Evaluation of the relationship between gastric emptying, metabolic status and diabetic neuropathy

Abstract

Introduction: The possible correlations between the metabolic status, the gastric emptying and the neuropathy are still not clearly explored by the studies of the past decades. The aims of this study were to perform a continuous glucose monitoring during the determination of gastric emptying and to evaluate the severity of neuropathy in patients (pts) with type-1 diabetes mellitus (DM). Patients and methods: 13 young pts with type-1 DM were included (duration of DM: 15.1±2.9 years; mean±SE). The emptying of the stomach was evaluated by scintigraphy. The subcutaneous glucose levels were determined by a CGMS method (Medtronic Hungária Kft) during the interval of the gastric emptying. Cardiovascular reflex tests were applied for the assessment of autonomic neuropathy (AN). Sensory nerve integrity was studied with a Neurometer (Neurotron Inc., Baltimore). Results: There was a longer period of gastric emptying in diabetic pts than in healthy subjects, but this difference did not reach significance (T1/2: 84.4±12.4 vs. 49.6±5.5min., p=0.06, pts vs. control). The glucose levels recorded during the gastric emptying (the lowest and highest, the mean, the highest difference) and the HbA1c did not correlate with the gastric motility. Moderately severe AN was found in pts (AN score: 2.9±0.5 vs. 0.3±0.2p<0.001, heart rate response to beathing: 16.4±1.9 vs. 26.3±2.3 beats/min, p<0.01; 30/15 ratio: 1.04±0.02 vs. 1.21±0.04, p<0.01; Valsalva ratio: 1.34±0.06 vs. 1.71±0.1, p<0.01; handgrip: 15.6±2.8 vs. 28.3±3.5mm Hg, p<0.05). The current perception thresholds (CPT) at 5Hz on the peroneal nerve of the pts differed from controls (CPT: 3.12±0.9 vs. 0.68±0.07 mA, p<0.05). Conclusions: Parameters of the continuously measured glucose levels did not correlate with the gastric emptying. Slightly slower gastric emptying was found in the presence of a moderately severe autonomic and sensory neuropathy in pts after a 15-year-long duration of DM. These data may strengthen the hypothesis that the current glucose levels have a less important role than neuropathy in the pathogenesis of delayed gastric emptying.