Individuals who are lonely appear to be at an increased risk of incident atrial fibrillation (AF), driven by unhealthy behaviours, suggests a study presented at AHA 2024 Scientific Sessions. In addition, women tend to suffer more from the harmful effects of loneliness.

“The role of socio-psychological factors, such as loneliness and social isolation, has gained increasing attention, especially in a post-COVID world,” said lead author Dr Zhiwei Zeng from the National Clinical Research Center of Cardiovascular Diseases, Chinese Academy of Medical Sciences, and Peking Union Medical College in Beijing, China.

Given the scarcity of related evidence on AF, Zeng and colleagues carried out a population-based study using data from the UK Biobank to determine whether loneliness and social isolation contributed to the increased risk of incident AF, as well as to identify which behavioural factors mediate such association.

A total of 459,282 participants (mean age 56.4 years, 55.0 percent female) without AF at baseline were included in the analysis. They were categorized into three-level loneliness and social isolation scales using self-reported questionnaires.

Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95 percent confidence intervals (CIs) of incident AF, with adjustments for potential confounders. 

Finally, a two-stage regression method for survival data was used to evaluate the mediating effects of behavioural factors, such as obesity, smoking, excessive alcohol use, insufficient physical activity, unhealthy diet, and sleep deprivation.

Zeng and colleagues documented 25,406 incident AF cases over a median follow-up of 12.1 years. In fully adjusted models, they observed a significantly higher risk of incident AF (HR, 1.21, 95 percent CI, 1.15?1.27) among individuals with the highest loneliness scale of 2 than those with the lowest loneliness scale of 0. [AHA 2024, abstract 4144170]

On the other hand, only a mild additional risk was observed for individuals with a social isolation scale of ≥2, which reached a marginal significance (HR, 1.06, 95 percent CI, 1.02?1.10).

Lonely women

Notably, sex significantly modified the increased risk of AF associated with loneliness. Specifically, female participants appeared to endure the more detrimental effect of being lonely. Furthermore, the top mediator of the association between loneliness and incident AF was obesity (20.3 percent), followed by current smoking (8.4 percent) and sleep deprivation (7.6 percent).

“Loneliness was independently associated with a higher risk of incident AF, which was mediated by unhealthy behaviours,” Zeng said.

These results were consistent with those of a recently published study that also used data from the UK Biobank. Researchers led by Dr Zechen Liu from the Chinese Academy of Medical Sciences and Peking Union Medical College in Beijing, China, observed a higher risk of AF (HR, 1.11, 95 percent CI, 1.07?1.16) among individuals who reported loneliness than those who did not. [Eur J Med Res 2024;29:508]

“Our findings reveal a robust positive link between loneliness and the long-term risk of AF, particularly pronounced in individuals without valvular disease,” Liu said. “Notably, the association between loneliness and AF risk remained significant regardless of genetic susceptibility, highlighting loneliness as an independent cardiovascular risk factor.”