The effect of obesity on the assessment of diabetic peripheral neuropathy: a comparison of Michigan patient version test and Michigan physical assessment.

Objective: Nerve conduction studies (NCS) and Michigan Neuropathy Screening Instrument (MNSI) are commonly used to make the diagnosis of diabetic peripheral neuropathy. The objective of this study was to compare the diagnostic values of MNSI patient version test and physical test for the assessment of the diabetic peripheral neuropathy in obese vs. non-obese patients.

Method: This study was conducted on 70 type 2 diabetic patients. We carried out the MNSI patient version test and MNSI physical assessment test. Nerve conduction studies were performed for the diagnosis of the diabetic peripheral neuropathy.

Results: In diabetic peripheral neuropathy (DPN) determined by NCS, the independent prediction of peripheral neuropathy was the score of Michigan physical assessment (odds 2.0; CI: 1.3-3.0). In BMI (body mass index) ≥ 30 diabetic patients who have peripheral neuropathy, Michigan patient version test is not significant. But the score of Michigan physical assessment is significantly increased in these patients compared to patients without peripheral neuropathy. In BMI<30 diabetic patients who have peripheral neuropathy, scores of both Michigan patient version and physical assessment instruments are significantly increased.

Conclusion: To screen diabetic peripheral neuropathy, Michigan physical assessment may be more useful instrument than Michigan patient version test in obese diabetic patients.