Rate pressure product predicts cardiovascular risk in type 2 diabetics with cardiac autonomic neuropathy

Abstract

Background: Unexplained sudden deaths due cardiac involvement are linked to autonomic neuropathy in diabetics but mechanisms remain unclear. Heart rate and pulse pressure etc have been used to predict cardiovascular risk. But the association of Rate Pressure Product remains unascertained. Objective: To predict cardiovascular risk in type 2 diabetic patients with cardiac autonomic neuropathy using a non-invasive indicator, rate pressure product. Materials and Methods: Case control study done on two groups of 20 each, age matched type 2 diabetics with/without cardiac autonomic neuropathy and matched with 20 controls of either sex (n=60). Rate Pressure Product was measured in response to cold pressor and hand grip test. Statistical analysis was done using SPSS software by paired and unpaired t test. Results: There was a significant increase in rate pressure product in controls and in patients without autonomic neuropathy after the tests (p0.001). The change in RPP (ΔRPP) was least in diabetics with autonomic neuropathy and significant in controls and non-neuropathy diabetics using unpaired t-test ( p< 0.05 ). Resting RPP was recorded highest in diabetic autonomic neuropathy patients. Conclusion: Heightened resting RPP and failure of Rate Pressure Product increment during cardiac sympathetic stimulation promotes aggravated ischemic episodes. This renders autonomic neuropathy diabetics vulnerable to adverse cardiovascular events leading to increased morbidity and mortality.