Grazia D'Onofrio

Metabolic Syndrome and Cognitive Impairment: Current Epidemiology and Possible Underlying Mechanisms

A possible role of vascular and lifestyle-related factors was recently proposed for age-related changes of cognitive function, predementia syndromes, and cognitive decline of degenerative (Alzheimers disease, AD) or vascular origin (vascular dementia, VaD). At present, cumulative evidence suggests that vascular risk factors may be important in the development of mild cognitive impairment (MCI), dementia, and AD. Among vascular-related factors, metabolic syndrome (MetS) has been associated with the risk of cognitive decline, overall dementia, and VaD, but contrasting findings also existed on the possible role of MetS in AD. If MetS is associated with increased risk of developing cognitive impairment, regardless of mechanism, then early identification and treatment of these individuals at risk might offer new avenues for disease-course modification. Strategies towards early and effective risk factor management could be of value in reducing risk of metabolic and cognitive decline. Future research is needed to confirm the association between MetS and cognitive impairment and to determine the exact mechanism linking them. Such would provide important insights into the causes and interdependencies of predementia and dementia syndromes, and inspire novel strategies for treating and preventing these disorders. At present, vascular risk factor and MetS management could be employed to delay the onset of dementia syndromes or to prevent the progression of predementia syndromes. In the future, trials could be undertaken to determine whether modifications of these risk factors, including inflammation, could lower risk of developing cognitive decline.

Mediterranean diet in predementia and dementia syndromes

There is a critical need to potentially individualize new strategies able to prevent and to slow down the progression of predementia and dementia syndromes. Only recently higher adherence to a Mediterranean-type diet was associated with decreased cognitive decline although the Mediterranean diet (MeDi) combines several foods, micro- and macronutrients already separately proposed as potential protective factors against dementia and predementia syndromes. In fact, elevated saturated fatty acids could have negative effects on age-related cognitive decline and mild cognitive impairment (MCI). Furthermore, at present, epidemiological evidence suggested a possible association among fish consumption, monounsaturated fatty acids and polyunsaturated fatty acids (PUFA) (particularly, n-3 PUFA) and reduced risk of cognitive decline and dementia. Light to moderate alcohol use may be associated with a reduced risk of incident dementia and Alzheimers disease (AD), while for vascular dementia, cognitive decline, and predementia syndromes the current evidence is only suggestive of a protective effect. Finally, the limited epidemiological evidence available on fruit and vegetable consumption and cognition generally supported a protective role of these macronutrients against cognitive decline, dementia, and AD. Moreover, recent prospective studies provided evidence that higher adherence to a Mediterranean-type diet could be associated with slower cognitive decline, reduced risk of progression from MCI to AD, reduced risk of AD, and decreased all-causes mortality in AD patients. These findings suggested that adherence to the MeDi may affect not only the risk for AD, but also for predementia syndromes and their progression to overt dementia. Nonetheless, at present, no definitive dietary recommendations are possible. However, high levels of consumption of fats from fish, vegetable oils, non-starchy vegetables, low glycemic fruits, and diet low in foods with added sugars and with moderate wine intake should be encouraged. In fact, this dietary advice is in accordance with recommendations for lowering the risk of cardiovascular disease, obesity, diabetes, and hypertension and might open new ways for the prevention and management of cognitive decline and dementia.

Therapeutic intervention for Alzheimer's disease with γ-secretase inhibitors: still a viable option?

Introduction: Compounds that inhibit or modulate γ-secretase, the pivotal enzyme which generates β-amyloid (Aβ), are potential therapeutics for Alzheimers disease (AD). Areas covered: This article briefly reviews the profile of γ-secretase inhibitors that have reached the clinic and discusses the clinical issues surrounding this new class of anti-AD compounds. Expert opinion: γ-Secretase inhibitors may cause significant toxicity in humans. Two large Phase III clinical trials of semagacestat in mild-to-moderate AD patients were prematurely interrupted because of detrimental cognitive and functional effects of the drug. These detrimental effects were mainly ascribed to the inhibition of Notch processing and the accumulation of the neurotoxic precursor of Aβ resulting from the block of the γ-secretase cleavage activity on amyloid precursor protein. New Notch-sparing γ-secretase inhibitors are being developed with the hope of overcoming the previous setbacks. It has also been argued that γ-secretase inhibitors should be used in the very early stages of the disease progression when neuronal loss is still limited. Thus, the inclusion of patients with mild-to-moderate AD in the semagacestat Phase III trials could also explain the negative outcome of these studies. Understanding the reasons for this failure may be important for future research on effective treatments for this devastating disease.

