The independent association between 25 (OH) vitamin D deficiency, HOMA-IR, and lipid profile with APOE genotyping in obese cases with and without T2DM.

Introduction: Vitamin D deficiency, insulin resistance, dyslipidemia, and APOE genotyping are implicated in the pathogenesis of obesity and type 2 diabetes mellitus (T2DM). We wanted to find out if there was a link between a lack of 25(OH) vitamin D, HOMA-IR, and lipids and APOE genotyping in obese people with and without T2DM.

Methods: We divided 300 Egyptians of both sexes into three groups in a case-control study: 100 obese cases with a body mass index of more than 30, 100 obese cases diagnosed with T2DM, and 100 controls with a body mass index of less than 30. Levels of 25 (OH) vitamin D, fasting blood sugar (FBS), HbA1C, fasting insulin, HOMA-IR, and lipid profile parameters were measured, and APOE genotypes were assessed using Applied BiosystemsTM TaqMan^® SNP Genotyping Assays.

Results: Higher levels of FBS, fasting insulin, HOMA-IR, and dyslipidemia were found in obese people with and without T2DM compared to the control group (p < 0.05). Lower levels of 25(OH) vitamin D were also found. Insulin resistance and lipid profile parameters, particularly in obese cases with T2DM, inversely correlate with vitamin D deficiency. The APOE genotyping analysis revealed strong links between vitamin D levels and certain APOE genotypes. Independent of metabolic parameters, higher vitamin D levels were associated with lower odds of E3/E4 and E4/E4 genotypes among obese cases with T2DM.

Conclusion: This study highlights the independent role of vitamin D deficiency in modulating APOE genotypes in obese T2DM individuals. The findings suggest potential implications for personalized interventions targeting vitamin D status to mitigate genetic predispositions to metabolic disorders such as obesity and T2DM.