Reduced foetal growth and growth hormone secretion in adult life

OBJECTIVES Recent studies suggest that growth restriction or other adverse influences acting in utero or during early infancy lead to permanent altera tions in growth hormone (GH) secretion. As GH secretion is known to predict cardiovascular risk, alterations in GH may contribute to the association b etween reduced foetal growth and cardiovascular disease. We have therefore assessed the relationship between birth size and GH secretion in a prospect ive study of young adults whose birth size was recorded and who have had th eir current blood pressure and glucose tolerance measured. DESIGN Prospective cohort study PATIENTS 153 healthy men and women, aged 20-21 years. MEASUREMENTS Subjects carried out a timed overnight urinary collection for analysis of GH excretion, Insulin sensitivity and insulin secretion were me asured using the intravenous glucose tolerance test with minimal model anal ysis. Blood pressure, height, weight, usual level of exercise, smoking habi ts, alcohol consumption, and socio-economic status were also recorded. RESULTS GH excretion ranged from 0.01 to 41.8 mu U per subject, It did not differ according to gender but was markedly reduced in obese subjects (P<0. 0001) Low birthweight was strongly associated with low GH excretion at age 20 years (P = 0.002). Low placental weight and short body length also predi cted low GH (P = 0.02 and P = 0.04, respectively). These relationships were independent of other confounding factors including obesity, GH excretion w as not independently related to current levels of blood pressure, insulin s ensitivity or insulin secretion. CONCLUSIONS Body size at birth predicts GH excretion in adult life, Low GH excretion in people who were small at birth may be one mechanism explaining their increased risk of cardiovascular disease.