Is Hypovitaminosis D Associated with Increased Pain in Patients with Knee Osteoarthritis?

Objective: Osteoarthritis is considered the most frequent joint pathology mostly interesting the knee. Hypovitaminosis D, frequent during postmenopausal period, is usually found during osteoarthritis. The aim of this study was to investigate a possible association between hypovitaminosis D in patients followed for knee osteoartritis and an increase in pain. Material and Methods: This is a retrospective descriptive and analytical study including 228 patients followed up for knee osteoarthritis in rheumatology consultation between January 2021 and February 2023. Patients who received vitamin D supplementation were excluded. Results: Of 385 patients with knee osteoarthritis, 228 had a vitamin D dosage and were subject of our study. The average age was 60.15+/-11.17 years. 205 of these patients were women (91%) and 23 were men (9%). The mean duration of progression of knee osteoarthritis was 5.61+/-3.6 years. Vitamin D deficiency (<30ng/L) was observed in 89.5% and only 10,5% had normal vitamin D levels. 94.3% were on analgesic treatment and 54.2% on non-steroidal anti-inflammatory drugs. In univariate analysis, a low vitamin D level was strongly associated with painful knee osteoarthritis with the use of anti-inflammatory drugs and conventional analgesics with an Odds Ratio and a p respectively at OR=2.774(1.05-7.27) - p=0.03 and OR=3.44 (1.41-8.39) - p=0.004. Conclusion: According to our study, the association of hypovitaminosis D and knee osteoarthritis could be responsible of an increase in pain in our patients explaining an increased use of analgesics and anti-inflammatory drugs (NSAID).