CRY1 polymorphism may influence the association of low carbohydrate diet (LCD) score on glucose homeostasis in overweight and obese women

Background and aims: We sought to examine the interaction between CRY1 genotypes and low carbohydrate diet (LCD) score and the effect on insulin resistance, insulin sensitivity, homeostasis model assessment of insulin resistance (HOMA- IR) and quantitative insulin sensitivity check index (ISQUKI). Methods: This cross-sectional study was conducted with a total of 228 overweight and obese women. The data related to anthropometric and biochemical measures were collected and a food frequency questionnaire (FFQ), with 147 items, was used to assess dietary intake. Based on the FFQ, we calculated an LCD score for each study participant, ranging from 0 to 70. Biochemical assessments, including TC, HDL, LDL, TG, FBS, insulin and HOMA-IR, were performed. Deoxyribonucleic acid (DNA) samples were assessed to be genotyped for the rs2287161, which was genotyped by the restriction fragment length polymorphism (PCR-RFLP) method. A generalised linear model was performed for interaction analysis. Results: The results of the study demonstrated that, after controlling for several confounders, increased adherence to an LCD (T3 vs. T1) in the interaction with one risk allele genotype (CG) increases ISQUKI level (β: 0.001, CI: 0.00, 0.002, p=0.041). Also, there was a marginally negative interaction between higher adherence to LCD and two risk alleles genotype (CC) on insulin level (β: -0.012, CI: 0-0.024, 0.001, p=0.054). Conclusions: This study revealed a negative interaction of CRY1 genotypes with two risk allele and higher LCD adherence on insulin level, and a positive interaction on ISQUKI. However, the mechanism of interaction between LCDs and CRY1 genotypes remains unclear.