In a large multisite study, we found that 24% of HIV-infected Veterans were food insecure and that food insecurity independently increased the likelihood of incomplete HIV viral suppression. While the prevalence of food insecurity in this study is lower than other estimates in HIV-infected populations in the U.S.,9,30
this study was conducted among patients who have accessed care through the Veterans Health Administration and are ostensibly less disenfranchised than previously studied homeless or drug using populations. Nonetheless, a quarter of participants in this study reported food insecurity, suggesting that food insecurity is more common among HIV-infected individuals in the U.S. compared to the general population.1
Similar to previous single site studies, we also found that food insecurity was associated with a 1.3 greater odds of lack of viral suppression when we controlled for other covariates, including measures of socioeconomic status, homelessness, and drug and alcohol use. While there is growing concern that food insecurity may compromise treatment effectiveness in ART treatment programs in developing countries,31–33
our findings suggest that food insecurity may be compromising treatment efficacy in well-resourced settings as well. Food insecurity was associated with ART non-adherence in a linear fashion. The finding that food insecurity is associated with lower levels of adherence is especially important given that lower ranges of adherence are more likely to be associated with incomplete viral suppression with currently available regimens.34
However, our data, like that of others, suggest that the association between food insecurity and viral suppression is not explained by a difference in adherence, in this case, an average yearly adherence.14
Veterans in this study received 98% of their medications from a VA pharmacy, making our use of administrative pharmacy data one of the best available adherence measurement strategies; however, these data may not capture patterns of adherence including treatment interruptions, that may be associated with viral rebound.34
Food insecurity was also associated with lower body mass index. However, when BMI was truncated into clinically meaningful categories, the association was marginally statistically significant. HIV-infected Veterans who were food insecure were more likely to be normo-weight or obese. Like others, our study found that obese individuals report anxiety about obtaining sufficient and high quality food.7,35
This finding deserves further exploration to better understand how to improve health outcomes among obese HIV-infected patients.
Another plausible biologic mechanism for the relationship between food insecurity and viral suppression is that food may impact the pharmacokinetics of antiretroviral medications. Several protease inhibitors including atazanavir, lopinavir, nelfinavir and ritonavir require food for maximal absorption, and the absence of timely access to food may negatively affect the absorption of these drugs.14
Since we did not assess the use of specific ART regimens, we cannot infer the effect of particular regimens on the association between food insecurity and viral suppression. Another possible mechanism is psychological distress which has been demonstrated in past studies to be associated with food insecurity and to impact HIV treatment outcome.36
Further research needs to be conducted to explore the mechanisms of the association between food insecurity and unsuppressed HIV-1 RNA in order to tailor interventions to improve the health outcomes for food insecure HIV-patients.
Finally, while several studies have demonstrated positive associations between food security and immunological status, we did not find such an association. One possible explanation for this discrepancy is that previous studies have reported that food insecure individuals had significantly lower CD4 counts prior to initiation of antiretroviral therapy, 9
whereas our study examined the association among individuals already prescribed antiretroviral medications. As a result, the effect of food insecurity on an individual’s immunologic response to HIV was less likely to be detected given the marked improvements in CD4 counts when individuals are started on antiretroviral medications.
There are several important limitations to this study. No conclusions about cause and effect can be made from this study due to its cross-sectional design. One possible explanation of our findings is that individuals with more advanced disease and poor functional health status are less able to obtain food. Additionally, our measurement for food insecurity was a single item taken from the HFIAS survey and thus captured only one of the domains of food insecurity—anxiety and uncertainty about food supply. We, therefore, were lacking accurate information about other components of food insecurity, including insufficient food intake or quality of food, as well as the duration, frequency, or extent of food insecurity. This information would be useful for understanding the effect of various domains of food insecurity on HIV disease outcomes. We did not adjust for previous time on ART, which may confound the observed associations. Finally, because we measured average adherence rather than patterns of adherence such as treatment interruptions, we were unable to determine whether adherence was on the causal pathway between food insecurity and HIV-1 RNA suppression.