Australia: More frequent and shorter exercise bouts are more beneficial for vascular health of diabetes patients than longer, less-frequent exercise sessions, suggests a recent study in the American Journal of Physiology-Heart and Circulatory Physiology.
Type 2 diabetes patients are at increased heart disease risk and reduced vascular (blood vessel) function. Heart disease risk can be determined by measuring vascular function. Activity bouts in between prolonged sitting in healthy and overweight/obese adults lessens impairment in vascular function. However, whether these benefits extend to type 2 diabetes (T2D) patients is not known. Also, it is not known whether an optimal frequency of activity interruptions exist. Frances C. Taylor, Australian Catholic University, Australia, and colleagues thereby examined the acute effects on vascular function in T2D of interrupting prolonged sitting with simple resistance activities (SRA) at different frequencies.
The study included 24 adults with T2D (35-70 years). They completed three 7-hour conditions: 1) uninterrupted sitting (SIT); 2) sitting with 3 minute bouts of SRA every 30 min (SRA3); and, 3) sitting with 6 minute bouts of SRA every 60 min (SRA6). Their femoral artery flow-mediated dilation (FMD), resting shear rate, blood flow and endothelin-1 were measured at 0h, 1h, 3.5h, 4.5h, and 6.5-7h.
Key findings of the study include:
Mean femoral artery FMD over 7 hours was significantly higher in SRA3 (4.1 ± 0.3%) compared to SIT (3.7 ± 0.3%), but not in SRA6.
Mean resting femoral shear rate over 7 hours was increased significantly for SRA3 (45.3±4.1/s) and SRA6 (46.2±4.1/s) relative to SIT (33.1±4.1/s).
Endothelin-1 concentrations were not statistically different between conditions.
Interrupting sitting with activity breaks every 30 minutes, but not 60 minutes, significantly increased mean femoral artery FMD over 7 hours, relative to SIT.
"Our findings suggest that more-frequent and shorter breaks may be more beneficial than longer, less-frequent breaks for vascular health in those with T2D," concluded the authors.
The study, "Acute Effects of Interrupting Prolonged Sitting on Vascular Function in Type 2 Diabetes," is published in the American Journal of Physiology-Heart and Circulatory Physiology.
DOI: https://journals.physiology.org/doi/abs/10.1152/ajpheart.00422.2020