title: Vitamin D, parathyroid hormone levels, and the prevalence of metabolic syndrome in community-dwelling older adults.
abstract: OBJECTIVE
  Accumulating research suggests low-circulating vitamin D concentrations, i.e., 25-hydroxyvitamin-D [25(OH)D], may be associated with an increased prevalence of metabolic syndrome; however, previous studies have not accounted for parathyroid hormone (PTH) levels. We examined the association of 25(OH)D and PTH with the prevalence of metabolic syndrome in a community-based cohort of older adults.
  
  
  METHODS
  Participants included 410 men and 660 women, 44-96 years old, who completed a follow-up clinic visit in 1997-1999 as part of the Rancho Bernardo Study. Sex-specific logistic regression models were fit to estimate the odds of ATP III (Adult Treatment Panel III)-defined metabolic syndrome across quintiles of 25(OH)D and PTH, adjusting for age, season, and major lifestyle factors.
  
  
  RESULTS
  In men, there was a significant trend (P = 0.03) of increasing adjusted odds for metabolic syndrome with increasing PTH concentrations, primarily due to an odds ratio of 2.02 (95% CI 0.96-4.24) in men in the top quintile (> or =63 ng/l) of PTH concentration. This association remained unchanged after taking into account 25(OH)D levels and excluding men with diabetes or impaired renal function; it was attenuated after adjustment for the homeostasis model assessment of insulin resistance. Neither PTH in women nor 25(OH)D levels in either sex was related to the metabolic syndrome.
  
  
  CONCLUSIONS
  These findings suggest an increased risk of metabolic syndrome with elevated PTH levels in older men and no effect of 25(OH)D concentrations in either sex. The reason for the sex difference in the PTH-metabolic syndrome association is unknown. Prospective studies are necessary to better determine the roles of 25(OH)D and PTH in the etiology of metabolic syndrome.
authors.affiliation: Department of Family and Preventive Medicine, University of California, San Diego, La Jolla, California 92093-0607, USA.
authors.forename: Jared P
authors.initials: JP
authors.lastname: Reis
authors.forename: Denise
authors.initials: D
authors.lastname: von Mühlen
authors.forename: Donna
authors.initials: D
authors.lastname: Kritz-Silverstein
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Wingard
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barrett-Connor
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D002112:Calcifediol / Q000097:blood; D002117:Calcitriol / Q000097:blood; D002140:California / Q000453:epidemiology; D005260:Female; D006798:Housing; D006801:Humans; D008075:Lipoproteins, HDL / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000453:epidemiology*; D008875:Middle Aged; D016017:Odds Ratio; D010281:Parathyroid Hormone / Q000097:blood*; D015995:Prevalence; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood; D014807:Vitamin D / Q000097:blood*
chemical_list: D008075:Lipoproteins, HDL; D010281:Parathyroid Hormone; D014280:Triglycerides; D014807:Vitamin D; D002117:Calcitriol; D002112:Calcifediol