# Presentation: 078386

## GLUCOSAMINE AND CHONDROITIN SULFATE REDUCE RISK OF OSTEOARTHRITIS

- Luke R. Bucci, PhD
- Vice President, Research
- Weider Nutrition Group
- Salt Lake City, UT

- Human tracheal cartilage – Bailey’s Textbook of Histology 1948, p.108

## This presentation will:

- Review the need for reducing risk of osteoarthritis (OA)
- List the proposed Health Claims
- Review roles of Glucosamine and Chondroitin Sulfate in reducing OA risk
- Explain credible evidence supporting claims

## OSTEOARTHRITIS IMPACT

- “Arthritis is the _**leading cause of disability**_ in the United States.”

## GLUCOSAMINE & CHONDROITIN REDUCE RISK OF OA - PROPOSED HEALTH CLAIMS

- Glucosamine may reduce the risk of osteoarthritis (OA).
- Chondroitin sulfate may reduce the risk of OA.
- Glucosamine may reduce the risk of joint degeneration.
- Chondroitin sulfate may reduce the risk of joint degeneration.
- Glucosamine may reduce the risk of cartilage deterioration.
- Chondroitin sulfate may reduce the risk of cartilage deterioration.

## ILLUSTRATIONS:JOINT CARTILAGE(Visual references for Glucosamine and Chondroitin Sulfate Roles)

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## Lifespan of aggrecan PG in adult human cartilage is 600-1000 days

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## HUMAN SUPPLEMENTATION STUDIES WITH GLUCOSAMINE AND CHONDROITIN SULFATE:APPLICABILITY TO RISK REDUCTION 

## SUPPLEMENTATION TRIALS IN OA: APPLICABILITY TO RISK REDUCTION

- Cartilage tissue turnover is constant and ongoing, but normally at a slow rate (half-life of aggrecan and collagen is 1-2 years)
- Normal “wear and tear” produces degraded fragments constantly (free radicals, shear stress)
- Cartilage responds to molecular pieces of most exposed macromolecular constituents (hyaluronan, chondroitin) to monitor structural integrity via CD36, CD44 receptors

## SUPPLEMENTATION TRIALS IN OA: APPLICABILITY TO RISK REDUCTION

- Joint tissues can only maintain themselves and resist degradation only by biosynthesis of more matrix
- The only way joint tissues can make more matrix is to utilize Glucosamine and manufacture more Chondroitin
- Biosynthesis of Chondroitin is essential to maintenance and thus, prevention of joint deterioration

## SUPPLEMENTATION TRIALS IN OA: APPLICABILITY TO RISK REDUCTION

- “The integrity of this matrix is critical for the unique biochemical properties of hyaline cartilage and depends on a maintenance of the quantity and quality of the matrix components.  Such maintenance must be the result of a balance between synthetic and degradative processes within the tissue.  Thus, any loss of, e.g., proteoglycan from the cartilage matrix due to physiologic or pathologic processes must be balanced by *de novo* synthesis of proteoglycans by the chondrocytes.”
- Lohmander LS, Kimura JH. Biosynthesis of cartilage proteoglycan. In *Articular Cartilage Biochemistry*, Kuettner K, et al, Eds., Raven Press, New York, 1986, p. 93.

## SUPPLEMENTATION TRIALS IN OA: APPLICABILITY TO RISK REDUCTION

- Same biochemical, regulatory, cellular, biosynthetic, anabolic, catabolic, metabolic mechanisms are operative in cartilage whether condition is perfect health or OA
- Maintenance of cartilage consists of the same processes and events that occur during normal wear and tear, during normal aging and in diagnosed OA

## SUPPLEMENTATION TRIALS IN OA: APPLICABILITY TO RISK REDUCTION

- There is an unbroken continuum of events in cartilage from health to degenerative disease
- Therefore, there is no agreed-upon threshold or marker that clearly defines the onset of OA

## SUPPLEMENTATION TRIALS IN OA: APPLICABILITY TO RISK REDUCTION

- Considerable overlap for biomarkers and appearance of cartilage exists between healthy controls and OA subjects
- Same type and extent of imbalance between matrix component synthesis and degradation can be seen in “healthy” and “osteoarthritic” subjects

## SUPPLEMENTATION TRIALS IN OA: APPLICABILITY TO RISK REDUCTION

- OA diagnosis based on clinical signs (pain, stiffness) and X-ray evidence of structural changes in joints (Kellgren-Lawrence staging)
- Staging is arbitrary and subjective
- Human studies with OA subjects have examined a portion of the continuum of joint health
- Pre-diagnostic joint damage must exist in greater incidence than diagnosed OA (i.e., damage does not start the day before diagnosis)

