Aims: This study investigated the influencing factors of foot plantar pressure and attempted to find practical indicators to predict abnormal foot pressure in patients with type 2 diabetes mellitus (T2DM).
Subjects and methods: Vibration perception threshold (VPT) and foot plantar pressure in 1,126 T2DM outpatients were examined. Patients were assigned to Group A (n=599), Group B (n=312), and Group C (n=215) according to VPT values and to Group I (n=555), Group II (n=436), and Group III (n=135) based on body mass index (BMI). The clinical characteristics and pressure-time integral (PTI) were compared among the three groups, and the associated factors of the total PTI in the entire foot (T-PTI) were analyzed.
Results: PTI of Group C in heel medial and heel lateral was significantly higher than that of Group A (all P<0.01). PTI of Group B in the right fifth metatarsal and heel medial was significantly higher than that of Group A (all P<0.05). T-PTI of Group C was significantly higher than those of Groups A and B, and that of Group B was higher than that of Group A (all P<0.01). PTI of Groups II and III in the second, third, and fourth metatarsal, midfoot, heel medial, and heel lateral was significantly higher than that of Group I (all P<0.05). T-PTI of Groups II and III was significantly higher than that of Group I (all P<0.01). Pearson correlation analysis showed that T-PTI was positively associated with age, VPT, waist circumference, waist-to-hip ratio, and BMI (P<0.05). In multiple stepwise regression analysis, VPT (P=0.004) and BMI (P=0.000) were independent risk factors of T-PTI, and each 1 unit increase in BMI increased the T-PTI by 5.962 kPa•s. Receiver operator characteristic curve analysis further revealed that the optimal cutpoint of VPT and BMI to predict the abnormal PTI was 21 V (odds ratio=2.33, 95% confidence interval 1.67-3.25) and 24.9 kg/m(2) (odds ratio=2.12, 95% confidence interval 1.55-2.90), respectively.
Conclusions: Having a VPT higher than 21 V and a BMI above 24.9 kg/m(2) increases the risk of excessive foot plantar pressure in Chinese T2DM.