Seven days of aerobic exercise training improves conduit artery blood flow following glucose ingestion in patients with type 2 diabetes

Abstract

The vasodilatory effects of insulin account for up to 40% of insulin-mediated glucose disposal; however, insulin-stimulated vasodilation is impaired in individuals with type 2 diabetes, limiting perfusion and delivery of glucose and insulin to target tissues. To determine whether exercise training improves conduit artery blood flow following glucose ingestion, a stimulus for increasing circulating insulin, we assessed femoral blood flow (FBF; Doppler ultrasound) during an oral glucose tolerance test (OGTT; 75 g glucose) in 11 overweight or obese (body mass index, 34 ± 1 kg/m²), sedentary (peak oxygen consumption, 23 ± 1 ml·kg⁻¹·min⁻¹) individuals (53 ± 2 yr) with non-insulin-dependent type 2 diabetes (HbA1c, 6.63 ± 0.18%) before and after 7 days of supervised treadmill and cycling exercise (60 min/day, 60-75% heart rate reserve). Fasting glucose, insulin, and FBF were not significantly different after 7 days of exercise, nor were glucose or insulin responses to the OGTT. However, estimates of whole body insulin sensitivity (Matsuda insulin sensitivity index) increased (P < 0.05). Before exercise training, FBF did not change significantly during the OGTT (1 ± 7, -7 ± 5, 0 ± 6, and 0 ± 5% of fasting FBF at 75, 90, 105, and 120 min, respectively). In contrast, after exercise training, FBF increased by 33 ± 9, 39 ± 14, 34 ± 7, and 48 ± 18% above fasting levels at 75, 90, 105, and 120 min, respectively (P < 0.05 vs. corresponding preexercise time points). Additionally, postprandial glucose responses to a standardized breakfast meal consumed under "free-living" conditions decreased during the final 3 days of exercise (P < 0.05). In conclusion, 7 days of aerobic exercise training improves conduit artery blood flow during an OGTT in individuals with type 2 diabetes.

Glycaemic control is improved by 7 days of aerobic exercise training in patients with type 2 diabetes

“…The exercise programme consisted of 60 min of supervised exercise (alternating 20 min of treadmill walking and stationary cycling) for 7 consecutive days at 60–75% heart rate reserve, as previously described [27]. Resting heart rate (HR rest ) and peak heart rate (HR peak ) values obtained from the cardiorespiratory fitness test were used to calculate the target heart rate (THR) by the Karvonen method: THR = [(HR peak – HR rest ) × %intensity] + HR rest [28].…”

Endurance, interval sprint, and resistance exercise training: impact on microvascular dysfunction in type 2 diabetes

“…Under healthy conditions, operating through the PI3K pathway, acute increases in circulating insulin stimulate the production of endothelial NO and increase vascular conductance in the lower limb (3,140). The vasodilatory effects of insulin appear to operate following insulin infusion (140) as well as glucosestimulated insulin secretion (100,113). Whether insulin is infused or secreted in response to glucose, the vasodilation is NO dependent (114).…”

Ejercicio físico interválico de alta intensidad mejora el control glicémico y la capacidad aeróbica en pacientes con intolerancia a la glucosa

“…Tal es el caso de pacientes con diabetes mellitus tipo 2 (DM2) sometidos a ejercicio continuo de moderada intensidad durante 60 min, que no lograron producir modificaciones en glicemia durante la prueba de PTGO 27 . En busca de un método más efectivo, los ejercicios HIIT se han convertido en una estrategia recurrente.…”