Exercise capacity and all-cause mortality in African American and Caucasian men with type 2 diabetes.
OBJECTIVE
The purpose of this study was to assess the association between exercise capacity and mortality in African Americans and Caucasians with type 2 diabetes and to explore racial differences regarding this relationship.


METHODS
African American (n = 1,703; aged 60 +/- 10 years) and Caucasian (n = 1,445; aged 62 +/- 10 years) men with type 2 diabetes completed a maximal exercise test between 1986 and 2007 at the Veterans Affairs Medical Centers in Washington, DC, and Palo Alto, California. Three fitness categories were established (low-, moderate-, and high-fit) based on peak METs achieved. Subjects were followed for all-cause mortality for 7.3 +/- 4.7 years.


RESULTS
The adjusted mortality risk was 23% higher in African Americans than in Caucasians (hazard ratio 1.23 [95% CI 1.1-1.4]). A graded reduction in mortality risk was noted with increased exercise capacity for both races. There was a significant interaction between race and METs (P < 0.001) and among race and fitness categories (P < 0.001). The association was stronger for Caucasians. Each 1-MET increase in exercise capacity yielded a 19% lower risk for Caucasians and 14% for African Americans (P < 0.001). Similarly, the risk was 43% lower (0.57 [0.44-0.73]) for moderate-fit and 67% lower (0.33 [0.22-0.48]) for high-fit Caucasians. The comparable reductions in African Americans were 34% (0.66 [0.55-0.80]) and 46% (0.54 [0.39-0.73]), respectively.


CONCLUSIONS
Exercise capacity is a strong predictor of all-cause mortality in African American and Caucasian men with type 2 diabetes. The exercise capacity-related reduction in mortality appears to be stronger and more graded for Caucasians than for African Americans.
Kokkinos
Peter
P
Veterans Affairs Medical Center, Washington, DC, USA. peter.kokkinos@va.gov
Myers
Jonathan
J
Nylen
Eric
E
Panagiotakos
Demosthenes B
DB
Manolis
Athanasios
A
Pittaras
Andreas
A
Blackman
Marc R
MR
Jacob-Issac
Roshney
R
Faselis
Charles
C
Abella
Joshua
J
Singh
Steven
S
D000368:Aged; D044383:Black People / Q000706:statistics & numerical data*; D001794:Blood Pressure; D002140:California / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000401:mortality* / Q000503:physiopathology*; D003925:Diabetic Angiopathies / Q000453:epidemiology; D004219:District of Columbia / Q000453:epidemiology; D015444:Exercise; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness; D044465:White People / Q000706:statistics & numerical data*; D001741:Black or African American