medwireNews : Middle-aged people who have a high level of physical fitness have a significantly lower and later incidence of chronic conditions in old age than those who are less fit, report researchers.
“We’ve determined that being fit is not just delaying the inevitable, but it is actually lowering the onset of chronic disease in the final years of life,” said study author Jarett Berry (University of Texas, Dallas, USA) in a press statement.
Berry and co-researchers followed up 18,670 healthy middle-aged individuals (21.1% women; median age 49 years) who were enrolled in the Cooper Center Longitudinal Study for a median period of 26 years to examine the combined incidence of eight chronic conditions.
Chronic conditions included congestive heart failure, ischemic heart disease, stroke, Type 2 diabetes, chronic obstructive pulmonary disease, chronic kidney disease, Alzheimer’s disease, and colon or lung cancer. At baseline, the participants were divided into quintiles depending on their degree of fitness (ie 1=lowest fitness; 5=highest fitness).
As reported in the Archives of Internal Medicine , the team found that men and women in the top quintile for fitness had a significantly lower combined incidence of chronic conditions over the follow-up period than those in the bottom. More specifically, men in quintile 5 versus 1 had combined chronic disease incidences of 15.6 versus 28.2 per 100 person-years and women in the corresponding quintiles had incidences of 11.4 versus 20.1 per 100 person-years.
Following multivariate adjustment, each 1 metabolic equivalent (MET; 3.50 mL oxygen per kg/min) increase in physical fitness reduced a man’s risk for developing a chronic condition by 5% and a women’s by 6%, both of which reductions were statistically significant.
The morbidity compression ratio, comparing age of chronic condition development with age at death, was also 10% lower per additional MET of fitness for men and women. This means that those with higher levels of fitness in midlife did not live longer than those with lower fitness levels, but had a significant delay in the age of onset of chronic conditions.
“What sets this study apart is that it focuses on the relationship between midlife fitness and quality of life in later years. Fitter individuals aged well with fewer chronic illnesses to impact their quality of life,” said co-author and fellow researcher at The University of Texas Benjamin Willis.
“In addition to observational studies such as the present one, clinical trials are needed to establish definitively the benefits and risks of approaches that have been shown in observational studies to be associated with extending health and life,” says Diane Bild (National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA), the author of an accompanying commentary.
By Helen Albert, Senior medwireNews Reporter