New study demonstrates long term relation between decline of peripheral nerve function and cumulative glycemic control

31 March 2016
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This prospective observational study, conducted for 24 years on patients with diabetes type 1, demonstrated for the first time that peripheral and autonomic nerve dysfunction can be completely prevented by long-term near-normoglycemia, maintained from the diagnosis of type 1 diabetes.

Diabetic polyneuropathy and cardiovascular autonomic neuropathy are common complications of diabetes, causing life altering symptoms such as neuropathic pain, foot ulcers and increasing the risk of mortality. Cumulative glycemic exposure has been recognized as a major factor in the development and progression of neuropathies. However, to date, no strategy for optimizing glucose control has shown to be efficient in fully preventing or delaying the onset of polyneuropathy or cardiovascular complications.

The current study is the first long term prospective study demonstrating that maintaining glycated hemoglobin (HbA1c) levels below 7% from the time of diagnosis can effectively prevent the onset of polyneuropathy and cardiovascular dysfunction.

The study followed 32 newly diagnosed patients with diabetes type 1 for a course of 24 years. During the study period, HbA1c levels were assessed periodically along with a comprehensive array of measurements including: Thermal and Vibration Quantitative Sensory Testing (QST), Nerve Conduction Velocity (NCV) and Heart Rate Variability (HRV) assessments.

The results of a 24 year follow-up demonstrated that patients who did not maintain a mean HbA1c level below 7%, displayed faster decrease in NCV and faster development of QST and HRV impairments. Clinical examination confirmed diabetic polyneuropathy (DSPN) in 64% percent of these patients by the end of the study period. In contrast, none of the patients who maintained good glycemic control were diagnosed with DSPN during the study.

This study confirms that the annual rates of change in NCV, QST and HRV assessments in well controlled patients compared with poorly controlled patients can be used as bio-markers in future clinical trials aiming at the prevention of diabetic neuropathy.

For the full article:

Ziegler D, Behler M, Schroers-Teuber M, Roden M. Near-normoglycaemia and development of neuropathy: a 24-year prospective study from diagnosis of type 1 diabetes. BMJ Open. 2015;5(6):e006559. doi:10.1136/bmjopen-2014-006559. 

http://bmjopen.bmj.com/content/5/6/e006559.long

Further reading about QST. The specific tool used for the Thermal Sensory Testing QST was Medoc’sTSA-II NeuroSensory Analyzer