Low serum 25-hydroxyvitamin D level predicts progression to type 2 diabetes in individuals with prediabetes but not with normal glucose tolerance

Abstract

Aims/hypothesis Vitamin D deficiency may increase the risk of type 2 diabetes. We therefore investigated whether serum concentrations of 25-hydroxyvitamin D [25(OH)D] would predict the development of prediabetes (impaired fasting glucose, impaired glucose tolerance or the two combined) and type 2 diabetes, either on their own or when combined with serum concentrations of IGF-1 or IGF-binding protein-1 (IGFBP-1), which may interact with 25(OH)D. Methods At baseline, participants aged 35-56 years without known type 2 diabetes were examined using OGTTs, 25 (OH)D and IGF peptide measurements, and anthropometric and lifestyle data. Participants who had prediabetes or type 2 diabetes at follow-up 8-10 years later were selected as cases; these were then age-and sex-matched to controls with normal glucose tolerance (NGT) at both baseline and follow-up, giving a total of 980 women and 1,398 men. Results Men but not women in the highest quartile of 25 (OH)D level had a decreased OR for developing type 2 diabetes after adjustment for confounders (OR 0.52, 95% CI 0.30, 0.90), an effect accounted for by individuals with prediabetes, but not with NGT, at baseline. In both sexes, progression from prediabetes to type 2 diabetes was reduced by about 25% per 10 nmol/l increase in 25(OH)D. A high IGFBP-1 value was a better predictor of a reduced risk of type 2 diabetes than high 25(OH)D for both sexes, whereas high IGF-1 concentrations predicted a decreased risk only in men. Conclusions/interpretation High serum 25(OH)D concentrations predict a reduced risk of type 2 diabetes in individuals with prediabetes, but not NGT. There were no significant interactions between 25(OH)D and IGFBP-1 or IGF-1 in terms of risk of diabetes. Our data suggest that vitamin D supplementation should be evaluated for the prevention of type 2 diabetes in prediabetic individuals.

No Effect of High-Dose Vitamin D Treatment on β-Cell Function, Insulin Sensitivity, or Glucose Homeostasis in Subjects With Abnormal Glucose Tolerance: A Randomized Clinical Trial

“…We demonstrated in a Swedish cohort that low 25(OH)D levels were predicting type 2 diabetes risk over 10 years in subjects with prediabetes, but not with normal glucose tolerance at baseline (4). Recently, a meta-analysis confirmed this association (5).…”

Pattern of vitamin D status in prediabetic individuals: a case control study at tertiary hospital in South India

“…12 The changing lifestyle, urbanization and modernization of Indian population has led to possible reduction of people being exposed to direct sunlight and inadequate intake of dietary vitamin D, thereby leaving the population at increased risk of vitamin D Deficiency and type 2 diabetes.…”

Effect of Vitamin D Supplementation on Glycemic Control in Patients With Type 2 Diabetes (SUNNY Trial): A Randomized Placebo-Controlled Trial

“…Longitudinal studies have reported that low vitamin D status is a predictor for incident type 2 diabetes (11,12). Still, it remains unclear whether vitamin D deficiency and insulin resistance are causally related or whether they constitute two independent features of patients with type 2 diabetes.…”