The Effect of Acute Hyperglycaemia Induced by Oral Glucose Load on Heart Rate Variability and Skin Microvascular Reactivity in Young Adults

Figures

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  Figure 1. Plasma glucose concentration (cglc) determined in capillary blood sample before and after OGTT. Fasting, before OGTT; Post-OGTT, 30 min after OGTT; End, at the end of the protocol (i.e., 50 min after OGTT). ** p ˂ 0.001, paired t-test, with respect to fasting.

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  Figure 2. The post-occlusion reactive hyperaemia (PORH) parameters change (Δ) correlated to increase of glucose concentration assessed from capillary blood (Δcglc) after oral glucose tolerance test (OGTT) (dark bars) and water load (W, control, the first—bright bar) on the forearm (left plots) and on the finger pulp (right plots), with the regression line. Middle bar represents the low-glucose (LG) group (Δcglc < 2.3 mM); the bar on the right (the darkest colour) represents the high-glucose (HG) group (Δcglc ≥ 2.3 mM). ΔLDpeak, pre-post glucose/water load change in peak laser Doppler flux; Δtpeak, pre-post post glucose/water load change in time to LDpeak; ΔAUC, pre-post glucose/water load change in the area under the hyperaemic response curve; PU, perfusion unit; p, p-values of ANOVA, post hoc Tukey.

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  Figure 3. The heart rate variability (HRV) parameters change (Δ) relative to glucose concentration increase (Δcglc) after oral glucose tolerance test (OGTT) and water load (W, control, left bar) with the regression line. Middle bar represents the low-glucose (LG) group (Δcglc < 2.3 mM); the bar on the right (the darkest colour) represents the high-glucose (HG) group (Δcglc ≥ 2.3 mM). ΔLF, pre-post glucose/water load change in low-frequency band of HRV; ΔHF, pre-post glucose/water change in high-frequency band of HRV; ΔLF/HF, pre-post glucose/water load change in low- to high-frequency band ratio of HRV; n.u., normalised unit; p, p-value of ANOVA, post hoc Tukey.