E. Colman et al., THE ROLE OF OBESITY AND CARDIOVASCULAR FITNESS LN THE IMPAIRED GLUCOSE-TOLERANCE OF AGING, Experimental gerontology, 30(6), 1995, pp. 571-580
The prevalence of impaired glucose tolerance (IGT) increases with agin
g. Although some data suggest that age is independently associated wit
h IGT, other studies suggest that age-associated changes in body compo
sition and reduced cardiovascular fitness are responsible for the deve
lopment of IGT. We, therefore, examined the relationship of age, total
and regional adiposity, and level of fitness (VO(2)max) to the presen
ce of IGT in 155 healthy, nondiabetic, nonsmoking, older community dwe
lling men. Sixty-two of 155 men (40%) had IGT, while 93 men (60%) had
normal glucose tolerance (WHO criteria). The subjects with IGT were of
similar age (61.0 +/- 1.0 vs. 59.0 +/- 0.7 years, p = 0.49) and had t
he same maximal aerobic capacity, (VO(2)max) (42 0 +/- 1.0 vs. 44.0 +/
- 0.8 mL/kg ffm/min, p = 0.42), but had a higher waist to hip ratio (W
HR) (0.98 +/- 0.01 vs. 0.96 +/- 0.01, p = 0.005) and percent body fat
(30.0 +/- 0.4 vs. 26.0 +/- 0.6, p = 0.004) than the men with normal gl
ucose tolerance. In univariate analysis, the 2-h glucose level correla
ted positively with percent body fat (r = 0.30, p = 0.0002), WHR (0.24
, p = 0.002), and age (r = 0.17, p = 0.03) and negatively with VO(2)ma
x (r = -0.23, p = 0.005). In both multiple logistic and linear regress
ion analyses, percent body fat was the only independent predictor of I
GT (p = 0.002). These results suggest that the age-associated increase
in total adiposity is a major contributor to the development of IGT i
n middle-aged and older men. Thus, lifestyle modifications that reduce
body fat should reduce the risk for IGT and the development of nonins
ulin-dependent diabetes mellitus in the elderly.