The Multidimensional Prognostic Index Predicts Short- and Long-Term Mortality in Hospitalized Geriatric Patients With Pneumonia

BACKGROUND Multidimensional impairment of older patients may influence the clinical outcome of acute or chronic diseases. Our purpose is to evaluate the usefulness of a multidimensional prognostic index (MPI) based on a comprehensive geriatric assessment (CGA) for predicting mortality risk in older patients with community-acquired pneumonia (CAP). METHODS This prospective study included 134 hospitalized patients aged 65 and older with a diagnosis of CAP. A standardized CGA that included information on clinical, cognitive, functional, and nutritional status as well as comorbidities, medications, and social support network was used to calculate MPI. The pneumonia severity index (PSI) was also calculated. The predictive value of the MPI for all cause mortality over a 1-year follow-up was evaluated and was compared with that of PSI. RESULTS Higher MPI values were significantly associated with higher mortality at 30 days (Grade 1 = 3%, Grade 2 = 12%, Grade 3 = 44%, p < .001), 6 months (Grade 1 = 7%, Grade 2 = 21%, Grade 3 = 50%, p < .001), and 1 year (Grade 1 = 10%, Grade 2 = 33%, Grade 3 = 53%, p < .001). A close agreement was found between the estimated mortality by MPI and the observed mortality. MPI had a significant greater discriminatory power than PSI both at 30 days (area under the receiver operating characteristic [ROC] curve = 0.83 vs 0.71, p = .019) and 6 months (0.79 vs 0.69, p = .035), but not after 1 year of follow-up (0.80 vs 0.75, p = .185). CONCLUSIONS This MPI, calculated from information collected in a standardized CGA, accurately stratifies hospitalized elderly patients with CAP into groups at varying risk of short- and long-term mortality. The predictive accuracy of the MPI was higher than the predictive value of the PSI.

The Multidimensional Prognostic Index (MPI), Based on a Comprehensive Geriatric Assessment Predicts Short- and Long-Term Mortality in Hospitalized Older Patients with Dementia

Aim of this study was to evaluate the usefulness of a Multidimensional Prognostic Index (MPI) based on a Comprehensive Geriatric Assessment (CGA) for predicting mortality risk in older patients with dementia. The present was a retrospective study with a year of follow-up that included 262 patients aged 65 years and older with a diagnosis of dementia. A standardized CGA that included information on clinical, cognitive, functional, and nutritional aspects, as well as comorbidity, medications, and social support network, was used to calculate MPI. The predictive value of the MPI for all-cause mortality over 1 month, 6 months, and 12 months of follow-up was evaluated. Higher MPI values were significantly associated with higher mortality at 1 month (MPI-1, low risk = 0%, MPI-2, moderate risk = 5.2%, MPI-3, severe risk = 13.7%; p < 0.002), 6-months (MPI-1 = 2.7%, MPI-2 = 11.2%, MPI-3 = 28.8%; p < 0.001), and 12-months (MPI-1 = 2.7%, MPI-2 = 18.2%, MPI-3 = 35.6%; p < 0.001) of follow-up. The discrimination of the MPI was also good, with areas under the ROC curves of 0.77 (sensitivity = 82.9%, specificity = 66.0%, with a cut off value > 0.16) at 12-months of follow up. In conclusion, the MPI, calculated from information collected in a standardized CGA, accurately stratified hospitalized elderly patients with dementia into groups at varying risk of short- and long-term mortality.

Anti-β-Amyloid Immunotherapy for Alzheimers Disease: Focus on Bapineuzumab

Recent advances in our understanding of the neurobiology of Alzheimers disease (AD) have led to the development of putative disease-modifying treatments. The most revolutionary of these approaches consists in the removal of brain β-amyloid (Aβ) via anti-Aβ antibodies. Brain imaging and neuropathological studies have shown the ability of both active and passive anti-Aβ immunotherapies of clearing Aβ deposits from the brain of the AD patients. An active anti-Aβ vaccine preparation, AN1792, has been used in AD patients with some clues of clinical efficacy but causing meningoencephalitis in about 6% of patients and it has been abandoned. Several second-generation active Aβ vaccines and passive Aβ immunotherapies have been developed and are under clinical investigation with the aim of accelerating Aβ clearance from the brain of the AD patients. The most advanced of these immunological approaches is bapineuzumab, composed of humanized anti-Aβ monoclonal antibodies, that has been tested in two Phase II trials, demonstrating to reduce Aβ burden in the brain of AD patients. However, the preliminary cognitive efficacy of bapineuzumab appears uncertain. The occurrence of vasogenic edema, especially in apolipoprotein E 4 carriers, may limit its clinical use and have led to abandon the highest dose of the drug (2 mg/kg). The results of four ongoing large Phase III trials on bapineuzumab will tell us if passive anti-Aβ immunization is able to alter the course if this devastating disease.

The genetics of the human APOE polymorphism

Abstract The genetic origin of the three common variants of the human apolipoprotein E (apoE) protein, known as E2, E3 and E4, was understood in 1981, and since the mid 1980s these are probably the most-studied protein variants in human races. They have been related to a number of age-related diseases, including Alzheimer disease, as well as to healthy aging and longevity. The gene variants underlying these protein isoforms, known as ε2, ε3, and ε4, are allelic forms of the APOE gene, resulting from different haplotypes at the APOE locus (19q13.31). In particular, they result from three of the four haplotypes expected by the combinations of the alleles of the two single-nucleotide polymorphisms rs429358 and rs7412. The fourth missing haplotype, known as ε3r, has been identified in only two Caucasian families from Italy and in one Yoruba family from Nigeria worldwide. Thus, this fourth APOE gene variant is rare, and it encodes a protein isoform, identified as E3r, showing identical physical characteristics to E3, that conversely, is the most common form of apoE in humans. In this review article, we report the identification of the haplotype ε3r in a third Caucasian family from Italy, and then attempt to re-examine the current knowledge regarding the APOE polymorphism, taking into account this fourth haplotype. We also focus on the commonly accepted hypothesis for the evolution of the common APOE gene variants, in which we include the ε3r haplotype, previously not considered.

