Vitamin D Levels and Mortality in Type 2 Diabetes

Abstract

OBJECTIVETo evaluate vitamin D as a predictor of all-cause and cardiovascular mortality and risk of progression to micro- or macroalbuminuria in type 2 diabetic patients.RESEARCH DESIGN AND METHODSIn a longitudinal observational follow-up study, 289 type 2 diabetic patients with normoalbuminuria (n = 172), microalbuminuria (n = 73), and macroalbuminuria (n = 44) at baseline were followed for a median (range) of 15.0 (0.2–23) years. Mean ± SD age was 54 ± 9 years. Plasma 25-hydroxyvitamin D3 levels were determined by high-performance liquid chromatography/tandem mass spectrometry on baseline samples. Severe vitamin D deficiency was defined as the lower 10th percentile (<13.9 nmol/l).RESULTSMedian (range) vitamin D level was 35.7 (5–136.7) nmol/l. Vitamin D levels were not associated with age, sex, estimated glomerular filtration rate, urinary albumin excretion rate (UAER), or A1C at baseline, but low levels were weakly associated with elevated systolic blood pressure (R = 0.13, P = 0.03). During follow-up, 196 (68%) patients died. All-cause mortality was increased in patients with severe vitamin D deficiency (hazard ratio 1.96 [95% CI 1.29–2.98]). The association persisted after adjustment for UAER, A1C, diabetes duration, and conventional cardiovascular risk factors (2.03 [1.31–3.13]). Severe vitamin D deficiency was associated with increased cardiovascular mortality (1.95 [1.11–3.44]), and the association persisted after adjustment (1.90 [1.15–3.10]). Severe vitamin D deficiency at baseline did not predict progression to micro- or macroalbuminuria.CONCLUSIONSIn type 2 diabetic patients, severe vitamin D deficiency predicts increased risk of all-cause and cardiovascular mortality, independent of UAER and conventional cardiovascular risk factors. Whether vitamin D substitution improves prognosis remains to be investigated.

MANAGEMENT OF ENDOCRINE DISEASE: The effect of vitamin D supplementation on glycaemic control in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

“…Furthermore, low vitamin D status is associated with future macrovascular events in patients with type 2 diabetes mellitus (10). This association may be the result of the link between vitamin D status and renin-angiotensin system (11), endothelial function (12), blood pressure (13) or chronic inflammation (4).…”

Effect of vitamin D supplementation on glycaemic control and insulin resistance: a systematic review and meta‐analysis

“…Low 25-hydroxyvitamin D (25OHD) levels are commonly found in patients with both Type 1 and Type 2 diabetes mellitus [1][2][3][4]. In patients with established diabetes mellitus and in the general population, low 25OHD levels are associated with higher fasting glucose and higher levels of glycated haemoglobin [5,6].…”

“…In patients with diabetes, low vitamin D levels predict future macrovascular events [2,4], although evidence for prediction of microvascular events is much less strong [15]. The macrovascular association may be attributable to effects on blood pressure [16], rennin-angiotensin system activity [17], endothelial function [3], vascular endothelial growth factor [18] or chronic inflammation.…”

Relationship between 25-hydroxyvitamin D Level and Metabolic Control and Albumin Excretion Rate in Elderly Patients with Type 2 Diabetes Mellitus

“…To our findings, 25(OH)D deficiency was found to be 30% in patients with type 2 DM. In type 2 diabetic patients, severe vitamin D deficiency predicts increased risk of all-cause and cardiovascular mortality, independent of urinary albümin excretion rate and conventional cardiovascular risk factors [2].…”

“…There is a tendency in increased prevalence of type-2 diabetes mellitus (DM) in elderly patients along with increased life expectancy [1][2][3][4]. Age has become the most dominant factor in the etiology of vitamin D deficiency [3,4].…”