Use of graded Semmes Weinstein monofilament testing for ascertaining peripheral neuropathy in people with and without diabetes

Aims: To assess peripheral neuropathy (PN) using graded Semmes Weinstein monofilaments (SWMs) and determine factors associated with PN among adult volunteers with and without diabetes.

Methods: Adult volunteers were assessed for distal sensory PN using three graded SWMs. Four PN levels were defined: 0 (no PN; felt all three filaments), 1 (subclinical PN; insensate to 1-g filament), 2 (insensate to 10-g), or 3 (insensate to 75-g). Levels 2-3 were considered clinical PN. Associations with PN were determined using ordinal logistic regression.

Results: In 1564 subjects (median age 41.9 years, 50.1% women), PN was subclinical or worse in 68.9% and clinical in 11.2%. Age-sex-race-adjusted prevalence of clinical PN was greater in people with diabetes (15.3%) than without (6.1%; P < 0.001). Associated factors included older age, male sex, greater BMI, greater heart rate, lower mean arterial pressure, and family history of diabetes or cardiovascular diseases. Higher PN levels associated with worse albuminuria and retinopathy. Only older age and male sex associated with PN both in people with and without diabetes.

Conclusions: PN is common in our sample, notably in those without diabetes, although diabetes greatly increases its risk. Using graded SWMs may have a prognostic value as it permits the identification of subclinical PN.