Gene-related prevalence of metabolically healthy obesity in different racio-ethnic groups

The metabolically healthy obesity (MHO) phenotype is partly influenced by race/ethnicity and genetic factors being relatively more prevalent in some groups compared to others. This review examines current evidence on the prevalence of MHO amongst children, adolescents and adults of different racio-ethnic groups; and explores gene variants and single nucleotide polymorphisms (SNPs) that may confer cardioprotection in some racio-ethnic groups compared to others. Literature search of articles published in English was conducted using PubMed, Medline and Google scholar databases, with search terms related to the prevalence of metabolically healthy obesity as well as genetic variants that decrease or increase the risk of metabolic syndrome (MetS). MHO prevalence differed across racio-ethnic groups and gene variants that confer cardioprotection were higher in some racio-ethnic groups compared to others. Lower prevalence of MHO across all ages was particularly reported in the Middle East, while high prevalence was reported in Africans, Americans and some Asian adult population. Excluding environmental and other risk factors, we observed that Caucasians were carriers of gene variants that confer protection against cardiometabolic diseases, whilst Asians showed high frequency of gene variants that increase susceptibility to MetS. A robust understanding of the role of these gene variants, their frequency distribution and racio-ethnic variations may facilitate conceptualisation of appropriate genome wide association studies (GWAS) to determine significant associations between various genetic factors and observed phenotype or disease. This will guide policy formulation and serve as a useful tool in pharmacogenomics and precision medicine. Keywords: Obesity, metabolically healthy obesity, single nucleotide polymorphism, ethnicity, race, metabolic syndrome, gene variant

Variant rs2237892 of KCNQ1 Is Potentially Associated with Hypertension and Macrovascular Complications in Type 2 Diabetes Mellitus in A Chinese Han Population

KCNQ1 has been identified as a susceptibility gene of type 2 diabetes mellitus (T2DM) in Asian populations through genome-wide association studies. However, studies on the association between gene polymorphism of KCNQ1 and T2DM complications remain unclear. To further analyze the association between different alleles at the single nucleotide polymorphism (SNP) rs2237892 within KCNQ1 and TD2M and its complications, we conducted a case-control study in a Chinese Han population. The C allele of rs2237892 variant contributed to susceptibility to T2DM (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.20–1.75). Genotypes CT (OR, 1.97; 95% CI, 1.24–3.15) and CC (OR, 2.49; 95% CI, 1.57–3.95) were associated with an increased risk of T2DM. Multivariate regression analysis was performed with adjustment of age, gender, and body mass index. We found that systolic blood pressure (P = 0.015), prevalence of hypertension (P = 0.037), and risk of macrovascular disease (OR, 2.10; CI, 1.00–4.45) were significantly higher in subjects with the CC genotype than in the combined population with genotype either CT or TT. Therefore, our data support that KCNQ1 is associated with an increased risk for T2DM and might contribute to the higher incidence of hypertension and macrovascular complications in patients with T2DM carrying the risk allele C though it needs further to be confirmed in a larger population