Correlates of cardiac autonomic neuropathy in Nigerian patients with type 2 diabetes mellitus.

Cardiac Autonomic Neuropathy (CAN) contributes significantly to increased cardiovascular morbidity and mortality in type2 diabetic patients. This manuscript aims to study the prevalence of CAN in T2DM patients in our environment and identify factors that correlate with and predict development of CAN. This is with the intention to prevent and intervene in these factors. One hundred and eight (108) T2DM patients were screened and investigated by the standard six non-invasive tests including heart rate variability, QTc and Valsalva manouvre. Patients who had abnormality in more than 2 of the tests were adjudged to have CAN. They were statistically compared with those without CAN. Thirty- seven (34.2%) patients had CAN. The commonest abnormality was in heart rate response to standing (76.9%) There was no significant difference in the mean age and sex of those with CAN and those without. Though significantly more males had CAN, when sex was entered into the logistic regression it did not correlate with CAN. Poor short-term glycaemic control as demonstrated by fasting blood glucose (130.87 + 56.1 vs 94.24 + 48.9 mg%, p < 0.05); serum creatinine (1.23 + 0.52 vs 0.86 + 0.39 mg%, p<0.05), presence of hypertension and first degree family history were significantly more in patients with CAN. There was more than 2-fold increased risk of developing CAN when serum creatinine was greater than 1.5 mg% (OR 2.013, 95% CI 0.543-2.657) and when FBG was more than 120 mg% (OR 2.106, 95% CI 0.834-2.897). CAN is common in our patients with T2DM. It is more prevalent in those with hypertension, first degree family history and renal damage. Poor short-time glycaemic control was also a contributory factor.