Diet Interventions: Remitted and Evaluated as Complementary Treatments for Pain (DIRECTPain)

University Of Alabama At Birmingham, Birmingham AL

Investigators

Abstract

Knee osteoarthritis (OA) is the most prevalent form of arthritis and a significant cause of lost productivity in the U.S. As the population ages and obesity rates increase, the rates of knee OA climb as well, impacting quality of life (QOL) for millions. Current national efforts to reduce analgesic utilization highlight the critical need for safe and effective alternatives for pain relief. Low-carbohydrate diets (LCDs) reduce inflammation and pain independent of weight loss, indicating that diet interventions offer a non-pharmacological complementary treatment. However, differences between individuals exist in metabolism that are rarely addressed in diet interventions. Thus, it is important to assess the potential of different diets in a broad population of chronic pain sufferers to determine the potential of diets to reduce knee OA pain. Here, we will recruit adults (n=200) with knee OA to complete our two-phase protocol. Phase 1 will involve a 1-week diet run-up that will allow for quantification of pain measures, psychosocial variables (socioeconomic status, nutritional knowledge, proximity to grocery stores, food insecurity), and diet quality to provide a baseline for comparison. Phase 2 will be a 6-week diet intervention (LCD or USDA diet) in which both groups will be provided with all meals at the direction of study personnel and input from participants. Evoked pain tasks, measures of pain severity, catastrophizing, and interference will be assessed every 3 weeks in addition to QOL measures, mood, and depression. Physiological variables will be assessed through blood draws (inflammatory profile) and dual-energy X-ray absorptiometry scans (DXA; body composition, visceral fat) at the end of Phases 1 and 2. This will be the first study to examine the efficacy of these diets to reduce knee OA pain and interactions with biopsychosocial variables. Changes in all pain measures following Phase 2 will be assessed with respect to published measures of clinically-meaningful differences in pain, as well as for statistical significance. The central hypothesis is that the LCD will improve pain and QOL in participants with knee OA more than the USDA diet, but that both will be beneficial.