Authors
Kohl HW. Gordon NF. Villegas JA. Blair SN.
Institution
Division of Epidemiology, Institute for Aerobics Research, Dallas, Texas
75230.
Title
Cardiorespiratory fitness,
glycemic status, and mortality risk in men.
Source
Diabetes Care. 15(2):184-92, 1992 Feb.
Abstract
OBJECTIVE--To determine the association of baseline
cardiorespiratory fitness to all-cause mortality across the
range of blood glucose levels. RESEARCH DESIGN AND METHODS--Data from a
prospective study of 8715 men (average age 42 yr), followed for an average of
8.2 yr (range 1-15 yr), were analyzed. Cardiorespiratory
fitness was assessed by maximal-exercise treadmill testing. Men with evidence
of clinical vascular disease or who did not achieve 85% of their
age-predicted maximum heart rate during exercise testing were excluded from
analyses. RESULTS--Age-adjusted death rates increased with higher levels, of
fasting blood glucose. Regardless of glycemic status, fit
men had lower age-adjusted all-cause death rates than their less fit
counterparts. For men with fasting blood glucose greater than or equal to 7.8
mM or physician-diagnosed non-insulin-dependent diabetes mellitus (NIDDM),
the age-adjusted death rates per 10,000 person-yr of follow-up in unfit and
fit subjects were 82.5 and 45.9, respectively. The age-adjusted relative risk
of death due to all causes was significantly elevated in the lower-fitness
group within each of three glycemic status levels: fasting
blood glucose less than 6.4 mM; relative risk (RR) = 1.93 (95% confidence
interval [95% CI] 1.15-3.26); fasting blood glucose 6.4-7.8 mM; RR = 3.42
(95% CI 2.27-5.15); and fasting blood glucose greater than or equal to 7.8 mM
or with NIDDM, RR = 1.80 (95% CI = 1.25-2.58). Multivariate analyses,
controlling for risk factors of mortality (age, resting systolic blood
pressure, serum cholesterol, body mass index, family history of heart
disease, follow-up interval, and smoking habit) showed a higher risk of death
due to all causes for unfit compared with fit men. Multivariate risks of
death associated with low fitness, compared with higher
fitness (RR), in the three glycemic status groups were:
fasting blood glucose less than 6.4 mM, RR = 1.38 (95% CI 1.09-1.74); fasting
blood glucose 6.4-7.8 mM, RR = 1.61 (95% CI 0.91-2.86); and fasting blood
glucose greater than or equal to 7.8 mM or with NIDDM, RR = 1.92 (95% CI
0.75-4.90).