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Background: Obstructive sleep apnea (OSA) is prevalent in 7.5% in urban Asian Indians. Peroxisome proliferator activated receptor gamma2 (PPARγ2) has been implicated in adipocyte differentiation. Neuropeptide Y (NPY) is also considered as a candidate gene for excess body fat accumulation. The association of PPARγ2 (Pro12Ala)} and NPY (Leu7Pro) gene polymorphisms with OSA has not been studied in Asian Indians. Objective: To study the distribution of PPARγ2 (Pro12Ala) and NPY (Leu7Pro) polymorphism in Asian Indians with and without OSA. Methods and results: This study was carried out in 252 obese subjects [(body mass index (BMI > 25 kg/m^{2})]; 142 with OSA and 110 without OSA. Measurements included anthropometric and biochemical parameters (fasting blood glucose, lipid profile, various circumferences and skin-fold thicknesses). PPARγ2 (Pro12Ala) and NPY (Leu7Pro) gene} polymorphisms were studied in all subjects. The frequency of the variant allele (Ala12) of PPARγ2 gene was significantly higher in subjects with OSA (14.4%) when compared with subjects without OSA (5.5%; χ^{2}= 9.7; p = 0.001). The distribution of the variant allele (Pro7) of NPY gene was comparable in subjects with OSA (3.5%) and without OSA (3.6%; χ ^{2} = 0.001, p = 0.94). Conclusion: This study reveals a significantly higher frequency of PPARγ2 (Ala12) allele in obese Asian Indians with OSA when compared to obese Asian Indians without OSA. [ABSTRACT FROM AUTHOR]

Objective:To evaluate whether polymorphisms in the peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PPARGC1A) gene were related to body fat in Asian Indians.Methods:Three polymorphisms of PPARGC1A gene, the Thr394Thr, Gly482Ser and +A2962G, were genotyped on 82 type 2 diabetic and 82 normal glucose tolerant (NGT) subjects randomly chosen from the Chennai Urban Rural Epidemiology Study using PCR-RFLP, and the nature of the variants were confirmed using direct sequencing. Linkage disequilibrium (LD) was estimated from the estimates of haplotypic frequencies using an expectation–maximization algorithm. Visceral, subcutaneous and total abdominal fat were measured using computed tomography, whereas dual X-ray absorptiometry was used to measure central abdominal and total body fat.Results:None of the three polymorphisms studied were in LD. The genotype (0.59 vs 0.32, P=0.001) and allele (0.30 vs 0.17, P=0.007) frequencies of Thr394Thr polymorphism were significantly higher in type 2 diabetic subjects compared to those in NGT subjects. The odds ratio for diabetes (adjusted for age, sex and body mass index) for the susceptible genotype, XA (GA+AA) of Thr394Thr polymorphism, was 2.53 (95% confidence intervals: 1.30–5.04, P=0.009). Visceral and subcutaneous fat were significantly higher in NGT subjects with XA genotype of the Thr394Thr polymorphism compared to those with GG genotype (visceral fat: XA 148.2±46.9 vs GG 106.5±51.9 cm2, P=0.001; subcutaneous fat: XA 271.8±167.1 vs GG 181.5±78.5 cm2, P=0.001). Abdominal (XA 4521.9±1749.6 vs GG 3445.2±1443.4 g, P=0.004), central abdominal (XA 1689.0±524.0 vs GG 1228.5±438.7 g, P<0.0001) and non-abdominal fat (XA 18763.8±8789.4 vs GG 13160.4±4255.3 g, P<0.0001) were also significantly higher in the NGT subjects with XA genotype compared to those with GG genotype. The Gly482Ser and +A2962G polymorphisms were not associated with any of the body fat measures.Conclusion:Among Asian Indians, the Thr394Thr (G → A) polymorphism is associated with increased total, visceral and subcutaneous body fat.International Journal of Obesity (2006) 30, 884–891. doi:10.1038/sj.ijo.0803228; published online 31 January 2006 [ABSTRACT FROM AUTHOR]

Aims The objective of the present investigation was to examine the relationship of three polymorphisms, Thr394Thr, Gly482Ser and +A2962G, of the peroxisome proliferator activated receptor-γ co-activator-1 alpha (PGC-1α) gene with Type 2 diabetes in Asian Indians. Methods The study group comprised 515 Type 2 diabetic and 882 normal glucose tolerant subjects chosen from the Chennai Urban Rural Epidemiology Study, an ongoing population-based study in southern India. The three polymorphisms were genotyped using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). Haplotype frequencies were estimated using an expectation–maximization (EM) algorithm. Linkage disequilibrium was estimated from the estimates of haplotypic frequencies. Results The three polymorphisms studied were not in linkage disequilibrium. With respect to the Thr394Thr polymorphism, 20% of the Type 2 diabetic patients (103/515) had the GA genotype compared with 12% of the normal glucose tolerance (NGT) subjects (108/882) ( P = 0.0004). The frequency of the A allele was also higher in Type 2 diabetic subjects (0.11) compared with NGT subjects (0.07) ( P = 0.002). Regression analysis revealed the odds ratio for Type 2 diabetes for the susceptible genotype (XA) to be 1.683 (95% confidence intervals: 1.264–2.241, P = 0.0004). Age adjusted glycated haemoglobin ( P = 0.003), serum cholesterol ( P = 0.001) and low-density lipoprotein (LDL) cholesterol ( P = 0.001) levels and systolic blood pressure ( P = 0.001) were higher in the NGT subjects with the XA genotype compared with GG genotype. There were no differences in genotype or allelic distribution between the Type 2 diabetic and NGT subjects with respect to the Gly482Ser and +A2962G polymorphisms. Conclusions The A allele of Thr394Thr (G → A) polymorphism of the PGC-1 gene is associated with Type 2 diabetes in Asian Indian subjects and the XA genotype confers 1.6 times higher risk for Type 2 diabetes compared with the GG genotype in this population. [ABSTRACT FROM AUTHOR]

The association between apolipoprotein E (apo E) polymorphism and stroke has been controversial. So far there are no studies reported on the polymorphism of apolipoprotein E in cerebrovascular diseases in the Asian Indians. A blinded case–control study was therefore undertaken and the apo E genotypes and lipid profile of a total of 120 subjects (63 stroke patients and 57 healthy controls) were done. The frequency distribution of apo E alleles and genotypes were assessed and their relation with the occurrence of stroke in Asian Indian subjects was determined. A significantly high frequency of apo ε4 allele (30%) was observed in the stroke patients than the controls (11%) (p < 0.005), and patients with ε4 allele had a fourfold higher odds to develop stroke OR (95%CI) 4.2 (1.8–10.1) (p < 0.005). On multivariate analysis, after adjusting for age, triglycerides and hypertension, the association of ε4 allele with stroke was found to be no longer statistically significant, OR (95%CI) 1.2 (0.4–4.5) (p = NS). On multiple logistic regression analysis age, OR (95%CI) 1.1 (1.1–1.2) (p < 0.001), and hypertension OR (95%CI) 15.1 (2.6–89.1) (p < 0.005) were found to be independent risk factors for development of stroke. This is the first report to have examined the association of apo E gene polymorphism with stroke in the Asian Indians. This study suggests that apo ε4 allele, triglycerides, age and hypertension are the predictors for stroke development. [ABSTRACT FROM AUTHOR]