A lifecourse study of bone resorption in men ages 49-51years: the Newcastle Thousand Families cohort study.

It has been suggested that bone health in adulthood is programmed by development in utero. Most previous investigations addressing this topic have focussed on bone mineral density or content, rather than other indicators of bone health, such as biochemical markers of bone turnover. This study investigated whether potential predictors, from different stages of life, influence bone resorption in men aged 49-51years in the Newcastle Thousand Families birth cohort. The cohort originally consisted of all 1142 births in the city of Newcastle upon Tyne, UK in May and June 1947. Detailed information was collected prospectively during childhood, including birth weight and socio-economic circumstances. At 49-51years of age, 574 study members completed a detailed 'Health and Lifestyle' questionnaire, including the European Prospective Investigation of Cancer (EPIC) food frequency questionnaire and 412 study members attended for clinical examination, including 172 men in whom bone resorption was assessed by measurement of serum beta C-telopeptide of type 1 collagen (CTX). A significant trend was seen between increasingly disadvantaged socio-economic status at birth and increased bone resorption (p=0.04, r-squared 2.6%). However, birth weight, standardised for sex and gestational age, was not associated with serum CTX (p=0.77, r-squared 0.05%). Significant trends were also seen between increasing total energy intake (p=0.03, r-squared 2.9%), dietary intake of saturated fat (p=0.02, r-squared 2.6%), protein (p=0.04, r-squared 2.5%) and carbohydrates (p=0.04, r-squared 2.6%) and higher serum CTX. However, on adjustment for total energy intake, none of the other dietary variables was significant at the univariate level maintained significance. Our findings suggest that early socio-economic disadvantage and later dietary factors may be associated with increased bone resorption in middle aged men. However, as little of the variance in serum CTX was explained by the variables included within this investigation, further longitudinal studies, with sufficient statistical power, are required to assess predictors of bone resorption in adulthood and their relative importance.