Vitamin D Not Linked to BMD or Fibrosis in US HIV/HCV+ Patients
Low vitamin D levels were common in a largely African-American population of US patients coinfected with HIV and hepatitis C virus (HCV). But vitamin D deficiency was not associated with liver fibrosis or bone mineral density (BMD) at any body site.
Vitamin D deficiency is highly prevalent in US populations with and without HIV infection. People with HIV and HCV run a high risk of liver fibrosis and low BMD. To assess potential links between low vitamin D and fibrosis or BMD, Johns Hopkins University researchers in Baltimore studied 116 HIV/HCV-infected people seen at some point from 2005 through 2007.
All study participants had a liver biopsy within 1 year of DXA scanning for BMD. The investigators measured 25-hydroxyvitamin D (25OHD) and parathyroid hormone in stored blood samples. They defined low BMD as 2 or more standard deviations lower than BMD for age-, sex-, and race-matched controls at the total hip, femoral neck, or lumbar spine. They staged fibrosis with the METAVIR score, with 0 meaning no fibrosis and 4 meaning cirrhosis.
Most cohort members (87%) were African American, and most (63%) were men. Median age stood at 49.9 years (interquartile range 46.5 to 53.3). Almost two thirds of the study group (64%) were taking antiretroviral therapy, and 89% had a CD4 count above 200 cells/µL.
Median 25OHD stood at 19 ng/mL (IQR 11.0 to 26.0), and 41% of the cohort had hypovitaminosis, defined as 25OHD at or below 15 ng/mL. Secondary hyperparathyroidism, defined as parathyroid hormone above 65 pg/mL, affected 24% of study participants.
One quarter of the study group (27%) had low BMD at the spine, femoral neck, or total hip, and 39% had significant fibrosis (a METAVIR score at or above 2). But multivariate analysis found no association between vitamin D deficiency and significant fibrosis or low BMD.
The researchers believe their findings “suggest that efforts to increase vitamin D levels in this population may not improve bone or liver outcomes.”
Source: Diala El-Maouche, Shruti H. Mehta, Catherine G. Sutcliffe, Yvonne Higgins, Michael S. Torbenson, Richard D. Moore, David L. Thomas, Mark S. Sulkowski, Todd T. Brown. Vitamin D deficiency and its relation to bone mineral density and liver fibrosis in HIV-HCV coinfection. Antiviral Therapy. 2013; 18: 237-242.
Written by Mark Mascolini on behalf of the International AIDS Society