Background: Reports on obesity, high blood pressure and reduced insulin sensitivity in children with classical congenital adrenal hyperplasia (CAH) indicate an increased cardiovascular risk.
Objective and Hypotheses: To evaluate potential mechanisms, we analysed various parameters of the carbohydrate metabolism in children and adolescents with CAH.
Method: Out of 86 patients with classical CAH, n=41 (21 m, 20 f; ages: 6.917.9 years) gave their consent to attend the study. All patients were healthy except for their underlying disease and did not take any other medication besides their substitution therapy. All children had an overnight fasting blood sample between 0800 and 0900 h and an oral glucose tolerance test. The study had been approved by the Ethical Committee and was not accompanied by a control group; for data comparison we used published reference values. The quality of glucocorticoid medication was classified in good (n=22; 11 m, 11 f) and bad (under-dosed: n=19; 10 m, 9 f) according to laboratory and urinary parameters.
Results: (mean±S.D.): The parameters fasting insulin, insulin 120 min, max insulin, total insulin, FGIR, HOMA-IR, Matsuda index, and QUICKI showed no statistically significant correlation with the quality of the metabolic control. The HbA1c, fasting blood glucose levels and 120 min glucose levels were within the normal range in all patients. However, we found 11 patients (5 m, 6 f; nine in puberty) with an elevated fasting insulin level (23.1±13.9 μU/ml). These patients had also higher insulin levels at 120 min (124.8±48.8), a lower fasting glucose/insulin ratio (FGIR) of 4.9±1.7, and higher HOMA-IR values (4.4±2.6) in comparison with CAH patients (n=30) with normal fasting insulin (7.0±2.4), Ins 120 min (71.1±51.6), FGIR (13.3±5.5), and HOMA-IR (1.44±0.5). The 11 CAH patients had also a statistically significant higher BMISDS (1.55±0.97 vs 0.38±1.19; P<0.01).
Conclusion: Our data show that already 26.8% of the CAH children and adolescents participating have reduced insulin sensitivity which is correlated with a higher BMI. We found no correlation with severity of CAH, genotype, gender, glucocorticoid medication, or quality of current metabolic control. We suggest that the prevention of overweight/obesity in CAH children and adolescents is of outstanding importance.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology