Several studies have shown relationships between growth in early life and adult bone mass; in this article, we evaluate the relative contributions of pre-and postnatal factors to bone mass in the seventh decade. A total of 498 eight men and 468 women who were born in Hertfordshire during the period 1931-1939 and still living there were recruited. Detailed birth records were available. Participants attended a clinic where they completed a detailed health questionnaire, before performance of anthropometric measurements and bone densitometry of the proximal femur and lumbar spine (Hologic QDR 4500). Birth weight was associated with bone mineral content in both men (proximal femur: r ϭ 0.16, p ϭ 0.0003; lumbar spine: r ϭ 0.10, p ϭ 0.03) and women (proximal femur: r ϭ 0.16, p ϭ 0.0008; lumbar spine: r ϭ 0.11, p ϭ 0.03); relationships with bone mineral density were weaker and were significant at the proximal femur in men only (p ϭ 0.03). Relationships between weight at 1 y and bone mineral content were even stronger (proximal femur: men r ϭ 0.22, p Ͻ 0.0001; women r ϭ 0.14, p ϭ 0.002). In men, 18% of the variance in proximal femoral bone area was explained by a model that included birth weight, weight at 1 y, and adult weight, with the relative contributions attributed to each being 2.8, 6.8, and 8.2%, respectively. In women, similar modeling produced figures of 6.7, 4.2, and 3.9% (overall variance of 15% in proximal femoral bone area). Hence, weight at each of these three points in the life course is important in the determination of adult bone mass, with greater contributions of earlier growth to bone size and mineral content than to bone mineral density. Abbreviations BMAD, bone mineral apparent density BMC, bone mineral content BMD, bone mineral density BMI, body mass index DEXA, dual-energy x-ray absorptiometry HRT, hormone replacement therapy Several epidemiologic studies from around the world have shown relationships between growth in early life and adult bone mass. Initial work in Bath (1) and Hertfordshire, UK (2), showed relationships between weight at 1 y and adult bone mineral content (BMC), but more recent studies (3-5) have also found evidence of an association between birth weight and adult bone mass. Furthermore, a Finnish study (6) demonstrated a direct association between low birth length, poor childhood growth, and later risk for hip fracture. Hence, we sought to evaluate the relative contribution of pre-or postnatal growth to the determination of adult bone mass by using a larger birth cohort of men and women who were born in Hertfordshire in the 1930s and still resident there, for whom extensive childhood records, including birth weight and weight at 1 y, were available.
METHODSA total of 768 men and 714 women who were aged 60 -75 y completed this study, based around East Hertfordshire. The selection procedure for these individuals was as follows: in brief, with the help of the National Health Service Central Registry at Southport and Hertfordshire Family Health Service Association, we traced men ...