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Категория: За стави и сухожилия Марка: Nature's Bounty Разфасовка: 60 капсули Глюкозаминът е естествен химически елемент, намиращ се в човешкото тяло. Той се намира в течността, която е около ставите. Глюкозаминът също така се съдържа и на други места в природата. Например, глюкозамин сулфат, който се използва в хранителни добавки, често се събира в черупките от миди. Глюкозамин сулфата, използван в хранителните добавки, не винаги идва от природни източници. Той може да бъде направен в лаборатория. Глюкозамин сулфат се използва широко при артрит. Учените са го разучавали екстензивно за тази употреба. Най-често се използва за типа артрит, наречен остеоартрит. Това е най-често срещаната разновидност на артрит. През годините, хората са използвали глюкозамина за различни цели. Например, той е използван за глаукома и за загуба на тегло. Глюкозаминът се среща естествено в организма. Той помага на хрущяла да стане по-силен и по-твърд. Глюкозаминовите добавки обикновено са направени от протеин, открит в черупките на скариди, раци и други. Някои изследвания показват, че глюкозаминовите добавки облекчават болката при някои хора с остеоартрит (OA) на коляното. Артрозата, наричана още дегенеративни ставни заболявания, е най-често срещаният тип на артрит. Тя е свързана с разпределението на хрущяла в ставите и често се среща в бедрата, колената и гръбнака, отразява се и на ставите на големия пръст. Има различни форми на глюкозамин включително и глюкозамин сулфат глюкозамин хидрохлорид N-ацетил-глюкозамин. Тези различни химикали имат някои прилики, но те не могат да имат същия ефект, когато се приемат като хранителна добавка. Повечето от научните изследвания за глюкозамин са направени на глюкозамин сулфат. Информацията на тази страница се отнася до глюкозамин сулфат. Хранителните добавки, които съдържат глюкозамин често съдържат допълнителни съставки. Тези допълнителни съставки са най-често хондроитин сулфат, МСМ, или хрущял от акула. Някои хора мислят, че тези комбинации работят по-добре, отколкото глюкозамин сулфат сам. Глюкозамин сулфат и хондроитин сулфат са компоненти на нормалния хрущял. Те са градивните блокове за proteoglycans и стимулират хондроцитите да направят нов колаген и proteoglycans. Тъй като с тези добавки стимулират създаването на нови компоненти на хрущяла, приложенията могат да бъдат в състояние да помогнат на тялото да ремонтира повреденият хрущял. Съществуват доказателства, от пациенти, че глюкозаминът може да намали болката от остеоартрозата, обикновено в рамките на няколко седмици до няколко месеца след започване на лечението. Глюкозаминът се съдържа също така в някои кожни кремове използвани за контрол на болката артрит. Тези кремове обикновено съдържат камфор и други съставки, в допълнение към глюкозамин. Как действа той? Глюкозамин сулфат е химически елемент, намерен в човешкото тяло. Той се използва от организма да произвежда различни химикали, които са свързани с изграждането на сухожилия, хрущяли и течността, която заобикаля ставите. Ставите са омекотени от течността и хрущяла, които ги обкръжават. При някои хора с остеоартрит, хрущяла се разгражда. Това води до повече съвместно триене, болка и скованост. Изследователите смятат, че приемането на допълнителен глюкозамин може да допринесе за увеличаване на хрущяла и течността около ставите или предотвратяване на разбиването на тези вещества. Някои изследователи смятат "сулфатната" част на глюкозамин сулфат също за важна. Сулфатът е необходим на организма да произвежда хрущял. Това е една от причините, защо учените смятат, че глюкозамин сулфат може да работи по-добре в сравнение с другите форми на глюкозамин. Глюкозамин сулфат е форма, която е изпитана в десетки клинични проучвания. Тя е много подобна на глюкозамин HCl (хидрохлорид) в ефективността, тъй като сулфат е просто молекула превозвач на действителния глюкозамин. Друга популярна форма на глюкозамин е известна като глюкозамин HCL, или хидрохлорид. Някои изследвания са показали HCL като по-ефективен, а някои са показали сулфата като по-ефективен, така че би било разумно да се пробват и двата или поотделно или просто да се намери продукт, който съдържа както HCL, така и сулфат. Всички форми на глюкозамин произхождат от миди, и е доказано, че са ефективни при облекчаване при дискомфортта, свързан с артрит. Сулфатът и глюкозаминът (HCL) също имат много малко странични ефекти в сравнение с НСПВС, които могат да причинят вътрешни кръвоизливи и чернодробна недостатъчност. Купи Цена: 20 лв. Посочените цени са крайни с включено ДДС.
