title: Hypertension in hypophosphatemic rickets--role of secondary hyperparathyroidism.
abstract: Hypertension has been anecdotally reported in children with familial hypophosphatemic rickets (XLH). To better identify and characterize the clinical and laboratory features of hypertensive XLH children, we reviewed the medical records of 41 XLH children, all treated with phosphate and vitamin D analogues. Eight children, who were originally normotensive, developed hypertension during the 2nd decade of life. At diagnosis of hypertension all had persistent secondary/tertiary hyperparathyroidism (HPTD), defined as high serum parathyroid hormone (PTH) for 12 months or longer. Seven had nephrocalcinosis (NC). Analysis of data showed that of 11 children with HPTD, 8 developed hypertension compared with 0 among 30 without HPTD (P<0.001). Of 40 children studied, 18 had NC that was significantly associated with both HPTD (P<0.01) and hypertension (P<0.025). At diagnosis of hypertension, serum calcium was elevated in 2. Plasma renin activity was high in 3 of 4 patients in whom it was measured. Doppler ultrasonography or renal scan was normal in the 5 children studied. Early echocardiography showed left ventricular hypertrophy in only 2 of 5 children studied. In 3 patients who underwent parathyroidectomy, hypertension persisted and 1 progressed to renal failure. Serum creatinine remained normal in all others. Successful treatment of hypertension consisted of beta-adrenergic blockers, angiotensin converting enzyme inhibitors, and Ca channel blockers as monotherapy or in combination. We conclude that hypertension in treated XLH children is closely associated with HPTD. Emphasis should therefore be placed on prevention of the development of HPTD as a complication of XLH treatment, and close monitoring for hypertension in those who do develop HPTD.
authors.affiliation: Section of Pediatric Nephrology, Children's Mercy Hospital, University of Missouri at Kansas City, 2401 Gillham Road, Kansas City, MO 64108, USA. ualon@cmh.edu
authors.forename: Uri S
authors.initials: US
authors.lastname: Alon
authors.forename: Roshanak
authors.initials: R
authors.lastname: Monzavi
authors.forename: Marc
authors.initials: M
authors.lastname: Lilien
authors.forename: Majid
authors.initials: M
authors.lastname: Rasoulpour
authors.forename: Mitchell E
authors.initials: ME
authors.lastname: Geffner
authors.forename: Ora
authors.initials: O
authors.lastname: Yadin
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003404:Creatinine / Q000097:blood; D004452:Echocardiography; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000139:chemically induced / Q000150:complications*; D006973:Hypertension / Q000209:etiology*; D007015:Hypophosphatemia, Familial / Q000150:complications* / Q000188:drug therapy; D008297:Male; D009397:Nephrocalcinosis / Q000150:complications; D010710:Phosphates / Q000009:adverse effects; D014807:Vitamin D / Q000009:adverse effects
chemical_list: D010710:Phosphates; D014807:Vitamin D; D003404:Creatinine