title: The Association of vitamin D status and fasting glucose according to body fat mass in young healthy Thais.
abstract: BACKGROUND
  Existing inconclusive data on the relationship between vitamin D status and human glucose homeostasis suggests that other factors, such as adiposity, might influence this relationship. The present study aimed to investigate the association between 25-hydroxyvitamin D [25(OH)D] and fasting plasma glucose (FPG) in the context of different amounts of total body fat in a healthy community-based population in Bangkok, Thailand.
  
  
  METHODS
  This cross-sectional study was a part of health survey of employees of the Electricity Generating Authority of Thailand. There were 1,990 healthy subjects (72.8% male) in this study. Total body fat was measured by bioelectrical impedance analysis. Total serum 25(OH)D, 25(OH)D3 and 25(OH)D2 were measured by LC-MS/MS.
  
  
  RESULTS
  Age (r = 0.134, p < 0.001) and FPG (r = 0.089, p < 0.001) were positively correlated with 25(OH)D levels, while total body fat mass (r = -0.049, p = 0.03) were negatively correlated with 25(OH)D levels. 25(OH)D levels were higher in males than in females (65.0 ± 0.5 vs. 53.5 ± 0.5 nmol/L, p < 0.001). After controlling for age, gender and total fat mass, FPG was no longer correlated with 25(OH)D. However, when subjects were stratified according to fat-free mass tertiles and controlled for age and gender, there was a positive, although weak association between 25(OH)D levels and FPG (p = 0.01) in the lowest tertile.
  
  
  CONCLUSIONS
  We therefore speculate that adiposity might influence the relationship of vitamin D status and FPG.
authors.affiliation: Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Rama 6 Rd,, Rajthevi, Bangkok 10400, Thailand. hataikarnn@hotmail.com.
authors.forename: Hataikarn
authors.initials: H
authors.lastname: Nimitphong
authors.forename: La-Or
authors.initials: LO
authors.lastname: Chailurkit
authors.forename: Suwannee
authors.initials: S
authors.lastname: Chanprasertyothin
authors.forename: Piyamitr
authors.initials: P
authors.lastname: Sritara
authors.forename: Boonsong
authors.initials: B
authors.lastname: Ongphiphadhanakul