Investigating Fitness Interventions in the Elderly (INFINITE)
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 180
- 试验地点
- 1
- 主要终点
- maximal aerobic capacity (VO2max) and functional endurance (400 m walk time)
研究概览
简要总结
Aging is associated with declines in aerobic capacity, exercise tolerance, and functional endurance that lead to physical disability and loss of independence. Furthermore, the existing high prevalence of obesity in the elderly is greatly exacerbating these aging-related declines in function. To date, regular exercise is the only known therapy to consistently improve aerobic function, and perhaps delay the onset of disability. Although aerobic exercise training does benefit both aerobic capacity and endurance even in obese persons, some data show that the maximal efficacy of exercise for improving aerobic function is blunted by obesity. In addition, our preliminary data show a potential dose-response benefit of concomitant fat loss on exercise-induced improvements in aerobic function. Thus, combining an exercise intervention with caloric restriction resulting in fat loss may be more efficacious for improving aerobic function than exercise alone in obese elderly, a population at high risk for disability. The purpose of this study is to determine whether the amount of fat loss (achieved through controlled underfeeding) affects the magnitude of improvement in aerobic function (maximal aerobic capacity and endurance) in response to a standardized exercise training stimulus that follows current recommendations for older persons.
详细描述
Design Overview:
Phase 1 involves recruitment and screening followed by baseline research testing (Phase 2). Next, subjects will be randomly assigned to one of three 5-month treatments (Phase 3): exercise and high-caloric restriction diet, exercise and low-caloric restriction diet, or exercise only. Subjects will complete follow-up testing after their 5 month intervention.
Interventions:
Dietary interventions: All participants will be randomly assigned to an exercise intervention with either no dietary intervention (EX Only), or 1 of 2 hypocaloric controlled diets: 1) -250 kcal/day deficit for low fat loss (EX+LOW CR) or 2) -600 kcal/day deficit for high fat loss (EX+HIGH CR) for 20 weeks.
All meals are prepared individually after participants choose from a hypocaloric menu designed by the RD to provide a balanced, healthy diet. The calorie level assigned for each person will provide him/her with an absolute daily caloric deficit consistent with their group assignment (-600 or -250 kcals/day). Individual calorie levels will be prescribed to provide calorie levels to the nearest 50 kcals (e.g., 1100 kcal, 1150 kcal, 1200 kcal, etc.). They are educated by the GCRC RDs and provided menus to guide their food purchasing and preparation of daily breakfast meals that are consistent with the prescribed calorie level. They are asked to consume only the food that is given to them or that is approved from the breakfast menu. All participants will pick up their food 3 times/wk during the intervention, and are asked to keep a log of everything they eat or drink.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Single (Outcomes Assessor)
入排标准
- 年龄范围
- 65 Years 至 80 Years（Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •BMI=30-34.9 kg/m2
- •Sedentary for past 6 months (<30 min, 3 d/wk of exercise, including walking)
- •Normal cognitive function (MMSE >24)
- •No contraindications for participation in weight loss or exercise (e.g., severe arthritis or musculoskeletal disorders)
- •Able to provide own transportation to study visits and intervention
- •No drug abuse or excessive alcohol use (> 7 drinks/week)
- •Not dependent on a cane or walker
排除标准
- •Weight loss or gain (±5%) in past 6 months
- •Body weight >136.4 kg (DXA limit is 300 lbs)
- •Smoker (No nicotine within past year)
- •Osteoporosis (T-score ≥ -2.5)
- •Abnormal kidney function tests
- •Insulin-dependent or uncontrolled diabetes
- •Uncontrolled hypertension (BP>200/110 mmHg)
- •Hypertriglyceridemia (TG>400 mg/dl)
- •Past or current ischemic heart disease, angina, heart failure, peripheral artery disease, stroke, chronic respiratory disease, uncontrolled endocrine/metabolic disease, neurological or hematological disease, clinically evident edema
- •Cancer requiring treatment in past 2 years, except non-melanoma skin cancers
- •Severe anemia (Hb<10 g/100 ml)
- •Hip fracture, hip or knee replacement, or spinal surgery in past 6 months
- •Regular use of medications that influence study variables (growth/steroid hormones, estrogen, anti-inflammatory, beta blockers, etc.
结局指标
主要结局
maximal aerobic capacity (VO2max) and functional endurance (400 m walk time)
时间窗: assessment visits will take place at baseline and post 5 months intervention
次要结局
- changes in specific CVD risk factors (inflammatory markers, blood lipids, blood pressure, and glucose tolerance)(baseline and 5-month follow-up)