Low Dietary Calcium Tied to Low BMD With HCV but Not HIV

Low dietary calcium might contribute to low bone mineral density (BMD) in men living with hepatitis C (HCV) but not in those with HIV, according to a 436-man Veterans Administration (VA) analysis. Eating spinach, almonds, milk, and yoghurt had the strongest positive dietary correlation with BMD.

Low BMD and consequent fractures pose a continuing threat to people living with HIV and/or HCV infection. Inadequate dietary calcium intake can contribute to low BMD but has not been closely studied in populations with HIV or HCV. Researchers at the University of Texas and the VA North Texas Health Care System conducted this cross-sectional study to chart the prevalence of osteopenia and osteoporosis among male veterans with HIV and/or HCV and to determine whether dietary calcium is associated with BMD in this population.

The analysis focused on four groups of male veterans: those with (1) HIV monoinfection, (2) HCV monoinfection, (3) HIV/HCV coinfection, and (4) no HIV or HCV. Everyone with HIV had an undetectable viral load on antiretroviral therapy, and no one with HCV had received treatment for the hepatitis virus. All participants had DXA scans to measure BMD at the lumbar spine, femoral neck, and total hip. They completed the Hertzler-Frary dietary calcium rapid assessment questionnaire, and the researchers used the answers to calculate calcium intake from the USDA Nutrient Database.

The study included 46 men with HIV/HCV, 141 with HIV monoinfection, 99 with HCV monoinfection, and 150 HIV/HCV-negative controls. Average age varied from 54 to 56 years across the four groups. Proportions of blacks were 68% with HIV/HCV, 42% with HIV, 74% with HCV, and 73% with neither infection (P < .001). Respective proportions of smokers were 48%, 33%, 68%, and 66% (P < .001). Median calcium intake ranged from 606 to 788 mg daily across the four groups, with no significant differences among groups. These values are low, according to the U.S. Institute of Medicine of the National Academies, which recommends 1,300 mg daily for 9- to 18-year-olds, 1,000 to 1,200 mg daily for 19- to 70-year-olds, and 1,200 mg daily for men older than 70.

Osteopenia and osteoporosis prevalence was high in veterans with HIV/HCV (65% and 15%, respectively), HIV monoinfection (53% and 14%), HCV monoinfection (53% and 11%), and uninfected controls (49% and 11%). In contrast, among men over age 50 in the general population, 38% have osteopenia and 4% osteoporosis.

There was no significant association between infection group and BMD (P = .339). In an analysis adjusted for age, body mass index, race, and smoking, median calcium intake did not differ among infection groups, even when researchers considered calcium supplementation. Among veterans with HIV monoinfection or HIV/HCV coinfection, median calcium intake did not differ between those with normal BMD and those with osteoporosis in adjusted analyses. However, HCV-monoinfected men with osteoporosis consumed less calcium than men with normal BMD (mean difference 409 mg, 95% confidence interval 35 to 784, P = .027).

Among foods eaten by 10% or more study participants, Spearman correlation identified four that correlated positively with BMD: spinach (spine, hip, femoral neck), milk (hip, femoral neck), almonds (hip, femoral neck), and yoghurt (hip). Corn tortillas correlated negatively with lumbar spine BMD.

The researchers concluded that low dietary calcium does not appear to contribute to low BMD in men with HIV or HIV/HCV, "but it is one of the possible explanations for monoinfected HCV patients." Because of the positive correlation between certain foods and higher BMD, they suggested that eating these foods "with a healthy diet might protect bone health" in men with HIV or HCV.