The influence of the obesity paradox and chronic kidney disease on long-term survival in a Japanese cohort with peripheral arterial disease

BackgroundThis study analyzed risk factors for mortality in peripheral arterial disease (PAD), including body mass index (BMI) and estimated glomerular filtration rate (eGFR). Risk factors for long-term survival are unclear in patients with PAD. The origin of the obesity paradox, a paradoxical decrease in mortality with increasing BMI, is also uncertain in these patients.MethodsA prospective cohort study was performed in 652 patients (aged 71.3 ± 9.4 years old) with PAD.ResultsThe 1-, 5-, 10- and 15-year survival rates were 94.5%, 70.4%, 45.2%, and 21.1%, respectively, in patients with intermittent claudication, and 72.7%, 27.2%, 11.6%, and 5.8%, respectively, in those with critical limb ischemia (CLI). In Cox multivariate analysis, a significant association with all-cause mortality was found for CLI (hazard ratio [HR], 1.931; 95% confidence interval [CI], 1.089-3.422; P = .024), diabetes (HR, 2.111; 95% CI, 1.247-3.572; P = .005), BMI (HR, 0.879; 95% CI, 0.804-0.962; P = .005), and eGFR (HR, 0.985; 95% CI, 0.971-0.998l; P = .028). These parameters were also significant risk factors for cardiovascular mortality. Fibrinogen (HR, 1.003; 95% CI, 1.001-1.005; P = .014) and cerebrovascular disease (HR, 1.730; 95% CI, 1.021-2.930; P = .045) were identified as risk factors for all-cause mortality. The adjusted HR for mortality of BMI <21.5 vs ≥21.5 kg/m2 was 1.772 (95% CI, 1.378-2.279; P < .001). BMI had positive correlations with triglyceride and albumin concentrations and negative correlations with the fibrinogen level and chronic obstructive pulmonary disease (P = .005).ConclusionsLow BMI, eGFR, CLI, and diabetes are significant risk factors for mortality in PAD. The obesity paradox was verified and may be partly explained by low BMI mediated by malnutrition and systemic inflammation due to PAD or chronic obstructive pulmonary disease.