Adrenal morphology and associated comorbidities in congenital adrenal hyperplasia

Abstract

Objective: Adrenonodular hyperplasia and tumour formation are potential long-term complications of congenital adrenal hyperplasia (CAH) with little known regarding the clinical implications. Our aim was to describe volumetric adrenal morphology and determine the association between radiological findings and comorbidities in adults with classic CAH.

Design: This was a cross-sectional study of 88 patients (mean age 29.2 ± 13 years, 47 females) with classic CAH seen in a tertiary referral centre.

Methods: CT imaging, performed at study entry or when reaching adulthood, was used to create 3-dimensional volumetric models. Clinical, genetic and hormonal evaluations were collected and correlated with adrenal morphology and tumour formation.

Results: Over one-third of the cohort was obese. 53% had elevated 17-OH-progesterone or androstenedione; and 60% had adrenal hyperplasia. Tumours included 11 myelolipomas, 8 benign adrenocortical adenomas, 1 pheochromocytoma and 50% of men had testicular adrenal rest tissue. CAH patients with adrenal hyperplasia had significantly higher number of comorbidities than those with morphologically normal adrenals (P = 0.03). Variables that positively correlated with adrenal volume included hypogonadal/oligomenorrhoeic status, hypertension, androstenedione, aldosterone, and triglyceride levels, and in women, low HDL and insulin resistance. Elevated aldosterone was observed in a subset of patients with simple virilizing CAH.

Conclusions: Adrenocortical hyperplasia is associated with a number of comorbidities, especially hypogonadism. Aldosterone production associated with adrenal enlargement may play a role in the development of metabolic risk factors. Further studies are needed to assess the long-term impact of the excess adrenal steroid milieu associated with adrenal enlargement to develop improved management strategies for CAH.

Keywords: 21-hydroxylase deficiency; CAH; adrenal hyperplasia; adrenal tumour; adrenal volume; congenital adrenal hyperplasia; testicular adrenal rest.