Relationship Between Chronic Pain Types (Nociceptive and Neuropathic-Like Symptoms) and Frailty in Community-Dwelling Japanese Older Adults: A Cross-Sectional Study

Purpose: Chronic pain may accelerate the development of frailty in older adults through a variety of mechanisms. There are no published investigations of the influence of neuropathic-like symptoms on physical frailty. We investigated the association between chronic pain types (nociceptive and neuropathic-like symptoms) and frailty in community-dwelling Japanese older adults. Participants and Methods: This was a population-based cross-sectional study conducted in 2017 in the city of Itoshima, Japan of 917 participants aged 65-75 years, not in need of long-term care, who had completed the physical function tests and questionnaires administered at measurement sessions held at community centers at three sites over a 1- to 2-month period. Their chronic pain types were classified as nochronic pain, nociceptive pain, and neuropathic-like symptoms according to their painDETECT scores. Frailty phenotypes were defined by the following five components: unintentional weight loss, low grip strength, exhaustion, slow gait speed, and low physical activity. A logistic regression model was used to compute the odds ratios (ORs) and 95% confidence interval (CIs) for frailty status outcomes. Results: The prevalence of pre-frailty was 51.9%, and that of frailty was 5.1%. In multinomial logistic regression analyses, compared to the no-chronic pain group, the OR for the presence of pre-frailty among the participants with nociceptive pain was 1.54 (95% CI: 1.04-2.30, p=0.03), and the OR for the presence of frailty among the participants with neuropathic-like symptoms was 4.37 (95% CI: 1.10-17.37, p=0.04). The neuropathic sensory symptoms of burning, tingling/prickling, and numbness were each associated with frailty, but not with the risk of pre-frailty. Conclusion: Neuropathic-like symptoms were significantly associated with the presence of frailty in community-dwelling Japanese older adults. Chronic pain types might have different effects on frailty status.