Vitamin D deficiency and its relation to bone mineral density and liver fibrosis in HIV-HCV coinfection

Background: Fractures and cirrhosis are major causes of morbidity and mortality among HIV-HCV-coinfected individuals. It is not known whether vitamin D deficiency is associated with these outcomes. Methods: Between 2005 and 2007, 116 HIV-HCV-coinfected individuals underwent dual-energy X-ray absorptiometry within 1 year of a liver biopsy. 25-Hydroxyvitamin D (25OHD) and parathyroid hormone were measured from archived samples. Low bone mineral density (BMD) was defined as BMD >= 2 standard deviations lower than age-, sex- and race-matched controls (Z-score <=-2.0) at the total hip, femoral neck or lumbar spine. Histological fibrosis staging was assessed according to the METAVIR system (0 [no fibrosis] to 4 [cirrhosis]). Results: The cohort was 87% African-American and 63% male. The median age (IQR) was 49.9 years (46.5-53.3). A total of 89% had a CD4(+) T-cell count >200 cells/mm(3) and 64% were receiving HAART. The median 25OHD was 19 ng/ml (IQR 11.0-26.0). Hypovitaminosis D (25OHD <= 15 ng/ml) was present in 41% and secondary hyperparathyroidism, defined by parathyroid hormone >65 pg/ml, was present in 24%. In total, 27% had low BMD (Z-score <=-2) at the spine, femoral neck or total hip, and 39% had significant hepatic fibrosis (METAVIR >= 2). In multivariate analysis, vitamin D deficiency was not associated with significant fibrosis or with BMD at any site. Conclusions: Vitamin D deficiency was highly prevalent in this mostly African-American HIV-HCV-coinfected population, but was not related to BMD or liver disease severity. These data suggest that efforts to increase vitamin D levels in this population may not improve bone or liver outcomes.