The Relationship between Birth Weight, Insulin Resistance and Glucose Intolerance in 7 - Year Old Black Children

We investigated the relationship between glucose tolerance and birth weight in a group of 7-year-old black South Africans on whom longitudinal anthropometric data were available. Oral glucose tolerance tests (OGTT’s) were carried out on 152 subjects and inverse correlations were found between birth weight and the total amount of insulin secreted during the first 30 minutes (r= -0.19, p=0.04) and the last 90 minutes (r= -0.19, p=0.04) of the oral glucose tolerance test and also between birth weight and the 30 minute glucose concentrations (r= -0.20, p=0.02). Children born with low birth weights but who had high weights at 7 years, had higher insulin concentrations and indices of obesity compared with those with low birth weights and low weights at 7 years of age. There were also positive correlations between weight velocity and BMI (r=0.24, p=0.02) and weight velocity and postprandial insulin levels (r=0.31, p=0.001). Thus low birth weight in conjunction with rapid childhood gains in weight especially as subcutaneous fat, produces poor glucose tolerance in 7-year-old children and may make them susceptible to the development of Type II diabetes later in life.