Hathairat Sawaengsri1, Peter R Bergethon2, Wei Qiao Qiu3, Tammy M Scott1, Paul F Jacques1, Jacob Selhub1, Ligi Paul4. 1. Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA. 2. Neuroscience and Pain Research Unit, Pfizer Inc., Cambridge, MA; and. 3. Boston University School of Medicine, Boston, MA. 4. Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA; ligi.paul_pottenplackel@tufts.edu.
Abstract
BACKGROUND: The 776C→G polymorphism of the vitamin B-12 transport protein transcobalamin gene (TCN2) (rs1801198; Pro259Arg) is associated with a lower holotranscobalamin concentration in plasma. This effect may reduce the availability of vitamin B-12 to tissues even when vitamin B-12 intake is adequate. Clinical outcomes associated with vitamin B-12 insufficiency could potentially be worsened by high folate intake. OBJECTIVE: We determined the association of the TCN2 776C→G polymorphism and folate intake with peripheral neuropathy in elders with normal plasma concentrations of vitamin B-12. DESIGN: Participants in this cross-sectional study (n = 171) were from a cohort of community-based, home-bound elderly individuals aged ≥60 y who underwent an evaluation by physicians including an assessment for peripheral neuropathy. Participants were administered food-frequency and general health status questionnaires, anthropometric measurements were taken, and a fasting blood sample from each subject was collected. RESULTS: Odds of neuropathy were 3-fold higher for GG genotypes than for CC genotypes (OR: 3.33; 95% CI: 1.15, 9.64). When folate intake was >2 times the Recommended Dietary Allowance (800 μg), GG genotypes had 6.9-fold higher odds of neuropathy than CC genotypes (OR: 6.9; 95% CI: 1.31, 36.36). There was no difference between the genotypes in the odds of peripheral neuropathy when folate intake was ≤800 μg (OR: 1.5; 95% CI: 0.18, 12.33). CONCLUSION: The TCN2 776C→G polymorphism is associated with increased odds of peripheral neuropathy in the elderly, even with a normal vitamin B-12 status, especially if their folate intake is >2 times the Recommended Dietary Allowance.
BACKGROUND: The 776C→G polymorphism of the vitamin B-12 transport protein transcobalamin gene (TCN2) (rs1801198; Pro259Arg) is associated with a lower holotranscobalamin concentration in plasma. This effect may reduce the availability of vitamin B-12 to tissues even when vitamin B-12 intake is adequate. Clinical outcomes associated with vitamin B-12insufficiency could potentially be worsened by high folate intake. OBJECTIVE: We determined the association of the TCN2 776C→G polymorphism and folate intake with peripheral neuropathy in elders with normal plasma concentrations of vitamin B-12. DESIGN:Participants in this cross-sectional study (n = 171) were from a cohort of community-based, home-bound elderly individuals aged ≥60 y who underwent an evaluation by physicians including an assessment for peripheral neuropathy. Participants were administered food-frequency and general health status questionnaires, anthropometric measurements were taken, and a fasting blood sample from each subject was collected. RESULTS: Odds of neuropathy were 3-fold higher for GG genotypes than for CC genotypes (OR: 3.33; 95% CI: 1.15, 9.64). When folate intake was >2 times the Recommended Dietary Allowance (800 μg), GG genotypes had 6.9-fold higher odds of neuropathy than CC genotypes (OR: 6.9; 95% CI: 1.31, 36.36). There was no difference between the genotypes in the odds of peripheral neuropathy when folate intake was ≤800 μg (OR: 1.5; 95% CI: 0.18, 12.33). CONCLUSION: The TCN2 776C→G polymorphism is associated with increased odds of peripheral neuropathy in the elderly, even with a normal vitamin B-12 status, especially if their folate intake is >2 times the Recommended Dietary Allowance.
Authors: Lindsay H Allen; Joshua W Miller; Lisette de Groot; Irwin H Rosenberg; A David Smith; Helga Refsum; Daniel J Raiten Journal: J Nutr Date: 2018-12-01 Impact factor: 4.798
Authors: R W Salatto; Graham R McGinnis; Dustin W Davis; Bryson Carrier; Jacob W Manning; Mark DeBeliso; James W Navalta Journal: Int J Environ Res Public Health Date: 2021-07-31 Impact factor: 3.390