Obesity continues to be a significant challenge for people who struggle with diabetes, especially when efforts to exercise do not result in weight loss. Despite the challenge and the sometimes significant disappointment for patients embarking on New Year’s fitness resolutions, research published recently in Diabetes Care indicates that efforts to become more fit may lower a patient’s risk of death from related disease. 

According to Seamus P. Whelton, MD, MPH, assistant professor of medicine at the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease at Johns Hopkins School of Medicine, although obesity contributes to poorer outcomes for patients with diabetes, those who are more physically fit, regardless of their BMI, have a lower risk of mortality. 

Dr. Whelton and colleagues explored the association between BMI and mortality in patients with diabetes and whether improved fitness plays a role in improving health outcomes. The 8,528 subjects were from the Henry Ford ExercIse Testing Project (FIT Project), and their diabetes status was identified through self-report, medication use, or electronic medical record diagnosis.

The subjects’ fitness levels were measured as metabolic equivalents (METs) recorded during a physician-referred treadmill stress test. Individuals who achieved 10 or more METs during the treadmill test were considered to have a high level of fitness, 6–9.9 METs indicated moderate fitness, and less than 6 METs was low fitness. Adjusted hazard ratios for mortality were calculated using standard kg/m2 BMI with cutoffs of 18.5–24.9 (normal), 25–29.9 (overweight), and ≥30 (obese). Roughly one-half of subjects were female (49%), and the mean age was 58 (± 11) years; mean follow-up was 10 (± 4.1) years. 

During the study period, 1,319 deaths were recorded. The researchers reported that, compared with nonobese patients, obese patients had a 30% lower mortality hazard (P <.001). Higher fitness patients had an approximately 50% (6–9.9 METs) and 70% (≥10 METs) lower mortality hazard regardless of BMI (P <.001) compared with the lowest fitness group.

In a recent report, Dr. Whelton said, “Our results demonstrate that a higher BMI at baseline testing was associated with a lower mortality rate among patients with diabetes predominantly when fitness was low or moderate. Importantly, a higher fitness level was associated with a consistent and significantly lower mortality rate regardless of BMI.” 

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