Role of cytochrome P4502D6 functional polymorphisms in the efficacy of donepezil in patients with Alzheimer's disease.

Objective Cytochrome P450 (CYP) 2D6 enzyme is the major responsible for the metabolism of donepezil, an inhibitor of acetyl cholinesterase currently used for the symptomatic treatment of mild-to-moderate Alzheimers disease (AD). Functional polymorphisms in the CYP2D6 gene may affect enzyme activity and thus, the metabolism of donepezil. The aim of this study was to evaluate the effect of 16 functional polymorphisms in the CYP2D6 gene on the clinical response to donepezil treatment in patients with mild-to-moderate AD. Methods In this multicenter prospective cohort study we evaluated 57 unrelated Caucasians clinically diagnosed as AD according to the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimers Disease and Related Disorders Association Work Group criteria. Patients were treated with donepezil (5–10 mg/daily) for 6 months. The response to donepezil treatment was evaluated at 6-month follow-up according to the National Institute for Health and Clinical Excellence requirements. The identification of 16 clinically relevant CYP2D6 gene variants was performed by a high-throughput genetic analysis. Results Thirty-eight of 57 patients (67%) were responders and 19 patients (33%) were nonresponders to donepezil treatment. A significantly higher frequency of gene variants conferring decreased or absent enzyme activity was observed in responder than in nonresponder patients (73.68% vs. 36.84%; P=0.005). The presence of gene variants conferring decreased or absent activity of the CYP2D6 enzyme was significantly associated with a clinical response to donepezil treatment (odds ratio=6.286; 95% confidence interval=1.828–21.667). Conclusions Functional polymorphisms in the CYP2D6 gene can influence the clinical efficacy of donepezil. The analysis of CYP2D6 genotypes may be useful in identifying subgroups of AD patients with different clinical response to donepezil treatment.

Information and communication technology systems to improve quality of life and safety of Alzheimer's disease patients: a multicenter international survey.

Within the frame of the European Commission funded Smart Home for Elderly People (HOPE) Project, relatives/caregivers of 223 Alzheimers Disease (AD) patients were recruited in Italy, Spain, and Greece for a multicenter international survey on the potential role of Information and Communication Technology system (ICT-systems) for AD patients. A five-minute video on HOPE ICT-systems was shown, and all relatives/caregivers completed a 13-item questionnaire that evaluated the potential role of: A) ICT-systems in improving quality of life, care, and safety; B) devices for monitoring personal movements, medication use, and ambient environmental conditions; C) devices to improve communication, home-based rehabilitation, and reduction of specific risks; and D) possible agreement in using ICT-systems by AD patients. Relatives/caregivers reported that ICT-systems could be very useful to improve: A) quality of life (66.4%), care (56.1%), and safety (87.0%); B) monitoring bed rest and movements (80.7%), medication use (87.4%), and ambient environmental conditions (85.2%); and C) emergency communication (83.4%). Relatives/caregivers reported that ICT-systems could be significantly more useful for AD patients aged 75-84 than patients aged <75 or ≥85 years (p < 0.0001) and with moderate than mild or severe dementia (p < 0.0001). Relatives/caregivers aged ≥50 years and with low educational level considered ICT-systems more useful than relatives/caregivers aged <50 years (p < 0.0001) and with high educational level (p < 0.0001). In conclusion, relatives/caregivers considered that the HOPE ICT-system could be useful to improve the management of AD patients.

Metabolic Syndrome, Mild Cognitive Impairment and Dementia

At present, the search for preventive strategies for cognitive decline and dementia appears to be of crucial importance, given that the therapeutic options currently available have demonstrated limited efficacy. Cumulative epidemiological evidence suggested that vascular and vascular-related factors may be important for the development of age-related cognitive decline (ARCD), mild cognitive impairment (MCI), and cognitive decline of degenerative (Alzheimers disease, AD) or vascular origin (vascular dementia, VaD). Among vascular-related factors, metabolic syndrome (MetS) has been associated with the reduced risk of predementia syndromes (ARCD and MCI), overall dementia, and VaD, but contrasting findings also exist on the possible role of MetS in AD. In the next future, trials could then be undertaken to determine if modifications of these risks including inflammation, another factor probably related to MetS, could lower risk of developing cognitive decline. If MetS is associated with increased risk of developing cognitive impairment, then early identification and treatment of these individuals at risk might offer new avenues for disease course modification. Future research aimed at identifying mechanisms that underlie comorbid associations will not only provide important insights into the causes and interdependencies of predementia and dementia syndromes, but will also inspire novel strategies for treating and preventing these disorders. At present, vascular risk factor management could be decisive in delaying the onset of dementia syndromes or in preventing the progression of predementia syndromes.