Research at the Australian National University has found increased body mass index (BMI) significantly increases the risk of heart disease – regardless of exercise level, smoking status and whether or not someone has diabetes.
Over 158,000 Australian participants of the Sax Institute's 45 and Up Study with no history of cardiovascular disease were tracked over four years to see how incremental increases in body mass index increased their risk of going to hospital for a range of cardiovascular diseases.
The study found even relatively minor increases in BMI come with increased cardiovascular risk.
"The risk of heart attack and angina increased by 23 per cent with each 5 unit increase in BMI," said lead author of the paper outlining the study, Dr Grace Joshy of the National Centre for Epidemiology and Population Health (NCEPH) at ANU.
"The lowest risk is for a BMI from 20 – 22.5 and then it increases gradually from there. For moderately overweight people, the risk is 43% higher. For a BMI of above 32.5, the risk of heart attack and angina is more than doubled."
"We used to think that it was only people with very serious weight problems that were at an elevated risk of heart disease," said senior author Professor Emily Banks of NCEPH and the Sax Institute.
"These are the first large-scale Australia data to show us that there is no 'safe' level of overweight, when it comes to heart disease. The increase in risk was found in people who did and did not exercise, those with and without diabetes and in urban, rural and remote areas."
"If you want to minimise your risk you need to pay attention to your weight. It's a serious matter and it does impact your risk of cardiovascular disease," said Professor Banks.
"Improving your odds is alright in a horse race but the race to a heart attack is certainly not one you would want to win," said Dr Rob Grenfell, Heart Foundation National Director, Cardiovascular Health.
"This study highlights that as you put more weight on you become more at risk of doing real damage to your heart. Which is why it's incredibly important for all Australians to manage their blood pressure, cholesterol and blood sugar levels, stop smoking, exercise daily and eat a healthy diet," said Dr Grenfell.
The 45 and Up Study is managed by the Sax Institute in collaboration with partners: Cancer Council NSW; National Heart Foundation of Australia (NSW Division); NSW Ministry of Health; beyondblue; Ageing, Disability and Home Care, Department of Family and Community Services NSW; the Australian Red Cross Blood Service; and UnitingCare Ageing.