Department of Public Health and General Practice, Norwegian University of Science and Technology, Medisinsk-teknisk senter, 7489 Trondheim, Norway. siri.forsmo@medisin.ntnu.no
The fracture incidence in Norway is among the highest in Europe, presumably due to osteoporosis. As part of a multipurpose health study in the county of Nord-Trondelag, Norway (the HUNT study), a 5% randomly selected sample (n=4,646) of the population >19 years of age was invited to undergo single X-ray absorptiometry (SXA) of the forearm. A total of 1,274 men (50.5 years) and 1,505 women (49.9 years) participated (60%). The aim of the study was to describe the variation in bone mineral density (BMD) and the prevalence of forearm BMD 2.5 standard deviations (SD) below the mean value for young adults in an unselected population sample. In women the BMD remained stable until the age of 50 years, whereupon a strong decline in BMD was observed. In men, a BMD increase was observed until about the age of 40 years; the decline after the age of 65 was, however, similar to that in women. Based on age and gender-specific reference values, the age-adjusted prevalence of T-scores