Chemosensory Perception and Psychophysics in the Aged

老年人的化学感觉和心理物理学

• 批准号: 7848447
• 负责人: CLAIRE L MURPHY
• 金额: $ 3.3万
• 依托单位: SAN DIEGO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2010-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7848447
• 关键词: Address; Admission activity; Adult; Affect; Age; Aged, 80 and over; Aging; Alleles; Alzheimer' s Disease; Alzheimer' s disease risk; American; Apolipoprotein E; Area; Behavioral; Biological Assay; Body Weight decreased; Brain; Brain region; Cardiovascular Diseases; Characteristics; Chronic Disease; Dementia; Desire for food; Developed Countries; Developing Countries; Diabetes Mellitus; Disease; Early Diagnosis; Eating; Elderly; Epidemic; Food; Functional Magnetic Resonance Imaging; Functional disorder; Future; Genetic Risk; Glucose; Grant; Health; Health Services; Healthcare; Home Nursing Care; Hospitalization; Human; Hunger; Hypothalamic structure; Image; Impaired cognition; Impairment; Individual; Intervention; Investigation; Laboratories; Lead; Leptin; Life; Long-Term Care; Malnutrition; Measures; Memory; Memory Loss; Metabolic; Metabolic Diseases; Metabolic syndrome; Methods; Morbidity - disease rate; Names; Neuraxis; Neurons; Nucleus Accumbens; Nursing Homes; Nutritional; Nutritional status; Obesity; Odors; Overweight; Pathologic Processes; Patients; Pattern; Perception; Performance; Persons; Phenotype; Population; Process; Prognostic Factor; Psychophysics; Psychophysiology; Public Health; Qualifying; Quality of life; Relative (related person); Rewards; Risk; Risk Factors; Satiation; Services; Signal Transduction; Smell Perception; Source; Spatial Distribution; Stimulus; Structure; Taste Perception; Testing; Weight; age related; aged; aging brain; base; behavior measurement; brain behavior; cardiovascular disorder risk; clinically significant; cognitive function; cohort; cost; design; diabetes risk; frailty; frontal lobe; functional loss; ghrelin; high risk; interest; memory recognition; middle age; mortality; neuroimaging; next generation; normal aging; novel; pre-clinical; preference; public health relevance; relating to nervous system; response; success; waist circumference

Description (provided by applicant): Optimum health, functioning and nutritional status are key to the quality of life in the older American. More than 35 million Americans are over the age of 60, and the oldest old represent the fastest growing segment of the American population. Older persons are more frequent consumers of health care services and, when health fails, of long-term care facilities. The costs of these services are considerable. Impairment of taste and olfactory function can negatively impact dietary selection, nutritional status, morbidity and mortality in older persons (Schiffman,1997). While frailty and weight loss in the elderly are poor prognostic factors for debility and mortality, epidemic increase in middle-aged obesity with associated risk for cardiovascular disease, diabetes, dementia and "metabolic syndrome" is creating an enormous public health burden with grave implications for the next generation of older adults (Poirier et al., 2006). The middle aged obese have a higher risk of nursing home admission in late life and reducing obesity rates may thus reduce the later societal burden of nursing home care (Elkins et al., 2006). Clear elucidation of age-related changes in brain response to appetitive stimuli, during hunger and satiety, may suggest interventions to modulate food intake, obesity in middle aged and frailty in older adults. Similar to obesity, Alzheimer's disease (AD) is a pathologic process for which risk exists in middle age and severe consequences emerge in old age. Bio-behavioral markers in non-demented older adults at genetic risk for AD because of the APOE e4 allele have potential clinical significance for signaling disease in the pre- clinical period. AD patients show early and dramatic loss of memory, and particularly odor memory, and they demonstrate profound olfactory dysfunction in old age (Murphy, et al., 1990). Chemosensory, behavioral, and metabolic abnormalities lead to malnutrition and weight loss, furthering morbidity in this precarious disease population (Guirin et al, 2005; reviewed in Reynish et al., 2001). Despite the importance of clarifying the impact of central processes on nutritional aberrations in the age-related progression of both obesity and Alzheimer's disease processes, in neither population has chemosensory function and brain processing been directly addressed in a middle-aged cohort. Neuroimaging is the only method capable of revealing precise spatial information about age-related differences in cortical response to chemosensory stimuli in living humans. The present study will use the power of fMRI to image the aging brain while it is processing taste and odor information in order to test the overarching hypothesis that functional changes in central nervous system activity, detectable in the cortical representation on fMRI, constitute a major neural substrate for altered chemosensory function and preference in normal aging and AD. A better understanding of chemosensory function and preference may suggest avenues to optimize health and qualify of life in aging Americans. PUBLIC HEALTH RELEVANCE: Middle aged obesity has become an epidemic with serious public health consequences and the "metabolic syndrome," a cluster of closely related disease states that doubles risk of cardiovascular disease, triples risk of diabetes, and impacts cognitive function, affects one in four adults in most developed countries (Poirier et al., 2006). Obesity is responsible for increased per capita health care spending of approximately 50%, with costs rising by age and degree of obesity, and because midlife obesity is associated with increased chronic illnesses, future dementia, hospitalizations, and nursing home admission in old age, reducing obesity rates may thus reduce the later societal burden of long-term nursing home care (Elkins et al., 2006; Whitmer et al., 2005). Elucidation of age-related changes in brain response to appetitive chemosensory stimuli may suggest avenues to modulate food intake and obesity in middle age, and metabolic disease and cognitive impairment in older adults.

