Association of Glucosamine and/or Chondroitin Use with Reports of Improved Health and Joint Pain among Individuals with Arthritis, National Health Interview Survey (NHIS) 2012

BACKGROUND: Arthritis is increasingly becoming a public health concern as it is the leading cause of disability. Glucosamine and chondroitin, which are alternative dietary supplements, are commonly marketed for persons with joint pain. The purpose of this study is to examine if selfreported 12-month and past 30-day use of glucosamine and/or chondroitin among persons with any arthritis, unspecified arthritis, and rheumatoid arthritis is associated with reports of past 12 month improved health and reports of past 30-day joint pain, aching, and stiffness, respectively. METHODS: The 2012 National Health Interview Survey (NHIS), a nationally representative cross-sectional household interview survey, was used for this study. The adult sample consisted of 34,525. Subgroup analyses were conducted on 7,654 respondents with any arthritis, 6,016 with unspecified arthritis, and 898 with rheumatoid arthritis. The independent variables were defined as the use of glucosamine only, chondroitin only, or glucosamine and chondroitin one or more times in the past 12 months and past 30 days. The dependent variables were defined as selfreported past 12 month improved health and past 30 day pain, aching, and stiffness. Descriptive, bivariate, and multivariate analyses were conducted using SAS 9.4 accounting for the complex survey design, computing missing values as missing completely at random for variance estimation. All multivariate logistic regression models included sociodemographics, use of other alternative therapies, and any other chronic conditions. RESULTS: Approximately 21.8% of U.S adults had any arthritis, 17.0% had unspecified arthritis and 2.5% had rheumatoid arthritis. Among persons with any arthritis, approximately 3.7% used glucosamine, 0.4% used chondroitin, and 3.4% used both glucosamine and chondroitin within the past 12 months while approximately 5.1% used glucosamine, 0.6% used chondroitin, and 0.4% used both glucosamine and chondroitin within the past 30 days. Among persons with unspecified arthritis, approximately 3.7% used glucosamine, 0.5% used chondroitin, and 3.8% used both glucosamine and chondroitin within the past 12 months while 5.5% used glucosamine, 0.5% used chondroitin, and 0.4% used both glucosamine and chondroitin within the past 30 days. Among persons with rheumatoid arthritis, approximately 2.4% used glucosamine, 0.3% used chondroitin, and 2.1% used both glucosamine and chondroitin within the past 12 months while approximately 2.9% used glucosamine, 0.7% used chondroitin, and 0.5% used both glucosamine and chondroitin within the past 30 days. Women used more of all supplements (past 12 months and past 30 days) except past 12 month use of chondroitin among persons with any arthritis. Persons 56 to 70 years old had the highest proportion of past 12 month and 30 day supplement use among persons with unspecified arthritis. After adjusting for sex, age, race, BMI, poverty level, other health conditions, and other CAM therapies (acupuncture, energy, mind-body, and chiropractic/osteopathic therapies), the use of chondroitin only (adjusted OR= 0.6; p= <0.01) and the use of both glucosamine and chondroitin (adjusted OR= 5.7; p= <0.01) during the past 30 days was associated with self-reported past 30 day joint pain, aching, and stiffness among persons with any arthritis. After adjusting for age, BMI, poverty level, region, other health conditions, and other CAM therapies (acupuncture, energy, mind-body, and chiropractic/osteopathic therapies), the use of chondroitin only was also associated with past 30 day joint pain, aching, and stiffness among persons with unspecified arthritis (adjusted OR= 0.5; p= 0.02). CONCLUSION: Chondroitin alone was associated reports of past 30 day joint pain, aching, and stiffness among persons with any arthritis and unspecified arthritis highlighting a potential effective role and use for this supplement. In addition, the use of both glucosamine and chondroitin were associated with reports of past 30 day joint pain, aching, and stiffness among persons with any arthritis. Marketing may play a role in these relationships and should be further examined. Association of Glucosamine and/or Chondroitin Use and Reports of Improved Health and Joint Pain among Individuals with Arthritis, National Health Interview Survey (NHIS) 2012