Relationship between cardiovascular autonomic (dys)function and microalbuminuria in type 2 Diabetes Mellitus

Background: Diabetic autonomic neuropathy is a serious and common complication of diabetes mellitus and in fact it is one of the most overlooked complications, thus very limited clinical and research data are available on early renal and cardiovascular autonomic complications in type 2 diabetes mellitus. Aims & Objective: To determine the possible association of elevated albumin excretion rate with cardiovascular autonomic activity in type 2 diabetes mellitus. Materials and methods: A cross-sectional study was conducted with one hundred and fifteen patients of type 2 diabetes mellitus. Microalbuminuria was defined as Albumin Excretion Rate (AER) > 30 mg/24 hr in an early morning urine sample. Nine parameters reflecting different aspects of cardiovascular autonomic function were measured and were summarized in a single cardiovascular autonomic function score (CAFS).The association between cardiovascular autonomic dysfunction and microalbuminuria was estimated by multiple linear regressions. Results: Patients with microalbuminuria had low levels of the autonomic function parameters i.e. mean CAFS, indicating impaired autonomic function. This association was consistent with increasing AER, and remained significant after multivariate adjustment for other clinical factors predictive of microalbuminuria. In additional analysis, we examined the autonomic function tests combined on the part of autonomic nervous system they predominantly represent. The results of these alternative combinations were comparable to those of the CAFS score. Conclusion: Cardiovascular autonomic dysfunction was independently associated with microalbuminuria in patients with type 2 diabetes mellitus, and that this association is independent of other previously identified determinants of albuminuria in type 2 diabetes mellitus. Therefore cardiovascular autonomic function tests should be monitored to pay attention to major potential cardiovascular complications even in asymptomatic patients, but especially among those with microalbuminuria. [Natl J Physiol Pharm Pharmacol 2012; 2(2.000): 84-92]