A 14-year prospective study of autonomic nerve function in Type 1 diabetic patients: association with nephropathy.
OBJECTIVE
Prospective studies of autonomic nerve function are rare. We have followed the progression of autonomic dysfunction in relation to nephropathy over 14 years in Type 1 diabetic patients.


METHODS
Autonomic nerve function was assessed by heart-rate responses to deep breathing (E/I ratio) and tilting (acceleration and brake indices) and by the postural blood pressure reaction in 58 patients, 43 of whom were reassessed after 14 years. Nephropathy was evaluated by the degree of albuminuria (albuminuria > 20 micro g/min or > 0.03 g/24 h) and glomerular filtration rate ((51)Cr-EDTA plasma clearance). The acceleration index had deteriorated after 7 years (P = 0.0155), whereas the E/I ratio (P = 0.0070) and the diastolic postural blood pressure reaction (P = 0.0054) had deteriorated 14 years after the baseline examination (age-corrected values). All those with albuminuria at the third examination showed signs of autonomic neuropathy at baseline (10 of 10) compared with only nine of 22 without (P = 0.0016). Multiple regression analysis showed that the association between autonomic dysfunction and future albuminuria was due to the E/I ratio. In addition, individuals with an abnormal postural diastolic blood pressure fall (n = 7) at baseline showed a greater fall in glomerular filtration rate more than others 7-14 years later [29 (16.5) ml/min/1.72 m(2) vs. 11 (9) ml/min/1.72 m(2); P = 0.0074].


CONCLUSIONS
Autonomic nerve function had deteriorated after 14 years. Autonomic neuropathy and abnormal postural diastolic blood pressure falls at baseline were associated with future renal complications.
Forsén
A
A
Department of Endocrinology, Lund University, Malmo University Hospital, Malmo, Sweden.
Kangro
M
M
Sterner
G
G
Norrgren
K
K
Thorsson
O
O
Wollmer
P
P
Sundkvist
G
G
D000293:Adolescent; D000328:Adult; D000419:Albuminuria / Q000209:etiology / Q000503:physiopathology; D001342:Autonomic Nervous System Diseases / Q000209:etiology* / Q000503:physiopathology; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D003922:Diabetes Mellitus, Type 1 / Q000209:etiology* / Q000503:physiopathology; D003929:Diabetic Neuropathies / Q000209:etiology* / Q000503:physiopathology; D005500:Follow-Up Studies; D006331:Heart Diseases / Q000209:etiology / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies
D001786:Blood Glucose