Blood pressure in children and adolescents with congenital adrenal hyperplasia (21-hydroxylase deficiency): a preliminary report

BACKGROUND Classical congenital adrenal hyperplasia (CAH) is characterized by a defect in cortisol and aldosterone secretion, adrenal hyperandrogenism, impaired adrenal medullary function and insulin insensitivity. The latter along with the increased tendency towards obesity raises questions whether other cardiovascular risk factors are altered in CAH. OBJECTIVE To evaluate 24-h ambulatory blood pressure and obesity in patients with salt-wasting 21-hydroxylase deficiency diagnosed in the neonatal period and treated with hydrocortisone and 9alpha-fludrocortisone thereafter. METHODS Thirty-eight children (15 males) aged 11.2 years (range 6.1-18.2 years) underwent 24-h ambulatory blood pressure monitoring in the hospital setting. Standard anthropometric measures of height, weight and skinfold thickness were undertaken and body mass index (BMI) derived. All data were expressed as standard deviation scores (SDS) using the UK Growth Reference data. RESULTS Mean daytime systolic blood pressure SDS (1.8, SD 1.1) was significantly higher than the reference population (P < 0.001), and 58% of patients (67% males; 52% females) had systolic hypertension. Mean daytime diastolic blood pressure SDS (0.8, SD 0.8) was also elevated and 24% (13% males; 37% females) had diastolic hypertension. Eighty-four per cent had absence of the physiological nocturnal dip in systolic blood pressure. Height SDS was similar to the reference population but BMI SDS was higher (P < 0.001). BMI SDS was related to systolic blood pressure SDS (r = 0.34; P = 0.03) and the effect was most marked in females where it was related to measures of truncal fat (r = 0.82; P = 0.002). CONCLUSIONS Children with salt-wasting 21-hydroxylase deficiency have elevated 24-h ambulatory blood pressure and absence of the physiological nocturnal dip in blood pressure. These abnormalities are associated with a raised BMI, particularly in females. Regular measurement and plotting of blood pressure should be part of the management of children with classical CAH.