Title : Impact of nutritional status on limb salvage in critical limb ischemia: A retrospective analysis from a multidisciplinary program
Abstract:
Background: The prevalence of Critical Limb Ischemia (CLI) is rising globally, and elderly patients often progress to major lower-limb amputation, resulting in loss of mobility and long-term disability. Our multidisciplinary limb-salvage program integrates revascularization therapy, bone marrow transplantation to promote angiogenesis, maggot debridement therapy as a minimally invasive wound-bed preparation method, infection management, glycemic optimization, antiplatelet therapy, and structured nutritional intervention. Because wound healing depends heavily on nutritional reserves, we evaluated which indicators best predict limb outcomes.
Methods: We conducted a retrospective cohort analysis of 293 CLI patients presenting with rest pain or ischemic leg ulceration (mean age 67±13 years). Patients were recruited at Nippon Medical School Hospital, Tokyo, Japan, between April 2002 and March 2017, with a mean follow-up duration of 10.6 years. Variables included BMI, Basal Energy Expenditure (BEE), hemoglobin, serum albumin, inflammatory markers, renal function, and the Controlling Nutritional Status (CONUT) score. The CONUT score is a validated nutritional screening tool incorporating serum albumin as an indicator of protein reserve, total lymphocyte count as a marker of immune competence, and total cholesterol as a reflection of caloric and lipid metabolism. Higher scores indicate poorer nutritional status. The primary outcome was major lower-limb amputation.
Results: During follow-up, major amputation was avoided in 80.6% of patients. Independent predictors of limb loss included hemodialysis dependence (p<0.001), ischemic leg ulceration (p=0.005), elevated CRP (p=0.012), hypoalbuminemia (p=0.017), and higher CONUT score (p<0.001). A cutoff value of ≥3.5 was strongly associated with increased amputation risk, underscoring the clinical utility of the CONUT score as a practical prognostic marker in CLI.
Conclusion: The CONUT score is a decisive factor in predicting limb salvage among patients with CLI. Early nutritional screening and timely intervention are essential. Strategies that improve albumin levels through adequate protein intake and inflammation control, enhance immune function by treating infection and correcting micronutrient deficiencies, and support caloric and lipid metabolism through appropriate energy provision may help reduce CONUT scores and promote better limb outcomes. Integrating targeted nutritional therapy into multidisciplinary CLI management may substantially reduce the risk of major amputation.
