Familial aggregation of forearm bone mineral density in Chinese

The Rotterdam Study: 2012 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Influence of heredity and environment on peak bone density: a parent-offspring study

The aim of the study was to determine the relative influence of heredity and environment on peak bone density and also to estimate the risk of having low peak bone density if the bone density of parents is low. The study comprised 83 families (48 daughters and 35 sons and their parents). The children were at an age when bone density is at its peak at most skeletal sites (22.2+/-1.8 girls; 23.1+/-1.2 boys). Bone mineral density (BMD; g/cm(2)) was determined by dual-energy X-ray absorptiometry. Anthropometric measurements were made, and calcium intake and physical activity were assessed. Heredity accounted for 22-42% of the variation in BMD of the children, depending on the skeletal site. Heritability for cortical BMD of mid-radius was considerably lower than that for spinal trabecular BMD. Children whose parents had low BMDs (T-score< or =-1) were 1.1 times more likely to inherit low BMD. Child BMD depended significantly on parent BMD and also on physical activity. In our study, heredity accounted for the total BMD variation more than the environmental factors. This influence was lower in the cortical than in the trabecular parts of the skeleton. Optimal environmental factors, such as physical activity, may influence the risk of inheriting low BMD.

The Rotterdam Study: 2010 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in close to a 1,000 research articles and reports (see www.epib.nl/rotterdamstudy). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.