Adjunct Role of Potassium in Rheumatoid Arthritis: A Randomized Controlled Trial of Diet and Food Supplement in Patients on Standard Care

IntroductionPotassium inadequacy (diet and body storage) may adversely affect rheumatoid arthritis (RA) and is sparsely reported. We evaluated the therapeutic benefits (RA) of food-based potassium intake, recommended daily allowance (RDA), and higher. ObjectiveTo evaluate pain reduction by oral potassium in chronic RA Methods172 consenting and eligible symptomatic patients (median duration 6.5 years) on ongoing standard care were randomized in a single-center study (80% power, significant p < 0.05) - Arm A (vegetarian diet as per the India RDA for potassium), Arm B (Arm A diet plus novel potassium food supplement) and Arm C (regular diet, control). Efficacy and safety, and diet intake (three-day recall, Food Composition tables) were assessed (blinded) at monthly intervals till 16-week of study completion and statistically analyzed using standard methods. Study groups were found matched and showed inadequate baseline dietary potassium (RDA). On study completion, the median daily potassium intake was 2959 mg in Arm A, 6063 mg in Arm B, and 2553 mg in Arm C. Study subjects remained normokalemic at all evaluations. Overall, the background medication remained stable. Results155 patients (90.1%) completed the study. Adverse events were mild. On comparison, the improvement in pain (primary efficacy) on study completion was significant in Arm B as per protocol analysis; the mean change in pain visual analog scale from baseline was -2.23 (95% confidence interval -2.99 to -1.48). Arm B showed impressive improvement in joint function. High potassium intake predicted low pain (Likelihood ratio 2.9, logistic regression). Compliance (intervention), diet recall, medication, complex nature of dietary intervention/other nutrients, and lack of placebo were potential confounders to ascertain the effectiveness of potassium. ConclusionA planned vegetarian diet and food supplement intervention with a predominantly increased potassium intake significantly reduced chronic RA pain. This adjunct treatment was found safe and well tolerated. However, it requires further validation. Trial RegistrationClinical Trial Registry of India- CTRI/2022/03/040726 KEY MESSAGE What is already known on the topic?O_LIRA is predominantly managed with drug therapy and diet is often neglected C_LIO_LIRA is complicated by hypertension and other cardiovascular disorders, and osteoporosis which may benefit from potassium intervention. C_LIO_LIPotassium and potassium ion channels are important the pathophysiology of pain (and probably inflammation) C_LIO_LIPatients of RA may be deficient in potassium due to inadequate diet or sarcopenia C_LI What does this study add?O_LIPotassium-rich vegetarian diet and a novel high-potassium food supplement significantly reduced pain in chronic RA on supervised standard drug care. C_LIO_LISeveral participants showed improved joint function and better blood pressure status C_LIO_LIHigher potassium intake based on food and diet was safe and well tolerated C_LI How this study might affect research, practice, or policy?O_LIPotassium rich predominantly vegetarian diet should be advocated in the management of RA as an adjuvant C_LIO_LIA judicious use of high potassium food supplement along with suitable diet may benefit difficult and chronic RA C_LIO_LIThe current guidelines on oral potassium intake in RA and other medical disorders need to be revised and call for more research C_LI