Impact of Physical Activity and Vitamin D on Osteoarthritic Knee Pain

Knee Osteoarthritis (KOA) is a major cause of pain and disability, particularly in those of increasing age and body fat. As there are no very effective therapies for KOA, disease often progresses until knee replacement surgery is needed. It has been observed Vitamin D and Physical Activity (PA) levels are lower in those with KOA, increased age and body fat. As the relationship between KOA, Vitamin D and PA levels are not clearly understood, this study aims to explore these relationships and the acceptability/feasibility of PA and Vitamin D interventions in those who would likely to benefit from these interventions.

200-300 people, 50-70 years, BMI 30-40kg/m2, meeting American College of Rheumatology (ACR) KOA Guidelines, will be recruited from North Tyneside and Liverpool Hospital trusts November 2014-January 2016 to participate in a single cross-sectional study visit, which will measure: Vitamin D/Calcium serum levels, BMI/Body Fat, mobility, Quality of life and pain (by questionnaire), and PA levels.

Those participants with insufficient Vitamin D levels (25-50nmol/L) and PA levels (<30min moderate PA/week), will be invited to take part in a 3 month pilot RCT study.

>64 people will be recruited for the pilot RCT and equally randomly allocated to 1 of 4 intervention groups: Vitamin D (1 capsule a day: 2000IU), Placebo (identical capsule: 1 a day), PA (online PA programme) and PA and Vitamin D. Additionally at the end of the 12 week study visit, up to 20 participants will be invited to take part in a qualitative interview exploring their experience during the two studies.