A little exercise prolongs life expectancy for people with heart disease

Exercising once a week can help prolong life expectancy for people with heart disease according to a new study from the Norwegian University of Science and Technology (NTNU) in Trondheim, Norway.

Patients with established coronary heart disease (CHD) are encouraged to be physically active to prevent disease progression and prolong their life expectancy. But how much exercise is required?

A study to be published in the European Journal of Cardiovascular Prevention & Rehabilitation concludes that one weekly exercise session is associated with lower all-cause mortality, both in women and men.

• The most important finding was that CHD patients lived longer even though they exercised only once a week, says Trine Moholdt a PhD student at the Department of Circulation and Medical Imaging at the Faculty of Medicine, NTNU.

The study is based on data collected in the Nord-Trøndelag Health Study (HUNT). Here, 3500 women and men with CHD were studied over an 18-year period.

Unique study

• Mortality decreased by 30 per cent among women who exercised once a week compared to those who did not exercise at all. For men the corresponding figure was 20 per cent, states Trine Moholdt.

This study is unique because it includes women and older CHD patients with heart conditions. In fact women who exercise more than 30 minutes each time can decrease mortality by up to 50 per cent.

• The more intense the exercise is, the better, Tine Moholdt adds. She hopes more cardiac patients start working out. A lot of people are apprehensive about exercise after a myocardial infarction. But it is more risky to be inactive than to do exercise.

HUNTing for data

The HUNT data, which this study is based on, is a population-based study launched in 1984 in the county of Nord-Trøndelag in mid-Norway. More than 100,000 people have participated in the study out of a total of 130,000 inhabitants in the region.

• We have extensive data from the population of Nord-Trøndelag through three comprehensive health surveys in 1984-86, 1995-97 and 2006-2008. The homogeneous and stable population of Nord-Trøndelag is a unique source of health information and biological material, says the director of HUNT biobank, Professor Kristian Hveem of the Faculty of Medicine, NTNU. - The fact that already in 1984 we collected health information and exposure data, then repeated this ten and twenty years later, enables us to establish some causal relationship between this early information and clinical disease outcome as exemplified in this study on coronary heart patients.
• It is satisfactory to see that the data we collected in 1984 are still a very valuable resource in research today. Also, in the most recent collection of HUNT data, completed in June 2008, we have applied a strict QA-protocol to make sure that the collected biological material has the best quality. This ensures its applicability for a wide variety of analyses in the years to come, says Professor Hveem.

A gold mine of biological material

Professor Hveem will present the HUNT Biobank in Washington at the Transatlantic Science Week 2008 in late October. The Norwegian Embassies in Washington DC and Ottawa are responsible for the Science Week. This is a collaborative effort with US and Canadian institutions, the Research Council of Norway, Innovation Norway and the Carnegie Institution for Science. The Science Week is a meeting place for cooperation in research, innovation and higher education.

The HUNT Study collaborates with national and international research groups on some of the most important health challenges facing the world today. These include cancer, diabetes, obesity, mental illness, migraine, cardiovascular and musculoskeletal disease.

• The HUNT Study is a gold mine for researchers. HUNT has compiled extensive medical, lifestyle and environmental data comprising about 800 exposure variables and nearly 3000 different variables per individual, says Professor Stig Slørdahl, Dean of the Faculty of Medicine, NTNU, and also one of the authors of the exercise study.
• The fact that most of the population of Nord-Trøndelag has participated in the three studies from 1984 until today, adds value to the HUNT Study.