Announcing CTX-II Testing, a cartilage and joint health marker
September 4th, 2018
Meridian Valley Lab is pleased to announce the arrival of a new marker that will help assess joint health, C-telopeptide of type II collagen (CTX-II). MVL now measures CTX-II in a single 2nd morning urine collection or 24-hour urine collection to assess cartilage damage and bone turnover due to arthritis or heavy exercise. The detection of arthritis during the early stages, with accurate and reliable biomarkers such as urinary CTX-II, can help preserve joint function, decrease pain, and prevent disease progression through early intervention. Human studies indicate that CTX-II can distinguish rapidly progressive osteoarthritis better than other urinary markers such as deoxypyridinoline (DPD).
Why Test CTX-II?
The Centers for Disease Control and Prevention predicted that by 2020 more new patients will have arthritis than any other disease form in America. Obesity or higher body mass index are among the most important risk factors of arthritis and are also risk factors for metabolic syndrome and type II diabetes. The association between hyperglycemia and arthritis is well-documented; large population studies show that up to 60% of those diagnosed with diabetes or metabolic syndrome may also have osteoarthritis. In patients with blood sugar dysregulation or obesity, the occurrence of hand arthritis is particularly significant.
Arthritis can be difficult to diagnose in the early stages; it is usually diagnosed by physical exam and imaging studies. Physical exam alone may lack accuracy in the early stages of arthritis, and imaging studies are not only expensive, but often only detect arthritis after irreparable damage has been done. There may be no way to tell if a patient’s preferred exercise style is damaging joint cartilage. A recent study demonstrated that when CTX-II levels were compared in young athletes, they were highest in runners, moderate in rowers, and lowest in swimmers. Increases in CTX-II have been shown to correlate with joint pain, and levels usually increase before radiological changes become obvious. The detection of osteoarthritis during the early stages, with accurate and reliable biomarkers such as CTX-II, may help preserve joint function, decrease pain, and prevent disease progression through early intervention.
CTX-II levels increase with increasing cartilage damage until all of the cartilage is destroyed. Type II collagen is the most abundant collagen type in articular cartilage and represents 10–20% of the wet weight of the cartilage. The interface between subchondral bone and articular cartilage where type II cartilage is found is a site of remodeling in arthritis. Normally, joint homeostasis is a balanced process of cartilage matrix degradation and repair performed by the resident chondrocytes. Early detection of arthritic cartilage changes is vital, as there is little or no cell division in normal adult articular chondrocytes, and no evidence of progenitor cells to replace dead chondrocytes if cartilage cell death occurs. Changes in cartilage and bone biomarkers are also common in peri-menopausal women. The use of non-steroidal anti-inflammatory medications (NSAIDs) significantly can inhibit cartilage matrix synthesis and repair. Cartilage destruction may also occur due to the accumulation of advanced glycation end products (hyperglycemia), mitochondrial dysfunction (increased oxidative stress), mechanical injury to the cartilage, and inflammatory cytokines. Recent studies also indicate that cartilage cells carry insulin receptors and the cells have demonstrated insulin resistance in diabetic patients. Due to the strong association of type II diabetes/ metabolic syndrome “metabolic osteoarthritis” is now considered a subtype of osteoarthritis.
CTX-II levels are not only diagnostic, but may be used to monitor the effects of cartilage-preserving interventions; levels may stabilize or decrease as cartilage-preserving therapies are employed:
Normalize Weight
- Dietary modification to control blood sugar, oxidative stress and dyslipidemia
- Moderate physical exercise to favor healthy cartilage
- Omega-3 fatty acids improve injury-induced osteoarthritis
Resveratrol
- Activates SIRT1 to promote chondrocyte survival and cartilage matrix gene expression
Improve vitamin levels
- Vitamin C to promote healthy cartilage
- Vitamin D levels to modulate inflammation
- Vitamin K for bone and cartilage mineralization
Evaluate Calcium and zink Status
- Urinary excretion of zinc and calcium is higher in knee osteoarthritis patients than controls.
- Higher levels of xanthurenic acid are also associated with metabolic syndrome and diabetes. Xanthurenic acid binds to zinc and increases its excretion. Xanthurenic acid is measured on MVL’s urine and dried urine hormone profiles.
Evaluate blood sugar and insulin status
- Screen for metabolic syndrome or type II diabetes using MVL’s Kraft Prediabetes Profile or the Glycemic Stress Index Profile
Evaluate hormone status
- Levels of both CTX-II and xanthurenic acid may increase during peri-menopause. Evaluate hormone status and xanthurenic acid levels using Meridian Valley Laboratory’s 24-hour urine hormone or dried urine hormone tests.
- Consider bio-identical hormone replacement as indicated by test results to decrease cartilage degradation.
