Postprandial hypotension is commonly defined as the decrease in systolic blood pressure of 20 mm Hg and more, observed within 2 hours after meal ingestion. This phenomenon was described in subjects with comprised function of autonomic nervous system. However, the data on its prevalence in diabetic patients are scarce. The aim of the study was to assess the concordance of postprandial hypotension and autonomic cardiovascular neuropathy in diabetes mellitus. The study included 67 patients (26 males, 41 females, mean age: 47.5 +/- 16.2 years) with diabetes type 1 or 2 (mean disease duration: 13.3 +/- 8.8 years), treated with diet and insulin injections. Postprandial hypotension was diagnosed based on results of automatic blood pressure recordings performed within 90 minutes after test meal ingestion. Tests of Ewing's battery were used to evaluate autonomic cardiovascular neuropathy.
Results: Mean postprandial decrease in systolic blood pressure of 17.7 +/- 11.7 mm Hg was noted at 48.0 +/- 13.7 min after meal ingestion. The study patients were divided into 2 groups based on results of systolic blood pressure recordings. In group A of 39 subjects (58.2%) the mean fall in systolic blood pressure of 8.9 +/- 4.4 mm Hg was observed. In group B of 28 (41.8%) subjects fulfilling the criteria of postprandial hypotension systolic blood pressure decreased after the meal of 30.0 +/- 6.2 mm Hg, the difference between groups was statistically significant (p < 0.001). Autonomic cardiovascular neuropathy was recognized in 41 (61.2%) of the study patients. The more advanced neuropathy was stated in group B (neuropathy scale score: group A--1.54 +/- 1.48 points, group B--5.11 +/- 1.93 points, p < 0.001). Statistically significant correlation between the magnitude of postprandial systolic blood pressure fall and cardiovascular neuropathy scale score was noted (Spearman's correlation co-efficient R: -0.612: p < 0.01). Postprandial blood pressure fall correlated significantly with orthostatic systolic blood pressure changes (correlation co-efficient R: 0.610; p < 0.001).
Conclusions: Postprandial hypotension is an important symptom of diabetic cardiovascular neuropathy. It is recommended to include postprandial blood pressure measurements in diagnostic algorithm of autonomic nervous system dysfunction in diabetic patients.