Efficacy of Shenkang Injection combined with renin-angiotensin-aldosterone system blockers in diabetic nephropathy: a systematic review and meta-analysis of randomized controlled trials

Shenkang injection (SKI), a Traditional Chinese Medicine formulation, is widely used in China for diabetic nephropathy (DN). This systematic review and meta-analysis aimed to evaluate the efficacy and safety of SKI combined with renin-angiotensin-aldosterone system (RAAS) blockers in patients with DN. A comprehensive search of seven databases was conducted up to September 18, 2024, for randomized controlled trials (RCTs) comparing SKI plus RAAS blockers versus RAAS blockers alone in DN patients. Meta-analysis was performed using RevMan 5.3 and Stata 17.0, with effect sizes expressed as weighted mean differences (WMDs) or odds ratios (ORs) with 95% confidence intervals (CIs). A total of 18 RCTs involving 1,497 patients were analyzed. Combination therapy significantly improved total effective rate (TER) (MD 2.61, 95% CI 1.62–2.64) and reduced key renal and metabolic markers. Urinary protein excretion rate (UPER), serum creatinine (SCr), blood urea nitrogen (BUN), 24-hour urinary protein (24h-UTP), total cholesterol (TC), and triglyceride (TG) levels all significantly decreased in the combination group. Subgroup analysis showed that patients aged ≤55 years had greater reductions in SCr (WMD −25.62, 95% CI −29.41 to −21.83) and BUN (WMD −2.51, 95% CI −2.75 to −2.27). Sensitivity analysis confirmed the robustness of findings. No publication bias was detected for TER, SCr, BUN, 24h-UTP, TG, and adverse reactions, though UPER and TC showed potential bias. SKI combined with RAAS blockers may enhance renal function and metabolic profiles in DN patients. Further high-quality RCTs are needed to validate these findings and assess long-term safety.