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Is There a Gradient of Mortality Risk among Men with Low Cardiorespiratory Fitness?

Stephen W Farrell1, Carrie E Finley, William L Haskell

  • 11Research Division, Cooper Institute, Dallas, TX; 2Department of Medicine, Stanford University, Palo Alto, CA; and 3Center for Human Nutrition, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX.

Medicine and Science in Sports and Exercise
|January 1, 2015
PubMed

Insights

Even within the lowest cardiorespiratory fitness (CRF) category, men with the least fitness (LL CRF) face the highest all-cause mortality risk. Improving fitness, especially for the LL CRF group, is crucial for reducing mortality.

Area of Science:

  • Cardiology
  • Preventive Medicine
  • Exercise Physiology

Background:

  • Low cardiorespiratory fitness (CRF) is a significant predictor of all-cause mortality in men.
  • Previous research has established a link between low CRF and increased mortality risk.
  • However, the specific mortality gradient within the lowest CRF category remained unclear.

Purpose of the Study:

  • To investigate whether a gradient of all-cause mortality risk exists within the lowest cardiorespiratory fitness (CRF) category in men.
  • To determine if specific subgroups within the low CRF classification experience differential mortality rates.
  • To provide evidence for targeted physical activity interventions.

Main Methods:

  • A cohort of 6251 healthy men (aged 40-69) underwent maximal treadmill exercise testing.
  • Low CRF was defined as treadmill time in the lowest quintile for each age group.
  • The low CRF cohort was further stratified into three tertiles: low/low (LL), mid/low (ML), and high/low (HL).

Main Results:

  • Over a mean follow-up of 19.1 years, 1259 deaths occurred.
  • Adjusted mortality rates per 10,000 man-years were highest in the LL CRF group (57.0), followed by ML (31.1) and HL (34.4) for the 40-49 age group (P trend = 0.007).
  • Similar inverse trends were observed in other age groups, and each 1-minute increase in treadmill time reduced mortality risk by 9-15%.

Conclusions:

  • A discernible inverse trend in all-cause mortality exists across the low, mid-low, and high-low cardiorespiratory fitness groups.
  • While all men with low CRF benefit from physical activity interventions, those in the lowest CRF (LL) category require particular attention.
  • Targeting the LL CRF group is especially important for mortality risk reduction.
Abstract

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