Association of folate with hearing is dependent on the 5,10-methylenetetrahdyrofolate reductase 677C-->T mutation.
Vascular disease and its risk factors have been associated with the age-related hearing loss. We examined the association of elevated plasma homocysteine and its determinants with hearing levels. Pure-tone air conduction thresholds in 728 individuals with sensorineural hearing loss were not associated with homocysteine, erythrocyte folate and Vitamin B6. Low concentrations of serum folate and Vitamin B12 were associated with better hearing. When folate status was below the median, 5,10-methylenetetrahydrofolate reductase (MTHFR) 677TT homozygotes had similar hearing levels to subjects with a C allele. However, when folate status was above the median, MTHFR 677TT homozygotes had on an average 5 dB (p = 0.037) and 2.6 dB (p = 0.021) lower PTA-high and PTA-low hearing thresholds, respectively, than the subjects with a 677C allele. The relationship between serum folate and hearing thresholds appeared to be dependent on MTHFR 677 genotype (CC, r = 0.13, p = 0.034; TT, r = -0.10, p = 0.291). This supports the hypothesis that a greater one-carbon moiety commitment to de novo synthesis of nucleotides and an increase in formyl-folate derivatives relative to methyl-folate derivatives is protective for hearing.
Durga
Jane
J
Division of Human Nutrition, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands. jane.durga@wur.nl
Anteunis
Lucien J C
LJ
Schouten
Evert G
EG
Bots
Michiel L
ML
Kok
Frans J
FJ
Verhoef
Petra
P
D045103:5,10-Methylenetetrahydrofolate Reductase (FADH2) / Q000097:blood* / Q000235:genetics*; D000368:Aged; D001309:Auditory Threshold; D005260:Female; D005492:Folic Acid / Q000097:blood*; D020022:Genetic Predisposition to Disease; D006319:Hearing Loss, Sensorineural / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009426:Netherlands / Q000453:epidemiology; D011110:Polymorphism, Genetic; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012720:Severity of Illness Index; D014805:Vitamin B 12 / Q000097:blood
D006710:Homocysteine; D005492:Folic Acid; D045103:5,10-Methylenetetrahydrofolate Reductase (FADH2); D014805:Vitamin B 12