Impact of dynamic changes in pain on cardiovascular disease in Chinese middle and elderly people: results from China Health and Retirement Longitudinal Study (CHARLS)

BACKGROUND: Previous studies found chronic pain was an important risk factor for cardiovascular disease (CVD), but only focused on baseline pain status, without exploring into the dynamic changes of pain status on CVD. This study aims to investigate the associations of dynamic changes in pain status with incident CVD. METHOD: This study used data from China Health and Retirement Longitudinal Study (CHARLS) aged 45 or older. The pain status is defined as whether the individual has frequently suffered from pain since the last survey (conducted every 2 or 3 years). Changes in pain status were assessed by pain status at baseline and the second survey which was three years after the baseline. CVD was ascertained by heart disease and/or stroke. This study employed multivariable logistics models adjusting for potential confounders. Moreover, different subgroup analysis and heart disease and stroke analysis respectively, were applied to test the consistence and robustness of the investigation result. RESULT: Eleven thousand, two hundred seventeen participants (female 50.94%, mean age 58.63 years) were included in pain status changes analyses. In comparison with stable painless participants, painless participants who progressed to pain had significantly elevated risks of CVD (Painless-Pain [OR 1.57, 95% CI 1.30–1.90]; Stable Pain [OR 2.23, 95% CI 1.79–2.77]). Further, participants were reclassified by pain status in the third survey. Compared with stable painless participants, participants who progressed to pain in the third survey had significantly elevated risks of CVD (painless-painless-pain: OR 1.51, 95% CI 1.12–2.04; painless-pain-pain: OR 2.15, 95% CI 1.66–2.79; pain-painless-pain: OR 2.26, 95% CI 1.44–3.52; stable pain: OR 2.57, 95% CI 1.90–3.48). Different subgroups analysis and outcomes analysis of CVD, heart disease and stroke had consistent results. CONCLUSION: Our findings demonstrate that progression from pain-free to chronic pain status significantly increases CVD incidence, while the pain relief status shows no increased CVD risk.