AKR1B1 and diabetic neuropathy: Three human studies have shown that the suppressed vagal activity can be enhanced (increase in HF power) and SNS can be decreased by gastric electrical stimulation or gastric neuromodulation [67], transcutaneous auricular vagus nerve stimulation [59], and epalrestat (an aldose reductase inhibitor, used for treating diabetic neuropathy) administration [62].