Prevalence, risk factors and effect of curative parathyroidectomy on nephrocalcinosis in Asian-Indian patients with symptomatic primary hyperparathyroidism.

Primary hyperparathyroidism (PHPT) is characterized by inappropriate secretion of parathyroid hormone, causing hypercalcemia and hypercalciuria, leading to renal stone diseases and nephrocalcinosis. The frequency, risk factors, and curative effect on nephrocalcinosis in post-parathyroidectomy have not been identified yet. Therefore, the present study evaluated the clinico-biochemical, radiological parameters and curative effect on nephrocalcinosis. A total of 583 PHPT patients were analysed in four groups viz. Group 1 (PHPT with nephrocalcinosis-98; 16.8%); Group 2 (PHPT with nephrolithiasis-227; 38.9%); Group 3 (PHPT with both nephrolithiasis and nephrocalcinosis-59; 10.1%); and Group 4 (PHPT without renal diseases-199, 34.1%). In the sub-group analysis, younger age (p ≤ 0.05), male gender (p ≤ 0.05), and hematuria (p ≤ 0.005) were significant in Group 1 vs. Group 4. Dysuria and low eGFR were significant in Group 1 vs. Group 2 (p ≤ 0.0005; p ≤ 0.05) and Group 1 vs. Group 4 (p ≤ 0.0005; p ≤ 0.0005). Polyuria (p ≤ 0.05; p ≤ 0.05, p ≤ 0.005), and gravluria (p ≤ 0.05; p ≤ 0.0005, p ≤ 0.005) were frequent in Group 1 vs. other groups. A significant difference was observed in S.Ca and, 24-hrs U.Ca in Group 1 vs. Group 2 {(12.2 (10.8-13.4) vs. 11.2 (10.7-12.4), p ≤ 0.05; 301 (189.5-465) vs. 180 (92.5-323.1), p ≤ 0.05} and Group 1 vs. Group 4 {(12.2 (10.8-13.4) vs. 11.4 (10.7-12.5), p ≤ 0.05 ; 301 (189.5-465) vs. 213 (110-360), p ≤ 0.0005}. Multivariate logistic regression showed gravluria [aOR = 9.2, p = 0.0001], S.Ca (aOR = 1.30, p = 0.003) and, 24-hrs U.Ca (aOR = 1.02, p = 0.042) to be independent predictors of nephrocalcinosis. Pre and post-operative assessment revealed decreased S. Ca levels [(11.9 ± 1.9) vs. (10.5 ± 1.0) mg/dL; p = 0.04] and complete radiological resolution (10.4%) in PHPT with nephrocalcinosis. Therefore, serum calcium, 24-hrs Urinary calcium, and gravluria were independent predictors of nephrocalcinosis with 10.4% showing complete radiological resolution post-operatively.