A new study published in the Journal of Epidemiology & Community Health, a sub-journal of the BMJ, by researchers at the University of Copenhagen in Denmark, shows that living alone for a long time or breaking up multiple times is closely associated with increased levels of inflammatory markers in the blood of men, increasing the risk of death.
In the study, researchers analyzed 4,835 participants in the Copenhagen Ageing and Midlife Biobank (CAMB), assessing the effect of the number of breakups or years of living alone on immune system responses in midlife, and whether gender and educational attainment make a difference.
Of all participants, 4612 (3170 men and 1442 women) provided information on consecutive breakups and 4835 (3336 men and 1499 women) provided information on years living alone, which were defined as: control group (less than 1 year), 2-6 years, 7 years, and longer. Inflammatory markers were measured in all participants, interleukin 6 (IL-6) and C-reactive protein (CRP) were measured in blood samples.
The analysis found that about 50 percent of the participants experienced a breakdown in their partnership, and 50 percent lived alone for more than a year. The study found that among men, those with the highest levels of inflammatory markers were those who had experienced the most number of relationship breakdowns, and their levels were 17 percent higher than those in the control group. Likewise, those who lived alone for more than seven years also had 12 percent higher levels of inflammatory markers than the control group.
In addition, the highest levels of both inflammatory markers were observed in men with hyperlipidemia who lived alone for many years. Living alone for 2-6 years has the highest C-reactive protein; living alone for 7 years or more has the highest interleukin-6. Importantly, these findings were only observed in men and not in women.
The researchers noted that men were more prone to behavioral behaviors, such as drinking alcohol, after a relationship broke up. Women, on the other hand, tend to internalize, manifesting as depressive symptoms, which may affect inflammatory levels in different ways. Also, the study included a relatively small number of women (1499), which may also explain the difference.
The researchers emphasized that the study was an observational study, so it was impossible to determine the cause. The weakening of the immune system with age, often resulting in systemic low-grade inflammation, is thought to play a key role in some age-related diseases such as cancer, cardiovascular disease and type 2 diabetes. The studies have shown that long-term solitary living and multiple break-ups significantly affect inflammatory markers CRP and IL-6 levels, although not at high levels, they are clinically relevant and likely to be a risk factor for increased mortality.