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Scientific Name(s): 2-Amino-2-deoxyglucose INTRODUCTION The purpose of this Backgrounder is to present the position of the Natural Products Association, based on the current state of scientific support, regarding the use of glucosamine as a dietary supplement. BIOCHEMISTRY Cartilage is a fibrous, elastic connective tissue that is important as a protective layer in joints. It is comprised of collagen (protein) and proteoglycans. The basic building blocks for collagen are amino acids such as proline, glycine and lysine. Proteoglycans consist of aminosugars called glycosaminoglycans such as chondroitin sulfate (A & C), keratain sulfates and other polysaccharides that are connected to a core protein that is subsequently linked to hyaluronic acid. The glycosaminoglycans or GAG's were formerly known as mucopolysaccharides. Glucosamine, which the body synthesizes from glucose and glutamine, is the key precursor for all of the glycosaminoglycans and comprises 50% of hyaluronic acid. The proteoglycans are subject to continuous metabolic turnover, undergoing constant breakdown and resynthesis in a process involving several enzymes. The changes in this processing that occur with aging are partially responsible for the development of osteoarthritis, a common condition in which the protective cartilage of joints is worn down with resultant pain and stiffness. CHEMISTRY Glucosamine is typically prepared from shellfish, specifically from chitin, the major indigestible carbohydrate in the shells of crustaceans (e.g. shrimp). A much smaller amount of glucosamine is chemically synthesized, usually as the sulfate form. The three most common commercial forms are glucosamine sulfate (as the sodium or potassium salts), glucosamine hydrochloride, and the acetylated derivative, N-acetylglucosamine. Individual products may vary in their chemical nature: for example, some may be glucosamine chemically bonded with sulfate while others may be mixtures of glucosamine hydrochloride with inorganic sulfate or chloride salts. The vast majority of clinical trials have used a chemically bonded glucosamine sulfate while most veterinary studies have used the hydrochloride form (1A). BIOLOGICAL EFFECTS Glucosamine sulfate has been used orally for the treatment of osteoarthritis since the early 1980's. Representative early studies (2-4) indicated positive clinical effects and the absence of significant adverse effects. Improvement in pain was slower than with non-steroidal anti-inflammatory drugs (NSAIDS), but appeared to be longer lasting. More recent clinical trials have provided somewhat mixed results but have generally shown some efficacy for glucosamine products in osteoarthritis. In the only study evaluating the hydrochloride form, 118 patients with osteoarthritis of the knee were enrolled in an 8-week trial (500mg glucosamine hydrochloride or placebo 3x/d). No significant difference in pain reduction was noted between the glucosamine and placebo groups as measured by a standard questionnaire. Pain diaries and knee examination did indicate benefits in some patients using glucosamine hydrochloride. Mild gastrointestinal symptoms were seen to the same extent in both placebo and glucosamine groups. The authors suggested larger studies to determine glucosamine's efficacy (5A). In another study with knee osteoarthritis patients, 114 subjects received either 500mg glucosamine (chemical type not specified) or placebo 3x daily for 2 months. Pain intensity was assessed after 30 and 60 days with no significant difference seen between the two groups. Two glucosamine and four placebo patients withdrew from the study because of adverse effects (gastrointestinal and dizziness in the glucosamine group). The authors discussed their results compared to earlier studies that showed beneficial effects of glucosamine and concluded that their patients may have had more severe disease and more pronounced joint damage (6A). A 3-month clinical trial conducted with 45 patients with temporomandibular joint osteoarthritis found glucosamine sulfate (500mg, 3x/d) to be superior to ibuprofen (400mg, 3x/d) in reducing functional pain (chewing, talking, etc) and the use of other analgesics. Glucosamine sulfate was also found to have a carry-over effect after cessation of use, unlike ibuprofen. Seventy percent of glucosamine sulfate