GDF15 and peripheral arterial disease: Although none of the mentioned parameters were found to be independent risk factors for obstructive PAD, CRP ([P = .006, β: 1.098, OR [(95% CI): 1.027–1.174]) and GDF-15 ([P = .002, β: 1.002, OR [(95% CI): 1.004–1.010]) were shown to be independent risk factors for lower- extremity ulcers.