Association of 25-hydroxyvitamin D with type 2 diabetes among patients undergoing coronary angiography: cross-sectional findings from the LUdwigshafen Risk and Cardiovascular Health (LURIC) Study
Correspondence: G. Neil Thomas, Public Health, Epidemiology and Biostatistics, University of Birmingham, Birmingham, B15 2TT, UK.Tel.: +44 121 4148696; Fax: +44 121 4147878; E-mail: firstname.lastname@example.org
Evidence suggests that vitamin D may protect against the onset of diabetes. However, the mechanisms underlying the role of vitamin D on glycaemic status are unclear and warrant further investigation. We sought to determine the relationship between serum 25-hydroxyvitamin D (25[OH]D) and glycaemic status among intermediate-to-high-risk patients scheduled for coronary angiography.
Participants were 3316 male and female patients (mean ± SD age, 62·7 ± 10·6 years). Four categories were formed according to serum 25[OH]D levels. The association between serum 25[OH]D and diabetes was assessed using multivariable logistic regression.
Fasting and 2 h post-load glucose, HbA1c and the HOMA-IR indices diminished with increasing serum 25[OH]D levels (P < 0·001). However, no associations were observed between insulin, pro-insulin or C-peptide and serum 25[OH]D concentrations. The pro-inflammatory markers IL-6 and hs-CRP also decreased considerably with higher vitamin D levels (P < 0·001). After full adjustment, those with optimal serum 25[OH]D levels had a reduced odds for fasting diabetes (OR = 0·63; 95% CI, 0·46–0·86; Ptrend = 0·01), 2 h post-load diabetes (OR = 0·46; 95% CI, 0·29–0·74; Ptrend = 0·004), both fasting/2 h post-load diabetes (OR = 0·61; 95% CI, 0·42–0·87; Ptrend = 0·001) and all of the combined hyperglycaemic states (OR = 0·68; 95% CI, 0·52–0·80; Ptrend = 0·01).
Higher serum 25[OH]D levels were associated with better glycaemic status and lower inflammation. Should these observations be confirmed in future studies, vitamin D supplementation may prove a useful adjunct in attenuating the onset of diabetes.