New-Onset Diabetes Mellitus in Patients with Idiopathic Membranous Nephropathy Undergoing Tacrolimus and Low-Dose Corticosteroid Therapy

Background: Idiopathic membranous nephropathy (IMN) is the most common cause of nephrotic syndrome in adults. Although various studies have demonstrated the efficacy of tacrolimus combined with corticosteroids for treating IMN, both tacrolimus and corticosteroids have been shown to be diabetogenic, particularly following organ transplantation. Furthermore, the frequency and risk factors for new-onset diabetes mellitus (NODM) in IMN patients treated with tacrolimus plus low-dose corticosteroids remain unclear. Objectives: To evaluate the incidence of NODM in IMN patients undergoing tacrolimus plus low-dose corticosteroid therapy and to confirm the risk factors for NODM development. Methods: This retrospective study recruited 72 eligible patients with biopsy-proven IMN from our center, between September 2013 and June 2018. All subjects were treated with tacrolimus plus low-dose corticosteroids for a minimum of 3 months. The primary outcome was NODM development during the follow-up period. The secondary outcome was complete or partial remission. Patients were divided into 2 groups: patients with NODM (NODM group) and those without NODM (No-NODM group). Demographic and clinical data at baseline and follow-up were assessed. Results: During follow-up, 31 of the 72 patients developed NODM (43.0%). The median time to occurrence was 3 months after treatment initiation. NODM patients were significantly older (median age 59 vs. 40 years) than No-NODM patients. Baseline fasting blood glucose levels were slightly higher in the NODM group; however, the difference was not significant (p = 0.07). Older age was an independent risk factor for NODM (OR 1.73 and 95% CI 1.20–2.47, p = 0.003). Overall kidney remission rates were 80.6%. There was no significant difference in remission rate between groups. There was a significant difference in development of pulmonary infection, which occurred in 7 NODM patients and only in 1 No-NODM patient (p = 0.018). IMN reoccurred in 5 NODM patients but only 1 No-NODM patient. Conclusions: Tacrolimus plus low-dose corticosteroid therapy was an efficient treatment for IMN; however, it was accompanied by increased NODM morbidity, which should be considered serious, due to the increased risk of life-threatening complications. Increasing age was a major risk factor for NODM in IMN patients treated with tacrolimus plus low-dose corticosteroid therapy.