描述（由申请人提供）：最佳的健康、功能和营养状况是美国老年人生活质量的关键。60岁以上的美国人有3500多万，老年人是美国人口中增长最快的一部分。老年人是保健服务的更频繁的消费者，如果健康状况不佳，则是长期护理设施的消费者。这些服务的费用相当可观。味觉和嗅觉功能的损害会对老年人的饮食选择、营养状况、发病率和死亡率产生负面影响（Schiffman,1997）。虽然老年人的虚弱和体重减轻是导致衰弱和死亡的不良预后因素，但中年肥胖的流行增加，并伴有心血管疾病、糖尿病、痴呆和“代谢综合征”的相关风险，正在造成巨大的公共卫生负担，对下一代老年人产生严重影响（Poirier等人，2006年）。中年肥胖者在晚年入住养老院的风险较高，降低肥胖率可能因此减轻养老院护理的后期社会负担（Elkins etal ., 2006）。明确阐明饥饿和饱腹时大脑对食欲刺激反应的年龄相关变化，可能为调节食物摄入、中年人肥胖和老年人虚弱提供干预措施。阿尔茨海默病（Alzheimer's disease， AD）与肥胖相似，是一种中年发病风险高，老年发病严重的病理过程。由于APOE e4等位基因而具有阿尔茨海默病遗传风险的非痴呆老年人的生物行为标记在临床前阶段对疾病信号传导具有潜在的临床意义。阿尔茨海默病患者表现出早期和显著的记忆丧失，尤其是气味记忆，他们在老年时表现出严重的嗅觉功能障碍（Murphy, et al., 1990）。化学感觉、行为和代谢异常导致营养不良和体重减轻，进一步增加了这一不稳定疾病人群的发病率（Guirin等人，2005年；评述于Reynish等人，2001年）。尽管在肥胖和阿尔茨海默病的年龄相关进展中阐明中枢过程对营养异常的影响很重要，但在这两种人群中，化学感觉功能和大脑处理在中年队列中都没有得到直接解决。神经成像是唯一一种能够揭示人类皮层对化学感觉刺激的年龄相关反应差异的精确空间信息的方法。本研究将利用功能磁共振成像成像老化的大脑，当它处理味觉和气味信息，以测试一个总体假设，中枢神经系统活动的功能变化，可检测到皮层表征的功能磁共振成像，构成改变化学感觉功能和偏好在正常衰老和阿尔茨海默氏症的主要神经基质。更好地了解化学感觉功能和偏好可能为优化美国老年人的健康和生活质量提供途径。公共卫生相关性：中年肥胖已成为一种具有严重公共卫生后果的流行病，“代谢综合征”是一组密切相关的疾病，可使心血管疾病的风险增加一倍，糖尿病的风险增加三倍，并影响认知功能，在大多数发达国家影响四分之一的成年人（Poirier等人，2006年）。肥胖导致人均医疗保健支出增加了约50%，费用随年龄和肥胖程度的增加而增加，而且由于中年肥胖与慢性病、未来痴呆、住院和老年入住养老院的增加有关，降低肥胖率可能因此减少长期养老院护理的后期社会负担（Elkins等人，2006；Whitmer等人，2005）。阐明大脑对食欲化学感觉刺激反应的年龄相关变化，可能为中年人调节食物摄入和肥胖，以及老年人代谢疾病和认知障碍提供途径。