has found that the health benefits of physical activity may be strong enough to outweigh the impact of being overweight or obese on cardiovascular disease in middle-aged and elderly people.
Carried out by a team from the Department of Epidemiology, Erasmus University Medical Centre, Rotterdam, the Netherlands, the observational study looked at more than 5,344 participants aged 55 to 97 years of age (average 70 years) and free of cardiovascular disease at the start of the research, who were followed for 15 years.
The team collected information from the participants about BMI, physical activity, smoking, alcohol use, diet, education, and family history of premature heart attack.
Participants were then categorized into groups according to their BMI: normal (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2) and obese (>30 kg/m2); and physical activity, low and high.
With 16 per cent experiencing a cardiovascular event in the 15-year period, analysis showed that physical activity on its own was associated with a decreased risk of cardiovascular disease, regardless of BMI category.
However there was no association between BMI alone and cardiovascular disease.
When the team analyzed the effect of physical activity and BMI combined, they found that in comparison to normal weight people with high physical activity levels (the ideal combination), overweight or obese individuals with high levels of physical activity were not at an increased risk of cardiovascular disease.
However overweight or obese people with low levels of physical activity had a higher risk for developing cardiovascular disease.
The results led the team to conclude that it is physical activity rather than a normal BMI that has a protective effect on cardiovascular risk, explaining that being overweight and obese increases cardiovascular risk by accelerating atherosclerosis -- the hardening of the arteries -- whereas physical activity helps to protect from atherosclerosis.
While the group was particularly active, with 'low' and 'high' levels of activity representing two and four hours a day, author Dr Klodian Dhana points out that "any physical activity is positive for cardiovascular health and in elderly people of all weights walking, biking and housework are good ways to keep moving. European guidelines recommend 150 minutes a week of moderate intensity physical activity to decrease the risk of cardiovascular disease."
The findings can be found published online in the .
