Search

Background: Evidence that vitamin E may preserve cognitive function in elderly subjects is conflicting. The most abundant and most investigated form of vitamin E in humans is [alpha]-tocopherol, but other antioxidant tocopherols ([beta], [gamma] and [delta]) exist in nature. Objective: We aimed to investigate plasma concentrations of the natural tocopherols and the tocopherol oxidation markers [alpha]-tocopherylquinone ([alpha]TQ) and 5-nitro-[gamma]-tocopherol (5NGT) in relation to cognitive function in the elderly. Design: Baseline plasma tocopherols and their oxidation markers were measured in 761 elderly Italian subjects from a population-based cohort assessed in 1999-2000 for mild cognitive impairment (MCI) and dementia. In 2003-2004, information about cognitive status was collected for 615 of the 666 subjects without baseline cognitive impairment. Tocopherols and oxidation markers were analyzed as plasma absolute values divided by serum total cholesterol because lipids affect their blood availability. Analyses were adjusted for sociodemographic, genetic, lifestyle, and medical confounders. Results: Compared with the corresponding lowest tertile, the risk of prevalent dementia was higher for the highest tertile of [delta]-tocopherol / cholesterol [odds ratio (OR): 3.87; 95% CI: 1.46, 10.27] and [alpha]TQ / cholesterol (4.02; 1.45, 11.14), but the risk of incident dementia was not directly associated with plasma vitamin E metabolites. A U-shaped association, with lower risk for intermediate tertiles, was found for prevalent MCI with 5NGT / cholesterol (0.39; 0.17, 0.91) and for incident dementia with [gamma]-tocopherol / cholesterol (hazard ratio: 0.42; 95% CI: 0.22, 0.84). Conclusions: Plasma concentrations of some non-[alpha]-tocopherol forms of vitamin E are associated with cognitive impairment in elderly people. However, the associations depend on concurrent cholesterol concentration and need further investigation.

Background: Apolipoprotein E (APOE) plays a central role in VLDL metabolism. Both APOE e4 allele (APOE4) and C-reactive protein (CRP) are associated with greater risk of dementia and vascular disease, but APOE4 carriers have lower blood concentrations of CRP than do noncarriers, possibly through a mechanism favoring the clearance of the CRP VLDL-bound fraction. Homocysteine, another risk factor for vascular disease and dementia, also binds to VLDL in blood. However, the association between APOE4 and hyperhomocysteinemia has never been thoroughly investigated. Objective: We investigated in an elderly population whether 1) APOE4 is associated with hyperhomocysteinemia [plasma total homocysteine (tHcy) > 15 [micro]mol/L], 2) hyperhomocysteinemia affects the association between APOE4 and high CRP (serum CRP > 3 mg/L), and 3) B vitamin status affects these associations. Design: APOE4 genotypes were assessed and tHcy, CRP, and serum concentrations of folate and vitamin B-12 were measured in 671 cognitively healthy subjects (52% women; mean age: 73 y) from an Italian population-based prospective cohort study. Results: APOE4 carriers without high CRP [multivariate-adjusted odds ratio (OR): 0.22; 95% CI: 0.08, 0.59] had a lower risk of hyperhomocysteinemia than did noncarriers. The risk of high CRP was lower in APOE4 carriers without hyperhomocysteinemia (multivariate-adjusted OR: 0.51; 95% CI: 0.31, 0.85) than in non-carriers. The associations were not affected by B vitamin status. Conclusion: Independently from B vitamin status, APOE4 carriers have a lower risk of hyperhomocysteinemia and of high CRP than do noncarriers, but the presence of one condition attenuates the association of APOE4 with the other condition. KEY WORDS Homocysteine, C-reactive protein, apolipoprotein E, elderly, lipid metabolism

OBJECTIVE--Little is known about the prevalence of the metabolic syndrome among elderly people in Italy, its association with all-cause mortality, and whether measurement of serum C-reactive protein (CRP) and interleukin [...]

Background: In cross-sectional studies, elevated plasma total homocysteine (tHcy) concentrations have been associated with cognitive impairment and dementia. Incidence studies of this issue are few and have produced conflicting results. Objective: We investigated the relation between high plasma tHcy concentrations and risk of dementia and Alzheimer disease (AD) in an elderly population. Design: A dementia-free cohort of 816 subjects (434 women and 382 men: mean age: 74 y) from an Italian population-based study constituted our study sample. The relation of baseline plasma tHcy to the risk of newly diagnosed dementia and AD on follow-up was examined. A proportional hazards regression model was used to adjust for age, sex, education, apolipoprotein E genotype, vascular risk factors, and serum concentrations of folate and vitamin B-12. Results: Over an average follow-up of 4 y, dementia developed in 112 subjects, including 70 who received a diagnosis of AD. In the subjects with hyperhomocysteinemia (plasma tHcy > 15 [micro]mol/L), the hazard ratio for dementia was 2.08 (95% CI: 1.31, 3.30; P = 0.002). The corresponding hazard ratio for AD was 2.11 (95% CI: 1.19, 3.76; P = 0.011). Independently of hyperhomocysteinemia and other confounders, low folate concentrations ([less than or equal to] 11.8 nmol/L) were also associated with an increased risk of both dementia (1.87; 95% CI: 1.21,2.89; P = 0.005) and AD (1.98; 95% CI: 1.15, 3.40; P = 0.014), whereas the association was not significant for vitamin B-12. Conclusions: Elevated plasma tHcy concentrations and low serum folate concentrations are independent predictors of the development of dementia and AD. KEY WORDS Homocysteine, dementia, Alzheimer disease, incidence, folate

