Osteoporosis is a disease characterized by decreased bone mass and pathological changes in the microarchitecture of the bones. The clinical significance of osteoporosis is the association with fragility fractures and, consequently, increases in both morbidity and mortality.

In men, genetical and life-style factors are known to affect the risk of fractures, however, data relating these factors with measures of bone mineral density and fracture risk are limited.

30.000 men aged 60-70 were randomly selected from the Central Office of Civil Registration in Denmark. Each receive a questionnaire addressing demographics, potential risk factors of osteoporosis, past medical history and medication by mail. In case of consent, the participants will complete a full medical examination including DXA and sampling of DNA if they have a fragility fracture. At the same time, 2 participants from the study population will be selected as control. The study period is 10 years.