## SUPPLEMENTATION TRIALS IN OA: APPLICABILITY TO RISK REDUCTION

- Normal aging shows loss of Chondroitin in cartilage and hyaluronan in synovial fluid
- Normal aging shows decrease in length of Chondroitin and proteoglycans synthesized routinely for upkeep
- Normal aging shows decrease of chondroitin, water and size in cartilage

## SUPPLEMENTATION TRIALS IN OA: APPLICABILITY TO RISK REDUCTION

- OA results from an imbalance of normal anabolic and catabolic activities in cartilage
- OA = deficiency of normal regulation of cartilage maintenance

## SUPPLEMENTATION TRIALS IN OA: APPLICABILITY TO RISK REDUCTION

- Both Glucosamine and Chondroitin Sulfate help regulate (normalize) cartilage maintenance
- Maintenance of normal balance of anabolic & catabolic actions = return towards health, reducing risk of OA

## GLUCOSAMINE

## GLUCOSAMINE FACTS RELEVANT TO RISK REDUCTION

- Availability of Glucosamine is the key, rate-limiting step for synthesis of connective tissue macromolecules
- Preformed Glucosamine is preferred 300% over glucose for GAG synthesis

## GLUCOSAMINE – TYPES OF PUBLISHED EVIDENCE

| Type of Substantiation | Number of Publications |
| --- | --- |
| Consensus Statement | 4 supportive
1 nonsupportive |
| Independent expert opinions (reviews) | 43 supportive
14 nonsupportive |
| Meta-Analyses | 14 supportive
0 nonsupportive |
| Large, Well-Designed Human Clinical Trials | 12 (18) supportive
2 (3) nonsupportive |
| Smaller, Well-Designed Human Clinical Trials | 13 (13) supportive
4 (5) nonsupportive |
| Uncontrolled Human Clinical Trials | 29 supportive
4 nonsupportive |
| Animal Intervention Studies | 20 supportive
3 (4) nonsupportive |
| In Vitro Studies | 45 supportive
9 nonsupportive |
| Total | 180 (186) supportive
33 (36) nonsupportive |

## BIOMARKERS AFFECTED BY GLUCOSAMINE

- Biosynthesis of HA, GAGs, collagen
- aminosugar unit precursor
- preferred substrate - 300% better than glucose
- Biosynthesis of HA, GAGs, collagen
- enhanced production, gene expression
- regulatory Biological Response Modifier

## BIOMARKERS AFFECTED BY GLUCOSAMINE

- Inhibition of cartilage breakdown
- Prevention of joint space loss in knee OA (humans)
- Correlation of keratan sulfate with radiologic image (humans)
- Prevention of joint degeneration in healthy animals induced to become osteoarthritic
- In vitro cartilage cultures – direct addition
- Inhibition of degradative enzymes
- In vitro:
- Matrix metalloproteinase expression
- Collagenase

## BIOMARKERS AFFECTED BY GLUCOSAMINE

- Antiinflammatory effects
- Animal models of acute inflammation
- Counteracts IL1-beta proteoglycan loss via NFKB
- Decreases levels and/or expression of inflammatory cytokines, COX2, PGE2, PLA2
- Synergy with NSAIDs

## BIOMARKERS AFFECTED BY GLUCOSAMINE

- Downregulates inducible nitric oxide
- Antioxidant protective effects
- Immune modulation
- Reduces T-cell activation & reactivity
- Reduces neutrophil chemotaxis, outputs

## CHONDROITIN SULFATE

## CHONDROITIN – TYPES OF PUBLISHED EVIDENCE

| Type of Substantiation | # |
| --- | --- |
| Consensus Statement | 4 supportive
0 nonsupportive |
| Independent expert opinions (reviews) | 103 supportive
10 nonsupportive |
| Meta-Analyses | 8 supportive
0 nonsupportive |
| Large, Well-Designed Human Clinical Trials | 18 (27) supportive
0 nonsupportive |
| Smaller, Well-Designed Human Clinical Trials | 14 (15) supportive
1 nonsupportive |
| Uncontrolled Human Clinical Trials | 35+ supportive
3 nonsupportive |
| Animal Intervention Studies | 13 supportive
3 (4) nonsupportive |
| In Vitro Studies | 51 supportive
3 nonsupportive |
| Total | 246 (256) supportive
20 (21) nonsupportive |

## BIOMARKERS AFFECTED BY CHONDROITIN

- Biosynthesis of HA, GAGs proteoglycans, collagen in joints
- aminosugar unit precursor
- enhance production (regulatory)
- upregulation of gene expression

## BIOMARKERS AFFECTED BY CHONDROITIN

- Inhibition of cartilage breakdown
- Prevention of new lesions in finger OA
- Prevention of joint space loss in knee OA
- Decrease in biomarkers of cartilage loss: cartilage oligomeric protein, keratan sulfate, urine pyridinoline/creatinine ratio, urine deoxypyridinoline/creatine ratio in humans
- Prevention of joint degeneration in healthy animals induced to become osteoarthritic
- In vitro cartilage cultures – direct addition (sizes)

