Association between chronic pain and cognitive frailty among middle-aged and elderly individuals: evidence from the China Health and Retirement Longitudinal Study

Abstract

Background: Frailty, particularly cognitive frailty, is an escalating public health issue. Cognitive frailty is defined by the simultaneous presence of physical frailty and cognitive impairment, without a confirmed diagnosis of dementia, and has become a significant geriatric syndrome. This study aimed to explore the association between chronic pain and the risk of cognitive frailty.

Methods: We utilized data from two waves (2011 and 2015) of the China Health and Retirement Longitudinal Study (CHARLS), conducting both cross-sectional and longitudinal analyses involving 17,705 Chinese adults aged 45 years and older. Chronic pain was defined as pain reported at both time points. Cognitive function was evaluated using a questionnaire adapted from the Telephone Interview for Cognitive Status. The frailty index (FI) was derived from a 30-item assessment. Cognitive frailty was characterized by the co-occurrence of cognitive impairment and physical frailty.

Results: Among the 14,285 participants, 5.39% exhibited cognitive frailty at baseline. Both cross-sectional and longitudinal analyses indicated that individuals suffering from chronic pain faced a higher likelihood of developing cognitive frailty compared to those without pain. After adjusting for potential confounders, multivariate models also indicated a higher odds of cognitive frailty for participants with chronic pain.

Conclusion: Chronic pain is significantly associated with an elevated risk of cognitive frailty among middle-aged and elderly individuals. These findings highlight the importance of managing chronic pain to mitigate the risk of cognitive frailty, thereby potentially enhancing the quality of life for the aging population and alleviating the economic burden on families and society.

Keywords: China Health and Retirement Longitudinal Study; aging; chronic pain; cognitive frailty; middle-aged and elderly population.

Figure 1

Study flow chart.

Figure 2

Subgroup analysis of the relationship between chronic pain and cognitive frailty at baseline. Adjustments for confounders were conducted using Model 4. The logistic regression analysis for subgrouping was performed using an identical sample as that employed in the baseline-wide logistic regression. Square symbols are employed to represent the odds ratios (ORs), while horizontal lines delineate the 95% confidence intervals (CIs). Diamond shapes are used to depict the population-level odds ratios, with the points at the vertices of the diamonds indicating the 95% confidence intervals. CI, Confidence Interval; OR, Odds Ratio; BMI, Body Mass Index.

Figure 3

Subgroup analysis of the association between chronic pain and cognitive frailty during the follow-up period. Adjustments for confounding variables were performed using Model 4. The sample for the subgroup logistic regression analysis mirrors that of the overall logistic regression conducted during the follow-up phase. The baseline frailty and mild cognitive impairment (MCI) subgroup excludes individuals diagnosed with cognitive frailty at baseline, as these subjects were not included during the follow-up due to subsequent exclusion criteria. Square symbols represent the odds ratios (ORs), and horizontal lines indicate the 95% confidence intervals (CIs). Diamond shapes depict the population-level odds ratios, with the points along the edges of the diamonds representing the 95% confidence intervals. CI, Confidence Interval; OR, Odds Ratio; BMI, Body Mass Index; MCI, Mild Cognitive Impairment.