Optimizing Protein Intake in Older Americans With Mobility Limitations
试验速览
- 阶段
- 3 期
- 状态
- 已完成
- 入组人数
- 92
- 试验地点
- 1
- 主要终点
- Change in Lean Body Mass as Measured by Dual Energy X-ray Absorptiometry (DXA)
研究概览
简要总结
This will be a randomized, placebo-controlled, parallel group, double blind, clinical trial in community dwelling, older men, 65 years of age or older, who have mobility limitation and low protein intake. The study will have a 2 X 2 factorial design, which will allow us to investigate the effects of dietary protein intake and testosterone separately and together.
详细描述
The recommended dietary allowance (RDA) for protein, set at 0.8 grams/kg/day for adult men and women, has engendered debate and many experts advocate protein intakes substantially above the RDA to help maintain muscle anabolism in older individuals. It is not known whether increasing protein intake in older Americans, whose current intake is below the RDA, increases skeletal muscle mass, muscle performance and physical function.
Our first aim is to determine whether administration of 1.3 g/kg/day of protein, compared to the RDA (0.8 g/kg/day), will result in greater improvements in lean body mass, maximal voluntary muscle strength and power, and self-reported and performance-based measures of physical function in older men. Our second aim is to determine whether the gains in lean body mass, maximal voluntary strength and self-reported and performance-based measures of physical function during testosterone administration are greater with 1.3 g protein than with the RDA in older men on a eucaloric diet.
We will conduct a randomized, placebo-controlled, double-blind trial using a 2 X 2 factorial design. Community dwelling men, 65 years or older, who have self-reported mobility limitation, a daily protein intake of <0.8 g/kg/day and no contraindications for testosterone therapy, will be randomly assigned to one of four groups: placebo injections plus protein 0.8 g/kg/day; placebo injections plus protein 1.3 g/kg/day; testosterone enanthate 100 mg weekly plus protein 0.8 g/kg/day; testosterone enanthate 100 mg weekly plus protein 1.3 g/kg/day. Treatment duration will be 6 months. The primary outcome is change in lean body mass from baseline to 6 months, measured by dual energy X-ray absorptiometry. Secondary outcomes include change in maximal voluntary strength in leg and chest press exercises, leg power, self-reported (physical function domain of SF-36) and performance-based measures of physical function (6-min walking distance and speed, stair climbing power, and load carrying), fatigue, well-being and affectivity balance. Safety measures include urinary calcium excretion, hematocrit, prostate specific antigen (PSA) and prostate examination.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Factorial
- 主要目的
- Treatment
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 65 Years 至 —（Older Adult）
- 性别
- Male
- 接受健康志愿者
- 否
入选标准
- •Community-dwelling men 65 years of age or older
- •A score of 3-10 on the short physical performance battery (SPPB)
- •Daily protein intake less than the recommended daily allowance of 0.83 g/kg/day (from 3 24-hour food recalls)
- •Able to give informed consent
排除标准
- •History of prostate or breast cancer
- •American Urological Association [AUA] symptom index score of >19
- •Prostate specific antigen (PSA) >4 ng/ml in White men or >3 ng/ml in Black men
- •Prostate specific antigen (PSA) > 4 ng/ml in non-Black men or >3 ng/ml in Black men. These subjects may be enrolled if they have a negative transrectal biopsy within the past year.
- •Myocardial infarction or stroke within the last 6 months
- •Uncontrolled congestive heart failure, based on the study physician's evaluation
- •Serum creatinine > 2.0 mg/dL; men on any kind of dialysis will be excluded.
- •History of celiac disease, Crohn's disease, or ulcerative colitis
- •History of any malignancy requiring treatment within the previous 2 years, except non-melanic skin cancers. Men with cancers who have not required active treatment within the past two years and who have not had disease recurrence within the past two years may be enrolled at the discretion of the study physician.
- •Neuromuscular diseases: motor neuron diseases, multiple sclerosis, adult muscular dystrophies, and myasthenia gravis
- •History of stroke with residual limb weakness that affected the individual's ability to walk; subjects with history of stroke who do not have residual limb weakness may be enrolled.
- •Schizophrenia, bipolar disorder, or untreated diagnosed depression. Subjects with unipolar depression who are on an antidepressant medication are eligible.
- •TSH levels <0.4 or >5 mlU/L
- •Systolic blood pressure (BP) >160 or diastolic BP >100 mm Hg (average of 2 measurements taken at Visit 1)
- •Hemoglobin A1c >8.0% or taking insulin. Men with diabetes mellitus whose A1C is less than 8.0% or who are not taking insulin will be eligible.
- •Mini-Mental Status Exam [MMSE] <24
- •Body mass index (BMI) less than 20 or greater than 40 kg/m2
- •Not willing to eat all of the following: red meat, eggs, poultry, fish and shellfish
- •Allergy to sesame, peanuts, soy, gluten or shellfish
- •Current alcohol use >21 drinks/week based on self-report
- •Confinement to a wheelchair
- •Use of anabolic therapies (Testosterone, DHEA, androstenedione, rhGH) within the past year
- •Current use of levodopa or anticoagulants
- •Current enrollment in a structured weight management program or participation in any weight intervention studies in the last 90 days
- •Serum ALT and AST greater than 3 x upper limit of normal
- •Hematocrit < 30% or >48%
- •Subject is not able to eat 3 frozen study meals per day for 6 months
- •Subject is unwilling to stop current nutritional supplements
- •Progressive intensive resistance training within 12 weeks of screening
- •Non-compliant with run-in diet and/or supplement
研究组 & 干预措施
Testosterone/Low Protein
Testosterone enanthate 100 mg intramuscularly weekly; 0.8 g/kg/day protein
干预措施: Testosterone enanthate (Drug)
Testosterone/High Protein
Testosterone enanthate 100 mg intramuscularly weekly; 1.3 g/kg/day protein
干预措施: Testosterone enanthate (Drug)
结局指标
主要结局
Change in Lean Body Mass as Measured by Dual Energy X-ray Absorptiometry (DXA)
时间窗: 6 months from baseline
Primary outcome is change in lean body mass, measured by dual energy X-ray absorptiometry (DXA)
次要结局
- Change of Psychological Well Being Index (PGWBI)(6 months from baseline)
- Change of Functional Assessment of Chronic Illness Therapy (FACIT) Fatigue Scale(6 months from baseline)
- Change of Derogatis Affective Balance Scale (DABS)(6 months from baseline)
- Change of Maximal Voluntary Strength(6 months from baseline)
- Change of Leg Press Power(6 months from baseline)
- Change of 6-minute Walking Distance(6 months from baseline)
- Change of Stair Climbing Tests(6 months from baseline)
- Change of 50-meter Loaded Walking Test(6 months from baseline)
- Change of Self-reported Physical Function Domain of Short Form Health Survey (SF-36)(6 months from baseline)
研究者
Shalendar Bhasin, MD
Shalendar Bhasin, MD
Brigham and Women's Hospital