levels of insulin receptor mRNA. Analyses of the hypervariable region in the myoglobin and pMCT118 loci were consistent with the assumption that the father and mother studied here are indeed the biological parents of the diseased patient. We hereby conclude that the patient is a compound heterozygote for two mutant alleles, both of which are responsible for the reduced levels of insulin receptor mRNA and insulin binding.

The beta-cell/liver glucose transporter (GLUT2) gene was screened for mutations using single-strand conformation polymorphism analysis (SSCP) in 30 Japanese subjects with non-insulin dependent diabetes mellitus (NIDDM). Analysis of all exons and adjacent intron regions identified six SSCP polymorphisms, three of which resulted in amino acid substitutions: V101I, T110I and G519E. The V101I and G519E, substitutions represent new polymorphisms in this gene. The six polymorphisms were observed in both NIDDM and control groups and there were no significant differences in allele frequencies between groups. A portion of the insulin receptor substrate 1 gene in 30 NIDDM subjects and in normal control subjects was also screened for mutations. Two SSCP variants that change the sequence of the protein, delta S686/687 (deletion of the codons for serine-686 and 687) and G972R, were identified in two different NIDDM subjects, both whom were also heterozygous for the V101I polymorphisms in GLUT2. The GLUT2 and IRS1 amino acid polymorphisms did not show a simple pattern of co-inheritance with NIDDM in the families of these subjects suggesting that neither polymorphism is sufficient to cause NIDDM but may increase diabetes-susceptibility through their interaction with other loci and environmental factors.

Encephalopathy with reversible lesion of the corpus callosum splenium has a favorable prognosis, but that in 2009 influenza A/H1N1 is unknown. We report a case of clinically mild encephalopathy with a reversible lesion of the corpus callosum splenium in which 2009 influenza A/H1N1 virus was confirmed by laboratory tests. A 15-year-old Japanese girl seen at the emergency unit for loss of consciousness 18 hours after fever onset had been diagnosed with influenza A, and administered zanamivir. Diffusion-weighted magnetic resonance imaging (MRI) indicated lesions of the corpus callosum splenium, and electroencephalography showed slow basic activity, suggesting influenza A related to encephalopathy. She required intensive care with ventilation for two days. Her consciousness had become normal by day 6 after onset, and MRI findings improved on day 7. She recovered without adverse sequelae.