Carbohydrate ingestion induces differential autonomic dysregulation in normal-tension glaucoma and primary open angle glaucoma

Figures

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  Fig 1. Hemodynamic changes in response to carbohydrate ingestion and postural stress (glaucoma N = 37 vs controls N = 36). From fasting (0 min) to postprandial state (30, 60, 90, and 120min), MAP maintained stable in controls, but was unstable in glaucoma patients; HR increased in both control and glaucoma subjects. (*P<0.05, **P<0.01, effect of carbohydrate ingestion; two-way ANOVA). From supine (○) to standing (▲), both MAP and HR increased in glaucoma and control groups. (**P<0.01, effect of postural change before and after carbohydrate ingestion; two-way ANOVA).

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  Fig 2. Autonomic changes in response to carbohydrate ingestion and postural stress (glaucoma N = 37 vs controls N = 36). From fasting (0 min) to postprandial state (30, 60, 90, 120 min), HRV LF nu increased, HRV HF nu decreased, and HRV LF/HF increased in glaucoma patients; whereas HRV parameters remained unaltered in controls, albeit an increase in HRV LF nu. SBP LF power increased and BRS reduced in both glaucoma and control subjects. (*P<0.05, **P<0.01, effect of carbohydrate ingestion; two-way ANOVA). From supine (○) to standing (▲) position, SBP LF power, BRS and all HRV parameters showed comparable changes in glaucoma and control groups. (*P< 0.05, **P<0.01, effect of postural change before and after carbohydrate ingestion; two-way ANOVA).

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  Fig 3. Hemodynamic responses 30 minutes following carbohydrate ingestion. MAP fell 30min after meal ingestion in POAG, whereas MAP maintained stable in control and NTG subjects. HR increased 30min after eating in all three groups. HR also increased in response to postural stress, i.e., from supine (○) to standing (▲).** P<0.01; data shown as Mean ± SEM.

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  Fig 4. Autonomic responses 30 minutes following carbohydrate ingestion. Soon after meal ingestion, POAG exhibited a reduced HRV LF power nu, an enhanced HRV HF power nu, with a decrease in HRV LF/HF, indicating a paradoxical sympathetic and vagal outflow, i.e., autonomic failure. This autonomic response was not seen in NTG, and control subjects. In response to postural stress (from supine (○) to standing (▲)), in pre-ingestion and early fed state, HRV LF power nu increased, HRV HF power nu decreased, and HRV LF/HF increased in control subjects; whereas in NTG and POAG, autonomic response was attenuated, despite a reduction in HRV HF power nu was observed. SBP LF power and BRS changes in response to either postural stress or carbohydrate ingestion were similar among control, NTG and POAG. *P<0.05, ** P<0.01; data shown as Mean ± SEM.

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  Fig 5. Hemodynamic responses at 60, 90 and 120 minutes following carbohydrate ingestion. Following carbohydrate ingestion, in the later phase of postprandial state, MAP maintained stable and HR increased in all three groups. In response to postural stress (from supine (○) to standing (▲)), MAP increased in control and PAOG, but not in NTG. HR increased in all three groups. *P<0.05, ** P<0.01; data shown as Mean ± SEM.

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  Fig 6. Autonomic responses at 60, 90 and 120 minutes following carbohydrate ingestion. Following carbohydrate ingestion, in the later phase of postprandial state, NTG showed an increased HRV LF power nu, a decreased HRV HF power nu, and an increased HRV LF/HF; this autonomic response is not seen in control and POAG groups. In response to postural stress (from supine (○) to standing (▲)), HRV HF power nu reduced in all three groups; whereas only control subjects exhibited an intact HRV parameters’ changes. SBP LF power and BRS changes in response to either postural stress or carbohydrate ingestion were similar among control, NTG and POAG. *P<0.05, ** P<0.01; data shown as Mean ± SEM.

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  Fig 7. Group comparison of HRV parameter changes to meal ingestion. A, B, C shows, in supine position, from pre-ingestion to early after meal ingestion (30min postprandially), HRV parameters’ changes are different in POAG, compared to NTG and Control. There are reductions in HRV LF power nu and HRV LF/HF ratio, and an increase in HRV HF power nu in POAG. D, E, F shows, in standing position, from fasting to 90 minutes after carbohydrate ingestion (maximal response), HRV parameters’ changes are different in NTG, compared to POAG and Control. There is an increase in HRV LF power nu and a decrease in HRV HF power nu in NTG. § P< 0.05, §§ P< 0.01, NTG vs POAG; P< 0.05, Control vs POAG; ¥ P< 0.05, Control vs NTG; data shown as Mean ± SEM.