Korean Diabetes J KDJ Korean Diabetes Journal 1976-9180 Korean Diabetes Association 10.4093/kdj.2008.32.5.402 Original Article Association Study of the Peroxisome Proliferators-Activated Receptor γ2 Pro12Ala Polymorphism with Diabetic Nephropathy Lee Kyu-Ho Jeong Hee seog Choi Khan Young Kim Hyun Lee Dal-Sic Kang Ji Young Jeon Hyun Jeong Oh Tae Keun Department of Internal Medicine, Chungbuk National University College of Medicine, Korea. 10 2008 31 10 2008 32 5 402 408 14 07 2008 13 10 2008 Copyright © 2008 Korean Diabetes Association 2008 Background

Peroxisome proliferators-activated receptor γ (PPARγ) is a member of the nuclear hormone receptor superfamily of ligand-activated transcription factors and known to play a role in regulating the expression of numerous genes involved in lipid metabolism, metabolic syndrome, inflammation, and atherosclerosis. The PPARγ2 Pro12Ala polymorphism has recently been shown to be associated with diabetic nephropathy. In this study, we evaluated the relationship between PPARγ2 Pro12Ala polymorphism and type 2 diabetic nephropathy whose duration of diabetes was over 10 years.

 Methods

We conducted a case-control study, which enrolled 367 patients with type 2 diabetes. Genotyping of PPARγ2 Pro12Ala polymorphism was performed using polymerase chain reaction followed by digestion with Hae III restriction enzyme.

 Results

The genotype or allele frequencies of PPARγ2 Pro12Ala polymorphism were not significantly different in diabetic patients with or without diabetic nephropathy. The genotype frequencies in terms of diabetic retinopathy and macrovascular complications such as coronary artery disease or stroke were not different either. Interestingly, nephropathy patients with Ala/Pro genotype showed lower C-peptide levels than those of Pro/Pro genotype.

 Conclusion

Our results suggest that PPARγ2 Pro12Ala polymorphism is not associated with diabetic nephropathy in type 2 diabetic patients.

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Genotyping of PPAR-γ2 gene. The amplified PCR products were digested with the restriction enzyme Hae III. The Pro12 alleles gives one 132-and 22-bp fragments whereas the Ala12 alleles gives one 155-bp fragment. Lane 1,3,5,6,7,8: Pro/Pro genotype, Lane 2, 4: Ala/Pro genotype.

Clinical characteristics of patients with type 2 diabetes with or without nephropathy

Data are means ± SD. BMI, body mass index; DBP, diastolic blood pressure; FBS, fasting blood sugar; HDL, high density lipoprotein cholesterol; LDL, low density lipoprotein cholesterol; PP2, postprandial 2 hours blood sugar; SBP, systolic blood pressure.

Distribution of PPARγ2 Pro12Ala genotypes and alleles in patients with or without DM nephropathy

PPAR, Peroxisome proliferators-associated receptor. HWP, Hardy-Weinberg equilibrium.

PPARγ2 Pro12Ala genotypes according to diabetic retinopathy and microvascular complications

PPAR, Peroxisome proliferators-associated receptor.

Clinical characteristics of the PPARγ2 Pro12Ala genotypes in patients with DM nephropathy

Data are means ± SD. BMI, body mass index; DBP, diastolic blood pressure; FBS, fasting blood sugar; HDL, high density lipoprotein cholesterol; LDL, low density lipoprotein cholesterol; PP2, postprandial 2 hours blood sugar; SBP, systolic blood pressure.