Fig. 4.

Orthogonal projection to latent structures discriminant analysis score plots (left panel) and the corresponding coefficient loading plots (right panel) based on the ¹H nuclear magnetic resonance spectra of (a) plasma, (b) urine and (c) tissue metabolites obtained from the patients with ankylosing spondylitis (red circles) and from the healthy control subjects and patients with femoral neck fracture (black squares). 2-PY 2-Pyridone-3-carboxamide, 4-CG 4-Cresol glucuronide, Ace Acetate, Ala Alanine, Crea Creatinine, GL Glycerol of lipids, Gln Glutamine, Glu Glutamate, Gly Glycine, GPC Glycerophosphocholine, His Histidine, Ile Isoleucine, L1 CH ₃(CH₂)n., L2 CH ₃CH₂CH₂C=, L3 -(CH ₂)n-, L4 CH ₂CH₂CO, L5 -CH ₂C = C-, L6 CH ₂CO, L7 C = CCH ₂C = C, L8 -CH = CH-, Lac Lactate, Leu Leucine, Lys Lysine, Met Methionine, NAG N-acetyl glycoprotein, PAG Phenylacetylglycine, Phe Phenylalanine, Pyr Pyruvate, Tyr Tyrosine, Val Valine