More evidence in favour of a healthy lifestyle in the prevention of cardiovascular disease

As the ESC Congress 2009 draws ever closer, the evidence in favour of a healthy lifestyle for the prevention of cardiovascular disease grows ever stronger. Prevention is the highlight theme of this year's event, which will take place in Barcelona from 29 August to 2 September. Lifestyle factors are heavily on the agenda.

There is now a substantial body of evidence showing that the adoption of a healthy lifestyle pays huge rewards in the prevention of cardiovascular disease. Indeed, a report in JAMA this week suggests that men who exercised regularly, drank moderately, did not smoke, were not overweight and had a diet that included cereal, fruits and vegetables had a lower lifetime risk of heart failure.(1) The findings have major public health implications, with heart failure now recognised as the leading cause of acute hospital admission and the most prevalent chronic cardiovascular condition.

According to an editorial in the same issue of JAMA, mortality rates after the onset of heart failure remain high, ranging from 20-50 per cent, despite improvements in medical and surgical management.(2) With the outlook so bleak for heart failure patients, the possibility that pursuing a healthy lifestyle may help reduce lifetime risk of heart failure is an important finding.

The study reported in JAMA - from the Physicians' Health Study in the USA - included data from 20,900 men who were followed up for an average of 22.4 years. The researchers found that normal body weight, never smoking, regular exercise, moderate alcohol intake, and consumption of breakfast cereal, fruits and vegetables were individually associated with a lower lifetime risk of heart failure than was "undesirable behaviour". There was an inverse association between the number of healthy lifestyle factors and lifetime risk of heart failure. "For example, the lifetime risk for heart failure was approximately 1 in 5 (21.2 per cent) in men adhering to none of the desirable lifestyle factors, compared to 1 in 10 (10.1 percent) in those adhering to 4 or more healthy lifestyle factors," the authors write.

A second study in the same issue of JAMA found that adherence to modifiable lifestyle factors was also associated with a significantly lower incidence of hypertension in women.(3) The findings emerged from the Nurses' Health Study, one of the world's landmark studies in women's health epidemiology, which included more than 80,000 women.

Six modifiable lifestyle factors (normal BMI, daily vigorous exercise, diet, modest alcohol intake, non-narcotic analgesics and folic acid supplementation) were all independently associated with lower blood pressure. Women who had all six low-risk factors (just 0.3 per cent of the study population) had an 80 per cent lower risk of developing high blood pressure.

This study too, says ESC spokesman Professor Joep Perk from Oskarshamn District Hospital in Sweden, has important public health implications, with women somewhat neglected in many of the prevention studies reported. "This is an important piece of evidence," says Professor Perk, "where we don't always have information specifically related to women. The Nurses' Health Study is an observational study, but because of the numbers involved I'm sure the results will be valid in broader female populations."

Professor Perk also noted the 80 per cent reduced risk of hypertension in those few women adhering to all six lifestyle factors studied. This, he explained, is a proportional benefit similar to that found in the Interheart study, the 2004 global study led by McMaster University in Canada, which showed that 90 per cent of first heart attacks were attributable to nine risk factors, all related to lifestyle. "So there's a consistent pattern here," explains Professor Perk, "suggesting that four out of five cases of hypertension or heart attack are amenable to lifestyle intervention. So, most of us can do something about prevention. It's a public health issue, and we need to put our heads together."

Professor Perk also reaffirmed the three essential lifestyle messages of the ESC Guidelines on CVD Prevention: no smoking, physical activity for at least 30 minutes a day, and maintenance of a normal BMI through exercise and appropriate calorie intake. "These two studies yet again confirm the wisdom of this advice," says Professor Perk, "and provide even more evidence to translate our knowledge into action."

A session on the female heart, which includes the impact of lifestyle factors (as well as an update on postmenopausal hormone therapy and statins in women), is one of 50 separate sessions on prevention in the prearranged scientific programme of this year's ESC Congress. The congress itself - the world's largest meeting in cardiovascular disease - will attract more than 30,000 participants with presentations drawn from more than 9000 abstracts submitted.

Bibliographic References:

1. Djoussé L, Driver JA, Gazioano JM. Relation between modifiable lifestyle factors and lifetime risk of heart failure. JAMA 2009; 302: 394-400.

2. Roger V. Lifestyle and cardiovascular health. JAMA 2009; 302: 437-439.

3. Forman JP, Stampfer MJ, Curhan GC. Diet and lifestyle risk factors associated with incident hypertension in women. JAMA 2009; 302: 402-411.