Neuropathy among the diabetes control and complications trial cohort 8 years after trial completion.
OBJECTIVE
To evaluate the impact of prior intensive diabetes therapy on neuropathy among former Diabetes Control and Complications Trial (DCCT) participants.


METHODS
At the conclusion of the DCCT, subjects in the intensive group were encouraged to maintain intensive therapy, and subjects in the conventional group were encouraged to begin intensive therapy. Thereafter, we annually assessed neuropathy as part of the Epidemiology of Diabetes Intervention and Complications (EDIC) study. Neuropathy was defined using the Michigan Neuropathy Screening Instrument (MNSI). We recorded potential adverse consequences of neuropathy.


RESULTS
At the first EDIC examination, 1,257 subjects participated in the neuropathy assessment. Consistent with DCCT results, the former intensive group showed a lower prevalence of neuropathy than the conventional group based on positive questionnaire (1.8 vs. 4.7%; P = 0.003) or examination (17.8 vs. 28.0%; P < 0.0001) results. Despite similar levels of glycemic control, symptoms and signs of neuropathy remained less prevalent among the former intensive group compared with the conventional group. At the beginning of the EDIC study, prior intensive therapy reduced the odds of having symptoms and signs of neuropathy using MNSI criteria by 64% (P = 0.0044) and 45% (P < 0.0001), respectively, with similar odds reductions observed for both neuropathic symptoms (51%, P < 0.0001) and neuropathic signs (43%, P < 0.0001) across 8 years of EDIC follow-up.


CONCLUSIONS
The benefits of 6.5 years of intensive therapy on neuropathy status extended for at least 8 years beyond the end of the DCCT, similar to the findings described for diabetic retinopathy and nephropathy.
Martin
Catherine L
CL
Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Intervention and Complications (EDIC) Research Group, Bethesda, MD 20892, USA.
Albers
James
J
Herman
William H
WH
Cleary
Patricia
P
Waberski
Barbara
B
Greene
Douglas A
DA
Stevens
Martin J
MJ
Feldman
Eva L
EL
D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D003929:Diabetic Neuropathies / Q000150:complications / Q000453:epidemiology / Q000517:prevention & control*; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis; D006306:Health Surveys; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D007328:Insulin / Q000008:administration & dosage / Q000627:therapeutic use*; D011795:Surveys and Questionnaires
D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin