Herbal remedies and hyperuricemia in a Central American population with elevated chronic kidney disease of unknown origin

Abstract

Background. Herbal remedies may expose consumers to environmentally harmful agents, yet some may use them to self-treat illnesses. We examined herbal consumption in a population of renal patients in Central America, an area with elevated chronic kidney disease of unknown origin (CKDu). We investigated whether herbals were related to hyperuricemia, a common ailment in patients.Methods. We enrolled 311 patients attending a renal clinic in northwestern Nicaragua who were male, non-diabetic former sugarcane workers with early to late stage kidney dysfunction. A questionnaire asked about use of 15 specific herbals (some nephrotoxic, others beneficial) in the past year and frequency used. Serum uric acid and serum creatinine were measured. Medical records provided information on the uric acid lowering prescription allopurinol. Unconditional logistic regression models estimated odds ratios (ORs) and 95% confidence intervals (CIs) for the association of prevalent hyperuricemia (uric acid >=7 mg/dL) and herbals, controlling for age, hypertension, disease stage, alcohol consumption, and allopurinol prescription.Results. Among patients, 40% were late stage disease and 85% were hyperuricemic. Sixty-one percent (n=191) reported using at least one herbal and 47 patients used 3 or more. No herbals purported to be nephrotoxic were related to hyperuricemia. Chamomile (manzanilla) was taken by 27% of patients and consumed a mean 61 (±102.6 SD) times per year, with some consuming daily. Chamomile was associated with a reduced prevalence of hyperuricemia (OR = 0.45 (0.20, 1.00)) in the adjusted model. The inverse association with hyperuricemia was more pronounced in those with late stage disease who consumed chamomile compared with early stage non-consumers (OR=0.25 95% CI (0.09, 0.70)).Conclusion. Research is needed to determine if chamomile may be beneficial in preventing hyperuricemia in this patient population. Although potentially harmful herbals were not associated with hyperuricemia, they should be examined in relation to other kidney measures.