Combining Nutritional Supplementation and Progressive Physical Activity Program Improves Functionality and Quality of Life in Healthy 50y+ Volunteers with Knee Joint Discomfort: A Baseline-Control Trial
Osteoarthritis and Cartilage VOLUME 25, SUPPLEMENT 1, S293-S294, APRIL 01, 2017 C. Chang
L.G. Karagounis
Purpose: The aim of this clinical trial was to evaluate the efficacy of a 6-month intervention program comprising of specific nutritional supplementation and a progressive physical activity component on outcomes inclusive of physical functionality, knee pain and quality of life, in healthy pre-OA volunteers.
Methods: This study was a single-center, single arm, baseline-controlled, open label, nutrition and exercise intervention clinical trial. A total of 54 healthy subjects with joint discomfort were recruited aged 45–65 years and were provided with a nutritional supplement consisting of a milk-based drink containing glucosamine sulfate (GS) to be taken orally twice a day (providing daily 1500 mg of GS, 850 mg of Calcium, 35 mg vitamin C, 8μg vitamin D, 6.5 mg of zinc and 11g of proteins,) for 6 months. Initially the supplement was provided alone for 2 months, and then combined with a progressive exercise program for 4 months. The progressive physical activity program, included a combination of Tai-chi, strength and aerobic training (walking), 3 times per week. Daily step counts were recorded using a Garmin pedometer. The primary endpoint was musculoskeletal functionality (mobility), assessed by validated physical functional tests: 6 min-walk test (6MWD) and dominant leg strength. Secondary outcomes were KOOS score (Knee injury and Osteoarthritis Outcome Score), Visual Analog Scale (VAS) score for knee discomfort, balance test, biomarkers for bone and joint metabolism and quality of life (evaluated by an EQ5D-5L questionnaire). Assessments were conducted at baseline, at 2 months and then every month for the remaining time. Subjects were classified into three levels based on average daily Garmin step count (low ≤ 9999; 10000 ≤ Average ≤ 13999 and High ≥ 14000). Baseline parameters were compared to 6 months of intervention, by use of ANCOVA analysis (with baseline value as covariate and levels of step counts as fixed effect). As secondary outcomes, longitudinal analysis of change from baseline at each visit was performed using Mixed Model Repeated Measures (MMRM), for three possible baseline quartile (Q1, Q2 as median and Q3) values of each outcome.
Results: Change from baseline for the 6MWD at 6 months was significantly increased for each level of step count (p<0.001) and for Q1 following the nutrition period alone (p<0.05). Flexor maximum torque was significantly increased following the 6-month intervention in both those with low and high step counts (p<0.05) and total work flexor only in those with low step count (p<0.05). The torque ratio (flexor/extensor) was also significantly improved following 2 months of intervention in all subjects (p<0.05). In addition, balance outcomes were improved in all subjects at the end of the intervention (p<0.001). Changes from baseline at 6 months were observed to be statistically significant for KOOS sub-scores Pain, ADL, Sport and Quality of Life for all levels of steps (p<0.001). This was partly reflected in the quality of life questionnaire which was improved in Q1(p<0.001). Impressively, VAS score showed 42% overall decrease in knee pain (p<0.001) and this decrease was already significant after 2 months of nutritional intervention (p<0.05). Finally, at 6 months, biomarkers of cartilage breakdown (CTX2), bone turnover (CTX1 and P1NP) as well as inflammation (IL-6) appeared to be positively modulated by the combined program of nutrition and exercise (p<0.01).
Conclusions: This study demonstrated improved physical mobility/functionality when combining nutrition (milk-based drink containing glucosamine sulfate) with progressive physical activity in healthy older volunteers. This intervention program was able to induce a very significant decrease in knee pain and thus led to an improved quality of life score for participants.