The Metabolic Syndrome and Carotid Intima-Media Thickness in Relation to the Parathyroid Hormone to 25-OH-D-3 Ratio in a General Population

BACKGROUND Parathyroid hormone (PTH) and vitamin D interactively regulate calcium fluxes across membranes, and thereby modulate insulin sensitivity, blood pressure, and arterial calcification. We hypothesized that lower calcium intake as reflected by circulating PTH and 25-OH-D-3 might be associated with the metabolic syndrome (MS) and arterial calcification. METHODS In a random population sample (n = 542; 50.5% women; mean age, 49.8 +/- 13.1 years), we measured MS prevalence (International Diabetes Federation (IDF) and American Heart Association (AHA) criteria), PTH and 25-OH-D-3, serum and 24-h urinary calcium, MS components, carotid intima-media thickness (CIMT), and calcium intake from dairy products. We assessed associations in multivariable-adjusted analyses, using linear and logistic regressions. RESULTS The prevalence of MS was 21.0% (IDF criteria) and 23.6% (AHA criteria). MS prevalence, blood pressure, waist circumference, body mass index, fasting blood glucose, insulin and triglycerides, and CIMT increased (