Exercise capacity is associated with hospital readmission among patients with diabetes

Abstract

Introduction: Patients with diabetes are at greater risk of hospital readmission than patients without diabetes. There is a need to identify more modifiable risk factors for readmission as potential targets for intervention. Cardiorespiratory fitness is a predictor of morbidity and mortality. The purpose of this study was to examine whether there is an association between exercise capacity based on the maximal workload achieved during treadmill stress testing and readmission among patients with diabetes.

Research design and methods: This retrospective cohort study included adult patients with diabetes discharged from an academic medical center between July 1, 2012 and December 31, 2018 who had a stress test documented before the index discharge. Univariate analysis and multinomial multivariable logistic regressions were used to evaluate associations with readmission within 30 days, 6 months, and 1 year of discharge. Exercise capacity was measured as metabolic equivalents (METs).

Results: A total of 580 patients with 1598 hospitalizations were analyzed. Mean METs of readmitted patients were significantly lower than for non-readmitted patients (5.7 (2.6) vs 6.7 (2.6), p<0.001). After adjustment for confounders, a low METs level (<5) was associated with higher odds of readmission within 30 days (OR 5.46 (2.22-13.45), p<0.001), 6 months (OR 2.78 (1.36-5.65), p=0.005), and 1 year (OR 2.16 (1.12-4.16), p=0.022) compared with medium (5-7) and high (>7) METs level. During the 6.5-year study period, patients with low METs had a mean of 3.2±3.6 hospitalizations, while those with high METs had 2.5±2.4 hospitalizations (p=0.007).

Conclusions: Lower exercise capacity is associated with a higher risk of readmission within 30 days, 6 months, and 1 year, as well as a greater incidence of hospitalization, in patients with diabetes. Future studies are needed to explore whether exercise reduces readmission risk in this population.

Keywords: cardiorespiratory fitness; diabetes mellitus; type 2.