Effect of Exercise Modality During Weight Loss on Bone Health in Older Adults

 描述(由申请人提供)：老年和肥胖是发病率和死亡率的普遍危险因素。体重减轻(WL)可以改善肥胖的许多临床后果；然而，尽管它有好处，对老年人进行有意的WL的建议仍然存在争议。不情愿的原因，至少部分是因为已知的伴随着整个WL的骨量丢失，以及与年龄相关的骨质疏松和骨折风险加剧的可能性。在WL基础上增加有氧运动可能是减缓WL相关的骨密度(BMD)下降的有效手段，但不能阻止。抵抗运动单独进行，或与有氧运动联合进行，也显示出对老年人在中度腰围期间骨密度丢失的保护作用。然而，一项直接比较WL期间运动方式(有氧和阻力)对超重和肥胖老年人骨密度和其他骨质量指标(即强度、结构和转换)的影响的研究尚未完成。这是一个研究不足的领域，非常需要科学研究。因此，这个指导式研究科学家发展奖(MRSDA)的主要研究目标是生成数据，为候选人领导的未来R级奖项提供信息，以确定将超重和肥胖老年人的骨丢失和随后的骨折风险降至最低的WL策略。我们假设，与有氧运动或单独进行WL相比，阻力运动将减少超重和肥胖老年人与WL相关的骨密度和质量的损失。如果得到证实，这一发现可能会影响这一人群中对体育锻炼和WL的推荐。本MRSDA的主要培训目标是通过向PI提供基于行为的WL干预措施的设计和实施方面的技能，以及对WL策略对老年人骨密度和质量的影响的深入了解，来满足PI的直接职业目标，并为候选人之前由NRSA支持的博士后工作提供必要的伴奏，研究WL相关的脂肪和瘦质量减轻对老年人心脏代谢风险和身体功能的影响。拟议的培训计划以卓越的指导团队和培训环境为特色，在健康老龄化、基于行为的白线干预和骨骼新陈代谢领域配备内容导师，以及精心挑选的骨生理学、图像分析和实验室技术方面的教学和实践培训。完成本MRSDA中概述的活动将使PI能够实现她作为独立临床调查员的长期职业目标，有能力全面确定最佳的WL疗法，以促进和保持超重和肥胖老年人的功能独立性。

 DESCRIPTION (provided by applicant): Old age and obesity are prevalent risk factors for morbidity and mortality. Weight loss (WL) ameliorates many clinical consequences of obesity; yet despite its benefits, recommendation of intentional WL in older adults remains controversial. Reluctance stems, at least in part, from loss of bone mass known to accompany overall WL and the potential for exacerbation of age-related risk of osteoporosis and fracture. Addition of aerobic exercise to WL may be an effective means to attenuate, but not stop, WL-associated reductions in bone mineral density (BMD). Resistance exercise alone, or when combined with aerobic exercise, has also shown protective effects on BMD loss during moderate WL in older adults. However, a study directly comparing the effect exercise modality (aerobic versus resistance) during WL on changes in BMD and other measures of bone quality (i.e. strength, structure, and turnover) in overweight and obese, older adults has yet to be done. This is an understudied research area of great scientific need. Thus, the main research objective of this Mentored Research Scientist Development Award (MRSDA) is to generate data that will inform future R-level awards, led by the candidate, in the identification of WL strategies that minimize bone loss and subsequent fracture risk in overweight and obese, older adults. We hypothesize that resistance exercise will reduce the loss of bone density and quality associated with WL in overweight and obese, older adults when compared to aerobic exercise or WL alone. If confirmed, findings have the potential to influence recommendations for physical exercise and WL in this population. The main training objective of this MRSDA is to meet the PI's immediate career goal by providing her with skill in the design and conduct of behavioral based WL- interventions as well as in-depth knowledge of the effect of WL strategies on bone density and quality in older adults, offering the necessary accompaniment to the candidate's previous NRSA- supported postdoctoral work studying the effects of WL-associated fat and lean mass loss on cardiometabolic risk and physical function in older adults. The proposed training plan features an exceptional mentoring team and training environment, with content mentors in the areas of healthy aging, behavioral based WL-interventions, and bone metabolism, as well as carefully selected didactic and hands-on training in bone physiology, image analysis, and laboratory techniques. Completion of the activities outlined in this MRSDA will allow the PI to achieve her long-term career goal as independent clinical investigator, with the ability to comprehensively identify of optimal WL therapies to promote and preserve functional independence in overweight and obese, older adults.