Differences in insulin resistance biomarkers, but not on serum zinc concentration, among individuals with different SLC30A8 genotypes: analysis of the São Paulo population-based study (2015 ISA-Nutrition)

Abstract

Background: Single nucleotide polymorphisms (SNPs) in the solute carrier family 30 member 8 (SLC30A8) gene related to zinc metabolism have been associated with an impaired insulin metabolic response. Objective: This study aimed to investigate variations in serum zinc concentration and insulin resistance biomarkers according to SNPs in the SLC30A8 gene among participants from the 2015 ISA-Nutrition. Methods: A total of 497 participants were genotyped for SNPs rs13266634, rs3802177, and rs11558471. Outcome variables included in the study were serum zinc concentration, fasting glucose, insulin, body mass index, and the homeostatic model assessment for insulin resistance (HOMA-IR). Results: The mean serum zinc concentration of participants was 85.5 µg/dL, without differences between sexes. The study population exhibited elevated glycemia and insulin resistance. No significant differences were found in serum zinc concentration and insulin resistance biomarkers between genotypes for all SNPs. However, men with the genotypes CC for rs13266634, GG for rs3802177, and AA for rs11558471 presented higher insulin concentration and HOMA-IR values compared to other genotypes, whereas there were no differences among women. Conclusion: These findings indicate that rs13266634, rs3802177, and rs11558471 SNPs in the SLC30A8 gene have no effect on serum zinc concentration but may contribute to insulin resistance effects in men.