¹Metabolism and Obesity Services, Department of Endocrinology, Royal Prince Alfred Hospital, Camperdown NSW

²Paediatrics and Child Health, Department of Medicine, University of Sydney, NSW

³Faculty of Health Sciences, University of Sydney, NSW, Australia

Correspondence to: K Steinbeck, Metabolism and Obesity Services, Department of Endocrinology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia 2050

OBJECTIVE: The aim of this study was to identify specifically which biochemical indices predict excessive weight gain over time in a cohort of pre-pubertal children.

SUBJECTS: Fifty nine healthy pre-pubertal children (age: 6.3-9.8 y).

MEASUREMENTS: Children were defined anthropometrically and biochemically at baseline. Height and weight measurements were then repeated after six (n=52) and 12 months (n=37).

RESULTS: Weight change after six months (defined by a change in body mass index (BMI) z-score from baseline) demonstrated no correlation with fasting plasma levels of leptin, insulin, insulin:glucose (IG) ratio, cholesterol, triglyceride or high density lipoprotein (HDL) cholesterol. However, after 12 months there was a significant negative correlation between BMI z-score change and initial plasma leptin (r=-0.35, P=0.048) and this relationship strengthened when adjusted for body fat (from bio-electrical impedance; r=-0.46, P=0.009). In addition, there was a significant positive relationship between plasma total cholesterol and BMI z score change (r=0.38, P=0.03) and this relationship remained unchanged when adjusted for body fat. No relationship was observed between weight change after 12 months and plasma levels of insulin, IG ratio, HDL cholesterol or triglyceride.

CONCLUSION: Plasma leptin and total cholesterol were found to be predictive of weight gain over 12 months in a cohort of pre-pubertal children. These two potential predictors can be readily measured in clinical practice and these findings may represent a method of defining the 'at risk of obesity' state in childhood.

obesity; weight gain; prepubertal children; leptin; total cholesterol