Originally posted by twistedneck
Dont forget glucosamine screws up your insuin resistance. TW.
New evidence in the New England Medical Journal September 2003 showed a new study conducted with Diabetic patients to test the effects of glucosamine and insulin resistance. Diabetics who took glucosamine 1500mg for 3 months showed no change in their HbA1C (a test used to predict the average glucose in the body over 3 month period-if there was insulin resistance due to glucosamine the HbA1C would have been elevated). From this study physicians have been more comfortable prescibing 1500mg of glucosamine to their diabetic patients with osteoporosis.
Here was the study for those interested
Can Glucosamine be Safely Used in Diabetes Patients?
Lead author: Linda Jo Rinkor, M.S., R.Ph.
Background
Glucosamine, which is synthesized in the body, is an essential element of glycosaminoglycans, glycoproteins, and glycolipids. Glycosaminoglycans, or mucopolysaccharides, function as the building blocks of tendons, ligaments, cartilage, synovial fluid, blood vessels, heart valves, and mucus membranes. Exogenous glucosamine, in either the sulfate or hydrochloride salt form, is promoted for use in osteoarthritis as an alternative to non-steroidal anti-inflammatory drugs.1 It has been suggested that exogenous glucosamine inhibits N-glycosylation. This, in turn, reduces metalloproteinases (MMP), nitric oxide, and prostaglandin E2, which play key roles in joint damage associated with osteoarthritis.2
Research had suggested that consumption of glucosamine sulfate may increase insulin resistance and decrease blood glucose control or decrease insulin production. In 1999 the Arthritis Foundation made a statement that diabetes patients taking glucosamine sulfate may need more frequent blood-glucose monitoring, as a result of animal studies showing glucosamine to induce insulin resistance.1,3-5 Thus, patients with type 2 diabetes are often cautioned that glucosamine might exacerbate their diabetes. About 40% of Americans over the age of 60 have osteoarthritis, and up to 15% of Americans over the age of 50 have type 2 diabetes. Many patients have an overlap of these two diseases. Glucosamine is increasingly used by diabetes patients and others to treat osteoarthritis. An important new study now suggests glucosamine hydrochloride with chondroitin and manganese supplementation does not cause clinically significant changes in glucose metabolism in patients with type 2 diabetes.6
Study Synopsis
In a placebo-controlled, double-blind, randomized clinical trial, 22 patients were randomized to receive Cosamin DS (500 mg glucosamine hydrochloride, 400 mg chondroitin sulfate, 5 mg manganese, and 66 mg ascorbic acid) and 12 patients were randomized to placebo. The purpose of the study was to evaluate effects of glucosamine on glycemic control in patients with type 2 diabetes. Patients took three tablets daily of Cosamin DS or placebo for 90 days. After 90 days of treatment, Cosamin DS did NOT significantly increase hemoglobin A1c levels (measurement of glycemic control). Mean hemoglobin A1c levels increased from 6.43% to 6.50% in the glucosamine group and decreased from 6.25% to 6.09% in the placebo group. An analysis of variance showed no significant differences between the glucosamine and placebo group in hemoglobin A1c levels (p=0.20). The authors concluded that oral glucosamine supplementation does not result in clinically significant changes in glucose metabolism in type 2 diabetes patients.6
Commentary
The above study was small, but was a human study designed using normal dosages of glucosamine. Most of the previous studies implicating that glucosamine may exacerbate diabetes were based on animal models using very high parenteral glucosamine dosages (up to 435,363 mg/kg/day). Recommended oral dosage for humans is about 20 mg/kg/day. In animal studies, the large glucosamine dosages were shown to decrease insulin secretion and/or induce insulin resistance in peripheral tissues. Research in humans with normal glucose metabolism suggests the effect of glucosamine on glucose metabolism is less marked than animals.1,4-8
