The Relationship Between Diet Quality and Chronic Neuropathic Pain in Veterans with Spinal Cord Injury

About This Grant

Significance to VA: The proposed research study addresses a critical yet unresolved need in the Veteran and civilian populations and is a high priority within the Veterans Affairs (VA) Health Administration. The prevalence of chronic pain in Veterans with spinal cord injury (SCI) is at a whopping 75%, which is more than triple that of the general population. This is problematic because chronic pain after SCI severely impacts quality of life, physical function, and activities of daily living, with an increased prevalence of poor sleep, disability, and depression. While the causes of chronic neuropathic pain after SCI are not fully understood, research on chronic pain has shown that it is associated with diet, obesity, and systemic inflammation in both SCI and non- SCI literature. Chronic pain has been associated with poor quality diets in the general, non-Veteran population without SCI, as well as in preliminary findings in a non-Veteran SCI sample. Diet quality is a comprehensive diet metric measured with indices such as the 2020 Healthy Eating Index (HEI), which assesses adherence to the 2020-2025 Dietary Guidelines for Americans (0-100, with a higher score indicating greater adherence). Although the diet quality of Veterans with SCI has not been examined yet, nor its association with pain, studies have shown worse diet quality of Veterans compared to their non-Veteran counterparts. Innovation and Impact: The proposed study will be the first to determine diet quality using the novel, validated remote food photography method and assess its relationship with chronic pain in Veterans with SCI. This will be the first step to identify a non-pharmacological and modifiable environmental factor, such as dietary intake, to mitigate chronic pain after SCI. Specific Aims: The proposed observational and cross-sectional pilot study aims to: 1) examine the relationship between diet quality and chronic neuropathic pain and 2) compare the measures of diet quality, pain, and pain-related outcomes across three cohorts: a) Veterans with SCI, b) Veterans without SCI, and c) non-Veterans with SCI. We anticipate a significant inverse correlation between diet quality and pain severity (Aim 1) and worse diet quality, pain, and pain-related psychosocial measures in Veterans with SCI compared to the other study cohorts (Aim 2). Methodology: Veterans with SCI (n=30; ~50% with paraplegia/tetraplegia) will be recruited from the Miami VA Hospital, undergo chronic pain assessments (questionnaires and quantitative sensory testing (QST)), and provide dietary data using food photography. Data from age-, sex- matched Veterans without SCI (n=30), and data from age-, sex-, and injury-level matched non-Veterans with SCI (n=30) will be compared to that acquired for Veterans with SCI to compare across groups. Dietary data will be entered into the Nutrition Data System for Research v.2023 to generate the nutrition analysis reports for diet quality (via HEI) and other diet metrics for exploratory purposes (e.g., individual nutrients). Correlation analyses (Pearson’s or Spearman’s) will be performed to assess the strength of association between diet quality, pain parameters (chronic pain questionnaires, QST measures), and pain-related outcomes (depression, quality of life). Observed associations between diet quality and chronic pain/pain-related outcomes will be compared across the three study cohorts to assess for potential Veteran- and SCI- influence on chronic pain. Path to Translation/Implementation: Completing the proposed CDA-1 pilot study will examine the strength of the association between diet quality and chronic pain in Veterans with SCI, which will then guide the applicant for a more focused mechanism-based (e.g., obesity, inflammatory factors) investigation for future studies (CDA-2, etc.). The long-term goal of this pilot project and future studies is to develop targeted nutrition interventions that could potentially affect chronic pain and maximize Veterans’ functional independence and quality of life after SCI.