## BIOMARKERS AFFECTED BY CHONDROITIN

- Inhibition of degradative enzymes
- Human synovial fluid
- In vitro:
- Aggrecanase
- Elastase
- Hyaluronidase
- Lysosomal enzymes (mixtures) – pH
- Cathepsin B release
- Matrix metalloproteinases

## BIOMARKERS AFFECTED BY CHONDROITIN

- Tensegrity (mechanostructural)
- Immune modulation
- Block complement, receptors
- Slow neutrophil chemotaxis
- Inhibit lysosomal content release
- Protect other cytokines or regulatory molecules
- Enhance cytokine secretion by macrophages

## BIOMARKERS AFFECTED BY CHONDROITIN

- Downregulates inducible nitric oxide
- Antioxidant protective effects
- Antiinflammatory effects
- Animal models of acute inflammation
- Counteracts IL-1β-induced loss of proteoglycans
- Decreases levels and/or expression of inflammatory cytokines

## SUMMARY OF EVIDENCE

## ORAL BIOAVAILABILITY OF GLUCOSAMINE AND CHONDROITIN

- Glucosamine in all its forms is readily absorbed almost entirely, and some is incorporated into joint tissues.
- Chondroitin is absorbed into the blood stream to 7-70% of an oral dose.
- Chondroitin is absorbed as intact chains and a spectrum of fragments down to monomers.
- Some chondroitin fragments are partially desulfated.
- Absorption and uptake into joint tissues has been confirmed for both Glucosamine and Chondroitin.

## ECONOMIC IMPACT OF CHONDROITIN

- 11000 subjects taking Chondroitin resulted in decreased NSAID use (63-85%)
- “The cost related to CS 4&6 treatment was compensated for by the reduction in physiotherapy costs and by fewer co-prescriptions for gastroprotective drugs.”
- Henry-Launois B. Evaluation of the use and financial impact of Chondrosulf 400 in current medical practice. *Litera Rheumatol* 1999; 24:49-51.
- Conrozier T. Les chondroitines sulfates (CS 4&6): schema d’utilisation et impact economique. [Chondroitin sulfate (CS 4&6): practical applications and economic impact.] *Presse Med *1998 Nov21; 27(36):1866-1868.
- Chondroitin use has beneficial economic impact

## HUMAN STUDIES OF OA:APPLICABILITY TO PREVENTION

- Both Glucosamine and Chondroitin prevented loss of cartilage over time
- Earlier stages of OA showed larger effects, indicating prevention of progression over treatment of symptoms
- Effects were long-lasting after cessation of administration

## BIOMARKER SUMMARY

- Both Glucosamine and Chondroitin affect many biomarkers known to cause, promote or exacerbate joint degeneration
- Biomarker effects illustrate overlapping and unique properties of each nutrient
- Biomarkers correlated with signs and symptoms of joint degeneration

## ANIMAL MODELS OF OA: APPLICABILITY TO PREVENTION

- Multiple methods of *rapid* induction of joint degeneration all produce same end result
- Glucosamine and Chondroitin administered *before* or during the induction of joint degeneration lessen the end result = prevention
- Relatively large intakes reflect relatively rapid onset of degeneration and extreme response of tissues
- Mechanisms of induction & biological response remain same whether onset is rapid or gradual

## IN VITRO STUDIES:APPLICABILITY TO PREVENTION

- In vitro studies have found *multiple* potential mechanisms of action for Glucosamine and Chondroitin
- These mechanisms exist and are operative *in vivo*
- Concentration dependency indicates effects at low doses seen *in vivo*.

## CONCLUSIONS

## GLUCOSAMINE & CHONDROITIN REDUCE RISK OF OA

- Data from all types of publications is extensive, reproducible and consistent for benefits supporting prevention of joint degeneration
- Time course of human findings fits the mechanisms of improving regulation of anabolic/catabolic ratio of joint tissues

## GLUCOSAMINE & CHONDROITIN REDUCE RISK OF OA

- Glucosamine supplementation has been shown to prevent progression of joint deterioration in human studies
- Chondroitin supplementation has been shown to prevent progression of joint deterioration in human studies
- Animal studies have shown prevention of progression of joint deterioration when given before stress

## GLUCOSAMINE & CHONDROITIN REDUCE RISK OF OA

- Glucosamine and Chondroitin have the ability to prevent joint deterioration and joint degeneration by all lines of evidence, and thus, reduce the risk of osteoarthritis (which is the progression of joint deterioration and degeneration)

## THANK YOU