Body Mass Index Correlates to Growth Hormone Stimulation Tests in Children

Current guidelines do not guide interpretation of peak growth hormone (GH) values in overweight or obese children—potentially leading to overdiagnosis of GH deficiency (GHD) among these patients. In a study, researchers examined the association between body mass index (BMI) standard deviation scores (SDS) and stimulated peak GH levels in children to identify influencers on the association and to specifically determine how much GH values are decreased in children with obesity. The report was published in Critical Reviews in Clinical Laboratory Sciences.

A total of 58 studies reporting the impact of weight status on peak GH in 5,135 children were collected from online databases. The primary outcome was the association between peak GH values and BMI SDS.

The researchers, led by Ozair Abawi, calculated a pooled correlation coefficient of –0.32 across all the included studies (95% confidence interval [CI], –0.41 to –0.23). Larger proportions of the included male patients were associated with less severe negative correlations (P = 0.04). Factors including pubertal status, syndromic obesity, mean and, and mean BMI SDS did not influence the pooled correlation coefficient (P >0.05). Analysis of individual data on 576 participants displayed a beta of –0.123 (95% CI, –0.160 to –0.086; P <0.0001), which the authors specified indicates a peak GH decrease of 11.6% for each one–point increase in BMI SDS (95% CI, 8.3–14.8).

The authors noted that this was the first study, to their knowledge, that investigated the association between BMI SDS and peak GH specifically in children. As such, the significant negative correlation—which exists in the normal BMI SDS range—could lead to overdiagnosis of GHD in children with overweight or obesity. To address this, the authors stressed the need for BMI SDS threshold values for GH stimulation tests in children.

Based on their analysis, they suggested the following weight–adjusted cutoffs for GH stimulation tests: for children with normal weight, 5, 7, 10, and 20 µg/L; for overweight children, 4.6, 6.5, 9.3, and 18.6 µg/L; and for children with obesity, 4.3, 6.0, 8.6, and 17.3 µg/L.