medwireNews: Factors including fludrocortisone use increase the risk of children with congenital adrenal hyperplasia (CAH) developing hypertension, report researchers in Clinical Endocrinology.

Kyriakie Sarafoglou (University of Minnesota Masonic Children’s Hospital, Minneapolis, USA) and team also found that overtreatment with hydrocortisone replacement  may play a part. The prevalence of hypertension was increased in patients with at least three recorded incidences of oversuppression, ie, 17α-hydroxyprogesterone levels below 400 ng/dL (12.12 nmol/L), and this was true irrespective of gender and CAH subtype.

For example, the rate of hypertension was 39% among boys with salt-wasting CAH who had fewer than three incidences of oversuppression, but 73% among those with three or more episodes.

Despite this, the team found no link between hydrocortisone dose and hypertension; in particular, they note that hypertension rates remained stable over the 4 decades of their study, despite reductions in daily glucocorticoid dose, “suggesting other factors may play a role such as glucocorticoid receptor sensitivity and non-circadian glucocorticoid administration.”

Hydrocortisone dose was higher among children born between 1970 and 1994 than those born between 1995 and 2013; among the 144 patients also given fludrocortisone, for example, the average daily dose among those aged 0–4 years fell from 18 to 13 mg/m2 and that among 5–18-year-olds fell from 14 to 8 mg/m2.

But the prevalence of hypertension among the patients remained similar, at 53% and 58% in the earlier and later periods, respectively.

Also, the researchers note that children with simple virilising CAH had lower hypertension rates than those with salt-wasting CAH, despite receiving a similar hydrocortisone dose.

The highest hypertension prevalence, of 60%, was in boys with the salt-wasting subtype, followed by 55% in girls with salt-wasting CAH. Almost all boys with hypertension were diagnosed within the first 5 years of life, whereas the diagnosis appeared more gradually among girls, which the team suggests could represent a protective effect of oestrogen.

But among patients with simple virilising CAH, hypertension rates were higher among girls than boys, at 48% versus 21%.

The researchers also found that the 36 patients who did not take fludrocortisone had markedly reduced rates of hypertension relative to those who did, at 31% and 29% in the earlier and later time periods, respectively, “underscoring the importance of closely monitoring blood pressure in children when increasing fludrocortisone dosing.”

They stress that while prompt initiation of fludrocortisone is vital in infants with classical CAH, “it is also critical that clinicians consider that patients whose phenotype and genotype are not consistent with [salt-wasting] CAH may be put at higher risk of hypertension by continuous fludrocortisone treatment beyond early childhood.”

By Eleanor McDermid

Clin Endocrinol 2016; Advance online publication

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