Growth hormone response to a bolus injection of 1-44 growth-hormone-releasing hormone in very short children with intrauterine onset of growth failure

Childhood growth, physical activity, and peak bone mass in women

Peak bone mass is an important determinant of the risk of osteoporotic fracture, and preventive strategies against osteoporosis require a clear understanding of the factors influencing bone gain in early life. We report a longitudinal study aiming to identify the relationships between childhood growth, lifestyle, and peak bone mass in women. One hundred and fifty-three women born in a British city during 1968-1969 were traced and studied in 1990. Data on their growth in childhood was obtained from linked birth and school health records; current bone mineral measurements were made by dual X-ray absorptiometry. There were statistically significant associations between weight at 1 year and BMC (but not BMD) at the lumbar spine (r = 0.32, p < 0.01) and femoral neck (r = 0.26, p < 0.01). These remained significant after adjusting for current weight. There were also strong relationships between childhood height measurements and adult BMC at the two skeletal sites. Physical activity was the major lifestyle determinant of BMD after allowing for body build. We conclude that infant growth and physical activity in childhood are important determinants of peak bone mass in women. Growth primarily determines the size of the skeletal envelope, and its trajectory is established by age 1 year. Activity, in contrast, modulates the mineral density within the skeletal envelope and may contribute to the consolidation of bone following the end of linear growth.

Fetal nutrition and cardiovascular disease in adult life

Babies who are small at birth or during infancy have increased rates of cardiovascular disease and non-insulin-dependent diabetes as adults. Some of these babies have low birthweights, some are small in relation to the size of their placentas, some are thin at birth, and some are short at birth and fail to gain weight in infancy. This paper shows how fetal undernutrition at different stages of gestation can be linked to these patterns of early growth. The fetuses' adaptations to undernutrition are associated with changes in the concentrations of fetal and placental hormones. Persisting changes in the levels of hormone secretion, and in the sensitivity of tissues to them, may link fetal undernutrition with abnormal structure, function, and disease in adult life.