title: Low vitamin D levels correlate with the proinflammatory state in type 1 diabetic subjects with and without microvascular complications.
abstract: Epidemiologic studies link vitamin D deficiency to onset of type 1 diabetes mellitus (T1DM). T1DM exhibits increased inflammation, which is pronounced with microvascular complications (T1DM-MV). However, there are a paucity of data on vitamin D in T1DM-MV in relation to biomarkers of inflammation, and this formed the aim of the study. Healthy control subjects (n = 36), patients with T1DM (n = 24), and patients with T1DM-MV (n =26) were recruited. Serum vitamin D levels, monocyte toll-like receptor (TLR) 2 and TLR4 expression and nuclear factor-κB (NFκB) activity were assessed. Patients with T1DM and T1DM-MV were significantly vitamin D deficient compared with control subjects (P < .01). There was a significant negative correlation between vitamin D levels and high-sensitivity C-reactive protein, NFκB activity, and TLR4 expression (P < .05). Preincubation with vitamin D significantly decreased lipopolysaccharide-activated TLR4 expression and cytokine levels in monocytes (P < .05). Low vitamin D levels may contribute to increased inflammation in T1DM. Future studies will elucidate the immunomodulatory effects of vitamin D in decreasing vascular risk in this population.
authors.affiliation: Laboratory for Atherosclerosis and Metabolic Research, UC Davis Medical Center, Sacramento, CA 95817, USA.
authors.forename: Sridevi
authors.initials: S
authors.lastname: Devaraj
authors.forename: Jung-Mi
authors.initials: JM
authors.lastname: Yun
authors.forename: Catherine R
authors.initials: CR
authors.lastname: Duncan-Staley
authors.forename: Ishwarlal
authors.initials: I
authors.lastname: Jialal
mesh_terms: D000328:Adult; D002097:C-Reactive Protein / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D003925:Diabetic Angiopathies / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D008297:Male; D055806:Microvessels / Q000473:pathology; D009000:Monocytes / Q000378:metabolism / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D014808:Vitamin D Deficiency / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D000097782:NF-kappaB-Inducing Kinase
chemical_list: D002097:C-Reactive Protein; D017346:Protein Serine-Threonine Kinases; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D000097782:NF-kappaB-Inducing Kinase; C495342:TLR2 protein, human; C495345:TLR4 protein, human