Study
Links Social Isolation to Higher Risk of Death
American Cancer Society
A
large American Cancer Society study links social isolation with a higher risk
of death from all causes combined and heart disease for all races studied, and
with increased cancer mortality in white men and women.
The study, appearing in the American Journal of Epidemiology, says addressing social isolation holds promise if studies show interventions are effective, as they could be relatively simple and could influence other risk factors, as social isolation is also associated with hypertension, inflammation, physical inactivity, smoking, and other health risks.
A
large American Cancer Society study links social isolation with a higher risk
of death from all causes combined and heart disease for all races studied, and
with increased cancer mortality in white men and women. The study, appearing in the American Journal of Epidemiology, says addressing social isolation holds promise if studies show interventions are effective, as they could be relatively simple and could influence other risk factors, as social isolation is also associated with hypertension, inflammation, physical inactivity, smoking, and other health risks.
Social
isolation has been linked to higher mortality in studies comprising mostly
white adults, yet associations among black adults are unclear.
The new prospective cohort study, led by the American Cancer Society’s Kassandra Alcaraz, PhD, MPH, evaluated whether associations of social isolation with all-cause, cardiovascular disease and cancer mortality differed by race and sex.
The study analyzed data from 580,182 adults enrolled into Cancer Prevention Study-II in 1982/1983, who were followed for mortality through 2012.
The new prospective cohort study, led by the American Cancer Society’s Kassandra Alcaraz, PhD, MPH, evaluated whether associations of social isolation with all-cause, cardiovascular disease and cancer mortality differed by race and sex.
The study analyzed data from 580,182 adults enrolled into Cancer Prevention Study-II in 1982/1983, who were followed for mortality through 2012.
Investigators
weighted several standard components of social isolation –marital status,
frequency of religious service attendance and club meetings/group activities,
and number of close friends/relatives—giving a score of 0 (least isolated) or 1
(most isolated) on each of the factors for a total on a 5-point isolation
scale.
For instance, someone who was married, frequently attended religious services, attended club meetings and/or group activities, and had seven or more close friends was given an isolation score of 0. Someone with none of those would have an isolation score of 4.
For instance, someone who was married, frequently attended religious services, attended club meetings and/or group activities, and had seven or more close friends was given an isolation score of 0. Someone with none of those would have an isolation score of 4.
They
found overall, race seemed to be a stronger predictor of social isolation than
sex; white men and white women were more likely to be in the least isolated
category than black men and women. In the full sample, a statistically
significant, positive dose-response relationship was found between social
isolation and all-cause mortality risk over the 30-year follow-up period.
However, associations were significantly stronger in the first 15 years of
follow up.
Social
isolation score was positively associated with heart disease (CVD) mortality in
all subgroups.
Although there was a positive association between social isolation score and cancer mortality among white men and white women, there was no association between social isolation score and cancer mortality among black men or black women.
Each social isolation component was associated with all-cause and CVD mortality, and all but one (having fewer close friends/relatives) were associated with cancer mortality.
Although there was a positive association between social isolation score and cancer mortality among white men and white women, there was no association between social isolation score and cancer mortality among black men or black women.
Each social isolation component was associated with all-cause and CVD mortality, and all but one (having fewer close friends/relatives) were associated with cancer mortality.
“[C]urrent
findings indicate that a composite measure of social isolation is a robust
predictor of mortality risk among men, women, blacks, and whites,” write the
authors. “Compared with the least isolated, the most socially isolated black
men and women had a more than 2-fold higher risk of death from any cause, and
white men and women had 60% and 84% greater risks of death, respectfully.”
The authors say as the era of precision medicine develops, several influences on health, including social factors, are expected to become more important to clinical care. Addressing social isolation is aligned with this more holistic approach, they write, saying: “Lack of interpersonal connections seems particularly detrimental.”
The
authors point to a recent meta-analysis that identified social isolation as an
independent risk factor for death on par with well-established mortality risk
factors such as physical inactivity, obesity, and lack of healthcare access.
“Persistent challenges in intervening on modifiable clinical risk factors such
as obesity make approaches based on social isolation promising if efficacy can
be established,” they conclude.
Article:
Alcaraz KI, Eddens KS, Blase JL, et al. Social isolation and mortality in US
black and white men and women [published online ahead of print November 16,
2018]. Am J Epidemiol. (doi: 10.1093/aje/kwy231)