Mediterranean Diet, Weight Loss, and Cognition in Obese Older Adults

 描述(申请人提供)：肥胖是美国死亡和残疾的主要原因，影响多达8000万美国人。众所周知，肥胖会导致代谢异常和心血管疾病(CVD)的一系列危险因素，包括高血压、糖尿病和高脂血症。此外，越来越多的证据表明，肥胖与多个领域的认知缺陷有关，即使是在其他方面健康的老年人中也是如此。随着美国人口迅速老龄化和老年人肥胖率居高不下，需要采取创新的策略来防止这一人群的认知能力下降。饮食模式是肥胖形成和维持的核心，有证据表明，饮食因素也可能影响认知。流行病学研究表明，坚持地中海饮食(MedDiet)与认知能力下降和痴呆症风险降低有关。通过限制卡路里来减肥也被证明可以改善肥胖成年人的认知功能。为饮食/体重管理确定有效的生活方式干预措施，以改善肥胖老年人的认知，是公共卫生的优先事项。然而，据我们所知，还没有随机临床试验(RCT)检验MedDiet在限制卡路里和不限制卡路里的情况下，促进肥胖老年人认知功能减轻的效果。我们提出了一项三臂随机对照试验，将180名55岁及以上的肥胖(体重指数[BMI]&Gt；30和&lt；50 kg/m2)老年人随机分为8个月的干预组，包括：1)单独服用MedDiet，不限制卡路里/减肥(MedDiet-A)；2)MedDiet生活方式干预+热量限制/减肥(MedDiet-WL)；或3)不限制卡路里/减肥的典型饮食控制(TDC)。我们将检验以下假设：1)随机服用MedDiet-A和MedDiet-WL的参与者将比随机服用TDC的参与者在认知方面获得更大的改善；2)与随机服用MedDiet-A的参与者相比，随机服用MedDiet-WL的参与者将在认知方面表现出更大的改善；3)与TDC的参与者相比，随机服用MedDiet-A和MedDiet-WL的参与者将在心血管/代谢危险因素、全身炎症、氧化应激(OxStress)和体重/成分方面表现出更大的改善；4)与MedDiet-A相比，随机服用MedDiet-WL的参与者将在心血管疾病/代谢风险因素、全身炎症、OxStress和体重/成分方面表现出更大的改善。我们还检查了潜在的治疗调节因素(例如，种族和基线认知功能)，并探索了饮食改善神经认知的中介因素，包括心血管疾病/代谢风险因素、体力活动、全身炎症和氧化应激的变化。我们还将确定在6个月的随访期内，饮食习惯、体重和认知功能的变化保持的程度。

 DESCRIPTION (provided by applicant): Obesity is a leading cause of death and disability in the United States (US), affecting as many as 80 million Americans. It is well-established that obesity contributes to a number of risk factors for metabolic abnormalities and cardiovascular disease (CVD), including hypertension, diabetes, and hyperlipidemia. In addition, there is growing evidence that obesity is associated with cognitive deficits in multiple domains, even in otherwise healthy older adults. With the rapidly aging US population and the high prevalence of obesity among older adults, innovative strategies to prevent cognitive decline in this population are needed. Dietary patterns are central to the development and maintenance of obesity and evidence suggests that dietary factors also may affect cognition. Epidemiologic studies have shown that adherence to a Mediterranean Diet (MedDiet) is associated with less cognitive decline and reduced risk for dementia. Weight loss through caloric restriction also has been shown to improve cognitive function in obese adults. The identification of effective lifestyle interventions for diet/weight management to improve cognition among obese older adults is a public health priority. However, to our knowledge, no randomized clinical trials (RCTs) have examined the effect of the MedDiet, with and without caloric restriction, to promote weight loss on cognitive functioning in obese older adults. We propose a three-arm RCT in which 180 obese (body mass index [BMI] >30 and < 50 kg/m2) older adults, aged 55 years and older, will be randomized to an 8-month intervention consisting of: 1) MedDiet Alone, without caloric restriction/weight loss (MedDiet-A); 2) MedDiet lifestyle intervention with caloric restriction/weight loss (MedDiet-WL); or 3) typical diet control (TDC) without caloric restriction/weight loss. We will test the following hypotheses: 1) participants randomized to MedDiet-A and MedDiet-WL will achieve greater improvements in cognition compared to participants randomized to TDC; 2) participants randomized to MedDiet-WL will exhibit greater improvements in cognition compared to participants randomized to MedDiet-A; 3) participants randomized to MedDiet-A and MedDiet-WL will show greater improvements in CVD/metabolic risk factors, systemic inflammation, oxidative stress (OxStress), and body weight/composition compared to participants in TDC; 4) participants randomized to MedDiet-WL will exhibit greater improvements in CVD/metabolic risk factors, systemic inflammation, OxStress, and body weight/composition compared to MedDiet-A. We also we examine potential moderators of treatment (e.g., ethnicity and baseline cognitive function) and explore mediators by which neurocognition is improved by diet, including changes in CVD/metabolic risk factors, physical activity, systemic inflammation, and OxStress. We also will determine the extent to which changes in dietary habits, weight, and cognitive functioning are maintained over a 6-month follow-up period.