Trajectories of obesity indices and their association with pain in community-dwelling older adults: Findings from the English longitudinal study of ageing.

BACKGROUND

The prevalence of pain has increased with the increase of obesity, and finding indicators to predict pain risk has become an urgent need. BMI, WC, and WHtR have the potential to be excellent predictors. However, the association of these obesity indicators with various pains remains unclear.

METHODS

This longitudinal cohort study included 2155 pain-free participants (mean age = 68.5 years, standard deviation [SD] = 8.6) from the English Longitudinal Study of Ageing (ELSA). BMI, WC, and WHtR were measured during nurse visits at waves 0, 2, and 4. The Group-Based Trajectory Model (GBTM) was used to identify optimal trajectories for BMI, WC, and WHtR. Self-reported pain at four anatomical sites (lower back, hip, knee and total pain) was assessed at Waves 4 to 9. Cox proportional hazards models were employed to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between obesity indices and pain risk.

RESULTS

Over a median follow-up period of 7.49 years, we observed 1,059 incident cases of all-cause pain. After adjusting for confounders, participants in the High-Stable WC group had a 30% higher risk of experiencing pain (HR: 1.30, 95 % CI: 1.05-1.60, P = 0.014), while those in the High-Stable WHtR group had a 29% higher risk (HR: 1.29, 95% CI: 1.06-1.56, P = 0.010) compared to the Low-Stable group. High-stable trajectories for BMI, WC, and WHtR were also associated with an elevated risk of back, hip, and knee pain.

CONCLUSION

This study identifies long-term obesity indices as significant predictors of pain, suggesting the importance of monitoring these measures for effective clinical risk assessments. Further research is needed to explore the underlying mechanisms of these associations.