| City: |
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Bethesda |
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State:
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MD |
| Zip Code: |
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20892 |
| Conditions: |
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Morbid Obesity - Diabetes Mellitus Type 2 - Insulin Resistance - Obstructive Sleep Apnea - Mood Disorders |
| Purpose: |
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This study will describe the phenotype (physical and behavioral traits) of overweight and
obese people. It will characterize the hormones, metabolism, food preferences, fitness and
physical activity levels, sleep patterns and thought processes in people with and without
weight problems. Genetic material will be collected for studies of the internal codes that
influence body weight.
People over 18 years of age from all weight categories (lean, overweight, obese) who are
reasonably healthy may be eligible for this study. Participants undergo the following tests
and procedures:
- Physical exam, electrocardiogram, blood and urine tests, instructions for recording
food intake for 7 days
- Metabolic studies for menstruating women.
- Resting metabolic rate to study how many calories the body burns at rest.
- Mixed meal test to measure hormones such as insulin that regulate blood sugar.
- Glucose tolerance test to determine how sensitive the body is to insulin.
- 24-hour energy expenditure to measure the amount of oxygen breathed in and the amount
of carbon dioxide breathed out.
- Repeat 24-hour energy expenditure.
- Diurnal blood sampling and temperature assessment to study the body's internal clock.
- Air-displacement plethysmography (Bod Pod) to measure body composition.
- Dual energy x-ray absortiometry (DEXA) to measure body fat and bone density.
- Repeat Bod Pod and DEXA.
- Anthropometric measurements and bioelectrical impedance to measure height, weight, and
circumferences, skinfold thickness, fluid status and percentage body fat.
- Bromide dilution to measure the amount of water not in cells in the body.
- Doubly labeled water to measure the amount of calories burned in a 7-day period.
- 24-hour diet reports.
- Endothelial reactivity to measure how the blood vessels stretch or dilate for assessing
cardiovascular health.
- Treadmill or bicycle exercise capacity test.
- Physical activity monitor.
- Unicorder to detect any breathing difficulties that may interfere with sleep.
- Fat and muscle biopsy to look for variations in gene expression in fat tissue and
muscle.
- Neurocognitive testing to check memory, decision-making, hand-eye coordination, and
reasoning.
- Evaluation of mood problems and assess personality type.
- Evaluation to assess the quantity and quality of pain experienced.
- Taste testing to determine the response to bitter, salty, sweet and sour substances.
- Occupational therapy evaluation to explore the subject's adaptations, if any, for
performing personal, social or professional activities; the subject's views on his or
her weight, body size and shape, and strategies to control weight.
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| Study summary: |
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Although complex metabolic, hormonal, and neural networks operate to control body weight,
obesity is in most cases, the result of over-feeding and inactivity. In the majority of
obese patients, patterns of fundamental behavior (eating, physical activity, sleeping)
determine the success or failure of weight loss interventions. Behavior is controlled to
some degree by conscious decision making and is influenced by signals from the integrated
networks involved in body weight regulation. The contributions of behavior, environment,
socioeconomic status, physiology and genetics assure that no single therapeutic regimen will
be successful in all obese individuals. In order to explore the factors that impede weight
loss and result in weight regain, the obese phenotype and its variants must be defined. The
purpose of this study is to detail hormonal, metabolic, cognitive and behavioral traits
across the spectrum of weight categories utilizing the state-of-the-art facilities of the
Metabolic Units at the Mark O. Hatfield Clinical Research Center, NIH. Genetic material
(blood and tissue) will be banked for analysis of phenotypic subgroups as they emerge.
Patients over the age of 18 are eligible for this study. While childhood obesity is an
important public health issue, the variables of growth and hormonal controls will be
delineated in separate studies. Over-weight and obese patients are encouraged to participate
in as full an evaluation as feasible. Lean individuals will be recruited to create a
normative database for body composition (dual energy x-ray absortiometry, air displacement
plethysmography), energy expenditure (resting energy expenditure, 24h respiratory chamber
and doubly labeled water) and other techniques used to study traits of importance. The
study will be conducted in both the inpatient and outpatient setting and can include
evaluation of hormones, diurnal variation, sleep, eating behavior and taste perception,
physical fitness, and psychological and neurocognitive functioning. Importantly, this
protocol is the means by which pilot data are obtained to develop novel approaches and
hypotheses for studying obesity and its associated traits. |
| Criteria: |
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- INCLUSION CRITERIA:
Obese subjects:
1. Obese men and women over the age of 18 years;
2. BMI greater than 30;
Overweight subjects:
1. Overweight men and women over the age of 18 years;
2. BMI greater than 25 and less than 30
Control subjects (may be matched for age, sex and years of education):
1. Normal weight men and women over the age of 18 years;
2. BMI greater than 18.5 and less than 25
EXCLUSION CRITERIA:
1. Patients with significant physical limitations that may preclude them from completing
the majority of the tests in this study.
2. Current, unstable medical conditions including cardiac ischemia; severe respiratory
insufficiency requiring oxygen therapy; hepatic or cardiac failure as assessed by
history and physical exam;
3. Any psychiatric condition that would preclude participation in the study;
4. Patients unwilling or unable to give informed consent.
Additional exclusion for lean control subjects:
1. Previous history of obesity as an adolescent or adult;
2. Current or past history of eating disorders such as anorexia nervosa or bulimia.
Exclusions for both cannabis users and controls:
1. Dependence on drugs other than nicotine, caffeine and cannabis, within the past 6
months
2. Any history of intravenous illegal drug use
3. Alcohol use of more than 5 drinks per day, on 3 or more days in a week; or more than
15 drinks per week
4. History of hepatitis B or C or current hepatitis A, B or C, or other liver disease
associated with steatosis
5. HIV
6. History of diabetes (type 1 or type 2) or polycystic ovary disease or other
conditions that may confound our study results
7. Professional or collegiate athletes or participation in more than 60 minutes per day
of vigorous exercise
8. Use of prescribed or over the counter or herbal/alternative medications/ preparations
with effects on glucose and lipid metabolism other than oral contraceptives
9. Pregnancy or lactation
10. Any condition or physical attribute which would interfere with MRI study e.g.
claustrophobia, cochlear implant, metal fragments in the eye, certain types of
tattoos or other metal implanted in the body |
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| Study is available at: |
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National Institutes of Health Clinical Center, 9000 Rockville Pike
Bethesda, MD 20892
United States
Primary Contact:
Patient Recruitment and Public Liaison Office
Email: prpl@mail.cc.nih.gov
Phone: (800) 411-1222 |
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If you are interested in this clinical trial please use the contact information above. If you would like to get additional information about this clinical trial please visit ClinicalTrials.gov.
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| Data Source: |
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ClinicalTrials.gov |
| Date Processed: |
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March 22, 2011 |
Modifications to
this listing: |
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Only selected fields are shown, please use the link
above to view all information about this clinical trial. |
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