Stability and predictors of somatic symptoms in men and women over 10 years: A real-world perspective from the prospective MONICA/KORA study

Objective: To assess the stability of somatic symptoms in community-dwelling participants. Methods: The study included 2472 participants (1190 men, 1282 women; mean age 44.3 ± 10.9) from the prospective population-based MONICA-S3 cohort (1994/95) and the 10-year follow-up KORA-F3 cohort. Somatic symptoms were assessed by an adapted version of the Somatic Symptom Scale-8 (SSS-8a) with scores ranging from 0 to 24. Somatic symptom stability was assessed by weighted kappa values (κ). Generalized Estimating Equation models assessing symptom stability were adjusted for sociodemographic, lifestyle, clinical and psychosocial risk factors, as well as pre-existing medical conditions. Results: The mean (±SD) SSS-8a was lower in men (S3: 6.88 ± 3.87, F3: 6.60 ± 3.86) than women (S3: 8.43 ± 4.0, F3: 8.31 ± 4.2) at both time points. However, somatic symptoms remained moderately stable in both genders over 10 years (κ =0.42 in men and κ = 0.48 in women), with the largest stability observed in trouble sleeping for men (κ =0.41) and pain in the joints for women (κ =0.41). Pre-existing somatic symptoms were significantly associated with increasing symptoms at follow-up [men: β = 0.82 (SE 0.12), women: β = 0.85 (SE 0.12)], followed by age and psychosocial factors, whereas higher education and recent health care utilization were inversely associated with increasing symptoms. Although hypertension and obesity were associated with increasing somatic symptoms in men, pre-existing medical conditions were not associated with increasing somatic symptoms in men nor women. Conclusions: The current findings indicate that somatic symptoms remain moderately stable in the general population during 10 years of follow-up, mainly driven by sociodemographic and psychosocial factors.