Long-term glycemic control and neurological function in IDDM patients.
OBJECTIVE
To examine the relationship between sensory modalities of neurological function and antecedent glycemic control in IDDM patients.


METHODS
Examinations were conducted on 220 IDDM patients (age at onset < 25 yr, duration < 18 yr) for the presence or absence of the right or left ankle reflex and determination of vibration perception threshold at each medial malleolus and great toe using biothesiometry. These parameters were related to the concurrent HbA1 and to a mean of serial measurements (mean HbA1) over the previous 6 yr.


RESULTS
Ankle reflexes were absent in 39 (right ankle) and 41 (left ankle) patients, respectively. Mean (right + left) ankle and toe VPTs were 8.7 +/- 3.6 and 6.3 +/- 4.2 (mean +/- SD) (arbitrary units), respectively. Both the mean and concurrent HbA1 were significantly different in patients with absent ankle reflexes (11.6 +/- 1.9 and 12.2 +/- 2.8%, respectively) compared with present ankle reflexes (10.3 +/- 1.7, 10.3 +/- 2.1%) (P < 0.0001). Similarly, a present ankle reflex was related to mean HbA1 arbitrarily divided into groups < 10, 10-12, > 12% (P = 0.0009). In contrast, mean ankle VPT (8.0 +/- 2.2, 8.8 +/- 3.1, and 10.3 +/- 6.2) and toe VPT (5.5 +/- 2.2, 6.1 +/- 2.9, and 8.5 +/- 8.2) did not increase significantly with poor glycemic control (P > 0.05). Age, right ankle reflex, retinopathy, 24-h urinary albumin excretion rate, and erect systolic blood pressure were the only independent variables predicting the toe VPT using linear regression analysis.


CONCLUSIONS
These findings support a role for glycemic control in neurological dysfunction in IDDM patients, but also suggest that other unknown factors may be involved.
McCance
D R
DR
Sir George E. Clark Metabolic Unit, Royal Victoria Hospital, Belfast, Northern Ireland.
Atkinson
A B
AB
Hadden
D R
DR
Kennedy
L
L
D000328:Adult; D017668:Age of Onset; D000419:Albuminuria; D000704:Analysis of Variance; D000843:Ankle Joint; D001786:Blood Glucose / Q000378:metabolism*; D001794:Blood Pressure; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000097:blood / Q000503:physiopathology*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008297:Male; D009460:Neurologic Examination; D012018:Reflex; D012684:Sensory Thresholds; D014732:Vibration
D001786:Blood Glucose; D006442:Glycated Hemoglobin