Exercise based assessment of cardiac autonomic function in type 1 versus type 2 diabetes mellitus

Figures

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  Figure 1. A. RR-intervals are demonstrated at rest, during exercise, and in recovery for each group during the initial baseline test and the second test with administration of atropine. With exercise, RR-intervals decrease in each group, and with recovery RR-intervals increase in each group. RR-intervals are shortest in the type 2 diabetes group during recovery. With atropine, the differences between groups are abolished, and RR-interval increase during recovery is blunted; the curves overlap for the three groups; B. Parasympathetic effect on the RR-intervals is shown at end exercise and in recovery for each group, defined as the difference of the RR-interval (ΔRR) at baseline without atropine and the RR-interval after parasympathetic blockade with atropine. Parasympathetic effect on RR-intervals during recovery is blunted in type 2 diabetes compared to controls and type 1 diabetes; DM — diabetes mellitus.

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  Figure 2. Norepinephrine (A) and epinephrine (B) during rest, exercise, and recovery. Plasma norepinephrine and epinephrine concentrations at rest, during exercise, and in recovery for each group. Resting norepinephrine concentration is highest in those with type 1 diabetes. With exercise, norepinephrine increases in each group, however the decrease in norepinephrine is blunted in the type 1 diabetes group compared to the type 2 diabetes group and controls. Resting epinephrine concentration is highest in type 1 diabetes. With exercise, epinephrine increases in each group, however the decrease in epinephrine is blunted in the type 1 diabetes group compared to the type 2 diabetes group and controls; DM — diabetes mellitus.

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  Figure 3. QT intervals over time. QT intervals are demonstrated at rest, during exercise, and in recovery for each group during the initial baseline test and the second test with administration of atropine toward the end of exercise. QT intervals decreased with exercise, and increased during recovery. QT intervals were shortest in the type 2 diabetes group during recovery. With atropine, the difference among groups was attenuated.