Is there a difference between glucosamine sulfate and glucosamine hydrochloride? Cosamin DS contains glucosamine hydrochloride. Even though glucosamine is administered in a salt form, it is likely the salt is cleaved off in the stomach. Glucosamine base is completely ionized in the stomach. Laboratory data suggests the glucosamine base, hydrochloride, and sulfate salt form may be equally active; however, there are no direct comparative clinical studies.7
Is 90 days an adequate length of time to determine the effects of glucosamine on glycemic control? In another randomized, double-blind placebo controlled trial, 212 patients with knee osteoarthritis were randomly assigned 1500 mg oral glucosamine sulfate or placebo once daily for three years. This study was designed to evaluate the long-term effects of glucosamine on osteoarthritis progression. Throughout the study, routine laboratory tests showed no significant abnormalities in system organs or metabolic functions in the two groups. No change in glycemic homeostasis, with fasting plasma glucose concentrations decreasing slightly, was reported in the glucosamine group. However, a subpopulation of type 2 diabetes patients was not identified in this study.8
Cosamin DS is a combination product containing glucosamine, chondroitin, and manganese. Can this data be generalized to glucosamine alone? As far as effectiveness of glucosamine, there is no evidence that the combination has greater benefit than either glucosamine or chondroitin alone. The National Institutes of Health (NIH) is sponsoring its first clinical trial (16 week, parallel group, double-blind randomized clinical trial) of glucosamine in combination with chondroitin sulfate. There is no evidence that either chondroitin or manganese alone affects glycemic control.5,7
What is the bottom line? It appears to be safe recommending glucosamine supplementation to your osteoarthritis patients who also have diabetes [Evidence level B, lower quality RCT].6 However, be on the safe side and remind diabetes patients to monitor their blood sugars extra close after starting glucosamine.
Levels of Evidence
In accordance with the trend towards Evidence-Based Medicine, we are citing the LEVEL OF EVIDENCE for the statements we publish.
Level
Definition
A
High-quality randomized controlled trial (RCT)
High-quality meta-analysis (quantitative systematic review)
B
Nonrandomized clinical trial
Nonquantitative systematic review
Lower quality RCT
Clinical cohort study
Case-control study
Historical control
Epidemiologic study
C
Consensus
Expert opinion
D
Anecdotal evidence
In vitro or animal study
Adapted from Siweck J, et al. How to write an evidence-based clinical review article. Am Fam Physician 2002;65:251-8.
References
Gregory PJ. Glucosamine and insulin resistance. Therapeutic Research Center. Pharmacist's Letter/Prescriber's Letter1999;15:151003.
Simon LS. Future therapeutics for osteoarthritis. American College of Rheumatology 2002 Annual Meeting.
http://www.medscape.com/viewarticle/445101.
Medscape Medical News. Study suggests glucosamine sulfate may promote development of insulin resistance. New York (MedscapeWire). April 18, 2000.
http://www.medscape.com/ viewarticle/411789.
Gregory PJ. Does glucosamine increase serum lipid levels and blood pressure? Therapeutic Research Center. Pharmacist's Letter/Prescriber's Letter 2001;17:171115.
Jellin JM, Gregory PJ, Batz F, et al. Glucosamine sulfate (monograph). Therapeutic Research Faculty. Natural Medicines Comprehensive Database.
http://www.naturaldatabase.com. (Accessed August 12, 2003).
Scroggie DA, Albright A, Harris MD. The effect of glucosamine-chondroitin supplementation on glycosylated hemoglobin levels in patients with type 2 diabetes mellitus. Arch Intern Med 2003;163:1587-90.
Jellin JM, Gregory PJ, Batz F, et al. Glucosamine hydrochloride (monograph). Therapeutic Research Faculty. Natural Medicines Comprehensive Database.
http://www.naturaldatabase.com. (Accessed August 12, 2003).
Reginster JY, Deroisy R, Rovati LC, et al. Long-term effects of glucosamine sulphate on osteoarthritis progression: a randomised, placebo-controlled clinical trial. Lancet 2001;357:251-6.
September 2003
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