users had at least a 39 percent reduction in pain; side effects were few and minor (7A). In a long-term (3 year) study of glucosamine sulfate in knee osteoarthritis, radiography was used to determine structural changes in the knee joint and pain reduction was assessed in comparing a single daily dose of 1500mg glucosamine to placebo. There were 212 patients enrolled in this trial; 71 in the glucosamine sulfate group and 68 in the placebo group completed the study. Dropouts due to adverse effects were 18 and 21 respectively in the glucosamine sulfate and placebo groups. Gastrointestinal effects were involved in most instances. Radiography (x-ray) of the knee indicated that joint damage had progressed in the placebo group but not in the glucosamine sulfate group. Pain symptoms worsened slightly on placebo and improved 20-25 percent after glucosamine sulfate treatment (8A). An accompanying commentary discussed this study in generally favorable terms, pointing out that radiographic severity is a poor predictor of pain and function, but that in this trial glucosamine sulfate's efficacy in pain reduction was impressive and not commonly observed with prescription pain relievers (9B). A meta-analysis of clinical trials evaluated six published studies of glucosamine [all chemical forms] (and nine of chondroitin sulfate) in treating osteoarthritis of the knee. Rigorous criteria for inclusion in this analysis limited the number of studies. Problems with the quality of even these selected studies were reported, but the authors of the meta-analysis concluded that glucosamine (and chondroitin) have efficacy in treating symptoms of osteoarthritis and are safe. The levels of efficacy claimed in some of the studies analyzed may be exaggerated and additional high-quality, independent trials were recommended to determine actual efficacy and usefulness (10A). In an editorial that accompanied this report, it was pointed out that the methodological flaws found in the glucosamine and chondroitin studies are probably no worse than those in NSAID trials. The authors further commented on the need for long-term efficacy and safety studies, the possible variability in commercial preparations marketed today, and the need for well-designed studies to determine effects on disease progression (11B). BIOAVAILABILITY The bioavailability of oral glucosamine sulfate is only 26 percent of that seen with intravenous injection. Blood levels are low after ingestion of glucosamine sulfate, which dissociates into glucosamine and sulfate ions (12A). To improve blood levels, and presumably increase glucosamine entry into cartilage, a polymer of N-acetyl-D-glucosamine (POLY-Nag) has been studied as a potential sustained- release form. Ingestion of POLY-Nag leads to prolonged elevation of blood levels of both N-acetylglucosamine and glucosamine. A small clinical trial indicated efficacy in treating osteoarthritis, but details of the study were not presented (13B). However, there do not appear to be any published studies comparing this or other forms of glucosamine to glucosamine sulfate. MECHANISM OF ACTIVITY The mechanisms by which glucosamine influences osteoarthritis are not known. From in vitro studies it has been learned that glucosamine increases sulfate uptake by cartilage and stimulates GAG synthesis by cartilage cells (chondrocytes). Glucosamine has been shown to have both anti-inflammatory and antioxidant activities. Its anti-inflammatory activity is independent of an effect on cyclooxygenase (COX) or inflammatory mediators such as bradykinin or histamine (reviewed in references 7A and 14A). Both glucosamine and N-acetylglucosamine have been shown to inhibit in human chondrocytes the formation of nitric oxide (NO) in response to pro-inflammatory agents. In addition, cyclooxygenase-2 (COX-2), but not COX-1, production was inhibited by NAG; COX-2 is an inducible pro-inflammatory enzyme. Glucosamine itself was apparently not studied for an effect on COX-2 expression. These in vitro effects required higher concentrations of both agents than the usual dosage of 1500mg/d would yield in the blood, and cannot be directly used to explain glucosamine's therapeutic effect (14A). Based in part on the very low blood levels of glucosamine found after oral administration of glucosamine sulfate, it has been theorized that sulfate itself is the active agent. Blood levels of sulfate rise rapidly in response to oral glucosamine sulfate, and sulfate levels in