Vitamin D Levels and Markers of Arterial Dysfunction in HIV

Abstract

HIV-infected patients have low vitamin D levels as well as an increase in cardiovascular (CVD) risk. We examined the relationship between vitamin D and three markers of arterial dysfunction among HIV-infected individuals on stable antiretroviral (ARV) therapy. Levels of 25-hydroxyvitamin D [25(OH)D] were assessed by chemiluminescent immunoassay (DiaSorin) in 100 enrollees into the Hawaii Aging with HIV-Cardiovascular Cohort Study, a cohort of HIV-infected subjects age ≥ 40 years on stable (≥ 6 months) ARV therapy. The relationships between 25(OH)D levels and brachial artery flow-mediated dilation (FMD), right common carotid artery intima-media thickness (cIMT), and coronary artery calcium (CAC) were examined. Analytical methods included Pearson's correlations, Kruskal-Wallis tests, relative risks, and linear regression models. The cohort was 86% male and 60% white with a median age of 52 years and CD4 of 510 cells/mm(3). The median (Q1, Q3) level of 25(OH)D was 27.9 ng/ml (21.8, 38.3). There were 72 FMD, 50 cIMT, and 90 CAC measurements available for analyses. A significant correlation was observed between 25(OH)D levels and FMD (r=0.30, p=0.01) but not with cIMT (r=-0.05, p=0.76). In a linear regression model, Framingham risk score attenuated the relationship between FMD and 25(OH)D. Those with lower 25(OH)D levels were at slightly higher risk of having CAC (RR=1.02, p=0.04). Among those with CAC, lower 25(OH)D levels were not associated with higher CAC scores (p=0.36). Lower vitamin D levels are associated with evidence of subclinical arterial dysfunction in HIV-infected individuals. The significance of these findings warrants further investigation.

Vitamin D and Calcium Abnormalities in the HIV-Infected Population

“…Among participants with mostly suppressed viremia in the Hawaii Aging with HIV-Cardiovascular Cohort Study, an increased likelihood of having coronary artery calcium (CAC) was demonstrated among vitamin D-deficient subjects. 84 In addition, higher levels of vitamin D were also shown in this study to be positively correlated with higher brachial artery flow-mediated dilatation (FMD). Possibly because of a small sample size, no association was seen with carotid artery intima-media thickness (cIMT).…”

HIV and coronary artery calcium score: comparison of the Hawaii Aging with HIV Cardiovascular Study and Multi-Ethnic Study of Atherosclerosis (MESA) cohorts

“…Hawaii Aging with HIV – Cardiovascular Study is a longitudinal study of the role of oxidative stress and inflammation in HIV cardiovascular risk. 9 Multi-Ethnic Study of Atherosclerosis is a prospective study on the prevalence, risk factors, and progression of subclinical CHD. The study design and methods for both cohorts have been previously published.…”

Measuring coronary artery calcification: Is serum vitamin D relevant?

“…Among these, 3 studies demonstrated significant association between vitamin D and CAC; only 2 controlled for confounders. One of the studies reporting a significant association, Shikuma et al, had modest elevated unadjusted risk (RR 1.02; p ¼ 0.04) and did not perform multivariable adjustment [8]. The three other studies with no association between vitamin D and CAC prevalence included studies conducted in a multi-ethnic population [7], among persons with type 1 diabetes [11] and in a population of persons with chronic kidney disease [9].…”