The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study reported that intensive glucose control as assessed by hemoglobin A1c (HbA1c) reduced the risk of diabetic peripheral neuropathy (DPN) and cardiovascular autonomic neuropathy (CAN) in type 1 diabetes (T1D), with long lasting benefits. We evaluated additional clinical parameters and risk factors that could contribute to the development of DPN and CAN in this cohort. DPN was assessed at three different times and defined as a composite of symptoms, signs, and abnormal nerve conduction studies in ≥2 nerves; CAN was assessed seven different times and defined based on R-R variation, Valsalva maneuver, and postural changes in blood pressure. Generalized estimating equation models were used to evaluate the association of DPN and CAN with individual risk factors over repeated time points spanning 30 years. Among 1,441 DCCT/EDIC participants, 32% developed DPN and 44% developed CAN. Higher mean HbA1c was the most significant risk factor for DPN (OR=1.56 per 1%, 95% CI 1.41,1.72). DPN was also associated with older age (1.43 per 5 years, 95% CI 1.31,1.55), longer duration of T1D, higher albuminuria, β-blocker use, higher mean diastolic blood pressure, and higher HbA1c at DCCT eligibility. CAN was associated (in order) with older age (1.51 per 5 years, 95% CI 1.40,1.63), longer duration of T1D (1.07 per 1 year, 95% CI 1.05,1.10), any sustained microalbuminuria (AER ≥30 mg/24 hour on two consecutive visits), higher mean HbA1c, higher mean and current pulse rate (likely as an indirect measure of CAN), higher mean systolic blood pressure, β-blocker use, any eGFR <60 mL/min/1.73 m2, higher HbA1c at DCCT eligibility, and current cigarette smoking. Higher mean HbA1c was the strongest risk factor for DPN, but not of CAN. These findings help identify patient phenotypes and modifiable risk factors for personalized approaches to neuropathy prevention.
B. Braffett: None. R. Gubitosi-Klug: None. J.W. Albers: Consultant; Self; Eli Lilly and Company. E.L. Feldman: None. C. Martin: None. N.H. White: None. T.J. Orchard: Consultant; Self; Boehringer Ingelheim International GmbH. M.F. Lopes-Virella: None. P. Raskin: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Gan & Lee Pharmaceuticals, Novo Nordisk A/S. R. Pop-Busui: Consultant; Self; Novo Nordisk A/S. Research Support; Self; AstraZeneca. Other Relationship; Self; American Diabetes Association.
Division of Diabetes Endocrinology & Metabolic Diseases (U01DK094176, U01DK094157); National Eye Institute; National Institute of Neurologic Disorders and Stroke; General Clinical Research Centers Program; Clinical Translational Science Center