Determinants of blood glucose and insulin in healthy 9-month-old term Danish infants; the SKOT cohort.

AIMS: Insulin secretion is important for early regulation of growth, but high insulin concentration is also a risk factor for insulin resistance later in life. It is therefore important to better understand how insulin and glucose are associated with early diet and growth. The aim of this study was to examine blood glucose and insulin concentration in relation to anthropometric measurements, growth, breastfeeding practice and complementary feeding in 9-month-old infants.
METHODS: This was a cross-sectional study (SKOT cohort), examining 312 healthy term infants from the age of 9 months. Of these, 265 infants had data on insulin and glucose and were included in this study. Measurements include weight, length, skinfold thickness, waist circumference, 7-day food records, 2-h fasting venous glucose and insulin analysis, and questionnaire.
RESULTS: At 9 months of age there was a strong negative association between number of breastfeedings per day and insulin concentration (P=0.0015). Insulin concentration was positively associated to waist circumference (P=0.042) and change in Z-score for weight-for-age between 5 and 9 months (P=0.004). Glucose concentration was positively associated to subscapular skinfold (P=0.002) and sum of skinfolds thicknesses (P=0.006).
CONCLUSION: At 9 months, breastfeeding still had a strong negative effect on insulin concentrations, which were positively associated with weight gain and current waist circumference, while glucose concentrations were associated with subcutaneous fat. These results are of interest in disentangling the association between early growth and later risk of disease.