Endocrine Abstracts

Introduction: In the literature, there are reports about nephrocalcinosis (NC), hypercalcemia, and hypercalciuria risk in patients with congenital adrenal hyperplasia (CAH). The prevalence and background of nephrocalcinosis is not established. Nephrocalcinosis refers to diffuse calcification in the renal parenchyma, generally in renal pyramids.

Aim of the study: The study aimed to evaluate the prevalence of nephrocalcinosis and nephrocalcinosis risk factors such as hypercalciuria, hyperphosphaturia, hyperuricosuria, hyperoxaluria, hypomagnesuria, and hypocitraturia among patients with CAH due to 21 hydroxylase deficiency.

Results: In 54 patients with confirmed 21 hydroxylase deficiency, an abdominal ultrasound was performed, and the excretion of electrolytes, uric acid, oxalates, and citrates was analyzed twice. A retrospective chart review was conducted for all patients. In 11 out of 54 (20%) patients with confirmed 21 hydroxylase deficiency nephrocalcinosis was described in the abdominal ultrasound. All 11 patients have salt-wasting CAH. The nephrocalcinosis was found in most cases accidentally during ultrasound examination due to different issues. The medium age of the diagnosis was 2 years 6 months (2 months - 7 years). In three patients, after a couple of years, the vanishing of the nephrocalcinosis features in the ultrasound was observed. All patients were treated with hydrocortisone, fludrocortisone, and salt supplementation during the 1st year of life. In 4 out of 11 patients with described NC, transient episodes of hypercalcemia during the 1st year of life were observed. In 5 out of 11 patients, hypercalciuria and 6 out of 11 increased calcium/creatinine ratio were identified. In 8 out of 11 patients, hiperphosphaturia was observed, and in 9 out of 11 hyperuricosuria was noted. In 4 out of 11 patients, hyperoxaluria was found. In 1 out of 11 patients, hypocitraturia was described, and in 5 out of 11 patients, a decreased magnesium/creatinine ratio was observed. Statistical analysis didn’t find a correlation between the prevalence of nephrocalcinosis and a dose of hydrocortisone in the 1st year of life. Statistical analysis showed that patients treated with a dose of hydrocortisone higher than 50 g/m² during the first six months of life have two times higher risk of developing nephrocalcinosis than patients treated with hydrocortisone dose lower than 50 mg/m² and showed that patients treated with a dose of fludrocortisone higher than 75 mg during the 1st year of life have 2,6 time higher risk of developing nephrocalcinosis than patients treated with fludrocortisone dose lower than 75 mg.

Conclusions: According to our research, children with salt-wasting congenital adrenal hyperplasia are at high risk of nephrocalcinosis development. In our study group also, the prevalence of nephrocalcinosis or nephrolithiasis risk factors such as hypercalciuria, hyperphosphaturia, hyperuricosuria, hyperoxaluria, hypomagnesuria, and hypocitraturia was high. In the group of patients with SW-CAH statistical analysis didn’t find a correlation between the prevalence of nephrocalcinosis and a dose of hydrocortisone in the 1st year of life. In the group of patients with SW-CAH statistical analysis showed that patients treated with a dose of hydrocortisone higher than 50 g/m² during the first six months of life have two times higher risk of developing nephrocalcinosis than patients treated with hydrocortisone dose lower than 50 mg/m², and showed that patients treated with a dose of fludrocortisone higher than 75 mg during the 1st year of life have 2,6 time higher risk of developing nephrocalcinosis than patients treated with fludrocortisone dose lower than 75 mg. The background, etiology, and natural history remain unclear. The impact of nephrocalcinosis on renal function in this group of patients lasts inexplicit. Further studies are needed to determine the prevalence, etiology, impact, and natural history of nephrocalcinosis in CAH.