Risk factors for major amputation in patients with diabetic foot: a Meta-analysis

Objective We conducted a systematic review and meta-analysis to clarify risk factors for major amputation in patients with diabetic foot. Methods Observational studies of risk factors for major amputation in patients with diabetic foot published before September 2017 were searched on PubMed and EMBASE. Analysis was performed using Stata 12.0 statistical software and study quality was rated by Newcastle-Ottawa scale (NOS). Results Ten observational studies was identified with 659 major amputation patients and 4 905 controls. Across studies, the overall odds ratios (OR) and 95% confidence intervals (95%CI) of significant risk factors were the depth of ulcer involved bone (OR=11.80, 95%CI 6.90-20.15), dialysis (OR=5.19, 95%CI 2.69-10.04), peripheral arterial disease (PAD) (OR=4.80, 95%CI 2.22-10.36), gangrene (OR=4.67, 95%CI 1.62-13.48), hind foot position (OR=3.64, 95%CI 1.19-11.13), decreased ankle brachial index (ABI) (OR=3.36, 95%CI 1.51-7.52), lower albumin levels (OR=3.13, 95%CI 1.82-5.37), anemia (OR=2.66, 95%CI 1.22-5.79), infection (OR=2.52, 95%CI 1.71-3.71), elevated serum creatinine (OR=1.19, 95%CI 1.08-1.31), ischemic heart disease (IHD) (OR=1.39, 95%CI 1.05-1.84). While there were no significant difference in white blood cell (WBC), C reactive protein (CRP), diabetic peripheral neuropathy (DPN), glycated hemoglobin A1c (HbA1c), hypertension and Charcot foot (all P>0.05). Conclusion Factors associated with major amputation in patients with diabetic foot are the depth of ulcer involved bone, dialysis, PAD, gangrene, hind foot position, decreased ABI, lower albumin levels, IHD, there is no relation with WBC, CRP, HbA1c, DPN, hypertension and charcot foot.