Aberrant telomeric structures and serum markers of telomere dysfunction in healthy aging: a preliminary study.

Telomeres undergo a progressive shortening process as individuals age, and it has been proposed that severely shortened and dysfunctional telomeres play a role in the aging process and the onset of age-related diseases in human beings. An emerging body of evidence indicates that the shortening of telomeres in cultured human cells is also influenced by other replication defects occurring within telomeric repeats. These abnormalities can be detected on metaphase chromosomes. Recent studies have also identified a set of serological markers for telomere dysfunction and DNA damage (elongation factor 1α [EF-1α], stathmin, and N-acetyl-glucosaminidase). With this study, the correlation between telomere abnormalities (by FISH) and these biomarkers as measured in blood serum (by ELISA) from a cohort of 22 healthy subjects at different ages (range 26-101 years) was analyzed. A strong positive correlation between aging and the presence of aberrant telomere structures, sister telomere loss (STL), and sister telomere chromatid fusions (STCF) was detected. When serum markers of telomere dysfunction were correlated with telomere abnormalities, we found that stathmin correlated with total aberrant telomeres structures (r = 0.431, p = 0.0453) and STCF (r = 0.533, p = 0.0107). These findings suggest that serum stathmin can be considered an easy-to-get marker of telomere dysfunction and may serve as valuable indicators of aging.

Tai chi, irisin and cognitive performance: a clinical and biological investigation in older adults.

BACKGROUND: Skeletal muscle is the main source of circulating irisin, both at rest and during physical activity. Previous studies have suggested that irisin can improve cognitive abilities. AIMS: We explored whether six months of Tai Chi (TC) practice can modulate such a relationship in healthy older persons. METHODS: This is a prospective clinical study to evaluate the effects of TC practice as compared with low intensity exercise (LI) and no exercise (NE) control groups on plasmatic irisin levels and cognitive performance. Forty-two healthy older persons were stratified into three groups according to physical activities. Biochemical assay and cognitive functions were assessed at the baseline and after six months. RESULTS: A significant change was found in circulating irisin levels in TC as compared with NE group (p = 0.050) across time. At six months in TC group irisin levels significantly correlated with a verbal memory test (p = 0.013) controlled by age and education. CONCLUSION: Our results suggest the potential benefits for cognitive health of TC practice by irisin levels modulation.

Hypomagnesemia and incident delirium in hospitalized older persons.

BACKGROUND: Altered serum magnesium (Mg) levels in older persons have been hypothesized to have a role in predicting hospitalization and mortality. Hypomagnesemia and delirium are frequent problems in older patients, but no study has evaluated such an association in acute geriatric setting. AIMS: We investigated the impact of hypomagnesemia on the incidence of delirium in an acute geriatric setting. METHODS: This retrospective study was conducted on 209 older hospitalized patients. All subjects underwent a comprehensive geriatric assessment. Mg was measured in serum by routine laboratory methods. The presence of incident delirium was determined by the 4AT screening tool. A logistic regression model was used to assess the association between serum Mg and delirium controlling for multiple covariates. RESULTS: 209 patients (77.9% women) were included in the study. The mean age of the participants was 85.7 ± 6.50 years (range 65-100). 27 subjects (12.9%) developed delirium during the hospitalization, with no difference between genders. Subjects with delirium had lower serum magnesium levels than those without (1.88 ± 0.34 versus 2.04 ± 0.28; p = 0.009). Delirium risk was significantly higher in patients with lower serum magnesium levels (OR 5.80 95% CI 1.450-23.222; p = 0.013), independent of multiple covariates. CONCLUSION: Our data show that low serum Mg level is a good predictor of incident delirium in acute geriatric settings. Present findings have relevant implications for clinical management, highlighting the need for analyzing Mg concentration carefully. Whether Mg supplementation in patients with hypomagnesemia could lead to delirium prevention and/or control needs further investigation.

Dealing with dehydration in hospitalized oldest persons: accuracy of the calculated serum osmolarity.

BACKGROUND:  Assessment of hydration status is complex and difficult to detect in older persons. Different methods have been developed to determine hydration status in clinical settings, but their diagnostic accuracy remains questionable. AIMS: The aim of this study was to determine and compare the diagnostic accuracy of all methods routinely used in acute settings to detect dehydration in a cohort of hospitalized oldest-old persons, using as primary reference standard blood urea nitrogen (BUN) to creatinine ratio. METHODS:  This retrospective study was conducted on 59 oldest-old subjects at hospital admission in an acute setting, with complete physical, biochemical, bioelectrical impedance analysis (BIA) and ultrasound assessment, including inferior vena cava diameters. RESULTS: Fifty-nine (45 women/14 men) subjects, with a mean age of 87.4 ± 5.9 years, were studied. Based on the value of the BUN/creatinine ratio, the whole population was divided into hyperhydrated (n = 10), normohydrated (n = 42), and dehydrated (n = 7) groups. Among parameters indicating the hydration status, serum sodium levels (p < 0.0001), serum chloride levels (p = 0.010), calculated plasma osmolarity (p < 0.0001), and fat mass (FM) (p = 0.030) differed significantly among groups. A ROC analysis showed that the highest and most significant value for dehydration detection was the calculated plasma osmolarity (AUC: 0.820, p = 0.013), which significantly correlated with clinical parameters including heart rate (r = 0.300; p = 0.021), capillary refill (r = 0.379; p = 0.013) and systolic blood pressure (r = - 0.261; p = 0.046). DISCUSSION: The measurement of calculated serum osmolarity is simple and inexpensive and may quickly provide high sensitivity and specificity indication of dehydration in hospitalized oldest-old persons.

