In people with HIV, low vitamin D levels have been linked to thicker carotid arteries as well as a weaker comeback for the immune system after starting antiretroviral therapy.
These results, published online recently in the journal Antiviral Therapy, are the first to confirm an association between low vitamin D levels and a measure of higher cardiovascular risk in people with HIV. They also suggest that the benefits of vitamin D supplementation for people with HIV should be evaluated in a clinical trial.
The advent of effective antiretroviral therapy against HIV has dramatically improved life expectancies for people with HIV over the last 15 years. The presence of HIV is known to perturb cardiovascular health, even in the absence of an active infection. Since vitamin D levels are known to have an impact on the immune system and cardiovascular disease risk, that drove infectious disease specialist Allison Ross and her colleagues to probe these connections in people living with HIV.Â The results were also described on the Web sitesÂ AidsMeds and NAM/AidsMap.
Ross studied a group of HIV-positive people enrolled in Case Western Reserve Universityâ€™s HIV clinic in Cleveland. Colleagues from Emory and Case Western were co-authors.
They tested vitamin D levels, immune function and heart health in 149 HIV-positive people and a matched group of 34 HIV-negative people. Vitamin D levels were significantly lower in the HIV-positive group, even when controlling for known factors that affect vitamin D.
The researchers looked at how much the immune system was able to come back after starting retroviral therapy. This involves comparing someoneâ€™s lowest ever CD4 T cell count from the current CD4 count. They found that people with the poorest level of immune restoration were the most likely to have the lowest level of vitamin D. In addition, people with the lowest vitamin D levels were more than 10 times as likely to have thickening of the carotid arteries, as measured by ultrasound.
Inflammation can be a driving factor for heart disease, but in the study, low vitamin D was not linked to higher levels of inflammation markers.Â Additional research could determine whether those who are starting antiretroviral therapy would see better immune recovery if they took a vitamin D supplement.
Researchers at Emory have been investigating several aspects of low Vitamin D levels and their impact on health, including a connection with Parkinson’s disease. Endocrinologist Vin Tangpricha notes that Emory studies are looking at vitamin D in the context of tuberculosis, sepsis, sickle cell disease, cancer, cystic fibrosis and pain sensitivity.