Should we add atorvastatin to irbesartan for improving renoprotective effects in early diabetic nephropathy? A meta-analysis of randomized controlled trials

Angiotensin II receptor blocker has exhibited their renal protective benefits in diabetic nephropathy. This meta-analysis aimed to evaluate the effects of adding atorvastatin to irbesartan in early diabetic nephropathy. A systematic literature search was performed in PubMed, Embase, Cochrane Library, CNKI, VIP, and Wanfang database until March 25, 2019. Randomized controlled trials evaluating the effects of adding atorvastatin to irbesartan in early diabetic nephropathy were eligible. Primary endpoint was urinary albumin excretion rate, serum creatinine, and blood urea nitrogen. Serum level of total cholesterol, triglyceride, fasting blood glucose, interleukin-6,and C-reactive protein (CRP) as well as blood pressure were secondary endpoints. Seventeen trials involving 1,390 patients were identified. Compared with irbesartan alone, co-administration of atorvastatin and irbesartan significantly reduced urinary albumin excretion rate (weighted mean differences [WMD] -21.22 μg/min; 95% confidence interval [CI] -26.95 to -15.50), serum creatinine (WMD -6.46 μmol/L; 95%CI -8.52 to 4.39),BUN (WMD -0.46 mmol/L; 95%CI -0.64 to -0.27), total cholesterol (WMD -1.79 mmol/L; 95%CI -2.34 to -1.23), triglyceride (WMD -0.93 mmol/L; 95%CI -1.20 to -0.67),and systolic blood pressure (WMD -2.27 mmHg; 95%CI -4.01 to -0.53), CRP (standard mean difference [SMD] 1.57; 95%CI -2.24 to -0.9), and Interleukin-6 (SMD 1.53; 95%CI -2.29 to -0.78). However, there was a significantly increased risk of nausea/vomiting (risk ratio 3.15; 95% CI 1.18–8.38) on the co-administration group. In conclusion, adding atorvastatin to irbesartan achieves additional renal protective benefits in early diabetic nephropathy patients. However, these findings should be interpreted with caution due to suboptimal methodological quality of the analyzed trials.