HOUSTON – Physical fitness nearly halved the risk of death in men with type 2 diabetes, regardless of whether they had left ventricular hypertrophy, a longitudinal study of 866 patients found.
During a follow-up period as long as 24 years (with a median 9-year follow-up), 236 men who had left ventricular hypertrophy and were within the lower 50th percentile of physical fitness were 20% more likely to die, compared with 225 men in a reference group who did not have left ventricular hypertrophy and also had a low level of fitness. The difference in mortality risk between these two groups did not reach statistical significance.
In contrast, compared with the reference group, the risk of death was 41% lower in 218 men who were physically fit (in the upper 50th percentile) and did not have left ventricular hypertrophy and 43% lower in 187 men who were fit and did have left ventricular hypertrophy, Dr. Khaled Alswat and his associates reported in a poster presentation at the annual meeting of the Endocrine Society.
The risk reductions in the two fit groups were statistically significant.
"We, as doctors, do a lot of testing, and one of those tests should be an exercise test" for patients with diabetes who have an increased risk for heart disease, said Dr. Alswat, an endocrinology fellow at Veterans Affairs Medical Center and George Washington University, Washington. An exercise stress test provides objective measures that physicians can use to work with patients on improving their physical fitness, he said in an interview.
The patients underwent a standardized exercise stress test and echocardiographic evaluation at the VA Medical Center during 1986-2011. Those who had a peak exercise capacity of at least six metabolic equivalence tasks (METs) were considered fit, and the rest were defined as having a low level of fitness (within the lower 50th percentile).
Left ventricular hypertrophy was defined by a left ventricular mass index, calculated by dividing left ventricular mass by height in meters to the power of 2.7. A left ventricular mass index greater than 48 g/m2.7 indicated left ventricular hypertrophy.
During follow-up, 346 patients died, for an annual death rate of 4%.
Smoking significantly increased mortality risk by 54%, a multivariate Cox proportional hazards analysis showed. The study controlled for the potential influences of age, body mass index, hypertension, smoking, and medications.
The adjusted mortality risk declined by 17% for every one-MET increase in fitness, Dr. Alswat reported.
Previous studies had shown that higher exercise capacity was associated with lower mortality risk in people with diabetes, but it had not been clear whether this applies to people with diabetes and left ventricular hypertrophy, he said.
Dr. Alswat reported having no relevant financial disclosures.