Walking more – not faster – can significantly lower the risk of heart failure in older women, according to the first ever study on the subject.
The study, involving more than 137,000 women aged 50 to 79, confirmed that exercise lowers the overall risk of heart failure by 25 percent.
It was also the first paper to show movement appeared to work just as well as drugs at lowering the risk of two hard-to-treat sub-types of heart failure – one linked to heart attacks and the other with high blood pressure or diabetes.
The researchers said their findings suggest that it’s the amount, not the intensity, of physical activity performed that matters, and to the relief of many, walking is one of the most effective methods.
Scores of studies have looked at how exercise affects risk of heart attacks and high blood pressure. But none had addressed heart failure, and very few had addressed women.
‘This is the first study to report physical activity levels are related to a lower risk of developing heart failure in older adults, particularly in women,’ lead author Dr Michael LaMonte, associate professor of epidemiology at the University at Buffalo School of Public Health and Health Professions, said: ‘This is pretty important from a public health standpoint, given the poor prognosis this type of heart failure has once it’s present.’
Heart failure disproportionately affects older adults, with around four out of five cases occurring in people 65 or older, an age group for whom heart failure is the leading cause of hospitalization.
It is measured by the American Heart Association using something called ‘ejection fraction’, which assesses how well a person’s heart is pumping out (ejecting) blood.
A number of factors can slow down that pumping rate, reducing their ‘ejection fraction’ to dangerous levels.
Dr LaMonte said reduced ejection fraction heart failure typically occurs in people who’ve had a heart attack.
The heart becomes a poorer pump, which leads to related complications, including the failure of other organs and, in a worst-case scenario, the need for a heart transplant or even sudden cardiac death.
Heart failure with ‘preserved ejection fraction’ tends to occur in people who haven’t had a heart attack, but do have high blood pressure or diabetes.
Dr LaMonte said: ‘The heart muscle more or less wears out and becomes an inefficient pump, although not to the extreme seen with reduced ejection fraction.’
The research team examined self-reported physical activity information from 137,303 participants in the Women’s Health Initiative (WHI), a long-term study that has yielded important findings on death and disease risk in postmenopausal women.
They then looked at a subset of 35,272 women who had either reduced ejection fraction or preserved ejection fraction heart failure.
Over an average 14-year follow-up, there were 2,523 cases of heart failure, including 451 with reduced ejection fraction and 734 with preserved ejection fraction.
As part of their analysis, the researchers accounted for heart attack development prior to the heart failure diagnosis.
Dr LaMonte said that’s critical because heart attack after the completion of the physical activity assessment, but before the diagnosis of heart failure, could lead to biased results by suggesting a stronger relationship than would be the case.
He said: ‘By accounting for this, our results are likely not being influenced in this regard.
‘We also showed that the protective relationship between physical activity and heart failure development held when we examined changes in physical activity levels over time.’
The cumulative incidence of overall heart failure was lower with increasing physical activity, compared to women who reported no physical activity at the start.
Each additional 30 to 45 minutes per day of activity was associated, on average, with a risk reduction of nine per cent for overall heart failure, eight per cent for heart failure with preserved ejection fraction and 10 percent for heart failure with reduced ejection fraction.
Physical activity and walking were inversely associated with the development of heart failure, whereas intensity-specific – mild, moderate, intense – physical activity was not.
Dr LaMonte said: ‘The finding that walking showed a protective association with heart failure and its subtypes is particularly important in a public health context.
‘This is especially relevant given that walking is by far the most commonly reported physical activity in older adults.’
He added: ‘Because heart failure is much more common after age 60, and because its treatment is very challenging and costly, the possibility of preventing its development by promoting increased physical activity levels, and specifically walking, in later life could have an important impact on the overall burden of this disease in an ageing society.’
The take home message, according to Dr LaMonte, is ‘move more, sit less, which is probably prudent advice for us all.’
The findings were published online by the Journal of the American College of Cardiology: Heart Failure.
5 September 2018