Independent predictor factors of supine tachycardia in patients with type 2 diabetes mellitus.

Introduction: Supine tachycardia, frequently encountered in diabetic patients, is usually considered as an isolated diabetic complication in cardiac autonomic neuropathy. The objective of this study was to determine independent predictor factors of supine tachycardia among the clinical characteristics of type 2 diabetes mellitus.
Methods: This prospective study included type 2 diabetic patients. Supine tachycardia was considered as 10 minutes resting heart rate equal or higher than 80 beats/minutes. According to presence or not of supine tachycardia, two groups were identified: tachycardia diabetic patients and none tachycardia diabetic patients. Cardiovascular autonomic tests: deep breathing, hand-grip, and mental stress tests and blood tests were performed in all patients. Statistical analysis was done using the Student's t-test, and univariate and multivariate logistic regression analysis.
Results: We included 91 patients. The vagal response measured by the deep breathing test was 24.5 ± 5.7% in tachycardia diabetic patients vs 35.6 ± 6.8% in none tachycardia diabetic patients (P=0.007). The odds of supine tachycardia increased with serum creatinine (OR=1.350, 95% CI: 1.065-1.712, P=0.013) and serum uric acid levels (OR=1.034, 95% CI: 1.005-1.064, P=0.02) respectively, in diabetic patients. The prevalence of moderate renal failure was 45.5% in tachycardia diabetic patients vs. 21.6% in none tachycardia diabetic patients (P=0.034).
Conclusion: A high frequency of supine tachycardia in type 2 diabetic patients was significantly related with an impairment of the parasympathetic nervous system but other independent predictor factors were associated to the occurrence of this supine tachycardia, such as higher levels of serum creatinine and uric acid and moderate renal failure.
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