Physical Activity and Nerve Structure and Function in Patients with Long-Standing Type 1 Diabetes

Physical activity (PA) is recommended for patients with diabetes to improve glycemic control. In prediabetes and T2D there is a causal relationship between PA and peripheral nerve health; however, the effect of PA on nerve structure and function in longstanding T1D is unclear. We aimed to determine the relationship between PA and small nerve fiber morphology, large nerve fiber function and cardiac autonomic function in this population. Data from 75 participants was collected as part of the Canadian Study of Longevity in T1D. Participants completed a physical exam, medical history and neuropathy assessment including nerve conduction studies (NCS), corneal confocal microscopy measurement of corneal nerve fiber length (CNFL) and assessment of heart rate variability. Participants also reported their daily PA from the preceding 12-months. There were 41(55%) female participants, mean ± SD age was 66 ± 8 years, median duration of diabetes was 54 [52,58] years, BMI was 26.6 ± 3.8, HbA1c of 7.3 ± 0.8. 65(89%) participants met the criteria for diagnosis of diabetic neuropathy. The weekly mean PA time was 156 ± 132 min and 35(47%) reported ≧150 minutes/week. PA time was associated with a greater cooling detection threshold (r=0.24; p=0.043), higher peroneal and sural amplitude (r=0.36; p=0.0017, rs=0.26; p=0.024) and conduction velocity (rs=0.28; p=0.015, r=0.23; p=0.050). Vibration perception threshold at the toe was inversely associated with PA (r=-0.31; p=0.025), whereas there was no association at the finger. There was no association between PA time and heart rate variability (r=-0.040; p=0.74) or CNFL (r=0.23; p=0.055). Linear regression for NCS, adjusting for age and A1c, showed that for each 30 min of PA there was an 0.09 mv higher peroneal amplitude (p=0.032) and 0.048 ms lower peroneal F-wave latency (p=0.022). In individuals with longstanding T1D, PA is associated with substantially better large nerve fiber function in the lower limbs and some better measures of small nerve fiber function. Disclosure E. J. H. Lewis: Board Member; Self; Nutarniq Corp, Board Member; Spouse/Partner; Nutarniq Corp, Research Support; Self; Canadian Institutes of Health Research. B. A. Perkins: Advisory Panel; Self; Abbott Diabetes, Boehringer Ingelheim International GmbH, Insulet Corporation, Novo Nordisk Canada Inc., Other Relationship; Self; Abbott Diabetes, Medtronic, Novo Nordisk Canada Inc. L. Lovblom: None. S. O. Lanctot: None. D. Scarr: None. N. Cardinez: None. A. Weisman: None. M. H. Brent: Advisory Panel; Self; Novartis Pharmaceuticals Canada Inc., Roche Canada, Research Support; Self; Bayer AG, Novartis Pharmaceuticals Canada Inc. V. Bril: Advisory Panel; Self; Akcea Therapeutics, Alnylam Pharmaceuticals, Inc., CSL Behring, Sanofi Genzyme, Consultant; Self; Janssen Research & Development, LLC, Research Support; Self; Takeda Canada. D. Cherney: Other Relationship; Self; AbbVie Inc., AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Janssen Scientific Affairs, LLC., Lilly Diabetes, Merck & Co., Inc., Mitsubishi-Tanabe, Maze Inc, Prometic, Novo Nordisk, Sanofi. Funding JDRF (17-2013-312)