Features of the clinical course of nephrolithiasis in patients with hyperparathyroidism

Abstract

Aim. To assess the incidence of kidney stone disease and to identify its clinical course in patients with primary hyperparathyroidism.
 Methods. 48 medical records of patients hospitalized with primary hyperparathyroidism were retrospectively analyzed. The average age of the patients was 57 [53; 61] years. The medical history, complaints upon admission, the clinical presentation, the results of laboratory test and instrumental examination were studied in evaluating the medical records. The patients were divided into the group with nephrolithiasis (n=33) and the group without nephrolithiasis (n=15). The differences between the two groups were tested for statistical significance by the MannWhitney U test.
 Results. Among patients with primary hyperparathyroidism, nephrolithiasis was detected in 69% of patients, of which 90% were women in the postmenopausal period. The course of the kidney stone disease in these patients was characterized by frequent recurrence with a predominance of bilateral renal impairment (62%). The duration of nephrolithiasis before the diagnosis of primary hyperparathyroidism was 6 [1; 19] years, and this complication was often the first manifestation of the disease. According to the instrumental examination of kidney in patients with nephrolithiasis, small stones up to 5 mm in diameter were detected in 42% of cases, asymptomatic kidney stones in 15% of cases. A severe complication of primary hyperparathyroidism staghorn calculi were found in 2 (10%) patients. The patients in the group with nephrolithiasis showed higher serum calcium (p=0.022) and parathyroid hormone (p=0.007) levels compared with patients in the group without nephrolithiasis.
 Conclusion. Nephrolithiasis is a common complication of primary hyperparathyroidism; the presence of nephrolithiasis is associated with more significant changes in calcium and phosphate metabolism and is also characterized by a frequent asymptomatic course, thus requiring attention of specialists to this type of complications in primary hyperparathyroidism.