Loneliness is bad for the heart and a strong predictor of premature death, according to a study presented today at EuroHeartCare 2018, the European Society of Cardiology’s annual nursing congress. The study found that feeling lonely was a stronger predictor of poor outcomes than living alone, in both men and women.

“Loneliness is more common today than ever before, and more people live alone,” said Anne Vinggaard Christensen, study author and PhD student, The Heart Centre, Copenhagen University Hospital, Denmark. “Previous research has shown that loneliness and social isolation are linked with coronary heart disease and stroke, but this has not been investigated in patients with different types of cardiovascular disease.”

The study investigated whether poor social network was associated with worse outcomes in 13,463 patients with ischaemic heart disease, arrhythmia (abnormal heart rhythm), heart failure, or heart valve disease.

Data from national registers was linked with the DenHeart survey, which asked all patients discharged from April 2013 to April 2014 from five heart centres in Denmark to answer a questionnaire about their physical and mental health, lifestyle factors such as smoking, and social support, Science Daily reported.

Social support was measured using registry data on living alone or not, and survey questions about feeling lonely — Do you have someone to talk to when you need it? Do you feel alone sometimes even though you want to be with someone? “It was important to collect information on both, since people may live alone but not feel lonely while others cohabit but do feel lonely,” explained Ms Vinggaard Christensen.

Feeling lonely was associated with poor outcomes in all patients regardless of their type of heart disease, and even after adjusting for age, level of education, other diseases, body mass index, smoking, and alcohol intake. Loneliness was associated with a doubled mortality risk in women and nearly doubled risk in men. Both men and women who felt lonely were three times more likely to report symptoms of anxiety and depression, and had a significantly lower quality of life than those who did not feel lonely.

“Loneliness is a strong predictor of premature death, worse mental health, and lower quality of life in patients with cardiovascular disease, and a much stronger predictor than living alone, in both men and women,” said Ms Vinggaard Christensen.

Ms Vinggaard Christensen noted that people with poor social support may have worse health outcomes because they have unhealthier lifestyles, are less compliant with treatment, and are more affected by stressful events. But she said: “We adjusted for lifestyle behaviours and many other factors in our analysis, and still found that loneliness is bad for health.”

She concluded: “We live in a time when loneliness is more present and health providers should take this into account when assessing risk. Our study shows that asking two questions about social support provides a lot of information about the likelihood of having poor health outcomes.”

European guidelines on cardiovascular prevention state that people who are isolated or disconnected from others are at increased risk of developing and dying prematurely from coronary artery disease. The guidelines recommend assessment of psychosocial risk factors in patients with established cardiovascular disease and those at high risk of developing cardiovascular disease.

The findings suggest hundreds of thousands should be given statins or other heart pills if they suffer a chest infection or bladder problem.

A project tracking 1.2million patients found those admitted to hospital for pneumonia or urinary tract infections were 40 % more likely to have a heart attack within eight years. They were also 150 % more likely to suffer a stroke, Daily Mail reported.

This suggests infections have an even greater impact on heart health than obesity, which raises the risk of strokes and heart attacks by about 25 %.

The research team, from Aston Medical School in Birmingham and the University of Cambridge, believe this is because infections cause long-term inflammation in blood vessels – making them more prone to clotting and clogging.

Patients who suffer an infection should be treated in the same way as someone with high blood pressure, raised cholesterol or diabetes, the researchers said. This could involve prescribing statins or aspirin as a preventive measure to cut the risk to their heart.

Nearly 600,000 people are admitted to hospital with chest infections such as pneumonia in England every year. About 300,000 are admitted with urinary infections.

The study, which will be presented today at the American College of Cardiology conference in Orlando, also found that those who had had infections were more likely to die if they did suffer a heart attack or stroke.

They were three times more likely to die from a heart attack than those who had not had infections, and almost twice as likely to die if they had a stroke.

Cardiologist Dr Rahul Potluri, of Aston University, said: ‘Our figures suggest that those who are admitted to hospital with a respiratory or urinary tract infection are 40 per cent more likely to suffer a subsequent heart attack, and 2.5 times more likely to have a stroke, than patients who have had no such infection – and are considerably less likely to survive from these conditions.’

Experts have shown greater interest in the role of inflammation in heart disease after a study last year found that treating patients with anti-inflammatory canakinumab could cut their risk of having a heart attack by 24 per cent. Doctors say this drug – not yet available for heart patients – could represent the biggest breakthrough in cardiovascular medicine since statins were developed 30 years ago.

Dr Potluri said: ‘Infection appears to confer as much, if not more, of a risk for future heart disease and stroke as very well established risk factors such as high blood pressure and diabetes.

‘Although inflammation has been linked to atherosclerosis [when plaque builds up in arteries], this is the largest study to show that common infection is such a significant risk factor.’

Lead author Dr Paul Carter, an academic clinical fellow at the University of Cambridge, said: ‘The data illustrate a clear association between infections and life-threatening heart conditions and strokes – and the figures are too huge to ignore.

‘Serious infections are amongst the biggest causes of death in the UK directly, but our research shows infections that are severe enough to lead to hospitalisation may present a delayed risk in the form of atherosclerotic diseases.

‘The sheer number of people who could be affected presents a challenge that needs investigation.’