Secondary Hyperparathyroidism in HIV-Infected Patients in Central Europe.

Secondary hyperparathyroidism (sHPT) might be a contributor to increased risk of osteoporosis in adult HIV patients but there is little data available on this issue in this particular population. The aim of the study was to investigate the prevalence of sHPT in an HIV-infected population with normal kidney function and to evaluate its risk factors in HIV patients. This cross-sectional study was carried out in a single HIV center in Germany using routine data from patients with normal kidney function attending the clinic between January 1st and December 31st, 2016. In total, 1263 patients were included [998 (79.0%) male, median age 48 (IQR 38-54) years]. In 214 patients (16.9%) elevated PTH levels with low or normal calcium levels were found. Multivariate logistic regression modeling showed significant associations with elevated PTH for African ethnicity [OR: 2.12 (95% CI: 1.42-3.16); p<0.001], low 25-hydroxyvitamin D levels [OR: 1.82 (95% CI: 1.32-2.51); p<0.001], low calcium levels [OR 1.69 (95% CI: 1.22-2.33); p=0.001], and use of tenofovir disoproxil fumarate [OR 2.33 (95% CI: 1.62-3.36); p<0.001]. Additional to common risk factors like vitamin D insufficiency and hypocalcemia, we found a significant association between the use of TDF and sHPT. Prospective data are needed to ascertain whether PTH-mediated bone loss is the underlying mechanism of TDF bone-toxicity. Additional screening of PTH even in HIV-infected patients with normal or low calcium levels may help to identify patients at increased risk of bone mineral density loss.