title: Vitamin D status and parathyroid hormone levels in relation to bone mineral density in apparently healthy Syrian adults.
abstract: Vitamin D deficiency was highly prevalent in this study. More than half of the participants with vitamin D level less than 5 ng/mL had secondary hyperparathyroidism, which implicated a major bone health concern. After adjustment for potential predictors, parathyroid hormone (PTH) explained about 3 % of the variance in total hip bone mineral density (BMD).
  
  
  OBJECTIVE
  Bone mineral density (BMD) is known to be influenced by serum 25-hydroxyvitamin D (25OHD) and intact parathyroid hormone (PTH) levels. The relationship between 25OHD and PTH with BMD has not been well documented in Syrian adults. We aimed to determine how differences in serum 25OHD and PTH levels impacted hip and lumbar spine BMD among apparently healthy Syrian adults.
  
  
  METHODS
  25OHD and PTH were measured in 156 participants aged 18-53 years from Damascus and its surroundings. Lumbar spine and hip BMD measurements were measured by dual-energy X-ray absorptiometry using Hologic Discovery Wi densitometer. Multivariate regression models were used to investigate the relationships between 25OHD, PTH, and BMD.
  
  
  RESULTS
  All participants, except one male, had 25OHD <30 ng/mL (<75 nmol/L), and 89.1 % of them had 25OHD levels less than 20 ng/mL (50 nmol/L). Secondary hyperparathyroidism was significantly more prevalent in the lowest 25OHD quartile compared to that in the highest quartile (59 vs. 10.3 %, p < 0.0001). Mean bone mineral density at all sites in our participants was lower when compared to that of their Caucasian counterparts in Europe and North America. No significant correlation was found between 25OHD and BMD either at hip or at lumbar spine. In the multivariate analyses, after adjustment for potential predictors, PTH explained about 3 % of the variation in total hip BMD.
  
  
  CONCLUSIONS
  Low BMD was relatively frequent at all measured sites. PTH, but not 25OHD, was a predictor for total hip BMD in a young population.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Damascus University, Damascus, Syria.
authors.forename: Rima
authors.initials: R
authors.lastname: Sayed-Hassan
authors.affiliation: Department of Family & Community Medicine, Faculty of Medicine, Damascus University, Mazzeh Autostrade, Damascus, Syria. sdcm@pisem.net.
authors.forename: Nizar
authors.initials: N
authors.lastname: Abazid
authors.affiliation: Department of Family & Community Medicine, Faculty of Medicine, Damascus University, Mazzeh Autostrade, Damascus, Syria.
authors.forename: Abir
authors.initials: A
authors.lastname: Koudsi
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, Damascus University, Damascus, Syria.
authors.forename: Zaynab
authors.initials: Z
authors.lastname: Alourfi
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D015519:Bone Density; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000097:blood / Q000453:epidemiology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D010281:Parathyroid Hormone / Q000097:blood*; D010384:Pelvic Bones / Q000000981:diagnostic imaging; D015995:Prevalence; D012044:Regression Analysis; D013593:Syria / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology; D055815:Young Adult
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Bone mineral density; Secondary hyperparathyroidism; Syria; Vitamin D deficiency