Genetic variation in the epithelial sodium channel (ENaC) and TRPV1 cation channel and sodium detection and habitual intake

The epithelial sodium channel (ENaC) and non‐specific cation channel TRPV1 may be involved in salt taste perception. Our objective was to determine whether genetic variation in the ENaC (Thr(T)663Ala(A)) and TRPV1 (Ile(I)315Met(M)) genes affects salt taste thresholds and sodium (Na) intake in men (n=28) and women (n=60) aged 20–35 yrs. Taste thresholds were determined using a 3 alternative forced choice staircase model with solutions ranging from 9 x10 −6 to 0.5 mol/L. Na intake was estimated using a 196 item semi‐quantitative food frequency questionnaire and genotyping was conducted using real time PCR. A general linear model adjusting for age and sex was used to compute differences between genotypes. For the T663A polymorphism, Na intake (mean mg/day ± SE) was 2876 ± 306, 2572 ± 143 and 2172 ± 122 mg/day (p=0.02) for the T/T, T/A, and A/A genotypes, respectively. For the I315M polymorphism, Na intake was 2280± 106, 2960 ± 215 and 2087 ± 833 mg/day (p=0.02) for the I/I, I/M and M/M genotypes, respectively. Salt taste thresholds (mean mmol/L ± SE) were not different between either the T663A genotypes (A/A (3.9 ± 0.69), A/T (4.1 ± 0.80), T/T (5.0 ± 1.7), p=0.6) or the I315M genotypes (I/I (4.3 ± 0.49), I/M (2.77 ± 0.49), M/M (10.0 ± 38.5), p=0.07). Our findings indicate that the T663A and I315M polymorphisms may affect Na consumption, but not Na detection. Grant Funding Source : Advanced Food and Materials Network