Frequency and associations of chronic kidney disease among gout patients from a University Teaching Hospital in Nigeria

OBJECTIVES: To highlight common precipitants and co-morbidities of gout in Nigerians; determine the frequency of chronic kidney disease (CKD) in Nigerian gout patients, as well as identify significant associations of CKD in gout patients. MATERIAL AND METHODS: Retrospective cross-sectional study of gout cases seen at the Rheumatology Clinic of the Lagos State University Teaching Hospital over five years from January 2011 to December 2015. Gout was diagnosed using the 1977 American Rheumatism Association (ARA) criteria. Clinical and laboratory data were extracted and examined for the presence of CKD defined using Kidney Disease Improving Global Outcomes (KDIGO) 2012 guidelines as estimated glomerular filtration rate (eGFR, CKD-EPI) < 60 mls/min/1.73 m(2) body surface area for > 3 months. RESULTS: One hundred and six gout patients were identified representing 4.5% out of a total of 2330 cases seen during the study period. There were 94 males and 12 females. Oligoarthritis was most frequent (41.5%) with the knee mostly affected (20.1%). Diuretic use was the most frequent precipitant (37.9%) with hypertension the commonest co-morbidity (62.9%). Of 70 patients with complete results, 29 had eGFR (CKD-EPI) < 60 mls/min (41.4%). Age, proteinuria, body mass index (BMI) and packed cell volume (PCV) were significant associations of CKD. Gout patients with CKD were significantly older (61.79 vs. 54.41 years, p = 0.003) with a significantly higher proportion developing proteinuria (15 vs. 4 patients, p ≤ 0.0001) compared to those without CKD. In contrast, those with CKD had a significantly lower BMI (27.31 vs. 29.65 kg/m(2), p = 0.026) and PCV (31.97 vs. 37.95%, p = 0.005). CONCLUSIONS: Thiazide diuretic use is the most common precipitant while hypertension is the commonest comorbidity in Nigerian gout patients. About two in five Nigerian gout patients had chronic kidney disease at presentation with age, proteinuria, BMI and PCV as significant associations. It is thus imperative to screen for chronic kidney disease when managing gout patients.