Associations between blood glucose and dynamic plantar pressure distribution in pre-DM patients: a cross-sectional study.

BACKGROUND: Prediabetes (Pre-DM) confers an elevated risk of peripheral neuropathy and subsequent diabetic foot complications, yet there is a lack of sufficient research on the biomechanical alterations of plantar pressure distribution associated with glycemic abnormalities. OBJECTIVE: To investigate the relationship between blood glucose and plantar pressure distributions of 11 zones in Pre-DM patients. METHODS: Fifty-five Pre-DM patients were enrolled. Fasting blood glucose (FBG), glycated hemoglobin (HbA1c), and two-hour postprandial plasma glucose (2hPG) levels were measured. Pressure-time integral (PTI), peak force (PF), and mean plantar pressure (MPP) during walking were recorded using the FreeStep plantar pressure measurement system. Spearman's rank correlation analysis was used to assess the associations between three glycemic indicators and plantar pressure parameters. A hierarchical linear regression analysis was conducted to examine the association between blood glucose and the related plantar pressure. RESULTS: Hierarchical linear regression analysis showed that in the first block, BMI was associated with on PF in left HL-L, MPP in left MH2, MPP in left HL-M/L (p < 0.01) and MPP in left MF-M (p< 0.05). Age was also associated with MPP in left MH2 (p< 0.01) and HL-M (p < 0.05). In the second block, 2hPG and HbA1c were independently associated with PTI and PF in left MH1, and 2hPG was associated with PF in left HL-L (p < 0.05); higher blood glucose levels were associated with increased plantar pressure. In contrast, 2hPG and HbA1c were associated with PF in left T2-5 and in both MH5 (p < 0.05); higher blood glucose levels were associated with decreased plantar pressure. FBG had no effect on plantar pressure (p>0.05). CONCLUSION: Our exploratory study provides the first evidence that 2hPG and HbA1c are independently associated with dynamic plantar pressure in Pre-DM patients. Higher glucose levels are associated with increased loading on left MH1 and heel; conversely, with decreased loading on bilateral MH5 and left T2-5. BMI and age are also the independently associated with dynamic plantar pressure in the left foot.