title: Metabolic Phenotype of Obesity in a Saudi Population.
abstract: Metabolic phenotyping of obese populations can shed light on understanding environmental interactions underpinning obesogenesis. Obesity and its comorbidities are a major health and socioeconomic concern globally and are highly prevalent in the Middle East. We employed nuclear magnetic resonance spectroscopy to characterize the metabolic signature of urine and blood plasma for a cohort of obese (n = 50) compared to non-obese (n = 48) Saudi participants. The urinary metabolic phenotype of obesity was characterized by higher concentrations of N-acetyl glycoprotein fragments, bile acids, lysine, and methylamines and lower concentrations of tricarboxylic acid cycle intermediates, glycine, and gut microbial metabolites. The plasma metabolic phenotype of obesity was dominated by sugars, branched chain amino acids, and lipids, particularly unsaturated lipids, with lower levels of plasma phosphorylcholine and HDL. Serum hepatic enzymes, triglycerides, and cholesterol mapped to specific metabolic phenotypes, potentially indicating the dysregulation of multiple distinct obesity-related pathways. Differences between urine and plasma phenotypes of obesity for this Saudi population and that reported for Caucasian individuals indicate population disparities in pathways relating to ketogenesis (more apparent in the Saudi obese population), dysregulated liver function, and the gut microbiome. Mapping population-specific metabolic perturbations may hold promise in establishing population differences relevant to disease risk and stratification of individuals with respect to discovery of new therapeutic targets.
authors.forename: Muhammad Saeed
authors.identifier: 0000-0003-1945-2739
authors.initials: MS
authors.lastname: Ahmad
authors.affiliation: Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London , South Kensington, London SW7 2AZ, United Kingdom.
authors.forename: Munirah
authors.initials: M
authors.lastname: Alsaleh
authors.affiliation: Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London , South Kensington, London SW7 2AZ, United Kingdom.
authors.forename: Torben
authors.initials: T
authors.lastname: Kimhofer
authors.forename: Sultan
authors.initials: S
authors.lastname: Ahmad
authors.affiliation: Department of Surgery, Faculty of Medicine, University of Jeddah , Jeddah 21589, Saudi Arabia.
authors.forename: Wisam
authors.initials: W
authors.lastname: Jamal
authors.forename: Siraj Omar
authors.initials: SO
authors.lastname: Wali
authors.affiliation: Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London , South Kensington, London SW7 2AZ, United Kingdom.
authors.forename: Jeremy Kirk
authors.initials: JK
authors.lastname: Nicholson
authors.forename: Zoheir Abdullah
authors.initials: ZA
authors.lastname: Damanhouri
authors.affiliation: Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London , South Kensington, London SW7 2AZ, United Kingdom.
authors.forename: Elaine
authors.identifier: 0000-0002-0556-8389
authors.initials: E
authors.lastname: Holmes
mesh_terms: D000293:Adolescent; D000328:Adult; D000597:Amino Acids, Branched-Chain / Q000097:blood*; D001647:Bile Acids and Salts / Q000652:urine; D001786:Blood Glucose; D002784:Cholesterol / Q000097:blood; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008239:Lysine / Q000652:urine; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D055432:Metabolomics / Q000379:methods; D008744:Methylamines / Q000652:urine; D009765:Obesity / Q000097:blood* / Q000473:pathology / Q000652:urine*; D012529:Saudi Arabia; D014280:Triglycerides / Q000097:blood
chemical_list: D000597:Amino Acids, Branched-Chain; D001647:Bile Acids and Salts; D001786:Blood Glucose; D008744:Methylamines; D014280:Triglycerides; D002784:Cholesterol; D008239:Lysine
keywords: NMR; metabolic profiling; metabonomics; obesity