Background: Plasma concentrations of several amino acids may affect the availability of important neurotransmitter precursors in the brain. Abnormalities in the plasma amino acid profile have been reported in elderly persons with cognitive impairment, but no data exist for the prodromal phase of Alzheimer disease (AD), which is characterized by amnestic mild cognitive impairment (aMCI). Objective: The objective was to investigate whether the plasma amino acid profiles of elderly patients with aMCI or AD are abnormal. Design: The plasma amino acid profile was assessed in 29 cognitively normal control subjects (age: 86.7 [+ or -] 5.9 y), 21 patients with aMCI (age: 84.9 [+ or -] 7.0 y), and 51 patients with AD (age: 86.7 [+ or -] 5.4 y). The participants were from the University of Bologna Research Center for Physiopathology of Aging, Italy. Results: Higher plasma concentrations of the aromatic amino acid phenylalanine were found in the aMCI (68 [micro]mol/L; 95% CI: 63, 73) and AD (62 [micro]mol/L; 95% CI: 59, 65) patients than in the control subjects (54 [micro]mol/L; 95 % CI: 48, 61; P < 0.05). The ratio of arginine to other basic amino acids was also higher in the aMCI (0.31 [+ or -] 0.04) and AD (0.27 [+ or -] 0.08) patients than in the control subjects (0.21 [+ or -] 0.05; P < 0.05). Adjustment for differences in body composition, serum vitamin B-12 concentrations, and serum folate concentrations did not significantly affect the results. Conclusions: The plasma amino acid profiles of elderly patients with aMCI or AD show abnormalities in aromatic and basic amino acids that potentially affect neurotransmitter biosynthesis. KEY WORDS Plasma amino acids, amnestic mild cognitive impairment, Alzheimer disease, dementia, elderly, aromatic amino acids, arginine

Background: Elevated plasma total homocysteine (tHcy) concentrations are common in the elderly and have been suggested to be a risk factor for dementia. Objective: In an elderly population, we examined the relation between plasma they and scores on the Mini-Mental State Examination (MMSE), a commonly used screening measure of cognitive impairment in general practice. Design: Fasting plasma they concentrations were measured in 650 healthy, cognitively normal Italian community dwellers aged > 65 y ([bar]x + SD: 72.8 [+ or -] 6.0 y). Socioeconomic status; serum folate, vitamin B-12, and creatinine; other potential dietary and lifestyle determinants of tHcy; and conventional vascular disease risk factors were also assessed. Results: Subjects with MMSE scores of 26-28 had higher plasma tHcy concentrations (12.7 [micro]mol/L; range: 12.2-13.2 [micro]mol/L) than did those with scores > 28 (11.9 [micro]mol/L; 11.4-12.3 [micro]mol/L; P < 0.01). Subjects with scores of 24-25 had higher plasma they concentrations (14.5 [micro]mol/L; 13.5-15.6 [micro]mol/L) than did subjects with scores of 26-28 (P < 0.01) or > 28 (P < 0.001). The risk of hyperhomocysteinemia (plasma they > 15 [micro]mol/L) was higher in subjects with scores of 24-25 (odds ratio: 3.81; 95% CI: 1.9, 7.5) or 26-28 (odds ratio: 1.96; 95% CI: 1.3, 3.0) than in those with scores > 28. The results did not change after adjustment for conventional vascular risk factors and for age, medical, dietary, and lifestyle determinants of plasma tHcy. Conclusion: Elevated plasma they has an independent, graded association with concurrent cognitive impairment as measured with the MMSE in healthy elderly community dwellers. KEY WORDS Elderly subjects, cognition, homocysteine, Mini-Mental State Examination, folate, vitamin B-12, Italy, Conselice Study

Background: Natural killer (NK) cells play a role in natural immunity against tumor and infected cells. Advanced aging is associated with functional impairment of NK cells and increased susceptibility to nutritional deficiencies. Objective: Our objective was to test whether micronutrient status affects NK cell activity in an older population. Design: The relations between NK cell variables (percentage of leukocytes and cytotoxicity) and blood concentrations of selected micronutrients were studied in 62 healthy, free-living northern Italian subjects (25 men, 37 women) aged 90-106 y. Anthropometric measurements were also made. Results: All subjects were well nourished according to age-specific anthropometric norms but many of them had micronutrient deficiencies. The prevalence of micronutrient deficiency was highest for selenium (in [approximately equals] 50% of both sexes), zinc (in 52% of men and 41% of women), and vitamin B-6 (in 40% of men and 59% of women), followed by vitamin A (in 16% of men and 27% of women) and vitamin E, vitamin B-12, and folate (each in [is less than] 10% of both sexes). Ubiquinone-10 status was inadequate in 40% of women and 24% of men (P = 0.02). The percentage of NK cells was associated with serum zinc (men: r = 0.573, P = 0.007; women: r = 0.373, P = 0.031) and selenium (women: r = 0.409, P = 0.018) concentrations. In women only, NK cell cytotoxicity at different effector-target cell ratios was positively associated with plasma vitamin E and ubiquinone-10 concentrations (P [is less than] 0.05). No significant associations with NK cell variables were found for the other measured nutrients. Conclusions: The results of this study strengthen the hypothesis that individual micronutrients may affect the number and function of NK cells in old age. The study also confirms the high prevalence of micronutrient deficiencies in healthy and apparently well-nourished persons aged [is greater than or equal to] 90 y. Am J Clin Nutr 2000;71:590-8. KEY WORDS Natural killer cells, vitamins, trace elements, zinc, selenium, aging, nutrition, micronutrients, oldest-old age group, northern Italy