Upper limbs manifestations of diabetic peripheral neuropathy in individuals with and without lower limbs neuropathy

This study verified and compared the characteristics of DPN in the upper limbs of people with DM with and without diagnosis of DPN in the lower limbs.

Fifty-six individuals with DM were assessed for DPN in the lower limbs using the Decision Support System for Classification of Diabetic Polyneuropathy (https://www.usp.br/labimph/fuzzy) and classified as with or without DPN. Next, they were assessed for symptoms of DPN in the upper limbs through an adaptation of the Michigan Neuropathy Screening Instrument, and for tactile (Semmes-Weinstein monofilaments) and vibration (128-Hz tuning fork) sensitivities. Mann-Whitney U and Fisher Exact (X²) tests were used for statistical analysis with a significance level set at 5%. 

Twenty-eight individuals presented with DPN in the lower limbs – Group with DPN (10 women and 18 men; median age of 50.0 years; average DM diagnosis time of 10.82 ± 6.53 years) and 28 did not – Group without DPN (10 women and 18 men; median age of 52.0, range 42.0 – 59.0 years old; average DM diagnosis time of 10.70 ± 7.21 years). The most reported symptoms of DPN in the upper limbs among all patients were tingling (24.59%) and numbness (19.67%). Group with DPN presented more symptoms of DPN in the upper limbs (50.0% of the group with at least one symptom) when compared to Group without DPN (28.6% of the group with at least one symptom) (p = 0.022). Also, Group with DPN showed worse tactile sensitivity in the three hand nerves pathways compared to Group without DPN (radial p = 0.036; median p = 0.006; ulnar p = 0.004), whereas 38.1% in the Group with DPN presented decreased sensitivity in at least one of the hand nerve pathways in comparison to only 23.81% in the Group without DPN. Worse vibration sensitivity in the hands was also observed in Group with DPN (median 5.31 seconds) when compared to Group without DPN (median 2.68 seconds) (p = 0.007).

These early findings indicate that diabetic patients with DPN in the lower limbs are more likely to experience symptoms and altered sensations from DPN in the upper limbs when compared to those without DPN in the lower limbs. This may suggest a progression pattern in DPN, starting with the lower limbs and later affecting the upper limbs.

Most guidelines of DM-related complications do not consider the manifestation of DPN in the upper limbs. Optimizing the assessment and management of DM-related complications is necessary to reduce the increasing burden in general practice, which includes a special concern for the upper limbs to avoid additional impacts on the quality of life.