Cardiac autonomic neuropathy (CAN), a common complication of type 2 diabetes (T2D), is often not detected until late in disease progression. Autonomic nervous system (ANS) dysfunction impairs control of heart rate (HR) and vascular dynamics, manifesting as decreased HR variability (HRV) and impaired blood pressure (BP) regulation. We hypothesized that ANS function is impaired in participants with uncomplicated T2D and correlates with cardiac measures. We measured HRV during cycled breathing and Valsalva and postural HR and BP on overweight physically inactive adults aged 22-70 years with (N=53) and without (N=56) T2D. HRV with cycled breathing and Valsalva was lower in participants with T2D (p=0.007 and 0.005, respectively). HRV with respiration was lower with age >50 years (p=0.0001). HRV with respiration correlated with increased age in T2D but not in overweight control participants. There were no significant changes in postural BP or HR with age >50 years or T2D. Significant correlations between ANS measures and cardiac function were only seen in those with T2D. Valsalva ratio was positively correlated with end-diastolic volume (Pearson’s r 0.58, p=0.02) and stroke volume (Pearson’s r 0.55, p=0.03). HRV with respiration was positively correlated with longitudinal, diastolic peak strain rate (SR) (Pearson’s r 0.68, p=0.007). Postural BP was positively correlated with circumferential and longitudinal, systolic peak SR (Pearson’s r =0.45 and 0.48 and p-value=0.05 and 0.04, respectively) and negatively correlated with radial and circumferential peak strain (Pearson’s r =-0.49 and -0.48 and p-value=0.03 and 0.03, respectively). These data suggest subclinical CAN associated with cardiac dysfunction is present in people with otherwise uncomplicated T2D and is exacerbated with age. Detecting CAN changes early may identify people at risk for cardiac disease and inform targeted intervention to restore cardiometabolic health in people with T2D.


A.Johnston: None. L.A.Abushamat: None. D.Enge: None. A.J.Barker: None. E.W.Clark: None. D.Rafferty: None. J.G.Regensteiner: None. J.E.B.Reusch: Advisory Panel; Medtronic.


American Diabetes Association (1-21-CMF-003 to L.A.A.); National Institutes of Health (T32DK120520-01A1); U.S. Department of Veterans Affairs (CX001532)

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