synovial (joint) fluid equilibrate with blood levels. Oral sodium sulfate, in contrast to glucosamine sulfate, does not increase blood levels of sulfate. The authors of this study did not claim to have proven that sulfate is the active agent, but urged further study (15A). It is noteworthy to mention that the two glucosamine studies that did use (5A), or apparently (6A) used the hydrochloride form did not observe the magnitude of positive effects seen in the most rigorous trials with glucosamine sulfate. The NIH is currently sponsoring an extensive clinical study designed to compare the effect of glucosamine HCl by itself, chondroitin sulfate by itself, a blend of glucosamine HCl and chondroitin sulfate, and placebo on osteoarthritis of the knee. The study also incorporates a COX-2 anti-inflammatory for comparison purposes. Over 1,600 patients are involved and the study is expected to take four years to complete. SAFETY Most clinical trials have found glucosamine to be safe and, indeed, to be safer than the NSAIDs used for pain relief in osteoarthritis. The authors of the 3-year study (8A) reported no significant difference between the placebo and experimental groups, with routine laboratory tests indicating no general changes and no alteration of glucose handling. A survey of clinical trials (12A) found glucosamine to be well tolerated, even by patients suffering from concurrent diseases. These authors suggested caution in cases of active peptic ulcers, type II diabetes, and those using diuretics. However, systematic evaluations of the safety of glucosamine in these patient populations have not yet been performed. NOTICE By furnishing this backgrounder, the Natural Products Association does not provide any opinion as to: - The safety of any product containing this ingredient; - The efficacy of any product containing this ingredient; - The use of any specific brand of product; or - The level of substantiation for either the safety or efficacy of any such product. Neither this backgrounder nor any portion of this backgrounder may be used in advertising or promotional materials. In addition, this backgrounder does not constitute, and is not to be used as, "third party literature" as that term is used in connection with section 5 of the Dietary Supplement Health and Education Act (DSHEA). As with any health-related product, consumers should discuss the use of any products with a health care practitioner. References: Fenton, JI, et al. The effects of glucosamine derivatives on equine articular cartilage degradation in explant culture. Osteoarthritis Cartilage 8: 444-51 (2000) Pujalte, JM et al. Double-blind clinical evaluation of oral glucosamine sulphate in the basic treatment of osteoarthritis. Curr Med Res Opin 7, 110-14 (1980) D'Ambrosio, E et al. Glucosamine sulphate: a controlled clinical investigation in arthrosis. Pharmatherapeutica 2, 504-8 (1981) Vaz, AL. Double-blind clinical evaluation of the relative efficacy of ibuprofen and glucosamine sulphate in the management of osteoarthritis of the knee in out-patients. Curr Med Res Opin 8, 145-9 (1982) Houpt, JB et al. Effect of glucosamine hydrochloride in the treatment of pain of osteoarthritis of the knee. Rindone, JP et al. Randomized, controlled trial of glucosamine for treating osteoarthritis of the knee. Western Journal of Medicine 172, 91-4 (2000) Thie, NMR et al. Evaluation of glucosamine sulfate compared to ibuprofen for the treatment of temporomandibular joint osteoarthritis: a randomized double blind controlled 3 month trial. Reginster, JY et al. Long-term effects of glucosamine sulphate on osteoarthritis progression: a randomized, placebo-controlled clinical trial. McAlindon, T. Glucosamine for osteoarthritis: dawn of a new era? Lancet 357, 247-8 (2001) (Commentary) McAlindon, T et al. Glucosamine and chondroitin for treatment of osteoarthritis: a systematic quality assessment and meta-analysis. Towheed, TE & TP Anastassiades. Glucosamine and chondroitin for treating symptoms of osteoarthritis. de los Reyes, GC et al. Glucosamine and chondroitin sulfates in the treatment of osteoarthritis: a survey. Progress in Drug Research 55, 83-103 (2000) Rubin, BR et al. Oral polymeric N-acetyl-D-glucosamine and osteoarthritis. J American Osteopathic Assoc 101, 339-44 (2001) Shikhman, AR et al. N-acetylglucosamine prevents IL-1B-mediated activation of human chondrocytes. Hoffer, LJ et al. Sulfate could mediate the therapeutic effect of glucosamine sulfate.