Higher vitamin D levels in HIV-infected out-patients on treatment with boosted protease inhibitor monotherapy

Abstract

Objectives: We investigated the vitamin D status of patients receiving frequently used types of combination antiretroviral therapy (cART), including boosted protease inhibitor (PI) monotherapy.

Methods: For this cross-sectional study, out of 450 HIV-infected patients followed in the Hospital Severo Ochoa (Madrid, Spain), we selected 352 patients for whom vitamin D levels had been measured (January 2009 to December 2010). We collected the following data: demographics, cART duration, main cART regimen, viral load (VL), CD4 cell count, and concentrations of 25(OH)-vitamin D [25(OH)-D], parathyroid hormone (PTH), albumin and calcium. Vitamin D status cut-off points were: (1) deficiency (vitDd): 25(OH)-D < 20 ng/mL; (2) insufficiency (vitDi): 25(OH)-D from 20 to 29.99 ng/mL; and (3) optimal (vitDo): 25(OH)-D ≥ 30 ng/mL.

Results: The percentages of patients with vitDd, vitDi and vitDo were 44, 27.6 and 28.5%, respectively. Twenty-nine out of 30 (96.7%) Black patients had vitDd or vitDi, vs. 71.6% in the global sample (P < 0.001). Former injecting drug users (IDUs) had a higher prevalence of vitDo (P < 0.001) than patients in other transmission categories. Among patients with vitDd, vitDi and vitDo, the proportions of patients with a VL ≤ 50 HIV-1 RNA copies/mL were 77.4, 68 and 91%, respectively (P < 0.0001). Of the cART regimens, only boosted PI monotherapy was associated with significant differences in vitamin D levels (P = 0.039). Multivariate logistic regression analysis showed an increased risk of vitDi or vitDd associated with the following variables: Black vs. Caucasian ethnicity [odds ratio (OR) 10.6; 95% confidence interval (CI) 1.2-94; P = 0.033]; heterosexual (OR 2.37; 95% CI 1.13-4.93; P = 0.022) or men who have sex with men (MSM) (OR 3.25; 95% CI 1.25-8.50; P = 0.016) transmission category vs. former IDU; and VL > 50 copies/mL (OR 2.56; 95% CI 1.10-7.25; P = 0.040). A lower risk of vitamin D insufficiency or deficiency was found in patients on boosted PI monotherapy vs. no treatment (OR 0.08; 95% CI 0.01-0.6; P = 0.018).

Conclusions: Our data show an increased risk of vitamin D deficiency or insufficiency in patients with detectable VL and a Black ethnic background. Among cART regimens, boosted PI monotherapy was associated with a lower risk of vitamin D deficiency or insufficiency. The more favourable vitamin D status in former IDUs was probably attributable to a higher frequency of outdoor jobs in this group of patients.

Keywords: HIV; antiretroviral therapy; combination antiretroviral therapy; deficiency; highly active antiretroviral therapy; regimen; vitamin D.