Serum alkaline phosphatase is elevated and inversely correlated with cognitive functions in subjective cognitive decline: results from the ReGAl 2.0 project.

BACKGROUND: Alkaline phosphatase has been found on neuronal membranes and plasma alkaline phosphatase (ALP) activity increases during brain injury and cerebrovascular diseases, suggesting that its levels may reflect the neuronal loss. It is known that ALP is higher in subjects affected by Alzheimer's dementia and inversely correlated with cognitive functions. No study has investigated the relationship between ALP and cognitive functions in old-age subject with pre-clinical cognitive impairment. METHODS: This is a cross-sectional study with data gathered from the ReGAl 2.0 project (Rete Geriatrica Alzheimer-Geriatric Network on Alzheimer's disease), a large Italian multicentric clinical-based study. A cohort of 209 old-age subjects healthy controls (HC), Subjective cognitive decline (SCD), and Mild Cognitive Impairment (MCI) was included in the study. Cognitive performances were assessed with a large neuropsychological battery. The same day, serum alkaline phosphatase activity was measured in all subjects. RESULTS: We found that the SCD group had significantly higher ALP levels as compared with HC (p = 0.001). Among all neuropsychological tests, in all population ALP levels negatively correlated with scores at attentional matrices (r = - 0.243, p = 0.002), Digit Span Forward (r = - 0.241, p = 0.003) and Letter Fluency Test (r = - 0.196, p = 0.044). Attentional Matrices (r = - 0.208, p = 0.014) and Letter Fluency Test (r = - 0.229, p = 0.019) remained significantly correlated with ALP even after controlling for gender. In the SCD group, only the Attentional Matrices significantly and negatively correlated with ALP (r = - 0.344 p = 0.035), while no significant correlations were found in HC or MCI. CONCLUSIONS: Results indicate that serum alkaline phosphatase activity is increased in SCD and inversely correlates with cognitive functions. Further studies are needed to investigate the role of ALP in the progression to AD.

Beta-carotene, telomerase activity and Alzheimer's disease in old age subjects.

PURPOSE: Advancing age represents the strongest risk factor for Alzheimer's disease (AD), and the identification of biomarkers able to define what characterizes physiological aging from AD may represent a potential starting point for novel preventive strategies. Among these biomarkers, telomeres seem to be a promising target. Interestingly, high intake of carotenoid-rich food may play a role in protecting telomeres by oxidative stress reduction. Accordingly, low plasma ß-carotene concentrations have been found in AD subjects when compared with cognitively healthy subjects. In this study, we aim at investigating the hypothesis that low ß-carotene might be associated with markers of accelerated cellular aging, including leucocyte telomere length (LTL) and peripheral mononuclear cell (PBMC) telomerase activity in a cohort of old age subjects. METHODS: The study was conducted in 68 old age subjects, 37 AD, and 31 age-matched healthy controls. In all subjects, ß-carotene plasma level, LTL and peripheral telomerase activity were measured. RESULTS: In all populations, ß-carotene significantly and positively (r = 0.320, p = 0.008) correlated with telomerase activity, independent of gender. A model having telomerase activity levels as the dependent variable, and age, gender, smoking habit, and ß-carotene as independent variables, confirmed that ß-carotene was independently associated with telomerase activity (ß = 0.319, p = 0.012). Subjects affected by AD had significantly lower plasmatic levels of ß-carotene (448 ± 66 mg/ml vs 497 ± 59 mg/ml, p = 0.001) and LTL (0.53 ± 0.25 vs 0.69 ± 0.29; p = 0.009) as compared with healthy controls. Β-carotene plasma level was associated with AD diagnosis (OR 0.988; IC95% 0.978-0.997; p = 0.013) independently of age, gender, smoking habit, ApoE genotype, and LTL. CONCLUSION: Our data show that ß-carotene may modulate telomerase activity in old age. Moreover, lower plasma ß-carotene levels, correlating with peripheral telomerase activity, are associated with AD diagnosis independent of multiple covariates.

Vitamin E and Alzheimer's disease: the mediating role of cellular aging.

