Biochemical markers of bone turnover and their relation to forearm bone mineral density in persons of Pakistani and Norwegian background living in Oslo, Norway: The Oslo Health Study.
OBJECTIVE
To evaluate whether Pakistanis have increased bone turnover compared with ethnic Norwegians due to their high prevalence of vitamin D deficiency and secondary hyperparathyroidism, and whether the relation between bone turnover and bone mineral density (BMD) differs between Pakistanis and ethnic Norwegians.


METHODS
A cross-sectional, population-based study conducted in the city of Oslo in 2000-2001. Random samples of 132 community-dwelling Pakistani men and women of ages 40, 45, and 59-60 years, and 580 community-dwelling Norwegian men and women of ages 45 and 59-60 years are included in this substudy.


METHODS
Venous serum samples were drawn for measurements of markers of the vitamin D endocrine system and the bone turnover markers osteocalcin (s-OC), bone alkaline phosphatase (s-bone ALP), and tartrate-resistant acid phosphatase (s-TRACP). BMD was measured at the forearm by single-energy X-ray absorptiometry.


RESULTS
Pakistanis had higher s-bone ALP compared with Norwegians. Mean (95% CI) age-adjusted levels were 22.5 (21.0, 24.1) U/l in Pakistani men versus 19.3 (18.6, 20.1) U/l in Norwegian men, P < 0.0005, and 20.3 (18.4, 22.1) U/l in Pakistani women versus 16.7 (16.0, 17.4) U/l in Norwegian women, P = 0.001. There tended to be an inverse association between bone turnover and BMD in men and women of both ethnic groups, and it was strongest for s-bone ALP. Overall mean (95% CI) distal BMD decrease was -16 (-20, -11) mg/cm(2) per 1 s.d. increase in s-bone ALP (P < 0.0005) when adjusting for age, sex, and ethnicity.


CONCLUSIONS
Except for somewhat higher s-bone ALP levels in Pakistanis, there were only minor ethnic differences in bone turnover, despite a strikingly different prevalence of secondary hyperparathyroidism. Bone turnover was inversely associated with forearm BMD in both ethnic groups.
Holvik
Kristin
K
Institute of General Practice and Community Medicine, University of Oslo, PO Box 1130 Blindern, N-0318 Oslo, Norway, Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway.
Meyer
Haakon E
HE
Søgaard
Anne Johanne
AJ
Selmer
Randi
R
Haug
Egil
E
Falch
Jan A
JA
D000135:Acid Phosphatase / Q000097:blood; D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D015519:Bone Density / Q000502:physiology*; D001862:Bone Resorption / Q000208:ethnology / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D005542:Forearm / Q000033:anatomy & histology; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000453:epidemiology; D007527:Isoenzymes / Q000097:blood; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D015675:Osteocalcin / Q000097:blood; D010012:Osteogenesis / Q000502:physiology*; D010154:Pakistan / Q000208:ethnology; D000071681:Tartrate-Resistant Acid Phosphatase; D014808:Vitamin D Deficiency / Q000503:physiopathology
D007527:Isoenzymes; D015675:Osteocalcin; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase