American Journal of Epidemiology Advance Access originally published online on July 2, 2008
American Journal of Epidemiology 2008 168(4):454-460; doi:10.1093/aje/kwn151
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ORIGINAL CONTRIBUTIONS |
Weight Change over Three Decades and the Risk of Osteoporosis in Men
The Norwegian Epidemiological Osteoporosis Studies (NOREPOS)
1 Section for Preventive Medicine and Epidemiology, Institute of General Practice and Community Medicine, University of Oslo, Oslo, Norway
2 Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
3 Section of Epidemiology and Biostatistics, School of Population Health, University of Auckland, Auckland, New Zealand
4 Centre of Endocrinology, Aker University Hospital, Oslo, Norway
5 Faculty of Medicine, University of Oslo, Oslo, Norway
6 Institute of Community Medicine, University of Tromsø, Tromsø, Norway
7 Department of Physiotherapy, University Hospital of North Norway, Tromsø, Norway
Correspondence to Professor H. E. Meyer, Institute of General Practice and Community Medicine, University of Oslo, P.O. Box 1130 Blindern, 0318 Oslo, Norway (e-mail: h.e.meyer{at}medisin.uio.no).
Received for publication March 11, 2008. Accepted for publication May 8, 2008.
The purpose of this study was to assess the effect of weight in middle-aged men and subsequent weight change on the risk of osteoporosis three decades later. The authors utilized data from 1,476 Norwegian men participating in two health screenings in Oslo (1972–1973 and 2000–2001) and Tromsø (1974–1975 and 2001). Height and weight were measured at baseline and follow-up. Total hip bone mineral density (BMD) was assessed at follow-up by dual energy x-ray absorptiometry. Baseline body mass index (BMI) was positively related to BMD three decades later. Subsequent weight change was also strongly related to BMD, and the proportion of persons with osteoporosis decreased from 15.1% among those who lost 
10% of their body weight to 0.6% among those who gained 10% of their body weight. Excluding participants with medical conditions did not change the association between weight change and BMD. Taking both BMI and weight change into account, the prevalence of osteoporosis in the lowest quarter of baseline BMI was 31% (95% confidence interval: 24, 37) in persons losing 5% of their weight and 4% (95% confidence interval: 1, 7) in persons gaining 5% of their weight. In this cohort of middle-aged men, low baseline BMI and weight loss during the following three decades were both strongly and negatively related to total hip BMD.
aging; body weight; body weight changes; bone density; men; osteoporosis
Abbreviations: BMD, bone mineral density; BMI, body mass index; CI, confidence interval; SD, standard deviation