In the interest of full disclosure, my most recent work on glucosamine has been both contradictory and illuminating.
For your review:
Research letter
Effect of oral glucosamine sulfate on serum leptin levels in human subjects*1
Blandine Laferr?re MD Corresponding Author Contact Information, E-mail The Corresponding Author, a, Pilar Garc?a-Lorda MD, PhD a, Colleen D. Russell PhD a and F. Xavier Pi-Sunyer MD, MPH a
a besity Research Center St Luke's/Roosevelt Hospital Center Columbia University College of Physicians and Surgeons, New York, New York, USA
Available online 21 February 2004.
Article Outline
? References
Glucosamine, an intermediate in hexosamine biosynthesis, is currently widely used as a dietary supplement for osteoarthritis. Many of the subjects who take glucosamine have obesity and/or diabetes, and its potential adverse metabolic effects on insulin and/or leptin are important to consider.
Obese individuals, with or without diabetes, tend to be hyperleptinemic, leptin resistant, hyperinsulinemic, and/or insulin resistant. Animal and in vitro data have suggested that glucosamine induces insulin resistance and increases leptin.[1 and 2] Although glucosamine induces insulin resistance in rodents, possibly by entering the hexosamine pathway, [3] human studies have failed to show that a 5- to 6-h infusion [4 and 5] or a 4-wk oral glucosamine treatment, as recently reported by Yu et al., [6] alters insulin sensitivity.
The stimulation of leptin secretion by hexosamines has been shown in vivo in rodents,[7 and 8] in vitro in 3T3-L1 cells, [9] and in human adipocytes. [10] We undertook this study to evaluate whether oral glucosamine increases leptin in vivo in human subjects.
Leptin is stimulated by nutritional and hormonal[11] factors, in particular by exogenous [12 and 13] and/or endogenous [14] glucocorticoids in humans. The stimulatory effect of dexamethasone on serum leptin levels in humans is dependent on fuel metabolism [13] and is impaired in diabetic patients. [15] Functionally, leptin has many overlapping effects with insulin and may play a role in lipotoxicity of pancreas islets and other organs. [16] Whether in vivo administration of glucosamine, like glucose, could trigger the stimulating effect of dexamethasone on leptin in healthy subjects was the secondary aim of this study.
Twenty healthy non-obese subjects, with normal glucose tolerance, body mass index of 20.8 to 29.5 kg/m2, 18 to 35 y old, were studied after an overnight fast and after another 9 h of fasting. Six subjects received 3000 mg and five received 6000 mg of oral Image-glucosamine sulfate in the morning. On a separate occasion, subjects received the same doses of glucosamine with 2 mg of dexamethasone administered intravenously at the same time. Nine control subjects were studied under the same conditions but without glucosamine.
The decreases in plasma glucose (10 ? 3%) and insulin (36 ? 10%) at 9 h of fasting did not change with either dose of glucosamine. Fasting leptin levels decreased by 24 ? 6% from baseline (from 5.5 ? 1.4 ng/mL to 3.7 ? 0.8 ng/mL, P < 0.001) at 9 h. The decline of leptin levels at 9 h were not statistically different with or without glucosamine or between the low dose (5.1 ? 3.4 to 3.8 ? 2.3 ng/mL, 28 ? 15%) and the high dose (10.0 ? 3.7 ng/mL to 6.2 ? 2.4 ng/ml, 40 ? 5%) of glucosamine.
With dexamethasone there was no difference in the decline of leptin after the low dose (7.1 ? 10%) or the high dose (15.4 ? 7%) of glucosamine (P = 0.545).
These data showed that a single dose of oral glucosamine 1) has no effect on serum leptin in humans in vivo, 2) does not trigger the stimulating effect of dexamethasone on leptin levels, unlike glucose,[12] and 3) does not modify glucose or insulin levels, in agreement with work from others. [6]
We recognize the limitations of our study concerning the absence of measurement of glucosamine levels and/or metabolites of the hexosamine pathway. It is therefore possible that the oral glucosamine load given to our subjects might have been too low to induce any changes in leptin or insulin. However, the intent of our study was to evaluate whether oral glucosamine, given at three to five times the recommended dose for treatment of osteoarthritis, had any metabolic effects on leptin or insulin. It is also possible that the glucosamine-stimulating effect on leptin described in vitro[9 and 10] cannot be extrapolated to an in vivo setting.
A second aim was to investigate whether glucosamine, like food or glucose and insulin, could act in synergy with dexamethasone to increase leptin levels. Our data showed that glucosamine does not. If oral glucosamine is absorbed and metabolized through the pentose pathway, then our data, contrary to animal[7 and 8] and in vitro [9 and 10] data, do not support a role for the pentose pathway in the dexamethasone-stimulating effect on leptin.
Given the very common use of over-the-counter glucosamine by obese patients, these negative findings are clinically relevant. Obese individuals tend to be hyperleptinemic, hyperinsulinemic, and/or leptin and insulin resistant. Although animal and in vitro data suggest that glucosamine induces insulin resistance and increases leptin, glucosamine does not appear to have any detrimental effect on glucose, insulin, and/or leptin in humans, based on our results and those of others.[4, 5 and 6] However, studies with prolonged administration of glucosamine and in metabolically compromised patients are needed to obtain a broader conclusion.
