BACKGROUND: Several reports have shown an association between homocysteine, cognitive functioning, and survival among the oldest-old. Two common polymorphisms in the genes coding for methylenetetrahydrofolate reductase (MTHFR 677C>T) and methionine synthase (MTR 2756A>G) have an impact on plasma homocysteine level. METHODS: We examined the effect of the MTHFR 677C>T and MTR 2756A>G genotypes on baseline cognitive functioning, cognitive decline over 5 years measured in three assessments, and survival in a population-based cohort of 1581 nonagenarians. Cognitive functioning was assessed by using the Mini-Mental State Examination (MMSE) and five brief cognitive tests (cognitive composite). RESULTS: There are no differences in MMSE score (p =.83) or in cognitive composite (p =.56) at intake as a function of genotype tested by analysis of variance, whereas sex and social group have a impact on MMSE (p < or =.03), and social group on the cognitive composite (p <.01). The mean MMSE was lower for women than for men. However, considering the group participating in all three assessments, there were no sex-related differences in MMSE (p =.34). The cognitive decline in the group participating in all three assessments was investigated using regression models for the relationship between cognitive performance and genotype, age, sex, and social group and revealed no significant difference. Furthermore, the MTHFR 677T and MTR 2756A heterozygous and homozygous genotype had no significant impact on survival, with hazard ratios of 1.05 (95% confidence interval [CI], 0.93-1.17), 0.93 (95% CI, 0.77-1.14), 1.05 (95% CI, 0.94-1.18), and 0.97 (95% CI, 0.74-1.28). CONCLUSIONS: MTHFR and MTR genotypes are not associated with cognitive functioning, cognitive decline, or survival among nonagenarians.
BACKGROUND: Several reports have shown an association between homocysteine, cognitive functioning, and survival among the oldest-old. Two common polymorphisms in the genes coding for methylenetetrahydrofolate reductase (MTHFR 677C>T) and methionine synthase (MTR 2756A>G) have an impact on plasma homocysteine level. METHODS: We examined the effect of the MTHFR 677C>T and MTR 2756A>G genotypes on baseline cognitive functioning, cognitive decline over 5 years measured in three assessments, and survival in a population-based cohort of 1581 nonagenarians. Cognitive functioning was assessed by using the Mini-Mental State Examination (MMSE) and five brief cognitive tests (cognitive composite). RESULTS: There are no differences in MMSE score (p =.83) or in cognitive composite (p =.56) at intake as a function of genotype tested by analysis of variance, whereas sex and social group have a impact on MMSE (p < or =.03), and social group on the cognitive composite (p <.01). The mean MMSE was lower for women than for men. However, considering the group participating in all three assessments, there were no sex-related differences in MMSE (p =.34). The cognitive decline in the group participating in all three assessments was investigated using regression models for the relationship between cognitive performance and genotype, age, sex, and social group and revealed no significant difference. Furthermore, the MTHFR 677T and MTR 2756A heterozygous and homozygous genotype had no significant impact on survival, with hazard ratios of 1.05 (95% confidence interval [CI], 0.93-1.17), 0.93 (95% CI, 0.77-1.14), 1.05 (95% CI, 0.94-1.18), and 0.97 (95% CI, 0.74-1.28). CONCLUSIONS:MTHFR and MTR genotypes are not associated with cognitive functioning, cognitive decline, or survival among nonagenarians.
Authors: Denish Moorthy; Inga Peter; Tammy M Scott; Laurence D Parnell; Chao-Qiang Lai; Jimmy W Crott; José M Ordovás; Jacob Selhub; John Griffith; Irwin H Rosenberg; Katherine L Tucker; Aron M Troen Journal: J Nutr Date: 2012-06-27 Impact factor: 4.798
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Authors: Tina Roostaei; Daniel Felsky; Arash Nazeri; Philip L De Jager; Julie A Schneider; David A Bennett; Aristotle N Voineskos Journal: Neurobiol Aging Date: 2017-10-13 Impact factor: 4.673
Authors: Nienke Legdeur; Maryam Badissi; Stephen F Carter; Sophie de Crom; Aleid van de Kreeke; Ralph Vreeswijk; Marijke C Trappenburg; Mardien L Oudega; Huiberdina L Koek; Jos P van Campen; Carolina J P W Keijsers; Chinenye Amadi; Rainer Hinz; Mark F Gordon; Gerald Novak; Jana Podhorna; Erik Serné; Frank Verbraak; Maqsood Yaqub; Arjan Hillebrand; Alessandra Griffa; Neil Pendleton; Sophia E Kramer; Charlotte E Teunissen; Adriaan Lammertsma; Frederik Barkhof; Bart N M van Berckel; Philip Scheltens; Majon Muller; Andrea B Maier; Karl Herholz; Pieter Jelle Visser Journal: BMC Geriatr Date: 2018-11-26 Impact factor: 3.921