VA Study Defines Optimum Exercise Capacity Threshold By Age

Peter Kokkinos PhD Veterans Affairs Medical Center, Cardiology Division Washington, DC 20422MedicalResearch.com Interview with:
Peter Kokkinos PhD
Veterans Affairs Medical Center, Cardiology Division
Washington, DC 20422

Medical Research: What are the main findings of the study?

Dr. Kokkinos: The main finding of the study is that we defined an exercise capacity threshold for each age category (<50; 50-59; 60-69; and ≥70 years of age). The mortality risk increases progressively below this threshold and decreases above it. We then calculated the 5 and 10-year mortality risk for each age category.

Medical Research: Were any of the findings unexpected?

Dr. Kokkinos: The unexpected findings of this study were:

  • 1) the strength of the impact of fitness across all age categories, including those ≥70 years;
  • 2) Exercise capacity 2 or more METs below the threshold (Least and Low fitness categories) had a more pronounced unfavorable impact in younger than older individuals. However, the favorable impact of exercise capacity above the age-specific category was similar across all age categories.

Medical Research: What should clinicians and patients take away from your report?

Dr. Kokkinos: Prior to this study, we knew that exercise capacity, estimated in METs (metabolic equivalents) by a standardized exercise test, was inversely associated with mortality risk. That is, the lower the exercise capacity the higher the risk of premature death. However, we did not know the exercise capacity threshold beyond which risk changed. Furthermore, since exercise capacity is strongly influenced by age, this elusive threshold was likely to be different for different age categories. The aim of the study was to define the exercise capacity threshold for each age category and then quantify the risk associated below and above this threshold. Health care professionals can now use this threshold to quantify the 5 and 10-year mortality risk for each patient undergoing an exercise tolerance test.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Kokkinos: The cohort of the current study consisted of 18,102 male veterans. Future studies should be conducted for females and perhaps for individuals with different chronic conditions such as hypertension, type 2 diabetes mellitus and obesity.

Citation:

Age-Specific Exercise Capacity Threshold for Mortality Risk Assessment in Male Veterans

Peter Kokkinos, Charles Faselis, Jonathan Myers, Xuemei Sui, Jiajia Zhang, and Steven N. Blair

Circulation. 2014;CIRCULATIONAHA.114.009666published online before print June 17 2014, doi:10.1161/CIRCULATIONAHA.114.009666

Last Updated on July 7, 2014 by Marie Benz MD FAAD