Gene-Environment Interaction of Interleukin 10 Gene Polymorphism, rs1800896, with Lifestyle on Cardiovascular Risk in Type 2 Diabetes

Gene–environment interactions play a major role in the phenotypic expression of complex disease traits such as those for cardiovascular diseases. This study aimed to determine the gene–environment interactions that underpin the relationship between interleukin-10 (IL-10) single-nucleotide polymorphism (1082 G/A [rs1800896]) with lifestyle on cardiovascular disease risk in adult Nigerians with type 2 diabetes mellitus (DM). This case–control study involved patients with type 2 DM with high cardiovascular risk, determined by the Framingham’s classification, and age, sex, and diabetes-duration matched subjects with low and intermediate cardiovascular risks. The genotypes were detected by polymerase chain reaction (PCR) followed by allelic discrimination using the Applied Biosystems 7900HT Fast Real-Time PCR System. One-way analysis of variance and logistic regression were employed for analysis. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated to estimate the risk caused by the polymorphism. P <0.05 was considered significant. The odds for cardiovascular risk decreased progressively in individuals with the GG, GA, and AA genotypes (OR = 0.80, 95% CI = 0.49–1.28, P = 0.345 and OR = 0.46, 95% CI = 0.24–0.88, P = 0.018 for GA and AA genotypes, respectively. A significantly higher proportion of homozygous (AA) individuals were in the low cardiovascular risk group (54.2%, P = 0.018). Compared with the whole study population, individuals with the AA genotype had consistently lower odds for cardiovascular risk in subpopulations like alcohol users (OR = 0.25 [0.11–0.55], P = 0.001), but the odds were higher among smokers (OR = 1.80 [1.14–2.90], P = 0.017) and those with sedentary lifestyles (OR = 2.46, 95% CI = 1.14–5.33, P = 0.024). The homozygous mutant genotype AA of the IL-10 gene 1082 G/A had a protective effect on cardiovascular risk in type 2 DM. However, this protection was absent in those leading a sedentary lifestyle.