A study of serum cystatin C as a marker of diabetic nephropathy among patients with type 2 diabetes mellitus: A systematic review and meta-analysis

Clinically type 2 diabetes mellitus (T2DM) without serum creatinine microalbuminuria, macroalbuminuria lacks predictors for diabetic nephropathy (DN). We utilized a meta-analysis technique to review the literature to evaluate whether serum cystatin C may be used as an early marker of diabetic nephropathy in light of the differing opinions regarding the utility of serum cystatin C as such. PubMed, Google Scholar, Web of Science, EMBASE, and Scopus Database were searched using various key search terms. Studies involving T2DM patients and containing serum cystatin C levels and the estimated glomerular filtration rate (eGFR) data were included. Pooled sensitivity, specificity, positive predictive value, and negative predictive value were also calculated. The pooled sensitivity and specificity of serum cystatin C for predicting DN were 0.87 (95% CI 0.84 - 0.91) and 0.84 (95% CI 0.83 - 0.88) respectively. The pooled positive and negative predictive values of serum cystatin C for predicting DN were 7.035 (95 % CI 4.30 – 11.43) and 0.15 (95% CI 0.09 - 0.21) respectively. The area under the summary receiver operating characteristic (SROC) curve was 0.9548 and the diagnostic odds ratio was 67.10 (95% CI 28.12 - 156.84). Serum cystatin C is a significant biomarker of DN among patients with T2DM. It can also positively monitor kidney function progression and prediction of adverse outcomes among T2DM patients