PPARγ gene polymorphisms in black South African females with Type 2 diabetes mellitus

Diabetes mellitus is a lifestyle disease, with complications affecting quality of life. It is also increasing in prevalence on a global scale. Type 2 diabetes mellitus (T2DM) accounts for more than 90% of all diabetes cases and is a growing public health concern. Diabetes mellitus is a complex disease, genetically based but environmentally influenced. Nutrition therapy, based on knowledge of genetic composition, can be used in the prevention of a chronic disease like T2DM. One of the genes associated with T2DM which plays a significant role in insulin metabolism is the peroxisome proliferator-activated receptor-gamma 2 (PPARy) gene. The Pro12Ala polymorphism of the PPARy gene is associated with T2DM in various studies around the world. In this study, the presence of the Pro12Ala allele in a black, female population with T2DM in the Free State, South Africa, was investigated, with the purpose of describing the association between Pro12Ala PPARγ gene polymorphisms and body adiposity in the study population and the association between Pro12Ala PPARγ gene polymorphisms and blood glucose control (measured as HbA1c levels). A total of 72 black, female participants were included in the study. The data obtained from the study showed that of the 72 participants, 71 had the Pro/Pro (C/C) allele and only one was a heterozygote with the Pro/Ala (C/G) allele. The presence of a homozygotic PPARy Ala (G/G) genotype was not found in this study. In this population body mass index (BMI) and total body fat percentage was very high, factors which are strongly associated with the risk and incidence of T2DM. Blood glucose control was poor, and showed no association with age, BMI or body adiposity. The allele frequency of this SNP is not known in the Black South African population and even though the sample used in this study represents a small subset of the population and is limited by the absence of a nondiabetic control group, it can be derived from the results that it is likely that the Ala/Ala (G/G) genotype is rare in the population. The PPARy Pro/Ala polymorphism can therefore not be regarded as a direct contributing factor to the development of T2DM in this population and can therefore also not be regarded as a suitable genetic marker for early risk prediction of T2DM.