Exercise more important than weight loss in people with CHD
The study observed 3307 people (1038 women) with CHD from the Nord-Trøndelag Health Study (HUNT) which is Norway’s largest collection of anonymized health information available for research in over 120,000 individuals. These patients were examined in 1985, 1996 and 2007, and followed up to the end of 2014. The data from HUNT were compared with data from the Norwegian Cause of Death Registry.
Participants in the study were divided into three categories: inactive; slightly physically active, but below recommended activity level; and physically active at or above recommended activity level (at least 150 minutes per week of moderate physical activity or 60 minutes per week of vigorous physical activity).
During the 30-year period, 1493 of the participants died and 55% of the deaths were due to cardiovascular disease. The study revealed that people who are physically active live longer than those who are not. Sustained physical activity over time was associated with substantially lower mortality risk. The risk of premature death was higher for the group of patients who were completely inactive than for either of the other groups. The prognosis for people who exercise a little bit, even if it is below the recommended level, is better than not exercising at all.
The findings in the study showed higher mortality among normal weight heart patients who lost weight. This was an observational study that did not focus on underlying causes, so these patients who lost weight may have been more ill. Despite the strong causal relationship between CVD and obesity, the results from the study indicate that people with CVD who have a body mass index above the normal weight range have better prognoses. This is often called the obesity paradox. So, clearly randomized controlled trials are needed to prove causality.
This study highlights the importance of regular exercise which has a beneficial effect on all organs in the body, rather than a focus on weight loss in patients with CVD. Intentional weight reduction may be useful for overweight or obese individuals, although there is little data to support this view in studies of coronary heart disease patients.
Moholdt T, Laview C, Nauman J. Sustained physical activity, not weight loss, associated with improved survival in coronary heart disease. J Am Coll Cardiol 2018;71(10): DOI: 10.1016/j.jacc.2018.01.011 https://www.ncbi.nlm.nih.gov/pubmed/29519349