High-throughput 1H NMR-based metabolic analysis of human serum and urine for large-scale epidemiological studies: validation study

• Published in: International journal of epidemiology 2008-04, Vol.37 (suppl-1), p.i31-i40
• Main Authors: Barton, Richard H, Nicholson, Jeremy K, Elliott, Paul, Holmes, Elaine
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biological Specimen Banks; Blood Chemical Analysis - standards; Cryopreservation; Humans; Medical sciences; Metabonomics; Miscellaneous; molecular epidemiology; multivariate; NMR; Nuclear Magnetic Resonance, Biomolecular - methods; Pilot Projects; Practice Guidelines as Topic; Public health. Hygiene; Public health. Hygiene-occupational medicine; serum; Serum - chemistry; Specimen Handling - methods; Time Factors; United Kingdom; Urinalysis - standards; urine; Urine - chemistry
• ISSN: 0300-5771; 1464-3685
• DOI: 10.1093/ije/dym284

Background Metabolic profiling of biofluid specimens is an established method for investigating disease states in clinical studies but is only recently being applied to large-scale human population studies. As part of protocol development for the UK Biobank study, a 1H nuclear magnetic resonance (NMR)-based metabonomic analysis of specimen storage effects and analytical reproducibility was carried out using urine and serum specimens from 40 volunteers. Methods Aliquots of each specimen were stored for t = 0 and t = 24 h at 4°C prior to freezing, and in the case of serum samples for a further 12 h (t = 36), to determine whether the storage times affected specimen composition and quality. A blinded split-specimen matching exercise was implemented to assign candidate spectral pairs stored for different times using multivariate statistical analysis of the NMR data. Results Using a chemometric strategy, split specimens at time t = 0 and t = 24 or 36 h after storage at 4°C were easily paired and the split-specimen matching task was reduced to a workable size. 1H NMR profiling established that the t = 24 h urine and serum groups showed no systematic metabolite changes, indicating biochemical stability. Some small differences in serum specimens stored for t = 36 h at 4°C were detectable only by multivariate analysis, and were attributed to generalized alterations in proteins and protein fragments, and possibly trimethylamine-N-oxide. No other specific metabolite was implicated. Conclusions For the purposes of NMR-based analysis, storage of urine and serum for up to t = 24 h at 4°C does not detectably affect the metabolic profile and the methodology is robust. Future application of multivariate methods to data-rich studies should substantially enhance information recovery from epidemiological studies.