Association between chronic pain and type 2 diabetes in older adults: A prospective study in the UK Biobank

The impact of chronic pain on the risk of type 2 diabetes in older adults remains uncertain, and chronic pain frequently involves multiple body sites. This study examined whether a greater number of chronic pain sites is associated with an increased risk of developing type 2 diabetes. Participants aged ≥60 years from the UK Biobank without type 2 diabetes at baseline were included. Chronic pain was self-reported and classified into six groups: none, one, two, three, four to seven sites, and pain all over the body. Incident type 2 diabetes was the primary outcome. Using Cox proportional hazards models, hazard ratios were estimated according to pain-site number, and mediation analysis assessed the roles of physical activity and body mass index. Among 84,565 participants, compared with those without chronic pain, pain at two, three, and four to seven sites and pain all over the body was associated with higher risks of incident type 2 diabetes, with adjusted hazard ratios of 1.102 (95% CI: 1.027-1.181), 1.143 (95% CI: 1.049-1.246), 1.198 (95% CI: 1.078-1.331), and 1.181 (95% CI: 1.023-1.363), respectively. Physical activity and body mass index jointly mediated this association, accounting for 6.25% and 45.83% of the effect. An increasing number of chronic pain sites was associated with a higher risk of type 2 diabetes in older adults, partly through reduced physical activity and elevated body mass index. These findings highlight the importance of promoting physical activity and healthy weight in chronic pain management to prevent type 2 diabetes. PERSPECTIVE: This study shows that multisite chronic pain increases type 2 diabetes risk in older adults, partly through reduced physical activity and elevated adiposity. These findings highlight that chronic pain burden and impaired energy balance may contribute to type 2 diabetes, informing future research on nociception-metabolic mechanisms.