ABSTRACT
The number of patients with diabetes mellitus (DM) in Japan is increasing. Progression of DM leads to the development of diabetic peripheral neuropathy, which causes foot sensory disturbances. This study examined the effect of DM on plantar tactile point pressure sensitivity (TPPS) and identified the site with the highest threshold of plantar TPPS. The subjects were 42 DM patients (aged 71.7±8.2 years) and 122 local elderly residents (aged 72.6±4.8 years). TPPS of eight sites, including the right and left halluces, hallux and fifth toe metatarsal heads, and heels was measured using the Semmes-Weinstein monofilament test. The measurement was performed three times at each site. The results were adopted when all repeated measurements were valid. The Friedman test was used for comparison among the four sites within the same group. The Mann-Whitney U test was used for comparison of sites between groups. A significance level of 5% was adopted. The ages of the DM patients were not significantly different, but the patients had significantly higher TPPS threshold for halluces, and hallux and fifth toe metatarsal heads, compared to the local elderly residents. The TPPS threshold was highest in the heels in both the DM patients and local elderly residents. The threshold of plantar TPPS increases in DM. It is important to evaluate both the forefoot and the heels.