Delayed gastric emptying rate in Type 1 diabetics with cardiac autonomic neuropathy

Gastroparesis is a frequent complication of longstanding diabetes and has been attributed to vagal nerve dysfunction, occurring as part of a generalized autonomic neuropathy. We wanted to clarify the relationship between delayed gastric emptying (GE) and cardiac autonomic neuropathy (CAN) in type 1 diabetics. Using a standardized ultrasound technique, GE was studied in 20 type 1 diabetic patients with poor glycaemic control despite good compliance and 10 normal healthy volunteers (Group 1). Measurements of GE were done on condition that the fasting blood glucose was 3.5-9.0 mmol/l. Diabetic patients were classified into two groups according to the absence (Group 2) or presence (Group 3) of CAN, using the deep breathing test (E:I ratio) to evaluate parasympathetic vagal nerve function. Age-related reference values were used to evaluate the indices of CAN. The supine resting heart rate was also checked, and the patients were asked for symptoms of gastroparesis. The three groups were similar in terms of sex and smoking habits, and there was no significant difference regarding the age and body mass index (BMI). The mean duration of diabetes and the glycaemic control (HbA1c) was insignificant between patients in Groups 2 and 3. Diabetic patients in Group 3 showed lower gastric emptying rates (GER) than the healthy volunteers in Group 1 (median GER 16% vs. 63%, P<.01) and the patients in Group 2 (median GER 16% vs. 54%, P<.01). No significant difference in GER could be seen between patients in Group 2 and subjects in Group 1 (median GER 54% vs. 63%, P=.08). Assuming that GER<45% indicated a delayed GE, 8 of 10 patients in Group 3 had delayed GE compared to only 3 of 10 patients in Group 2. There were disagreements between symptoms of gastroparesis and delayed GE. We conclude that there is a significant lower GER in type 1 diabetic patients with CAN than in those without, unrelated to symptoms of gastroparesis.