Relationship between Alcohol Intake and Chronic Pain with Depressive Symptoms: A Cross-Sectional Analysis of the Shika Study

Although alcohol intake is associated with chronic pain (CP) and analgesia, epidemiological studies have not yet examined the factors affecting the relationship between alcohol intake and CP in detail. Therefore, the present cross-sectional study investigated the relationship between alcohol intake and CP in community-dwelling middle-aged and elderly individuals with/without depressive symptoms. Participants comprised 2223 inhabitants of Shika town in Ishikawa prefecture, located on the Noto Peninsula facing the Sea of Japan, and included 1007 males and 1216 females. CP, depressive symptoms, and alcohol intake were assessed using a CP questionnaire, the Geriatric Depression Scale-15 and the brief-type self-administered diet history questionnaire, respectively. In males without depressive symptoms, mean alcohol intake was significantly higher at 5.70% energy (27.92 g/day) in the CP group than that of 3.75% energy (20.00 g/day) in the non-CP group. The prevalence of low back/knee pain was also significantly higher in males with than in those without depressive symptoms. The present results suggest that long-term alcohol intake is related to CP by reducing the pain threshold and enhancing nociceptive pain as a possible mechanism. However, even a low alcohol intake was associated with psychogenic pain in participants with depressive symptoms. Further studies to investigate the involvement of depressive symptoms and alcohol intake in CP and its prevention are needed.