April 18, 2000 SAN DIEGO (Reuters Health) -- Use of glucosamine sulfate, a popular anti-arthritis supplement, may contribute to insulin resistance in diabetics or those at risk for the disease, researchers report.
Insulin resistance -- a decrease in the body's response to the blood sugar-regulating hormone insulin -- is a condition that is a precursor to type 2 (adult-onset) diabetes. Increasing insulin resistance could result in more difficult-to-control blood sugar levels.
While the results of the small study should not prompt diabetic users to abandon the supplement, "it may be wise for them to be aware of (potential risks) and chat a bit with their physicians or be more rigorous in monitoring their blood sugar," explained researcher Anthony Almada, president and chief scientific officer of IMAGINutrition, a for-profit industry 'think tank.' The preliminary findings were presented at the Experimental Biology 2000 conference, held here this week.
A growing number of the 21 million Americans with osteoarthritis are turning to glucosamine sulfate supplements to help ease the symptoms of the painful bone and joint disease. US sales of the supplement, usually derived from the shells of shellfish, now top $230 million a year, according to the Nutrition Business Journal.
However, a recent editorial in the British medical journal The Lancet suggested that glucosamine might help raise insulin resistance.
Investigating further, researchers at the Los Angeles College of Chiropractic and MetaResponse Sciences (a sister company to IMAGINutrition), examined levels of insulin resistance and blood sugar in 15 non-diabetic patients. The subjects were given either 1500 milligram glucosamine sulfate supplements a day (the usual dose) or an inactive placebo for 12 weeks.
By the end of the study, blood insulin levels had risen in those subjects taking glucosamine sulfate, compared with those taking a placebo. "Given that we didn't do it in diabetics and we saw a mild effect, it would suggest that in a diabetic the effect would be more striking," Almada told Reuters Health, "although maybe not life-threatening or even close to it."
He stressed that the results of the study need to be replicated in larger, controlled trials before any firm conclusions can be drawn regarding the use of glucosamine among the nation's nearly 16 million diabetics. Larger studies are planned, but until those results are in, Almada stated there is no reason for diabetic users to toss their glucosamine tablets away.
"We're trying to convey that if you're taking it, be aware that if you're at risk for diabetes or you have diabetes it may have a mild effect -- let your doctor know that you are taking it," Almada added.