Association of the ITLN1 gene polymorphism with dietary patterns, glycemic factors, and anthropometric indices in women with prediabetes

BACKGROUND: Prediabetes is an early stage of type 2 diabetes mellitus (T2DM) that is prevalent around the world. A combination of genetic and lifestyle factors is contributed in conversion of prediabetes to T2DM. The present study aimed to investigate the association of the ITLN1 gene Val109Asp polymorphism with dietary patterns, glycemic factors, and anthropometric indices in women with prediabetes. METHODS: This cross-sectional study was carried out on 202 women with prediabetes aged 18-65 years who were selected from the healthcare center using the convenience sampling method. Fasting blood samples, anthropometric measurements, and information about the dietary intake of the participants were collected. The ITLN1 gene Val109Asp polymorphism genotypes were recognized by the high-resolution melting-polymerase chain reaction (HRM-PCR) method. Dietary patterns were obtained by exploratory factor analysis and JASP software. Data analyses were conducted by analysis of covariance and ordinal regression using IBM SPSS Statistics software. RESULTS: AA, AT, and TT genotypes of the ITLN1 polymorphism were found in 15.8%, 52.0%, and 32.2% of participants, and three dietary patterns, including vegetarian, high-fat, and mixed dietary patterns, were extracted. According to the ordinal regression, participants in the AT genotype had a lower chance of having a high-fat dietary pattern compared to the AA genotype (Adjusted odds ratio (AOR) (CI 95%): 0.466 (0.219, 0.989), p = 0.047). The ANCOVA test also indicated that participants with the AT (Mean difference (MD) (CI 95%): -3.073 (-5.245, -0.901), p = 0.007) and TT (MD (CI 95%): -3.188 (-5.513, -0.862), p = 0.006) genotypes had a decreased body weight compared to the AA genotype. Moreover, women in the TT genotype group had higher waist circumference compared to the AA genotype (MD (CI 95%): 2.557 (0.060, 5.055), p = 0.045). Individuals with genotypes AT (MD (CI 95%): 0.028 (0.011, 0.044), p = 0.001) and TT (MD (CI 95%): 0.022 (0.005, 0.040), p = 0.013) also have higher WHthR compared to the AA genotype. There was no significant association between the ITLN1 polymorphism genotypes and glycemic parameters in the adjusted model. CONCLUSION: The findings revealed a link between the ITLN1 Val109Asp polymorphism and dietary pattern 2 and general and central obesity in women with prediabetes. Further well-designed studies are required to confirm these findings and clarify the association of the ITLN1 polymorphism with glycemic factors.