Potential biomarkers and study design for joint health: How to quantify mobility enhancing effects of foods Dr. S. Buchwald-Werner 23. May 2012
Joint health and consumer needs Mobility is essential for everyday living and quality of life Many of us experience limited mobility caused by joint pain and stiffness after unaccustomed exercise or as a consequence of general aging A balanced diet and regular, moderate exercise to strengthens the joints and muscles is sometimes not enough to maintain healthy mobility Foods and functional ingredients with proven effects, to support and maintain mobility in healthy people and healthy aging people are demanded But how to quantify mobility enhancing effects? In general, it is very difficult to demonstrate that healthy people will become healthier when consuming a specific product with a health benefit The main challenge is to design a nutritional study which is able to investigate and prove effects that support the maintenance of healthy joints in healthy people One way to define and measure the status of health is the ability to recover from a challenge 3
Agenda Challenge recovery concept Selection of biomarkers & functional markers Exercise model Questionnaire design Recommendations - overall study design 4
Challenge recovery concept A challenge-recovery-concept allows the investigation of health ingredients in healthy subjects, representing the general population No extrapolation of data is necessary because the maintenance, improvement of physical function and recovery is determined directly 5
Challenge exercise model The challenge applied is e.g. an eccentric exercise model (downhill treadmill walking) The exercise level needs to be defined to ensure that the changes of the values for the selected markers are statistically significant and biologically relevant in healthy people without supplementation Consequently the selected biomarkers may be able to indicate an improved recovery process under supplementation with a health ingredient Parameter for the exercise model: - inclination (%) - m duration (min.) - speed (km/h) - additional load (% body weight) 6
Selection of biomarkers Downhill treadmill walking exercise may results in sensations of muscle soreness and pain and an increase in the biomarkers of cartilage degeneration as well as in an inflammatory response The following biomarkers were investigated: At time points pre and post exercise blood samples were taken to determine the biomarkers 7
Most relevant biomarkers The concentration of cartilage related biomarkers increased during and after exercise The most relevant biomarker for cartilage degeneration was COMP (cartilage oligomeric matrix protein) showing highest increase after 3 hours and return to baseline levels after 72 hours CP2 (C-pro-peptide of type II pro-collagen), a biomarker for cartilage syntheses, showed a high deviation and no uniform tendency in value progressing could be determined The two biomarkers indicating inflammation, prostaglandin E metabolite (PGEM) and Interleukin 6 (IL6), increased their amount within 3 hours after exercise and recovered to the initial base line after 24 hours Creatine kinase (CK) is a typical biomarker to measure exercise related muscle damage. Values increase with 24 hours and recover within 72 hours 8
Selection of functional markers: Markers were chosen to quantify the improvement of the physical function and recovery of the musculoskeletal system after defined exercise - Flexibility of the knee joint - Isometric muscle strength Flexibility is defined as the range of motion allowed at the joint and was measured with a goniometer Directly after the exercise a trend for slightly improved flexibility was observed This was followed after 24 hours by slightly reduced flexibility Exercise led to a reduction in muscle strength after three hours, with recovery after 72 hours The muscle strength of the leg extension musculature was measured using a DAVID analysis system Both markers would be suitable to be used in a nutritional joint health study 9
Questionnaire design The assembling of a suitable questionnaire is very difficult Questionnaires should be validated and match the target group Existing joint health questionnaires have been designed to assess the status of osteoarthritic subjects, e.g. knee injury and osteoarthritis outcome score (KOOS) and therefore the questions do not fit for healthy people It is recommended to set up a questionnaire which combine questions out of existing validated questionnaires together with self designed questions, which specifically target the study objectives Subjects tend to reported very low values of pain. In order to design a questionnaire to investigate mobility and functionality of the joints and their improvement after recovery additional objectives needs to be included 10
Recommendations or overall study design A challenge-recovery-concept allows the investigation of health ingredients in healthy subjects, representing the general population The challenge - the exercise model needs to be carefully designed to ensure that the applied exercise is a real challenge for the subjects, leading to significant changes in the values of selected biomarkers as well as functional markers The following biomarkers showed a good response to the challenge recovery - model: - COMP cartilage degeneration - PGEM and IL6 inflammation - CK muscle damage Flexibility of the knee joint and isometric muscle strength are suitable functional markers Set up of specific questionnaires is important 11
Acknowledgement Thank you for your attention! Vital Solutions GmbH Hausinger Straße 4-8 D-40764 Langenfeld Dr. Sybille Buchwald-Werner Phone: +49 (0) 2173 10 98 202 Fax: +49 (0) 2173 10 98 210 Mobile: +49 (0) 174 1666 856 E-Mail: sybille.buchwald-werner@vitalsolutions.biz All information given in this presentation reflects our current knowledge and interpretation of relevant legislation and legal practice. 12