REDUCED GASTRIC-EMPTYING AND MESENTERIC BLOOD-FLOW IN IDDM WITH CARDIAC AUTONOMIC NEUROPATHY

Our objective was to investigate the relationship between gastric empt ying and mesenteric blood flow in type 1 diabetic patients with (CAN+) and without (CAN-) cardiac autonomic neuropathy. CAN was determined b y a series of cardiovascular reflex tests and power spectral analysis of heart rate variations (HRV) using a computerized system. We calcula ted from these data a score for cardiac autonomic neuropathy with a ma ximum of 7 points (1 point for abnormal value of: CV of HRV at supine rest, CV of HRV during deep breathing, Valsalva ratio, lying-to-standi ng ratio, PSA of HRV,in the low frequency band, PSA of HRV in the mid frequency band, blood pressure response to standing). Patients were co nsidered to have CAN if at least 3 of the 7 parameters were found to b e abnormal (CAN score greater than or equal to 3). The resulting group s (CAN-, n = 14 vs. CAN+, n = 16) were well matched with respect to ag e (53 +/- 11 vs. 51 +/- 12 years), BMI (27.2 +/- 3.3 vs. 25.9 +/- 3.6 kg/m(2)), duration of diabetes (162 +/- 157 vs. 158 +/- 100 months), f asting blood glucose (6.9 +/- 2.6 vs. 6.8 +/- 2.4 mmol/l) and HbA(1c) (7.2 +/- 1.5 vs. 7.3 +/- 2.0%). Gastric emptying was determined by rea l-time ultrasonography (antral planimetry) during 60 min after a semil iquid test meal (Fresubin diabetes 300 ml, 53% carbohydrate, 32% lipid , 15% protein) and the blood flow of the superior mesenteric artery wa s measured by Doppler ultrasound technique. Type I diabetic patients w ith CAN had a significantly higher CAN score than those without CAN (6 .1 +/- 0.4 vs. 1.3 +/- 0.7). Mean preprandial (before ingestion of the test meal) as well as postprandial (immediately after ingestion of te st meal) antral areas of CAN+ (5.2 +/- 2.0v/10.9 +/- 2.8 cm(2)) and CA N-(5.1 +/- 1.5/10.8 +/- 2.2 cm(2)) were comparable. CAN+ had significa ntly slower decrease of postprandial antral areas at 15, 30, 45 and 60 min after ingestion of test meal (-1.7 +/- 0.4/-8.3 +/- 1.2/-9.5 +/- 0.9/-19.5 +/- 2.0 Delta% compared to postprandial value) compared to C AN-(-8.9 +/- 1.8/-22.5 +/- 2.6/ -29.1 +/- 2.9/-35.5 +/- 2.9 Delta%). T he increase in mesenteric blood flow at 15, 30 and 45 min after the me al was significantly reduced in CAN+ compared to CAN- patients. Signif icantly negative correlations were found between the CAN score and the decrease of antral area as well as between CAN score and the increase of diastolic mesenteric blood flow and significantly positive correla tions between the decrease of antral area and the increase of diastoli c mesenteric blood flow. In conclusion, type 1 diabetic patients with cardiac autonomic neuropathy showed delayed gastric emptying and dimin ished mesenteric blood flow during 60 min after ingestion of a semiliq uid test meal.