@article {6660, title = {Urine Collagen Fragments and CKD Progression-The Cardiovascular Health Study.}, journal = {J Am Soc Nephrol}, volume = {26}, year = {2015}, month = {2015 Oct}, pages = {2494-503}, abstract = {

Tubulointerstitial fibrosis is common with ageing and strongly prognostic for ESRD but is poorly captured by eGFR or urine albumin to creatinine ratio (ACR). Higher urine levels of procollagen type III N-terminal propeptide (PIIINP) mark the severity of tubulointerstitial fibrosis in biopsy studies, but the association of urine PIIINP with CKD progression is unknown. Among community-living persons aged >=65 years, we measured PIIINP in spot urine specimens from the 1996 to 1997 Cardiovascular Health Study visit among individuals with CKD progression (30\% decline in eGFR over 9 years, n=192) or incident ESRD (n=54) during follow-up, and in 958 randomly selected participants. We evaluated associations of urine PIIINP with CKD progression and incident ESRD. Associations of urine PIIINP with cardiovascular disease, heart failure, and death were evaluated as secondary end points. At baseline, mean age ({\textpm}SD) was 78{\textpm}5 years, mean eGFR was 63{\textpm}18 ml/min per 1.73 m(2), and median urine PIIINP was 2.6 (interquartile range, 1.4-4.2) μg/L. In a case-control study (192 participants, 231 controls), each doubling of urine PIIINP associated with 22\% higher odds of CKD progression (adjusted odds ratio, 1.22; 95\% confidence interval, 1.00 to 1.49). Higher urine PIIINP level was also associated with incident ESRD, but results were not significant in fully adjusted models. In a prospective study among the 958 randomly selected participants, higher urine PIIINP was significantly associated with death, but not with incident cardiovascular disease or heart failure. These data suggest higher urine PIIINP levels associate with CKD progression independently of eGFR and ACR in older individuals.

}, keywords = {Aged, Cardiovascular Diseases, Case-Control Studies, Disease Progression, Female, Heart Failure, Humans, Kidney Failure, Chronic, Male, Peptide Fragments, Procollagen, Prospective Studies, Renal Insufficiency, Chronic}, issn = {1533-3450}, doi = {10.1681/ASN.2014070696}, author = {Ix, Joachim H and Biggs, Mary L and Mukamal, Kenneth and Djouss{\'e}, Luc and Siscovick, David and Tracy, Russell and Katz, Ronit and Delaney, Joseph A and Chaves, Paulo and Rifkin, Dena E and Hughes-Austin, Jan M and Garimella, Pranav S and Sarnak, Mark J and Shlipak, Michael G and Kizer, Jorge R} } @article {7347, title = {The Relation of Serum Potassium Concentration with Cardiovascular Events and Mortality in Community-Living Individuals.}, journal = {Clin J Am Soc Nephrol}, volume = {12}, year = {2017}, month = {2017 Feb 07}, pages = {245-252}, abstract = {

BACKGROUND AND OBJECTIVES: Hyperkalemia is associated with adverse outcomes in patients with CKD and in hospitalized patients with acute medical conditions. Little is known regarding hyperkalemia, cardiovascular disease (CVD), and mortality in community-living populations. In a pooled analysis of two large observational cohorts, we investigated associations between serum potassium concentrations and CVD events and mortality, and whether potassium-altering medications and eGFR<60 ml/min per 1.73 m(2) modified these associations.

DESIGN, SETTING, PARTICIPANTS, \& MEASUREMENTS: Among 9651 individuals from the Multi-Ethnic Study of Atherosclerosis (MESA) and the Cardiovascular Health Study (CHS), who were free of CVD at baseline (2000-2002 in the MESA and 1989-1993 in the CHS), we investigated associations between serum potassium categories (<3.5, 3.5-3.9, 4.0-4.4, 4.5-4.9, and >=5.0 mEq/L) and CVD events, mortality, and mortality subtypes (CVD versus non-CVD) using Cox proportional hazards models, adjusting for demographics, time-varying eGFR, traditional CVD risk factors, and use of potassium-altering medications.

RESULTS: Compared with serum potassium concentrations between 4.0 and 4.4 mEq/L, those with concentrations >=5.0 mEq/L were at higher risk for all-cause mortality (hazard ratio, 1.41; 95\% confidence interval, 1.12 to 1.76), CVD death (hazard ratio, 1.50; 95\% confidence interval, 1.00 to 2.26), and non-CVD death (hazard ratio, 1.40; 95\% confidence interval, 1.07 to 1.83) in fully adjusted models. Associations of serum potassium with these end points differed among diuretic users (Pinteraction<0.02 for all), such that participants who had serum potassium >=5.0 mEq/L and were concurrently using diuretics were at higher risk of each end point compared with those not using diuretics.

CONCLUSIONS: Serum potassium concentration >=5.0 mEq/L was associated with all-cause mortality, CVD death, and non-CVD death in community-living individuals; associations were stronger in diuretic users. Whether maintenance of potassium within the normal range may improve clinical outcomes requires future study.

}, issn = {1555-905X}, doi = {10.2215/CJN.06290616}, author = {Hughes-Austin, Jan M and Rifkin, Dena E and Beben, Tomasz and Katz, Ronit and Sarnak, Mark J and Deo, Rajat and Hoofnagle, Andrew N and Homma, Shunichi and Siscovick, David S and Sotoodehnia, Nona and Psaty, Bruce M and de Boer, Ian H and Kestenbaum, Bryan and Shlipak, Michael G and Ix, Joachim H} }