Reduced final height and indications for insulin resistance in 20 year olds born small for gestational age: regional cohort study

Abstract

Objective: To investigate whether the association between low birth weight and increased risk of developing impaired glucose tolerance, insulin resistance, hypertriglyceridaemia, and hypertension in middle age is apparent by the age of 20 in people born small for gestational age. Design: Regional cohort study. Setting: Maternity registry, Haguenau, France. Subjects: 236 full term singleton babies born small for gestational age (birth weight or length, or both, below third centile) during 1971-8 and 281 with normal birth weight (between 25th and 75th centile). All subjects were contacted and evaluated at a mean (SD) age of 20.6 (2.1) years. Main outcome measures: Adult height; concentrations of glucose, insulin, and proinsulin during an oral glucose tolerance test; lipid and fibrinogen concentrations; and blood pressure. Results: After sex and target height were adjusted for, subjects who had been born small for gestational age were significantly shorter at age 20 than those with a normal birth weight (men 4.5 cm shorter (95% confidence interval 6.0 to 3.0 cm); women 3.94 cm shorter (5.2 to 2.7 cm). After sex and body mass index were adjusted for, mean plasma glucose concentration 30 minutes after a glucose load, fasting insulin concentration (in women), and insulin and proinsulin concentrations 30 and 120 minutes after a glucose load were significantly higher in subjects who had been born small for gestational age than in those with a normal birth weight. Mean lipid and fibrinogen concentrations and blood pressure were not different between the two groups. Conclusions: Intrauterine growth retardation has long term consequences such as reduced final height. Raised insulin and proinsulin concentrations are present in young adults born small for gestational age and could be markers of early changes in insulin sensitivity. An inverse relation between birth weight and increased risk of developing impaired glucose tolerance, insulin resistance, hypertriglyceridaemia, and hypertension (syndrome X) in middle age has been reported In this study reduced final height and raised serum insulin and proinsulin concentrations during oral glucose tolerance testing were found in young adults born small for gestational age compared with young adults with an appropriate birth weight for gestational age Reduced fetal growth was not associated with impaired glucose tolerance, higher blood pressure, or abnormalities in lipid and fibrinogen concentrations Further longitudinal studies are required to examine the risk of developing the other elements of syndrome X later in life