Increased Cardiovascular Response to a 6-Minute Walk Test in People With Type 2 Diabetes

Jonathon W Senefeld; Sarah E D'Astice; Alison R Harmer; Sandra K Hunter

doi:10.2337/ds19-0002

Increased Cardiovascular Response to a 6-Minute Walk Test in People With Type 2 Diabetes

Diabetes Spectr. 2020 Feb;33(1):104-110. doi: 10.2337/ds19-0002.

Authors

Jonathon W Senefeld¹, Sarah E D'Astice¹, Alison R Harmer², Sandra K Hunter¹

Affiliations

¹ Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, WI.
² Musculoskeletal Health Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, Australia.

Abstract

Background and objective: Exercise is a cornerstone of management for type 2 diabetes; however, little is known about the cardiovascular (CV) response to submaximal functional exercise in people with type 2 diabetes. The aim of this study was to compare performance and CV response during a 6-minute walk test (6MWT) between people with type 2 diabetes and matched control subjects.

Methods: CV response and distance walked during the 6MWT were assessed in 30 people with type 2 diabetes, matched for age, body composition, physical activity, and estimated aerobic capacity with 34 control subjects (type 2 diabetes group: 16 men, 59.8 ± 8.8 years of age, 33.3 ± 10.9% body fat, physical activity of 7,968 ± 3,236 steps·day^-1, estimated aerobic capacity 31.9 ± 11.1 mLO₂·kg^-1·min^-1; control group: 19 men, 59.3 ± 8.8 years of age, 32.7 ± 8.5% body fat, physical activity 8,228 ± 2,941 steps·day^-1, estimated aerobic capacity 34.9 ± 15.4 mLO₂·kg^-1·min^-1).

Results: People with type 2 diabetes walked a similar distance (590 ± 75 vs. 605 ± 69 m; P = 0.458) compared with control subjects during the 6MWT and had similar ratings of perceived exertion (RPE) after the 6MWT (4.19 ± 1.56 vs. 3.65 ± 1.54, P = 0.147). However, at the end of the 6MWT, people with type 2 diabetes had a higher heart rate (108 ± 23 vs. 95 ± 18 beats·min^-1; P = 0.048), systolic blood pressure (169 ± 26 vs. 147 ± 22 mmHg, P = 0.003), and rate-pressure product (18,762 ± 5,936 vs. 14,252 ± 4,330, P = 0.009) than control subjects.

Conclusion: Although people with type 2 diabetes had similar performance and RPE during the 6MWT compared with control subjects, the CV response was greater for people with type 2 diabetes, indicating greater cardiac effort for similar perceived effort and performance of 6MWT. These data suggest that observation and prescription of exercise intensity should include both perceived effort and CV response.