Vitamin D, the renin-angiotensin system, and insulin resistance

Abstract

Insulin resistance is characterized by the systemic impairment of insulin action and is usually the result of aging, obesity, chronic inflammation, or another factor that may contribute to the inhibition of the insulin signaling pathway. Insulin resistance is accompanied by defects in lipid metabolism and blood coagulation, hypertension, obesity, and vascular inflammation in a syndrome called syndrome X or metabolic syndrome. Metabolic syndrome is involved in the development of atherosclerosis with consequent cardiovascular complications including acute myocardial infarction, stroke, and vascular disease. Recent data have shown that vitamin D acts as a negative regulator of the renin gene and that vitamin D deficiency is followed by increased renin-angiotensin II expression. The link between the insulin signaling pathway/insulin resistance and the renin-angiotensin system has been well documented in previous studies. The present review focuses on disorders characterized by a reduction in vitamin D concentration or its receptor function and the development of insulin resistance or metabolic syndrome, and discusses also possible therapeutic interventions.

Serum 25-hydroxyvitamin D is independently associated with high-density lipoprotein cholesterol and the metabolic syndrome in men and women

“…32,33 Vitamin D may be involved in the regulation of this system because induction of vitamin D deficiency is followed by increased renin-angiotensin II expression. 34 Thus, adequate vitamin D status may prevent angiotensin II-induced stimulation of nuclear factor kappa-light-chainenhancer of activated B cells, resulting in greater insulin sensitivity. Another possible mechanism may be related to insulin like growth factor-1 (IGF-1) receptors.…”

Vitamin D and cardiovascular risk

“…These recognize specific sites within the DNA, denoted vitamin D responsive elements, and direct transcription of approximately 3% of the whole genome [2]. The list of target genes amongst others includes renin, insulin and different cytokines, which are orchestrated in a cell-specific manner [3]. A comprehensive insight into the antiinflammatory potency of vitamin D activities has recently been provided by the group of Liu [4].…”

Effect of Activated Vitamin D on Glucoparameters in HCV Seropositive and Seronegative Patients on Chronic Hemodialysis

“…[1][2][3][4] Recent evidence in the pathogenesis of type 2 diabetes milletus (DM) suggests that alterations in vitamin D status may affect insulin sensitivity, β-cell function, or both, given the discovery of vitamin D receptors (VDRs) in β cells and vitamin D-dependent calcium-binding proteins in pancreatic tissue. 5 Vitamin D is essential for normal insulin release in response to glucose and for maintenance of glucose tolerance, whereas deficiency results in decreased insulin secretion without altering glucagon secretion.…”