title: Relationship among 25-hydroxyvitamin D concentrations, insulin action, and cardiovascular disease risk in patients with essential hypertension.
abstract: BACKGROUND
  Although low plasma 25-hydroxyvitamin D (25(OH)D) concentrations have been shown to predict risk of hypertension and associated cardiovascular disease (CVD), vitamin D repletion has not consistently lowered blood pressure or decreased CVD. One possibility for this discrepancy is the presence of considerable metabolic heterogeneity in patients with hypertension. To evaluate this possibility, we quantified relationships among insulin resistance, 25(OH)D concentration, and CVD risk factor profile in patients with essential hypertension.
  
  
  METHODS
  Measurements were made of 25(OH)D concentrations, multiple CVD risk factors, and insulin resistance by the steady-state plasma glucose concentration during the insulin suppression test in 140 otherwise healthy patients with essential hypertension.
  
  
  RESULTS
  As a group, the patients were overweight/obese and insulin resistant and had low 25(OH)D concentrations. The more insulin resistant the patients were, the worse the CVD risk profile was. In addition, the most insulin-resistant quartile had significantly lower 25(OH)D concentrations than the most insulin-sensitive quartile (20.3±1.4 vs. 25.8±1.4ng/ml; P = 0.005). In the entire group, 25(OH)D concentration significantly correlated with magnitude of insulin resistance (steady-state plasma glucose concentration; r = -0.20; P = 0.02).
  
  
  CONCLUSIONS
  There was considerable metabolic heterogeneity and substantial difference in magnitude of conventional CVD risk factors in patients with similar degrees of blood pressure elevation. The most insulin-resistant quartile of subjects had the lowest 25(OH)D concentration and the most adverse CVD risk profile, and they may be the subset of patients with essential hypertension most likely to benefit from vitamin D repletion.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California; fahim@stanford.edu.
authors.forename: Fahim
authors.initials: F
authors.lastname: Abbasi
authors.affiliation: Division of Endocrinology, Gerontology, and Metabolism, Department of Medicine, Stanford University School of Medicine, Stanford, California;
authors.forename: David
authors.initials: D
authors.lastname: Feldman
authors.affiliation: Quest Diagnostics Nichols Institute, San Juan Capistrano, California.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Caulfield
authors.affiliation: Quest Diagnostics Nichols Institute, San Juan Capistrano, California.
authors.forename: Feras M
authors.initials: FM
authors.lastname: Hantash
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California;
authors.forename: Gerald M
authors.initials: GM
authors.lastname: Reaven
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use; D001786:Blood Glucose; D002318:Cardiovascular Diseases / Q000097:blood* / Q000453:epidemiology; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D050171:Dyslipidemias / Q000097:blood / Q000453:epidemiology; D000075222:Essential Hypertension; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000453:epidemiology
chemical_list: D000959:Antihypertensive Agents; D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D007328:Insulin; D014280:Triglycerides; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: blood pressure; cardiovascular disease; hypertension; insulin action; vitamin D.