Association between vitamin D serum levels and insulin resistance assessed by HOMA-IR among non-diabetic adults in the United States: Results from NHANES 2007–2014

Abstract

Insulin resistance, a pathological response to insulin hormone in insulin-dependent cells, is characterized by the presence of high glucose and insulin concentrations. The homeostasis model of insulin resistance (HOMA-IR) is one of the most used indexes to estimate insulin resistance by assessing the fasting glucose and insulin levels. An association was observed between vitamin D levels and insulin resistance, which varied in different ethnic groups, and there is some evidence that vitamin D supplementation could contribute to the improvement of insulin resistance. This study assessed the association between 25-hydroxyvitamin D (25[OH]D) concentration and HOMA-IR in American adults aged 20 years and older, without diabetes and other chronic diseases that can influence insulin resistance. The data from the National Health and Nutrition Examination Survey (NHANES) 2007–2014 were used by exploiting the free and publicly-accessible web datasets. Linear regression models were performed to evaluate the association between serum 25(OH)D concentration and HOMA-IR, and a negative association was observed, which remained significant following the adjustment for age, gender, race/ethnicity, education, body mass index (BMI), physical activity, the season of examination, current smoking, hypertension, the use of drugs which can influence insulin resistance, serum bicarbonates, triglycerides, and calcium and phosphorus levels. Only in non-Hispanic Blacks was this inverse association between vitamin D and HOMA-IR not observed in the fully adjusted model. Further studies are needed to explain the mechanisms of the observed ethnic/racial differences in the association of vitamin D levels with HOMA-IR.

The effect of vitamin D status on the occurrence of Kawasaki Disease: a meta-analysis

“…The status of vitamin D can vary depending on factors such as age, sex, race, and seasonal alterations. This variability might contribute to the inconsistent findings regarding the association between serum vitamin D levels and KD observed across different case–control studies [ 45 – 48 ]. Moreover, the clinical manifestation heterogeneity of immune diseases linked to vitamin D metabolism further complicates the understanding of the current relationship between VD and KD.…”

Association between a metabolic score for insulin resistance and hypertension: results from National Health and Nutrition Examination Survey 2007–2016 analyses

“…Physical activity was quantified using Physical Activity Level (PAL) scores, which assess the intensity and frequency of various activities, including vigorous (2 points) or moderate (1 point) work-related activity, vigorous (2 points) or moderate (1 point) leisure-time physical activity, and walking or bicycling for transportation (1 point). PAL scores ranged from 0 (minimum) to 5 (maximum) ( 26 ). Based on these scores, we categorized physical activity as mild (PAL score 0-1), moderate (PAL score 2-3), or vigorous (PAL score 4-5).…”