Prevalence of structural central nervous system abnormalities in early-onset type 1 diabetes mellitus.
OBJECTIVE
To characterize the effects of severe hypoglycemia on the developing brain in children with early-onset type 1 diabetes mellitus (T1DM).


METHODS
Children diagnosed with T1DM before age 6 years were studied. Those with prospectively monitored severe hypoglycemia (coma/seizure; n = 32) were compared with age-matched peers (n = 30) with no history of such events using magnetic resonance imaging. Glycemic control (evaluated based on glycated hemoglobin [HbA(lc)] level), episodes of diabetic ketoacidosis (DKA), and clinical variables were monitored continuously since diagnosis in all subjects.


RESULTS
Mean HbA(lc) from diagnosis and the duration of T1DM were similar in those with and without a history of severe hypoglycemia (9.0% +/- 0.9% vs 8.8% +/- 0.9%; 7.2 +/- 2.7 years vs 6.7 +/- 2.3 years). A high prevalence of central nervous system (CNS) structural abnormalities was detected (29%), and mesial temporal sclerosis (MTS) was detected in 16% of the total sample (n = 62). The presence of MTS was not associated with a history of severe hypoglycemia or DKA. Analysis of brain matter volumes suggested relatively less gray matter density in those subjects with a history of severe hypoglycemia.


CONCLUSIONS
Early age of onset of T1DM per se is associated with a high incidence of CNS abnormalities, particularly MTS, suggesting hippocampal damage. Early-onset severe hypoglycemia may have an effect on gray matter volume.
Ho
Margaret S
MS
Telethon Institute for Child Health Research, Centre for Child Health Research, University of Western Australia, Perth, Australia.
Weller
Narelle J
NJ
Ives
F Jay
FJ
Carne
Christine L
CL
Murray
Katherine
K
Vanden Driesen
Rohan I
RI
Nguyen
Thai P
TP
Robins
Peter D
PD
Bulsara
Max
M
Davis
Elizabeth A
EA
Jones
Timothy W
TW
D017668:Age of Onset; D002493:Central Nervous System Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications* / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D014904:Western Australia / Q000453:epidemiology
D006442:Glycated Hemoglobin