THE ROLE OF LEPTIN AND CYTOKINES IN BODY WEIGHT REGULATION OF OLDER ADULTS

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。老年患者的体重减轻是一个常见且令人担忧的问题。面对持续的体重减轻，食欲不振的病因尚不清楚。以前的研究表明，在老年人中，非自愿减肥的死亡率，虚弱和功能残疾增加。其他研究报告了老年男性在热量限制后可能的能量摄入失调以及瘦素稳态异常。拟议项目的具体目标是确定是否一段时间的适度热量限制抑制综合昼夜血浆瘦素水平（AUC-瘦素）和静息能量消耗（REE）在健康的老年受试者在相同的程度在年轻人，并确定是否代偿性增加能量摄入后的一段时间的饮食能量限制是强大的老年人，因为它是在年轻人。假设老年人在一段时间的热量限制后无法增加他们的能量摄入和/或减少他们的能量消耗，这是由于瘦素或促炎细胞因子水平不适当地升高。在为期八周的控制饮食干预期间，对健康的老年人和年轻人进行了横断面比较。两周的体重维持饮食，随后依次为2周的30%热量减少和4周的自由进食。在每个饮食阶段后，测量24小时血浆瘦素水平（AUC leptin）、促炎细胞因子水平、DEXA身体成分扫描和静息能量消耗（REE）。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Weight loss in geriatric patients is a common and worrisome problem. The etiology of lack of appetite in the face of continued weight loss is unknown. Previous studies have shown an increase in mortality rates, frailty, and functional disability among older persons with involuntary weight loss. Other studies have reported possible dysregulation of energy intake in older men after calorie restriction as well as abnormalities in leptin homeostasis. The specific aims of the proposed project are to determine whether a period of moderate caloric restriction suppresses integrated diurnal plasma leptin levels (AUC-leptin) and resting energy expenditure (REE) in healthy older subjects to the same degree as in young adults, and to determine whether the compensatory increase in energy intake following a period of dietary energy restriction is as robust in older subjects as it is in young adults. The hypothesis is that older adults are unable to increase their energy intake and/or decrease their energy expenditure after a period of calorie restriction due to inappropriately elevated levels of leptin or pro-inflammatory cytokines. A cross-sectional comparison of healthy older and younger adults during an eight-week controlled diet intervention was performed. Two weeks of a weight-maintaining diet were followed in sequence by 2 weeks of 30% caloric reduction and 4 weeks of ad libitum (ad lib) food intake. Integrated 24-hour plasma leptin levels (AUC leptin), pro-inflammatory cytokine levels, DEXA scan for body composition, and resting energy expenditure (REE) were measured after each diet phase.