Influence of physical inactivity on arterial compliance during a glucose challenge

Abstract

Acute hyperglycaemia has been shown to augment indices of arterial stiffness in patients with insulin resistance and other co-morbidities; however, conflicting results exist in healthy young individuals. We examined whether acute hyperglycaemia after an oral glucose tolerance test (OGTT) increases arterial stiffness in healthy active men before and after reduced ambulatory physical activity to decrease insulin sensitivity. High-resolution arterial diameter traces acquired from Doppler ultrasound allowed an arterial blood pressure (BP) waveform to be obtained from the diameter trace within a cardiac cycle. In 24 subjects, this method demonstrated sufficient agreement with the traditional approach for assessing arterial compliance using applanation tonometry. In 10 men, continuous recordings of femoral and brachial artery diameter and beat-to-beat BP (Finometer) were acquired at rest, 60 and 120 min of an OGTT before and after 5 days of reduced activity (from >10,000 to <5000 steps day ). Compliance and β-stiffness were quantified. Before the reduction in activity, the OGTT had no effect on arterial compliance or β-stiffness. However, after the reduction in activity, femoral compliance was decreased (rest, 0.10 ± 0.03 mm mmHg versus 120 min OGTT, 0.06 ± 0.02 mm mmHg ; P < 0.001) and femoral β-stiffness increased (rest, 8.7 ± 2.7 a.u. versus 120 min OGTT, 15.3 ± 6.5 a.u.; P < 0.001) during OGTT, whereas no changes occurred in brachial artery compliance (P = 0.182) or stiffness (P = 0.892). Insulin sensitivity (Matsuda index) was decreased after the reduction in activity (P = 0.002). In summary, in young healthy men the femoral artery becomes susceptible to acute hyperglycaemia after 5 days of reduced activity and the resultant decrease in insulin sensitivity, highlighting the strong influence of daily physical activity levels on vascular physiology.

Early vascular parameters in the micro- and macrocirculation in type 2 diabetes

“…Our patients with T2DM had higher FPG compared to patients without T2DM. Hyperglycemia has been also shown to augment indices of arterial stiffness, especially in people with reduced insulin sensitivity and in patients with T2DM [ 36 , 37 ]. The difference in cPP between our patients with and without T2DM remained significant even after adjustment with FPG and HbA1c.…”

Postprandial augmentation index is reduced in adults with prediabetes following continuous and interval exercise training

“…Arterial stiffness increases CVD risk, in part, by elevating blood pressure and plaque formation, thereby reducing oxygen/nutrient delivery for tissue utilization and function. Even in healthy adults, arterial stiffness increases in response to an oral glucose tolerance test (OGTT; Credeur et al, 2018). Even in healthy adults, arterial stiffness increases in response to an oral glucose tolerance test (OGTT; Credeur et al, 2018).…”

“…Fasting arterial stiffness is an independent predictor of future CVD and allcause mortality (Mitchell et al, 2010), and obese individuals have blunted reductions in arterial stiffness in response to a high-fat meal (Phillips et al, 2010). Even in healthy adults, arterial stiffness increases in response to an oral glucose tolerance test (OGTT; Credeur et al, 2018). This is clinically relevant, because the postprandial period is considered a stronger predictor of future CVD than fasting alone (Cavalot et al, 2006) owing, in part, to impaired blood vessel function as a result of hyperglycaemia (Ceriello, 2010) and the promotion of vasoconstriction by chronic hyperinsulinaemia (Greenfield, Samaras, Chisholm, & Campbell, 2007).…”

An accumulation of muscle macrophages is accompanied by altered insulin sensitivity after reduced activity and recovery

“…Indeed, hindlimb immobilization and hindlimb unloading with intermittent weight bearing resulted in greater muscle water content reflective of oedema. Unfortunately, we did not utilize methods to directly confirm venous pooling, oedema or alterations in the vasculature with reduced physical activity as others have indicated . Although we did not measure blood flow directly, reduced muscle blood flow in humans in response to physical inactivity has been observed …”

“…Unfortunately, we did not utilize methods to directly confirm venous pooling, oedema or alterations in the vasculature with reduced physical activity as others have indicated. 52,53 Although we did not measure blood flow directly, reduced muscle blood flow in humans in response to physical inactivity has been observed. 37,54,55 We cannot rule out that macrophages also increased in response to muscle damage caused by the intermittent reloading during this period of reduced activity.…”