Department of Clinical Medicine

TY - JOUR

T1 - Determinants of hypercalciuria and renal calcifications in chronic hypoparathyroidism

T2 - A cross-sectional study

AU - Ridder, Lukas Ochsner

AU - Harsløf, Torben

AU - Sikjær, Tanja

AU - Underbjerg, Line

AU - Rejnmark, Lars

N1 - Publisher Copyright: © 2021 John Wiley & Sons Ltd

PY - 2021/8

Y1 - 2021/8

N2 - Objective: Hypercalciuria, impaired kidney function and renal calcifications are common in chronic hypoparathyroidism (HypoPT). We aimed to study associations between indices of known importance to the kidney in HypoPT by hypothesizing adverse effects of hypercalciuria on renal outcomes. Design: We used cross-sectional design. Patients: We identified all patients followed for chronic HypoPT at our department and who had been examined by a 24-h urine collection for measurement of renal calcium excretion (24 h U-Ca). Measurements: By chart review, we identified additional biochemistry measured in close connection with the collection of urine, as well as demographic, treatments and anthropometrics. Results: The 166 included patients (79.5% females) had a high prevalence of hypercalciuria (65.7%). In multiple adjusted analyses, hypercalciuria was in an independent manner inversely associated with (residual) levels of plasma PTH and positively associated with levels of 1,25-dihydroxyvitamin D and ionized calcium as well as 24 h U-phosphate, gender, and etiology (surgical vs. non-surgical). Overall, this model explained 54% (p <.001) of the variation in the presence of hypercalciuria. Chronic kidney disease stage three or above was present in 18.3% of the patients, and 42.6% of the 54 patients examined by renal imaging had renal calcifications. However, neither renal function nor renal calcifications were associated with 24 h U-Ca. Conclusions: Hypercalciuria, impaired renal function and renal calcifications are common in hypoparathyroidism. Hypercalciuria is to a large extent explained by indices of known physiological importance to 24 h U-Ca. However, in the present study, a high renal calcium excretion did not explain renal impairment or kidney calcifications.

AB - Objective: Hypercalciuria, impaired kidney function and renal calcifications are common in chronic hypoparathyroidism (HypoPT). We aimed to study associations between indices of known importance to the kidney in HypoPT by hypothesizing adverse effects of hypercalciuria on renal outcomes. Design: We used cross-sectional design. Patients: We identified all patients followed for chronic HypoPT at our department and who had been examined by a 24-h urine collection for measurement of renal calcium excretion (24 h U-Ca). Measurements: By chart review, we identified additional biochemistry measured in close connection with the collection of urine, as well as demographic, treatments and anthropometrics. Results: The 166 included patients (79.5% females) had a high prevalence of hypercalciuria (65.7%). In multiple adjusted analyses, hypercalciuria was in an independent manner inversely associated with (residual) levels of plasma PTH and positively associated with levels of 1,25-dihydroxyvitamin D and ionized calcium as well as 24 h U-phosphate, gender, and etiology (surgical vs. non-surgical). Overall, this model explained 54% (p <.001) of the variation in the presence of hypercalciuria. Chronic kidney disease stage three or above was present in 18.3% of the patients, and 42.6% of the 54 patients examined by renal imaging had renal calcifications. However, neither renal function nor renal calcifications were associated with 24 h U-Ca. Conclusions: Hypercalciuria, impaired renal function and renal calcifications are common in hypoparathyroidism. Hypercalciuria is to a large extent explained by indices of known physiological importance to 24 h U-Ca. However, in the present study, a high renal calcium excretion did not explain renal impairment or kidney calcifications.

KW - alfacalcidol

KW - calcium

KW - hypoparathyroidism

KW - parathyroid hormone

UR - http://www.scopus.com/inward/record.url?scp=85104124872&partnerID=8YFLogxK

U2 - 10.1111/cen.14470

DO - 10.1111/cen.14470

M3 - Journal article

C2 - 33756016

AN - SCOPUS:85104124872

VL - 95

SP - 286

EP - 294

JO - Clinical Endocrinology

JF - Clinical Endocrinology

SN - 0300-0664

IS - 2

ER -