Prediabetes associated with early changes in walking variables
Biomechanical changes to the natural walking strategy begin with impaired glucose tolerance, before development of type 2 diabetes. The changes, associated with small fiber neuropathy, include a reduction in ankle joint power, greater step width and increased unsteadiness, according to recent findings.
“This is the first study to show an early alteration in the natural walking strategy and dynamic sway in people with IGT, which was similar to that in people with type 2 diabetes,” Neil D. Reeves, PhD, professor of musculoskeletal biomechanics at the School of Healthcare Science at Manchester Metropolitan University, United Kingdom, and colleagues wrote. “This challenges the belief that balance impairment during walking only occurs in people with diabetes and advanced large fiber neuropathy. Furthermore, we show that small rather than large fiber abnormalities are more strongly associated with balance impairment.”
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Reeves and colleagues analyzed data from 60 adults: 20 with type 2 diabetes (15 men; eight with mild neuropathy); 20 with IGT (16 men; 10 with neuropathy) and 20 with normal glucose tolerance (controls; 13 men). Participants underwent assessments of gait, ankle joint strength, and power and dynamic sway during walking. Researchers assessed neuropathy status and levels of serum 25-hydroxyvitamin D.
In assessing neuropathy status, researchers found that neuropathy disability scores were higher for those with IGT (P = .02) or type 2 diabetes (P = .04) vs. controls. Corneal nerve fiber density was also lower in participants with IGT (P = .004) and type 2 diabetes (P = .004) vs. controls; however, corneal nerve branch density was lower only in participants with IGT (P = .002) vs. controls.
During walking, peak ankle plantar flexion strength and power were lower in participants with type 2 diabetes vs. those with IGT or controls (P = .01 and .003, respectively). Those with type 2 diabetes also had a slower walking speed vs. controls (P = .008).
Among participants with IGT, dynamic walking sway was higher (P = .007), whereas posterior maximal movement was lower (P < .0001) vs. controls, according to researchers. There were no between-group differences for step length, but researchers observed a greater step width in participants with IGT vs. controls (P = .005).
Researchers also found that dynamic medio-lateral sway was associated with corneal nerve fiber length (P = .001) and corneal nerve branch density (P = .001), but not vibration perception threshold (P = .19).
Vitamin D status (low vs. normal) was not associated with walking variables or dynamic sway.
The researchers noted that the study did not include participants with severe diabetic neuropathy or vitamin D deficiency, which can limit translation to the general diabetes population, and walking in a more challenging environment, such as stairs, was not assessed.
“There are two main take-home messages,” Reeves told Endocrine Today. “Firstly, that gait is not only impaired when a person has diabetes, but we show here significant gait and balance are affected before people even develop diabetes. The second key point would be that in this study we show how measurements of small fiber neuropathy (taken by measuring small nerve fibers in the eye) seem to be an early indicator of balance problems in people with diabetes and IGT.” – by Regina Schaffer
For more information:
Neil D. Reeves, PhD, can be reached at the School of Healthcare Science at Manchester Metropolitan University, John Dalton Building, Oxford Road, Manchester M1 5GD, UK; email: N.Reeves@mmu.ac.uk.
Disclosure: The NIH and JDRF funded this study. The researchers report no relevant financial disclosures.