Effects of Oral Glucosamine on Insulin and Blood Vessel Activity in Normal and Obese People

NCT00065377 | Completed Phase 1

• 2 other identifiers: 03025103-AT-0251
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This study will examine whether glucosamine affects the way the body responds to insulin. Insulin is a hormone that causes the body to use glucose (sugar). Insulin does not work as well in overweight people, causing a condition called insulin resistance. Insulin also increases the flow of blood into muscle by opening inactive blood vessels. This study will test whether glucosamine, a nutritional supplement that many people take to treat arthritis, can cause or worsen insulin resistance or change how blood vessels react to insulin in normal weight and overweight people. Healthy normal weight and overweight volunteers between 21 and 65 years of age may be eligible for this study. Candidates will be screened with a brief physical examination, medical history, and blood and urine tests. After screening, participants will have three additional outpatient clinic visits for the following procedures: Visit 1

• Glucose clamp test to measure the body's response to insulin: For this procedure, a needle is placed in a vein of each arm, one for drawing blood samples, and one for infusing glucose and a potassium solution. The glucose is infused continuously during this 4-hour test and blood is drawn frequently to monitor glucose and insulin levels. After the test, blood glucose levels are monitored for another 2 hours to make sure they remain at an adequate level to prevent hypoglycemia (low blood sugar).
• Blood flow measurement: Blood flow in the brachial artery of the arm is measured to assess how many capillaries (very small blood vessels) are being used to supply nutrients and oxygen to the muscle in the forearm. This test is done at the same time as the glucose clamp test. Blood flow is measured using a technique called contrast ultrasound. A small amount of contrast agent consisting of gas-filled bubbles the size of red blood cells is infused over 10 minutes through one of the catheters placed in the vein for the glucose clamp test. The contrast agent is infused twice, once at the beginning of the glucose clamp test and once at the end of the test. The contrast material creates a signal in response to ultrasound that provides information about the distribution of capillaries in the forearm.
• Assignment to medication group: Participants are randomly assigned to take either glucosamine or placebo three times a day by mouth for 6 weeks. At the end of the 6 weeks, no study drug is taken for 1 week, and then participants "cross-over" medications, those who took glucosamine for the first 6 weeks take placebo for the next 6 weeks and vice versa. Visits 2 and 3 For these visits, the glucose clamp test and blood flow measurements are repeated. Visit 2 is scheduled at the end of the first 6-week treatment period, and Visit 3 is scheduled at the end of the second 6-week treatment period.

Conditions

Obesity; Insulin Resistance

Keywords

Diabetes; Insulin Resistance; Capillary Blood Flow; Osteoarthritis; Endothelial Dysfunction; Obesity; Healthy Volunteer; HV

Interventions

Glucosamine Hydrochloride DRUG

Eligibility Criteria

• Age: 21 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• HEALTHY VOLUNTEERS:
• Males or females in good general health with no significant underlying illnesses, on no medication, between the ages of 21-65 years of age with HbA1C less than 6.5, fasting blood glucose less than 100 mg/dl, blood pressure less than 130/85, and BMI between 20-26 kg/m(2). Subjects should have never smoked tobacco or not smoked within the previous 2 years.
• OBESE SUBJECTS:
• Males or females in good general health with no significant underlying illnesses, on no medication, between the ages of 21-65 years of age with HbA1C less than 6.5, fasting blood glucose less than 110 mg/dl, blood pressure less than 130/85, and BMI between 30-40 kg/m(2).

You may not qualify if:

• Subjects will be excluded if they have diabetes, hypertension, pregnancy, liver disease, pulmonary disease, renal insufficiency, coronary heart disease, heart failure, peripheral vascular disease, coagulopathy, actively smoking within last two years, in treatment for any form of cancer, positive tests for HIV, hepatitis B or C, or take systemic corticosteroids.
• Subjects will also be excluded if they have an allergy to shellfish since glucosamine is derived from shellfish. Subjects will be excluded if they have taken glucosamine within the last three months. Subjects with allergies to blood products or eggs or known hypersensitivity to albumin will also be excluded from participating because of potential adverse effects from microbubble contrast agent. Subjects will be excluded from this study because children do not typically take glucosamine or have osteoarthritis.

Sponsors & Collaborators

• National Center for Complementary and Integrative Health (NCCIH): lead

Study Sites (1)

National Center for Complementary and Alternative Medicine (NCCAM)

Bethesda, Maryland, 20892, United States

Location

Related Publications (2)

• Barclay TS, Tsourounis C, McCart GM. Glucosamine. Ann Pharmacother. 1998 May;32(5):574-9. doi: 10.1345/aph.17235.

  PMID: 9606479 BACKGROUND

• Muniyappa R, Karne RJ, Hall G, Crandon SK, Bronstein JA, Ver MR, Hortin GL, Quon MJ. Oral glucosamine for 6 weeks at standard doses does not cause or worsen insulin resistance or endothelial dysfunction in lean or obese subjects. Diabetes. 2006 Nov;55(11):3142-50. doi: 10.2337/db06-0714.

  PMID: 17065354 DERIVED

MeSH Terms

Conditions

Obesity; Insulin Resistance; Diabetes Mellitus; Osteoarthritis

Interventions

Glucosamine

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Arthritis; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases

Intervention Hierarchy (Ancestors)

Hexosamines; Amino Sugars; Carbohydrates

Study Design

• Study Type: interventional
• Phase: phase 1
• Purpose: TREATMENT
• Sponsor Type: NIH

Study Record Dates

• First Submitted: July 21, 2003
• First Posted: July 22, 2003
• Study Start: July 1, 2003
• Study Completion: June 1, 2006
• Last Updated: June 26, 2006

Record last verified: 2006-06

Locations

US (1)