Renal complications in chronic hypoparathyroidism - a systematic cross-sectional assessment

Context

Although renal long-term complications are acknowledged in chronic hypoparathyroidism (HPT), standardized investigations are scarce.

Objective

To systematically investigate renal complications and their predictors in hypoparathyroid patients compared to matched individuals.

Design

Prospective observational study in 161 patients with chronic HPT.

Methods

Patients received renal ultrasound, clinical and laboratory assessments. An individual 1:3 matching with participants from the German population-based Study of Health in Pomerania was performed.

Results

Of 161 patients (92% postoperative HPT), prevalence of eGFR <60ml/min/1.73m2 was 21%, hypercalciuria 41%. Compared to healthy individuals, HPT patients had a significantly lower eGFR (74.2 vs. 95.7 ml/min/1.73m², p<0.01). Renal ultrasound revealed calcifications in 10% (nephrocalcinosis in 7% and calculi in 3%). Patients with renal calcifications had higher levels of 24-hour urine calcium excretion (8.34 vs. 5.08 mmol/d, p=0.02), spot urine calcium excretion (4.57 vs. 2.01 mmol/L, p=0.01) and urine calcium-to-creatinine ratio (0.25 vs. 0.16, p<0.01) than patients without calcifications. Albumin-corrected calcium, phosphate, calcium-phosphate product, 25-hydroxyvitamin D in serum, eGFR, daily calcium intake or disease duration were not significantly different between these two groups. Including patients receiving rhPTH therapy, a lower serum phosphate concentration (odds ratio 1.364 [95% confidence interval (CI) 1.049-1.776], p<0.05) and a longer disease duration of HPT (odds ratio 1.063 [95% CI 1.021-1.106], p<0.01) were significant predictors for renal calcifications. Excluding patients receiving rhPTH therapy, a higher 24-hour urine calcium excretion (odds ratio 1.215 [95% CI 1.058-1.396], p<0.01) was a significant predictor for renal calcifications but not serum magnesium or disease duration.

Conclusions

Prevalence of impaired renal function among patients with chronic HPT is increased and independent from visible renal calcifications. Depending on exclusion of patients with rhPTH therapy, regression analysis revealed disease duration and serum phosphate or disease duration and 24-hour urinary calcium excretion as predictors for renal calcifications.

Clin Trials Identifier

NCT05585593.

[Validity of the Gram and Lendrum stains in conjunctival smears for the identification of Chlamydia trachomatis]

With the objective of finding reliable, valid, and economic diagnostic tests to identify Chlamydia trachomatis in conjunctival smears, the sensitivity, specificity, and positive and negative predictive values of Lendrum and Giemsa stains were evaluated using direct immunofluorescence as the gold standard. In addition, inter- and intraobserver reproducibility were estimated through the use of two independent observers, who were blinded to the results during their readings. The prevalence of ocular chlamydiosis in the study area was around 50%. In all, 103 persons (206 eyes) were studied. Three smears from each eye were taken for each subject. The kappa statistic was used to estimate the reproducibility of the stains. Interobserver reproducibility was null, and intraobserver reproducibility ranged between 0.35 and 0.79. The sensitivity of the Giemsa stain was a bit higher than that of the Lendrum stain (28% and 22%, respectively), and the specificity was similar (82% and 85%, respectively). Based on these results, the ability of both stains to detect positive cases was judged to be low, as was their reliability. The Lendrum and Giemsa stains are not adequate tests for the diagnosis of ocular chlamydiosis. For this purpose the use of direct immunofluorescence is recommended.