Abstract B50: A church-based diet, physical activity, and stress intervention results in lower waist to hip ratios and reduced chronic inflammation in African-American males
Authors: Hebert James R. , Wirth Michael D. , Harmon Brook E. , Shivappa Nitin , Hurley Thomas G. , Davis Lisa C. , Armstead Cheryl A. , Murphy Angela E. 
Published: March 2017

Introduction: Acute inflammation, the body's response to infection or physical insult, helps to control infection, heal wounds, and promote tissue regeneration. When normal systems of negative feedback fail to turn off inhibitory signaling, persistent chronic inflammation results. Such chronic inflammation has been shown to be associated with cancers of many anatomic sites and other chronic diseases that are both more prevalent and more virulent among African Americans in the Southeastern United States. Also, chronic inflammation has been associated with poor diet, low levels of physical activity, and high levels of psychosocial stress. Using principles of community-based participatory research (CBPR), this randomized controlled trial (RCT) was designed and administered jointly by members of African-American churches and academic researchers. Its goal was to test the effectiveness of a community-based diet, physical activity and stress reduction intervention in reducing inflammation in overweight and obese African-American adults.

Methods: The RCT was conducted in greater Columbia, SC from 2010 to 2014. Churches were randomized to receive the intervention either immediately or with a 12-month delay. The latter served as the study's control arm. Church members were the unit of measurement for all health-related outcomes. Three lay health leaders, who constituted the Church Education Team (CET) and facilitated the study, were selected by the pastor of each church. The first intervention phase consisted of 12 weekly group classes led by a trained community health educator and involving hands-on cooking of mainly vegetable-based meals, sharing of healthy recipes, increasing physical activity, and mindfulness-based stress reduction. The second phase included monthly boosters conducted over an additional 9 months, and was meant to reinforce and expand on topics introduced in the more intensive, 12-week phase. Anthropometric measures were taken along with C-reactive protein (CRP), interleukin (IL)-6 and Monocyte Chemoattractant Protein (MCP)-1. A composite inflammatory score was computed by summing the z-scores for CRP, IL-6 and MCP-1. Linear regression models were fit to test intervention effectiveness and to identify predictors of success.

Results: Males in the intervention arm had lower mean adjusted CRP values compared to controls (2.6 vs. 3.7mg/L, p=0.05) at 12-week follow-up (immediately after weekly intervention classes). After 1-year follow-up, a difference of similar magnitude, but not statistically significant, was observed (2.6 vs. 3.9, p=0.17). A nearly statistically significant difference in the composite inflammatory biomarker score also was observed between intervention and control arms among males (-0.38 vs. 0.17, p=0.07). Adjustment for ratings of intervention attendance and sustainability revealed a statistically significant difference in waist-to-hip ratio (WHR) between intervention and control group subjects (0.84 vs. 0.86, p=0.03) at 12-week follow-up among all participants.

Conclusion: This RCT showed a significant reduction in CRP among males, but not females; and WHR reductions among all participants at 12-week follow-up. Results also included a large dropout and relatively large differences in factors related to retention and participants' investment in the process. Therefore, alternatives to randomization as a method of treatment allocation may be more appropriate from a public health perspective, especially in communities with large cancer-related health disparities.

Citation Format: James R. Hebert, Michael D. Wirth, Brook E. Harmon, Nitin Shivappa, Thomas G. Hurley, Lisa C. Davis, Cheryl A. Armstead, Angela E. Murphy. A church-based diet, physical activity, and stress intervention results in lower waist to hip ratios and reduced chronic inflammation in African-American males. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr B50.