Evaluation of Social Isolation Trajectories and Incident Cardiovascular Disease Among Middle-Aged and Older Adults in China: National Cohort Study

Abstract

Background Although the association between social isolation and the risk of subsequent cardiovascular disease (CVD) is well documented, most studies have only assessed social isolation at a single time point, and few studies have considered the association using repeatedly measured social isolation. Objective This study aimed to examine the association between social isolation trajectories and incident CVD in a large cohort of middle-aged and older adults. Methods This study used data from 4 waves (wave 1, wave 2, wave 3, and wave 4) of the China Health and Retirement Longitudinal Study. We defined the exposure period as from June 2011 to September 2015 (from wave 1 to wave 3) and the follow-up period as from September 2015 to March 2019 (wave 4). On the basis of the inclusion and exclusion criteria, our final analytic sample included 8422 individuals who had no CVD in the China Health and Retirement Longitudinal Study in waves 1 to 3 and were fully followed up in wave 4. Social isolation was ascertained using an extensively used questionnaire at 3 consecutive, biennial time points from waves 1 to 3, and individuals were assigned to 3 predefined social isolation trajectories based on their scores at each wave (consistently low, fluctuating, and consistently high). Incident CVD included self-reported physician-diagnosed heart disease and stroke combined. Cox proportional hazard models estimated the associations of social isolation trajectories with risks of incident CVD, adjusting for demographics, health behaviors, and health conditions. Results Of the 8422 participants (mean age 59.76, SD 10.33 years at baseline), 4219 (50.09%) were male. Most of the participants (5267/8422, 62.54%) had consistently low social isolation over time and 16.62% (1400/8422) of the participants had consistently high social isolation over the exposure period. During the 4-year follow-up, 746 incident CVDs occurred (heart disease: 450 cases and stroke: 336 cases). Compared with individuals with consistently low social isolation, those with fluctuating social isolation (adjusted hazard ratio 1.27, 95% CI 1.01-1.59) and consistently high social isolation (adjusted hazard ratio 1.45, 95% CI 1.13-1.85) had higher risks for incident CVD after adjusting for demographics (ie, age, sex, residence, and educational level), health behaviors (ie, smoking status and drinking status), and health conditions (ie, BMI; history of diabetes, hypertension, dyslipidemia, chronic kidney disease; use of diabetes medications, hypertension medications, and lipid-lowering therapy; and depressive symptoms scores). Conclusions In this cohort study, middle-aged and older adults with fluctuating and consistently high social isolation exposure had higher risks of the onset of CVD than those without the exposure. The findings suggest that routine social isolation screenings and efforts to improve social connectedness merit increased attention for preventing CVD among middle-aged and older adults.

Association of increased participation in social activity in later life with risk of all-cause mortality and heart diseases in older people: results from the Chinese Longitudinal Healthy Longevity Survey (CLHLS)

“…In fact, evidence about the association between social participation or social isolation [defined as a state of complete or near-complete lack of contact between an individual and society ( 26 )] and cardiovascular disease is controversial. In a large cohort of 8,422 middle-aged and older subjects, Guo et al demonstrated that subjects with fluctuating social isolation and consistently high social isolation showed significantly higher risk of incident cardiovascular disease when compared to those with consistently low social isolation ( 17 ). Conversely, in a previous study consisted of 33,538 middle-aged Japanese, Oshio et al reported that social participation had no impact in preventing the onset of heart disease ( 18 ).…”

“…Therefore, among older people who never participate in social activity at baseline, it is largely unknown whether increased participation in social activity in later life is associated with reduced risk of health outcomes. Second, previous results regarding the effect of social participation on heart diseases were inconsistent, some of which indicated protective effect ( 17 ), while others indicated neutral effect ( 18–20 ) in middle aged and older population or general population. Still, for older people, the impact of increased participation in social activity on the new onset of heart diseases remains to be investigated.…”

Evaluation of Changes in Social Isolation and Loneliness with Incident Cardiovascular Events and Mortality

“…Similarly, Guo et al have shown that the fluctuating and consistently high social isolation is associated with high risks of developing CVD. However, they only evaluated the association between changes of social isolation and onset of CVD but overlooked the mortality [12]. To our knowledge, how changes in social isolation and loneliness affect the risks of incident CVD and mortality remains largely unclear.…”

Social pain and physical pain: a cohort study to explore the association of social isolation and loneliness with chronic pain among older adults in China

“…Loneliness is a self-perceived or subjective feeling of being disconnected from social relationships [17] while social isolation is an objective condition, measured by the number of relationships, participation in social activities, and frequency of social engagements [16,18]. Biopsychosocial modeling has identified loneliness and social isolation, as well as depression, anxiety, and education [19][20][21] , as factors impacting a range of chronic diseases, such as hypertension [16], cardiovascular diseases [18,22], digestive disease [23], and diabetes [18].…”