Vitamin D status and the risk of type 2 diabetes: The Melbourne Collaborative Cohort Study. (March 2019)

• Record Type: Journal Article
• Authors: Heath, Alicia K.; Williamson, Elizabeth J.; Hodge, Allison M.; Ebeling, Peter R.; Eyles, Darryl W.; Kvaskoff, David; O'Dea, Kerin; Giles, Graham G.; English, Dallas R.
• Is Part Of: Diabetes research and clinical practice. Volume 149(2019)
• Page Start: 179
• Page End: 187
• Publication Date: 2019-03
• Subjects: Vitamin D -- 25-Hydroxyvitamin D -- Vitamin D deficiency -- Type 2 diabetes mellitus; Diabetes -- Periodicals; Diabetes Mellitus -- Periodicals; 616.462
• DOI: 10.1016/j.diabres.2018.05.007
• Languages: English
• ISSNs: 0168-8227

Abstract

Abstract: Aims: Inverse associations between vitamin D status and risk of type 2 diabetes observed in epidemiological studies could be biased by confounding and reverse causality. We investigated the prospective association between vitamin D status and type 2 diabetes and the possible role of reverse causality. Methods: We conducted a case-cohort study within the Melbourne Collaborative Cohort Study (MCCS), including a random sample of 628 participants who developed diabetes and a sex-stratified random sample of the cohort ( n = 1884). Concentration of 25-hydroxyvitamin D (25(OH)D) was measured using liquid chromatography-tandem mass spectrometry in samples collected at recruitment. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of type 2 diabetes for quartiles of 25(OH)D relative to the lowest quartile and per 25 nmol/L increase in 25(OH)D, adjusting for confounding variables. Results: The ORs for the highest versus lowest 25(OH)D quartile and per 25 nmol/L increase in 25(OH)D were 0.60 (95% CI: 0.44, 0.81) and 0.76 (95% CI: 0.63, 0.92; p = 0.004), respectively. In participants who reported being in good/very good/excellent health approximately four years after recruitment, ORs for the highest versus lowest 25(OH)D quartile and per 25 nmol/L increase in 25(OH)D were 0.46 (95% CI: 0.29, 0.72) and 0.71 (95% CI: 0.56, 0.89; p = 0.003), respectively. Conclusions: In this sample of middle-aged Australians, vitamin D status was inversely associated with the risk of type 2 diabetes, and this association did not appear to be explained by reverse causality.