Endocrine Abstracts

Background: Birth weight has been associated with low bone mass in later life. Previous studies, however, have relied on self-reported data on birth weight, included select populations, or been of a limited size. Moreover, it is unclear if the association between birth weight and bone mass is be mediated by body weight, lean body mass, or fat mass.

Aim: We hypothesize that birth weight is associated with peak bone mass in men independent of current lean body mass and body weight.

Participants and design: The Odense Androgen Study is a population-based, prospective, observational study on the inter-relationship between endocrine status, body composition, muscle function, and bone metabolism in young men. In brief, 3000 males aged 20–30 years were randomly selected from the civil registration database in Funen County, Denmark, and invited by mail to participate in the study. Seven hundred and eighty three gave written informed consent to participate in the study and the data are presented here. Bone mass measurements (spine, hip, and whole body) were performed using a hologic-4500a densitometer. Data on birth weight, length at birth, and gestational age was retrieved in a national database covering all birth clinics in Denmark in the current period. The relationship between Birth weight, BMC, Lean body mass and fat mass as tested using multiple regression analysis is shown in the table as partial correlation coefficients.

Results: Data on birth weight and birth length were available on 754 participants. In bivariate analyses, BMC at whole body, spine, and hip were significantly associated with current body weight (R=0.50–0.30, P<0.001) and birth weight (R=0.17–0.09, P<0.01). Birth weight was also significantly associated with current body weight (R=0.09, P<0.01), current lean body mass (R=0.15, P<0.001) but not current fat mass (*P<0.05, **P<0.01, ***P<0.001).

Conclusion: Birth weight predicts peak bone mass, but this seems to be due to correlation between birth weight and body weight (and lean body mass) in young adult life.