Growth from birth to adulthood and bone phenotype in early old age: A British birth cohort study

There is growing evidence that early growth influences bone mass in later life but most studies are limited to birth weight and/ or early infant growth and DXA measurements. In a British birth cohort study with prospective measures of lifetime height and weight, we investigated the growth trajectory in relation to bone in males (M) and females (F) at 60-64 years. Outcomes were DXA measures of hip and spine areal bone density (aBMD) (n = 1658) and pQCT measures of distal and diaphyseal radius cross-sectional area (CSA), strength and volumetric bone density (vBMD) (n = 1350 of the 1658). Regression models examined percentage change in bone parameters with standardised measures of birth weight, and height and weight. A series of conditional growth models were fitted for height and weight gain (using intervals birth-2, 2-4, 4-7, 7-15, 15-20, 20-36, and 36-64 years) and height gain (using intervals 2-4, 4-7, 7-15 and 15-36 years) Birth weight was positively related to bone CSA (1.4% (95% confidence intervals: 0.3, 2.5) M; 1.3 (0.3, 2.4) F per standard deviation (SD) increase in birth weight for diaphyseal CSA) and strength (1.8% (0.3, 3.4) M; 2.0% (0.5, 3.5) F). No positive associations were found with trabecular, total or cortical vBMD. One SD change in pre- and post-pubertal height and weight velocities were associated with between 2-5% greater bone CSA and strength. Height gain in later years was negatively associated with trabecular vBMD. Weight gain velocity during the adult years was positively associated with up to 4% greater trabecular and total BMD, and 4% greater aBMD at hip and spine. In a cohort born in the early post war period, higher birth weight, gaining weight and height faster than others, particularly through the pre-pubertal and post-pubertal periods, was positively related to bone strength, mostly through greater bone CSA, at 60-64 years.