Obesity is an independent poor prognostic factor in lupus nephritis

ObjectiveTo investigate whether obesity is a risk factor for chronic kidney disease G3 (CKD G3; eGFR <60 mL/min/1.73 m²) in lupus nephritis (LN).MethodsWe retrospectively reviewed 132 cases of biopsy-proven class III, IV or V incident LN for which quarterly data were available during a long follow-up period (median 140 months). Rates of complete renal remission, renal flare and CKD G3 were compared between obese (body mass index ≥30 kg/m²) and non-obese patients. Complete renal remission was defined as a urine protein to creatinine ratio (uPCR) < 0.5 g/g and a serum creatinine value <120 % of baseline. Renal flare was defined as the reappearance of an uPCR >1 g/g, leading to a repeat kidney biopsy and/or treatment change.ResultsBaseline characteristics of obese patients did not differ from non-obese patients. By contrast, time to CKD G3 and time to renal flare were statistically shorter in obese patients. Obesity significantly increased long-term risk for the progression of CKD [HR = 2.72 (CI95% 1.11-6.64), <i>p</i> = .028]. In a multivariate analysis, obesity was an independent risk factor for CKD G3 (<i>p</i> = .029).ConclusionA BMI ≥30 kg/m² is an independent poor prognostic factor for the progression of CKD in LN. More attention should therefore be paid to weight control in LN patients.