Introduction: In this retrospective cohort study, we compared HbA1c levels of all diabetic patients with foot infections, and between those treated with major amputation (below-knee and above-knee) or conservatively.
Methods: After ethics review board approval, a systematized chart review was performed. Three-hundred two feet from 264 consecutive patient referrals were enrolled in the study from January 1 to December 31, 2014. HbA1c result upon admission and routine histopathology of amputated limb posterior tibial artery were collected and tabulated in a spreadsheet, together with demographic and clinical data.
Results: Majority of the patients were males (58.94%). The mean HbA1c of study participants was 9.81% (SD: 2.89%). Majority (78.15%) had uncontrolled blood sugar (HbA1c >7.0%). Forty-five percent underwent major amputation. The mean HbA1c of patients who did not undergo surgery was 7.89% (SD: 2.41%) while patients with major surgery had 11.20% (SD: 2.68%). The mean percentage for posterior tibial artery occlusion among amputated limbs was 31.46% n=135 (95% CI: 27.01% to 35.91%). On univariate analysis using linear regression analysis, Hba1c correlates with percentage occlusion in posterior tibial artery (F value=57.17, R square=0.1601, p value=0.000). Based on the linear regression analysis equation, the lowest HbA1c level that could predict a 90% occlusion of the posterior tibial artery is 14.11%.
Conclusion: Patients with poor glucose control have higher incidence of undergoing major amputation. Among amputees, poor glucose control is associated with increased occlusion in the posterior tibial artery.