DISCONTINUOUS DISTRIBUTION OF N-OXIDATION OF DIETARY-DERIVED TRIMETHYLAMINE IN A BRITISH POPULATION

1. Whilst the majority of individuals within a British white populatio n are able to convert > 90% of their dietary-derived trimethylamine to its N-oxide, outliers exist who show varying degrees of decreased met abolism. Such individuals, excrete unoxidized trimethylamine in their urine and, if N-oxidation is sufficiently low, may experience malodour problems (Fish-Odour Syndrome). 2. Such observations have now been ex tended to a much larger group (n = 421; 221 males) of British white vo lunteers recruited from staff and students of Imperial College Medical School at St Mary's, London. Each subject collected a 0-24-h urine sa mple, which was subsequently analysed for total trimethylamine and tri methylamine N-oxide content. 3. Sixteen subjects (3.8% population; sev en male, nine female) excreted < 90% of their total trimethylamine out put as N-oxide. All six subjects who excreted < 80% as N-oxide (indica tive of potential heterozygous status for deficient N-oxidation-fish o dour syndrome) were female.