- ICH GCP
- US-Register für klinische Studien
- Klinische Studie NCT00341406
Fat Cell Size in Insulin Resistance
Adipose Cell Size In Human Insulin Resistance
This study, conducted at Stanford University in Palo Alto, California, will examine how insulin metabolism and cardiovascular risk are altered in response to weight loss. Insulin is a natural hormone that causes cells to remove glucose (sugar) from the blood. People who are insulin-sensitive remove glucose efficiently. People who are insulin-resistant require more insulin to remove glucose from the blood.
Adult volunteers will be recruited for this study through advertisements in local newspapers in communities around Stanford University.
Participants will undergo the following tests and procedures:
- Insulin sensitivity testing: Before beginning the study, participants will be tested for insulin sensitivity. For the test, two small catheters (plastic tubes) are placed into two veins - one for infusing glucose, insulin, and sandostatin (a drug that blocks insulin secretion from the pancreas), and one for drawing blood samples. The infusions are done over 3 hours. Blood samples are collected before, during, and at the end of the study to measure how well the cells remove glucose from the blood in response to insulin.
- Research diet: Participants are assigned to a low-calorie diet tailored to the individual's metabolic rate. The diets contain either 40 or 60 percent of total calories as carbohydrates, 40 or 20 percent as fat, and the rest as protein. People with type 2 diabetes who are taking diabetes medicine with have a diet of 45 to 50 percent carbohydrates, 35 to 40 percent fat, and the rest protein.
- Meal profile: Before beginning the diet and after 4 months on the diet, participants are tested for the effects of the various study diets on control of blood sugar and fats. On the day of each test, participants have a physical examination and provide a medical history. Then, a small catheter is placed in a vein. Blood samples are drawn before breakfast and then hourly for up to 8 hours.
- Participants who are diabetic are randomly assigned to take one of three diabetes medications - rosiglitazone, glucophage, or a sulfonylurea compound - to help control blood glucose levels.
- Magnetic resonance imaging: This diagnostic test uses a strong magnetic field and radio waves to show structural and chemical changes in tissues. During the scan, the participant lies on a table in a narrow cylinder containing a magnetic field, wearing ear plugs to muffle loud knocking and thumping sounds that occur during the scanning process. He or she can speak with a staff member via an intercom system at all times during the procedure.
In addition to these procedures, patients may be asked to have a fat cell biopsy. This is done to determine whether insulin-resistant people have fewer fat cells but more fat per cell than insulin-sensitive people. For this test, a small piece of fat tissue is surgically removed, under local anesthetic, from an area of the lower abdomen. With the participant's consent, genetic testing may be done on the fat tissue sample to look for genes that may link central obesity to insulin resistance.
Some participants may be asked to be followed for an additional 3 months after completion of the study for a continued weight loss program. The follow-up includes weekly visits for weight measurements and a review of food records.
Studienübersicht
Status
Bedingungen
Detaillierte Beschreibung
Studientyp
Einschreibung (Tatsächlich)
Kontakte und Standorte
Studienorte
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Maryland
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Bethesda, Maryland, Vereinigte Staaten, 20892
- National Institute of Diabetes and Digestive and Kidney Disorders (NIDDK), 9000
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Teilnahmekriterien
Zulassungskriterien
Studienberechtigtes Alter
Akzeptiert gesunde Freiwillige
Studienberechtigte Geschlechter
Probenahmeverfahren
Studienpopulation
Beschreibung
- INCLUSION AND EXCLUSION CRITERIA:
Without regard to gender, race, or socioeconomic status, all subjects will be adult men and women. The racial/ethnic composition of the study population will be reflective of the communities surrounding Stanford University. Subjects will be recruited through placement of advertisements in local newspapers, but no subjects will be seen at NIH.
Studienplan
Wie ist die Studie aufgebaut?
Designdetails
- Beobachtungsmodelle: Kohorte
- Zeitperspektiven: Interessent
Kohorten und Interventionen
Gruppe / Kohorte |
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Healthy volunteers
healthy, non-overweight or other medical conditions
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Patients overweight
Those who are generally healthy but overweight
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Patients with health conditions
Those with diabetes and cardiovascular disease.
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Was misst die Studie?
Primäre Ergebnismessungen
Ergebnis Maßnahme |
Maßnahmenbeschreibung |
Zeitfenster |
---|---|---|
adipose cell size distribution
Zeitfenster: end of study
|
to look at role of the to look at role of the fat cell in relation to obesity and insulin resistance, the role of anti-inflammatory helper cells in protecting against insulin resistance, look at effects of overfeeding on fat cells and insulin resistance, measure inflammatory markers (during and after weight loss), quantify production of fat cells, total triglycerides production, and breakdown of fat cells.
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end of study
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Mitarbeiter und Ermittler
Ermittler
- Hauptermittler: Arthur Sherman, Ph.D., National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Studienaufzeichnungsdaten
Haupttermine studieren
Studienbeginn (Tatsächlich)
Primärer Abschluss (Tatsächlich)
Studienabschluss (Tatsächlich)
Studienanmeldedaten
Zuerst eingereicht
Zuerst eingereicht, das die QC-Kriterien erfüllt hat
Zuerst gepostet (Schätzen)
Studienaufzeichnungsaktualisierungen
Letztes Update gepostet (Tatsächlich)
Letztes eingereichtes Update, das die QC-Kriterien erfüllt
Zuletzt verifiziert
Mehr Informationen
Begriffe im Zusammenhang mit dieser Studie
Schlüsselwörter
Zusätzliche relevante MeSH-Bedingungen
Andere Studien-ID-Nummern
- 999903290
- 03-DK-N290
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