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Background: There is strong biologic plausibility to support change in albuminuria as a surrogate endpoint for progression of chronic kidney disease (CKD), but empirical evidence to supports its validity in epidemiologic studies is lacking. Methods: We analyzed 28 cohorts including 693,816 individuals (80% with diabetes) and 7,461 end-stage kidney disease (ESKD) events, defined as initiation of kidney replacement therapy. Percent change in albuminuria was quantified during a baseline period of 1, 2 and 3 years using linear regression. Associations with subsequent ESKD were quantified using Cox regression in Coresh et al.

; for the Chronic Kidney Disease Prognosis Consortium ‡ Background: Although measuring albuminuria is the preferred method for defining and staging chronic kidney disease (CKD), total urine protein or dipstick protein is often measured instead. Objective: To develop equations for converting urine proteincreatinine ratio (PCR) and dipstick protein to urine albumincreatinine ratio (ACR) and to test their diagnostic accuracy in CKD screening and staging. Design: Individual participant-based meta-analysis. Setting: 12 research and 21 clinical cohorts. Participants: 919 383 adults with same-day measures of ACR and PCR or dipstick protein. Measurements: Equations to convert urine PCR and dipstick protein to ACR were developed and tested for purposes of CKD screening (ACR, ≥30 mg/g) and staging (stage A2: ACR, 30 to 299 mg/g; stage A3: ACR, ≥300 mg/g). Results: Median ACR was 14 mg/g (25th to 75th percentile of cohorts, 5 to 25 mg/g). The association between PCR and ACR was inconsistent for PCR values less than 50 mg/g. For higher PCR values, the PCR conversion equations demonstrated moderate sensitivity (91%, 75%, and 87%) and specificity (87%, 89%, and 98%) for screening (ACR, >30 mg/g) and classification into stages A2 and A3, respectively. Urine dipstick categories of trace or greater, trace to +, and ++ for screening for ACR values greater than 30 mg/g and classification into stages A2 and A3, respectively, had moderate sensitivity (62%, 36%, and 78%) and high specificity (88%, 88%, and 98%). For individual risk prediction, the estimated 2-year 4-variable kidney failure risk equation using predicted ACR from PCR had discrimination similar to that of using observed ACR. Limitation: Diverse methods of ACR and PCR quantification were used; measurements were not always performed in the same urine sample. Conclusion: Urine ACR is the preferred measure of albuminuria; however, if ACR is not available, predicted ACR from PCR or urine dipstick protein may help in CKD screening, staging, and prognosis.

Background and aims: Constipation is one of the most frequent symptoms encountered in daily clinical practice and is implicated in the development of atherosclerosis, potentially through altered gut microbiota. However, little is known about its association with incident cardiovascular events. Methods: In a nationally representative cohort of 3,359,653 U.S. veterans with an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m 2 between October 1, 2004 and September 30, 2006 (baseline period), with follow-up through 2013, we examined the association of constipation status (absence or presence; defined using diagnostic codes and laxative use) and