A prospective cohort study that started in 1990 in Ommoord, a suburb of Rotterdam, The Netherlands among 10,994, men and women aged 55 and over. The main objective of the Rotterdam Study is to investigate the prevalence and incidence of and risk factors for chronic diseases in the elderly. The chronic diseases of interest are cardiovascular, neurological, locomotor and ophthalmologic diseases. The findings from the Rotterdam Study will hopefully contribute to a better prevention and treatment of chronic diseases in the elderly. The osteoporosis genetic studies comprise 5746 individuals with information on Fx/DXA and GWAs assesment.