Autonomic nerve function in adolescents with Type 1 diabetes mellitus: relationship to microalbuminuria

Aims Thirty adolescent patients with Type 1 diabetes mellitus and microalbu minuria were studied for evidence of early autonomic neuropathy Methods Using tests involving cardiovascular and pupillary reflexes, the ad olescents were compared with a normoalbuminuric group of patients with diab etes, who were matched for age, sex, puberty and duration of diabetes. Results There was an increased prevalence of autonomic nerve dysfunction in the patients with microalbuminuria. These patients had higher resting hear t rates (86 beats/min in the microalbuminuric group vs. 77 beats/min in nor moalbuminuric controls, P = 0.002), and impaired pupillary dilatation in da rkness (pupillary diameter % 56.5% vs. 62.5%, P = 0.003). Patients with mic roalbuminuria also had poorer long term glycaemic control (mean HbA(1C) 8.7 % vs. 7.8%, P = 0.002) and higher blood pressures (systolic 125 vs. 116 mmH g, P = 0.001; diastolic 69 vs. 62 mmHg, P = 0.0001; mean arterial pressure 90 vs. 53 mmHg, P = 0.002) than those with normal urinary albumin excretion . Conclusions Microalbuminuria and autonomic nerve dysfunction co-exist in pa tients with Type 1 DM. Longitudinal studies will determine whether these fi ndings have implications for the identification of patients at higher risk of progression of early renal complications.