The Nutrition to Optimize, Understand, and Restore Insulin Sensitivity in HIV for Oklahoma (NOURISH-OK) Study uses a cross-cutting research design that is widely-applicable to the prevention and treatment of many chronic co-morbidities in HIV disease. It uses a community-based participatory orientation to maximize inclusion of minorities and other underrepresented populations, which also ensures study findings will be relevant, actionable, and yield the greatest potential for reducing health disparities. Broadly, NOURISH-OK will elucidate nutritional and non-nutritional behavioral risk pathways linking food insecurity to insulin resistance among low- income people living with HIV. Its primary focus will be rigorous evaluation and manipulation of dietary intake as an influential pathway, which is complemented by secondary investigation of additional biological pathways, including chronic inflammation and microbiome. The study will be conducted in Oklahoma, and include HIV- positive individuals living in urban and rural communities. It is comprised of three aims. First, the research team will test and refine a conceptual integrated framework of food insecurity and insulin resistance to identify significant structural, social, behavioral, and biological pathways as candidate intervention points.
This aim will be accomplished using a cross-sectional survey (n=500) and a one-month observational sub-study from the main study sample (n=100) to collect intensive measures of dietary intake and gut microbiome samples. Data analysis will adjust for measurement error in dietary intake using replicate recalls from the sub-study. Structural equation modeling will be used to test the study?s overall conceptual multi-level framework of food insecurity and insulin resistance. Second, the research team will then adapt a home-delivered grocery and cooking self-care NOURISH-OK intervention to address key nutrition disparities and other health risk behaviors identified as significant path contributors to insulin resistance among people living with HIV. This adaptation will be informed by findings from the first aim, and further refined and finalized through a series of interviews and focus groups with people living with HIV who are food insecure (n=56 qualitative study subjects). Third, the research team will implement the 12-week NOURISH-OK intervention and assess it for feasibility, acceptability, and preliminary impact using a randomized wait-list control design (n=270). This study will use a simple randomized wait-list control trial design with stratification by geography (urban/rural) and further stratification in the urban group by low and very low food security status. Primary study outcomes include insulin resistance, along with multiple secondary outcomes that are also strongly relevant to the mission of NIDDK. These secondary outcomes include dietary intake and nutritional status, chronic inflammation, health risk behaviors, including tobacco use, physical inactivity, and inadequate sleep, and microbiome composition changes.
The NOURISH-OK Study will identify how food insecurity contributes to insulin resistance, an important surrogate marker of many co-morbidities in HIV disease, using an integrated framework to identify key leverage points for insulin resistance. Drawing from these pathways, this study will adapt and evaluate a community-driven, science-informed ?food as medicine? intervention designed to lower insulin resistance through healthy food access, food utilization skills, and other self-care behaviors. Knowledge gained from this study can benefit those living with HIV through the prevention and more effective management of pre-diabetes, diabetes, obesity, and non-alcoholic fatty liver disease.