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Thread: Avant Synthesize
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02-01-2008, 10:23 AM #31
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Avant Research R&D/Rep
Contact: derek [.at.] avantlabs -> com
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02-02-2008, 09:11 AM #32
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02-04-2008, 05:27 PM #33
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interested on what avant reps have to say in response to this...
posted by Dinoiii at leanbulk.com
Before I proceed, I will preface this by suggesting this is merely an opinion on a product I was asked about. There are no intentions to call-out and/or question Avant and/or the reps nor any expectations as a result. That said, if any of them feel the need to speak up in this thread, I am more than happy to listen to their reasoning.
First, Do you have their write-up?
I am uncertain why certain things were used actually.
For instance, the AMINOGEN...I just don't see rationale with it in this formula.
By prop blend rules, the NAC is highly underdosed for most well-trained bodybuilders.
I do NOT like CEE! I think studies have suggested it to MINIMALLY not hold superiority to monohydrate (depsite the "anti-bloat" offering that usually plagues ad-campaigns - here it should be no matter as they also stuck the CM in there anyway).
Calcium and magnesium could offset one another in this formula due to the salts that they chose, but really I don't have issues with the rest of the formula - it should likely be inconsequential.
Again - anyone want to aid my cause and stick up their write-up in this thread for me please (I apologize but I am press for time at the moment...these are all quick thoughts for now until I see more and perhaps rationale for their employment).
Thanks
D_
Continued...
Rapid-fire comments in response to the product write-up:
(1) Aminogen is simply NOT necessary for a normal human being. Sounds catchy and neat and I appreciate the citation of TM-holders, but the reality remains; most people digest proteins just fine. In the case of metabolic derrangements where individual aminos may be of supplemental benefit, there is likely some rationale for the potential incorporation of this, HOWEVER, you could just supplement with the individual aminos of concern as well.
I will cite an example. I am currently working with 9 cases of aminoacidurias (very rare to have that high incidence in office). Three of the cases are cystinuria which provides and auto****l recessive defect in the transport of what I collectively reference the "COLA" amino acids (Cysteine, Lysine, Ornithine, and Arginine). Read any old bodybuilding supplement ad and you'd probably say - them is some big players, no? Not really ... outside of an alkaline diuresis, they fare pretty well on supplementation and if they can process ok...trust me - you can as well!
(2) The NAC remains underdosed for what is being suggested. This is as I suspected and far too many approximate the acetaminophen research to translate into oral dosing parameters; it does NOT! This is probably the most misunderstood of all of the nutrients I could assume. After 5 years of direct research with it; I'd say this is unfortunate. Plus - the schnazzy ads suggesting free-radicals are always a bad thing is incorrect.
(3) In order for betaine (nature's cheap version of SAMe essentially, which SHOULD BE SUPPLEMENTED WITH PARTICULAR co-factor B-vitamins to actually work the way they suggest) is FAR UNDERDOSED.
(4) Anyone see an issue with calcium, magnesium, and zinc being supplemented at once?
(5) Fortunately they did add the CM to compensate for the CEE, however - if you were trying to avoid the bloat, et al...would you really have rationale to buy into a formula that still incorporates CM?
Again, this is NOT intended as derogatory, per se...but truthful approximations on the formula I was asked about. This does NOT appear well-thought out in my estimation. I would prefer the above ammendments as a start to make the formula into something. What that something is is probably anyone's guess.
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02-06-2008, 09:49 AM #34
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Was addressed here. http://www.leanbulk.com/forum/ask-dr...thesize-2.html
Avant Research R&D/Rep
Contact: derek [.at.] avantlabs -> com
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02-06-2008, 09:54 AM #35
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And there's more to come.
Par Deus himself is going to respond, so I have bowed out.
But I will say this- it's important to remember that SyntheSIZE is not just a "cell-volumizer". It's also a meal-optimizer. You take it three times per day, with meals, to get more out of each one.
The fact that you're taking zinc, magnesium, and calcium at the same time doesn't really matter because you're taking it with food, which contains those three and a whole lot more. The point is just to make sure you're getting enough of each essential mineral.
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02-06-2008, 09:56 AM #36
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02-06-2008, 09:59 AM #37
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02-06-2008, 10:03 AM #38
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02-06-2008, 10:10 AM #39
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02-06-2008, 10:17 AM #40
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02-06-2008, 12:52 PM #41
I still have most of my tub back in Hawai'i. I was using this with the recommended amount of Glucosamine to mimic Leptigen 2.0. I was using Glucosamine Sulfate though, and was getting diaherra all the time. I was talking to Avant and they said it was possibly the Magnesium.
That's my unbiased feedback. But I look forward to trying it again, and hopefully not getting those results. Because it seems to be an awesome product.
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02-12-2008, 10:03 AM #42
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There was another user over at Mind and Muscle who also noted the Mg might be causing some gastrointestinal issues. Thankfully for us, there are very few cases of this.
Also, DX was the ****!Avant Research R&D/Rep
Contact: derek [.at.] avantlabs -> com
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02-12-2008, 10:20 AM #43
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02-12-2008, 10:28 AM #44
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08-05-2008, 06:25 AM #45
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08-05-2008, 07:35 AM #46
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08-05-2008, 07:47 AM #47
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08-05-2008, 07:57 AM #48
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08-05-2008, 08:02 AM #49"Blood, Sweat, and Tears doesn't mean crying while you struggle to put your tampon in." ~dsade
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08-05-2008, 08:04 AM #50
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08-05-2008, 08:05 AM #51
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08-05-2008, 02:52 PM #52
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