title: Alterations in different indices of skeletal health after prolonged residency at high altitude.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effect of prolonged residency at high altitude (HA) on different indices of bone health in sea level (SL) residents staying at an altitude of 3450 m for 4 months to 1 year. The assessment of bone health parameters included multisite quantitative bone speed of sound (SOS), and markers of bone metabolism such as serum alkaline phosphatase (ALP), bone specific alkaline phosphatase (BAP), urinary deoxypyridinoline (DPD), C-terminal propeptide of type I collagen (CICP), N-telopeptide of type I collagen (NTX), and hormonal regulators such as 25-hydroxy vitamin D3 (25Vit D), intact parathyroid hormone (i-PTH), and cortisol.
  
  
  RESULTS
  The body weight in all the age groups was significantly lower at HA as compared to SL values. Prolonged residency at HA led to a significant decline in bone strength in terms of SOS, both at radius and phalanx. There was a significant increase in circulating Ca and ALP levels. Serum i-PTH and 25VitD levels decreased significantly. Significant decreases were also observed in CICP and BAP, bone formation markers, and serum NTX, DPD/Cr ratio, markers of bone resorption.
  
  
  CONCLUSIONS
  These observations suggest that prolonged residency under hypoxic environment is associated with a decline in both bone formation and bone resorption markers, reflecting a lower bone turnover at HA.
authors.affiliation: Defence Institute of Physiology and Allied Sciences , Delhi, India .
authors.forename: Minakshi
authors.initials: M
authors.lastname: Basu
authors.forename: Anand Swarup
authors.initials: AS
authors.lastname: Malhotra
authors.forename: Karan
authors.initials: K
authors.lastname: Pal
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Rajeev
authors.initials: R
authors.lastname: Bajaj
authors.forename: Saroj Kumar
authors.initials: SK
authors.lastname: Verma
authors.forename: Dishari
authors.initials: D
authors.lastname: Ghosh
authors.forename: Yogendra Kumar
authors.initials: YK
authors.lastname: Sharma
authors.forename: Ramesh Chand
authors.initials: RC
authors.lastname: Sawhney
mesh_terms: D000328:Adult; D000531:Altitude; D015415:Biomarkers / Q000097:blood; D016723:Bone Remodeling / Q000502:physiology*; D016022:Case-Control Studies; D006801:Humans; D007194:India; D008297:Male; D008682:Metatarsal Bones / Q000502:physiology; D008875:Middle Aged; D011884:Radius / Q000502:physiology; D012111:Residence Characteristics; D013977:Tibia / Q000502:physiology
chemical_list: D015415:Biomarkers
keywords: 25VitD; bone turnover; calcitonin; high altitude; i-PTH