Cardiac autonomic neuropathy as a predictor of deterioration of the renal function in normoalbuminuric, normotensive patients with type 2 diabetes mellitus

Our study was performed to determine whether cardiac autonomic neuropathy can predict deterioration of the renal function in normoalbuminuric, normotensive people with type 2 diabetes mellitus (DM). One hundred and fifty-six normoalbuminuric, normotensive people with type 2 DM were included in our retrospective longitudinal study. We categorized normal patterns, early patterns, and definite or severe patterns according to the results of the cardiac autonomic function test. Of 156 patients included, 54 had normal patterns, 75 had early patterns, 25 had definite or severe patterns, and 2 had atypical patterns. During a median follow-up of nine years, glomerular filtration rates (GFR) remained stable in the normal and early pattern groups (mean changes, 4.50% and 0.77%, respectively) but declined in those with definite or severe patterns (mean change, -10.28%; p=0.047). An abnormal heart response to the deep breathing test of the cardiac autonomic function tests was an independent predictor of GFR decline. Our data suggest that cardiac autonomic neuropathy, especially with a definite or severe pattern, might be associated with a subsequent deterioration in renal function in normoalbuminuric, normotensive people with type 2 DM.