Reduction in Aerobic Capacity and Cardiac Output in Diabetic Adolescents

Abstract

Aerobic capacity is reduced in diabetic adults. Type 1 diabetic (T1D) adolescents also have reduced aerobic capacity; however it is not known whether recently diagnosed type 2 diabetic (T2D) adolescents have similarly impaired aerobic capacity. PURPOSE: To determine whether T2D and T1D adolescents have reduced aerobic capacity and whether stroke volume (SV) and heart rate (HR) response to exercise are impaired in diabetic adolescents. METHODS: Eight T2D, 10 non-diabetic obese (NDO), 11 T1D and 7 lean (L) female adolescents were recruited for this study. Baseline data included peak aerobic capacity (cycle ergometer) and a DEXA scan. On a separate day, cardiac output (CO) was determined at rest and during workloads eliciting 100(±5)and 120 (±5) beats per minute (bpm). RESUITS: Maximal O2 consumption (ml/kgFFM/min) and HR (bpm) were lower in the T2D vs. NDO, T1D and L groups (p< 0.05). Resting CO and SV indexed for fat free mass (COFFM and SVFFM) were lower in both diabetic and NDO groups compared to L group (p< 0.05). Exercise COFFM and SVFFM were lower during both workloads in the T1D and T2D vs. NDO and L groups (p< 0.05). Arterio-venous O2 difference was not different in any condition (p> 0.05). CONCLUSION: T2D adolescents have lower aerobic capacity than T1D and NDO adolescents even when indexed to fat free mass. However both T1D and newly diagnosed T2D adolescents have blunted stroke volume response to exercise.TableData are means ± standard deviation. B= p< 0.05 significantly ≠ between T2D and O, C= p< 0.05 significantly ≠ between T2D and L, D= p< 0.05 significantly ≠ between O and T1D, E= p< 0.05 significantly ≠ between O and L, F= p< 0.05 significantly ≠ between T1D and L.