Measures of Autonomic Dysfunction in Diabetic and Idiopathic Gastroparesis

BACKGROUND: Gastroparesis is a condition classically characterized by delayed gastric emptying and is associated with considerable morbidity. While the etiology of gastroparesis remains elusive, autonomic dysfunction may play an important role, especially as many patients with gastroparesis also have diabetes. The aim of this study was to determine whether measures of autonomic function differ between adults with diabetic gastroparesis (DG) and adults with idiopathic gastroparesis (IG). METHODS: Tests of systemic autonomic function were performed among 20 adults with GD (six men and 14 women, mean age: 42 years) and 21 adults with IG (seven men and 14 women, mean age: 37 years). Measures included vagal cholinergics by R-R interval percentage variation (RRI-PV) and sympathetic adrenergics by vasoconstriction to cold (VC) and postural adjustment ratio (PAR). The two groups were compared using Wilcoxon rank sum tests and linear regression analysis (STATA 10.0). RESULTS: In univariate analysis, the following autonomic measures differed significantly between DG and IG: VC (P = 0.004), PAR (P = 0.045), VC + PAR (P = 0.002) and RRI-PV (P < 0.001). In multivariate analysis (P = 0.002, R(2) = 0.55), only RRI-PV (adjusted odds ratio (aOR): 1.02, 95% confidence interval (CI): 1.01 - 1.03) differed significantly between DG and IG patients. CONCLUSIONS: Vagal cholinergics are affected to a greater degree in DG compared to IG, suggesting that impaired vagal tone is not a universal mechanism for gastroparesis.