Insulin responses to glucose in healthy males are associated with adult height but not with birth weight.

Objective. To investigate the relations between height, birth weight and insulin secretion. Subjects and design. Subjects were selected from a register of all male healthy volunteers who had previously participated in insulin secretion studies. All men in whom a 1-h glucose infusion test had been performed on two or more occasions were selected (n = 88). Subjects were divided into two equally sized groups according to 0-10-min insulin responses. Main outcome measures. Insulin responses were measured by standardized glucose infusion tests. Heights and weights were measured on these occasions. Birth weights were obtained from questionnaires and validated from obstetric records. Results. The average height for the 50% of subjects with the lowest insulin response was 3.5 cm less [95% confidence interval (CI): 1.1 to 5.9] than in those with the highest response, P < 0.005. These differences were also significant when expressed relative to heights of national cohorts with the same years of birth [1.7% less in those with lowest response (95% CI: 0.3 to 3.0), P < 0.02 for difference]. However, birth weight (known to 69% of subjects) was not associated with insulin response (3706+/-126 g in the 50% with lower insulin response, 3590+/-136 g in those with higher insulin response). Conclusions. An early insulin response to glucose associates with postnatal growth. This suggests that physiological variations in postnatal insulin secretion can influence growth and height in healthy subjects. Furthermore, in the present study group, a low birth weight is not an important determinant of postnatal insulin secretion.