BACKGROUND: Vitamin E represents a potent antioxidant and anti-inflammatory system, playing a role in Alzheimer's disease (AD). Different plasma concentrations of the forms of vitamin E are observed in AD compared to cognitively healthy subjects. AIM: Since these modifications may modulate the markers of oxidative stress and cellular aging, we aim to explore the relationship between vitamin E forms and leukocyte telomere length (LTL) in AD. METHODS: 53 AD subjects and 40 cognitively healthy controls (CTs) were enrolled. The vitamin E forms (α-, ß-, γ- and δ-tocopherol, α-, ß-, γ- and δ-tocotrienol), the ratio of α-tocopherylquinone/α-tocopherol and 5-nitro-γ-tocopherol/γ-tocopherol (markers of oxidative/nitrosative damage) and LTL were measured. RESULTS AND DISCUSSION: Regression model was used to explore the associations of vitamin E forms and LTL with AD. The interaction of LTL in the association between vitamin E forms and AD was tested. AD subjects showed significantly lower concentrations of α-, ß-, γ- and δ-tocopherol, α- and δ-tocotrienol, total tocopherols, total tocotrienols and total vitamin E compared to CTs. AD subjects showed higher values of nitrosative/oxidative damage. The adjusted analyses confirmed a significant relationship of AD with plasma concentrations of α- and ß-tocopherols, δ-tocotrienol, total tocopherols, total tocotrienol, total vitamin E and oxidative/nitrosative damage. However, nitrosative damage was significantly associated with AD only in subjects with higher LTL and not in those expressing marked cellular aging. CONCLUSIONS: Our study confirms the role of vitamin E in AD pathology and indicates that nitrosative damage influences the association with AD only in subjects characterized by longer LTL.

miRNAs and Alzheimer's Disease: Exploring the Role of Inflammation and Vitamin E in an Old-Age Population.

Alzheimer's disease (AD) is the most frequent cause of dementia worldwide and represents one of the leading factors for severe disability in older persons. Although its etiology is not fully known yet, AD may develop due to multiple factors, including inflammation and oxidative stress, conditions where microRNAs (miRNAs) seem to play a pivotal role as a molecular switch. All these aspects may be modulated by nutritional factors. Among them, vitamin E has been widely studied in AD, given the plausibility of its various biological functions in influencing neurodegeneration. From a cohort of old-aged people, we measured eight vitamin E forms (tocopherols and tocotrienols), thirty cytokines/chemokines, and thirteen exosome-extracted miRNAs in plasma of subjects suffering from subjects affected by AD and age-matched healthy controls (HC). The sample population included 80 subjects (40 AD and 40 HC) with a mean age of 77.6 ± 3.8 years, mostly women (45; 56.2%). Of the vitamin E forms, only α-tocopherol differed between groups, with significantly lower levels in AD. Regarding the examined inflammatory molecules, G-CSF, GM-CSF, INF-α2, IL-3, and IL-8 were significantly higher and IL-17 lower in AD than HC. Among all miRNAs examined, AD showed downregulation of miR-9, miR-21, miR29-b, miR-122, and miR-132 compared to controls. MiR-122 positively and significantly correlated with some inflammatory molecules (GM-CSF, INF-α2, IL-1α, IL-8, and MIP-1ß) as well as with α-tocopherol even after correction for age and gender. A final binary logistic regression analysis showed that α-tocopherol serum levels were associated with a higher AD probability and partially mediated by miR-122. Our results suggest an interplay between α-tocopherol, inflammatory molecules, and microRNAs in AD, where miR-122 may be a good candidate as modulating factor.

A Long Journey into Aging, Brain Aging, and Alzheimer's Disease Following the Oxidative Stress Tracks.

The Editors of the Journal of Alzheimer's Disease invited Professor Patrizia Mecocci to contribute a review article focused on the importance and implications of her research on aging, brain aging, and senile dementias over the last years. This invitation was based on an assessment that she was one of the journal's top authors and a strong supporter of the concept that oxidative stress is a major contributor to several alterations observed in age-related conditions (sarcopenia, osteoporosis) and, more significantly, in brain aging suggesting a pivotal role in the pathogenesis and progression of one of the most dramatic age-related diseases, Alzheimer's disease (AD). Her first pioneering research was on the discovery of high level of 8-hydroxy-2'-deoxyguanosine (OH8dG), a marker of oxidation in nucleic acids, in mitochondrial DNA isolated from cerebral cortex. This molecule increases progressively with aging and more in AD brain, supporting the hypothesis that oxidative stress, a condition of unbalance between the production of reactive oxygen species and antioxidants, gives a strong contribution to the high incidence of AD in old age subjects. OH8dG also increases in peripheral lymphocyte from AD subjects, suggesting that AD is not only a cerebral but also a systemic disease. The role of antioxidants, particularly vitamin E and zinc, were also studied in longevity and in cognitive decline and dementia. This review shows the main findings from Mecocci's laboratory related to oxidative stress in aging, brain aging, and AD and discusses the importance and implications of some of the major achievements in this field of research.