Similar level of impairment in exercise performance and oxygen uptake kinetics in middle-aged men and women with type 2 diabetes

Eamonn O'Connor, Catherine Kiely, Donal O'Shea, Simon Green, Mikel Egaña
2012 American Journal of Physiology. Regulatory Integrative and Comparative Physiology  
O'Connor E, Kiely C, O'Shea D, Green S, Egaña M. Similar level of impairment in exercise performance and oxygen uptake kinetics in middle-aged men and women with type 2 diabetes. The present study tested the hypothesis that the magnitude of the type 2 diabetes-induced impairments in peak oxygen uptake (V O2) and V O2 kinetics would be greater in females than males in middle-aged participants. Thirty-two individuals with type 2 diabetes (16 male, 16 female), and 32 age-and body mass index
more » ... y mass index (BMI)-matched healthy individuals (16 male, 16 female) were recruited. Initially, the ventilatory threshold (VT) and peak V O2 were determined. On a separate day, subjects completed four 6-min bouts of constant-load cycling at 80% VT for the determination of V O2 kinetics using standard procedures. Cardiac output (CO) (inert gas rebreathing) was recorded at rest, 30, and 240 s during two additional bouts. Peak V O2 (ml·kg Ϫ1 ·min Ϫ1 ) was significantly reduced in men and women with type 2 diabetes compared with their respective nondiabetic counterparts (men, 27.8 Ϯ 4.4 vs. 31.1 Ϯ 6.2 ml·kg Ϫ1 ·min Ϫ1 ; women, 19.4 Ϯ 4.1 vs. 21.4 Ϯ 2.9 ml·kg Ϫ1 ·min Ϫ1 ). The time constant (s) of phase 2 (2) and mean response time (s) of the V O2 response (MRT) were slowed in women with type 2 diabetes compared with healthy women (2, 43.3 Ϯ 9.8 vs. 33.6 Ϯ 10.0 s; MRT, 51.7 Ϯ 9.4 vs. 43.5 Ϯ 11.4s) and in men with type 2 diabetes compared with nondiabetic men (2, 43.8 Ϯ 12.0 vs. 35.3 Ϯ 9.5 s; MRT, 57.6 Ϯ 8.3 vs. 47.3 Ϯ 9.3 s). The magnitude of these impairments was not different between males and females. The steady-state CO responses or the dynamic responses of CO were not affected by type 2 diabetes among men or women. The results suggest that the type 2 diabetes-induced impairments in peak V O2 and V O2 kinetics are not affected by sex in middle aged participants. cycling; sex; cardiac output
doi:10.1152/ajpregu.00012.2012 pmid:22538515 fatcat:57akh5wroje4vdv7rgk4wlgezu