Background Cystatin C is recommended as a confirmatory test to eGFR when more precise estimates are needed for clinical decision making. Although eGFR on the basis of both creatinine and cystatin ... Show moreBackground Cystatin C is recommended as a confirmatory test to eGFR when more precise estimates are needed for clinical decision making. Although eGFR on the basis of both creatinine and cystatin (eGFR(cr-cys)) is the most accurate estimate in research studies, it is uncertain whether this is true in real-world settings, particularly when there are large discordances between eGFR based on creatinine (eGFR(cr)) and that based on cystatin C (eGFR(cys))Methods We included 6185 adults referred for measured GFR (mGFR) using plasma clearance of iohexol in Stockholm, Sweden, who had 9404 concurrent measurements of creatinine, cystatin C, and iohexol clearance. The performance of eGFR(cr), eGFR(cys), and eGFR(cr-cys) was assessed against mGFR with median bias, P-30, and correct classification of GFR categories. We stratified analyses within three categories: eGFR(cys) at least 20% lower than eGFR(cr) (eGFR(cys)eGFR(cr)).Results eGFR(cr) and eGFR(cys) were similar in 4226 (45%) samples, and among these samples all three estimating equations performed similarly. By contrast, eGFR(cr-cys) was much more accurate in cases of discordance. For example, when eGFR(cys)eGFR(cr) (8% of samples), the median biases were -4.5, 8.4, and 1.4 ml/min per 1.73m(2). The findings were consistent among individuals with cardiovascular disease, heart failure, diabetes mellitus, liver disease, and cancer.Conclusions When eGFR(cr) and eGFR(cys) are highly discordant in clinical practice, eGFR(cr-cys) is more accurate than either eGFR(cr) or eGFR(cys). Show less
Background Limited information exists regarding the safety of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in patients with CKD treated in routine care. We evaluated the safety of SGLT2i in... Show moreBackground Limited information exists regarding the safety of sodium-glucose cotransporter-2 inhibitors (SGLT2i) in patients with CKD treated in routine care. We evaluated the safety of SGLT2i in patients with CKD and type 2 diabetes treated in US routine practice.Methods Using claims data from Medicare and two large US commercial databases (April 2013-December 2021), we included 96,128 adults with CKD stages 3-4 and type 2 diabetes who newly filled prescriptions for SGLT2i versus glucagon-like peptide-1 receptor agonists (GLP-1RA). Safety outcomes included diabetic ketoacidosis (DKA), lower limb amputations, nonvertebral fractures, genital infections, hypovolemia, AKI, hypoglycemia, and severe urinary tract infections (UTIs). Hazard ratios (HRs) and incidence rate differences per 1000 person-years were estimated after 1:1 propensity score matching, adjusted for >120 baseline characteristics.Results Compared with GLP-1RA, SGLT2i initiators had a higher risk of nonvertebral fractures (HR, 1.30 [95% confidence interval (CI), 1.03 to 1.65]; incidence rate difference, 2.13 [95% CI, 0.28 to 3.97]), lower limb amputations (HR, 1.65 [95% CI, 1.22 to 2.23]; incidence rate difference, 2.46 [95% CI, 1.00 to 3.92]), and genital infections (HR, 3.08 [95% CI, 2.73 to 3.48]; incidence rate difference, 41.26 [95% CI, 37.06 to 45.46]). Similar risks of DKA (HR, 1.07 [95% CI, 0.74 to 1.54]; incidence rate difference, 0.29 [95% CI, -0.89 to 1.46]), hypovolemia (HR, 0.99 [95% CI, 0.86 to 1.14]; incidence rate difference, 0.20 [95% CI, -2.85 to 3.25]), hypoglycemia (HR, 1.08 [95% CI, 0.92 to 1.26]; incidence rate difference, 1.46 [95% CI, -1.31 to 4.23]), and severe UTI (HR, 1.02 [95% CI, 0.87 to 1.19]; incidence rate difference, 0.35 [95% CI, -2.51 to 3.21]) were observed. SGLT2i had lower risk for AKI (HR, 0.93 [95% CI, 0.87 to 0.99]; incidence rate difference, -6.75 [95% CI, -13.69 to 0.20]).Conclusions In US patients with CKD and type 2 diabetes receiving routine care, SGLT2i use was associated with higher risks of genital infections and potentially lower limb amputations and nonvertebral fractures. Show less
