Clinical Risk Factors For Kidney Tubule Biomarker Abnormalities Among Hypertensive Adults With Reduced eGFR in the SPRINT Trial.

BACKGROUND: Urine biomarkers of kidney tubule health may distinguish aspects of kidney damage that cannot be captured by current glomerular measures. Associations of clinical risk factors with specific kidney tubule biomarkers have not been evaluated in detail. METHODS: We performed a cross-sectional study in the Systolic Blood Pressure Intervention Trial among 2,436 participants with a baseline estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2. Associations between demographic and clinical characteristics with urine biomarkers of kidney tubule health were evaluated using simultaneous multivariable linear regression of selected variables. RESULTS: Each standard deviation higher age (9 years) was associated with 13% higher levels of chitinase-3-like protein-1 (YKL-40), indicating higher levels of tubulointerstitial inflammation and repair. Men had 31% higher levels of alpha-1 microglobulin and 16% higher levels of beta-2 microglobulin, reflecting worse tubule resorptive function. Black race was associated with significantly higher levels of neutrophil gelatinase-associated lipocalin (12%) and lower kidney injury molecule-1 (26%) and uromodulin (22%). Each standard deviation (SD) higher systolic blood pressure (SBP) (16 mmHg) was associated with 10% higher beta-2 microglobulin and 10% higher alpha-1 microglobulin, reflecting lower tubule resorptive function. CONCLUSIONS: Clinical and demographic characteristics, such as race, sex, and elevated SBP, are associated with unique profiles of tubular damage, which could reflect under-recognized patterns of kidney tubule disease among persons with decreased eGFR.

Functional health and white matter hyperintensities as effect modifiers of blood pressure-lowering on cognitive function and vascular events in older Secondary Prevention of Small Subcortical Strokes trial participants.

OBJECTIVE: To determine whether cerebral small vessel disease or disability modify the effect of SBP treatment on cognitive and vascular outcomes in older patients with recent lacunar stroke. METHODS: Participants aged at least 65 years of the Secondary Prevention of Small Subcortical Strokes Trial were randomized to a higher (130-149 mmHg) or lower (<130 mmHg) SBP target. The primary outcome was change in cognitive function (Cognitive Abilities Screening Instrument); secondary outcomes were incident mild cognitive impairment, stroke, major vascular events (all-stroke, myocardial infarction), and all-cause death. Results were stratified by severity of white matter hyperintensities (WMH; none/mild, moderate, severe) on baseline MRI, and by disability (no vs. at least one limitation in activities of daily living). RESULTS: One thousand, two hundred and sixty-three participants (mean age 73.8 ±â€Š5.9 years, 40% women) were included. Participants with severe WMH or disability had worse cognitive function at baseline and after a mean follow-up of 3.9 years. No significant interactions existed between treatment group and effect modifiers (WMH, disability) for change in cognitive function (P for interaction 0.42 and 0.66, respectively). A lower SBP target appeared more beneficial among those with worse WMH burden for vascular outcomes (P for interaction = 0.01 for stroke and 0.03 for major vascular events). CONCLUSION: There was no difference in the effect of lowering SBP to less than 130 mmHg on cognitive function by cerebral small vessel disease or disability among older adults with a history of lacunar stroke. Those with evidence of small vessel disease may derive greater benefit from lower SBP on prevention of subsequent vascular events. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT00059306.

Cerebral White Matter Hyperintensities, Kidney Function Decline, and Recurrent Stroke After Intensive Blood Pressure Lowering: Results From the Secondary Prevention of Small Subcortical Strokes ( SPS 3) Trial.

Background We aimed to determine whether cerebral white matter hyperintensities ( WMHs ) can distinguish stroke survivors susceptible to rapid kidney function decline from intensive blood pressure ( BP ) lowering. Methods and Results The SPS3 (Secondary Prevention of Small Subcortical Strokes) trial randomized participants with recent lacunar stroke to systolic BP targets of 130 to 149 and <130 mm Hg. We included 2454 participants with WMH measured by clinical magnetic resonance imaging at baseline and serum creatinine measured during follow-up. We tested interactions between BP target and WMH burden on the incidence of rapid kidney function decline (≥30% decrease from baseline estimated glomerular filtration rate at 1-year follow-up) and recurrent stroke. Rapid kidney function decline incidence was 11.0% in the lower- BP -target arm and 8.1% in the higher-target arm (odds ratio=1.40; 95% CI=1.07-1.84). Odds ratio for rapid kidney function decline between lower- and higher-target groups ranged from 1.26 in the lowest WMH tertile (95% CI , 0.80-1.98) to 1.71 in the highest tertile (95% CI , 1.05-2.80; P for interaction=0.65). Overall incidence of recurrent stroke was 7.9% in the lower-target arm and 9.6% in the higher-target arm (hazard ratio=0.80; 95% CI , 0.63-1.03). Hazard ratio for recurrent stroke in the lower-target group was 1.13 (95% CI , 0.73-1.75) within the lowest WMH tertile compared with 0.73 (95% CI , 0.49-1.09) within the highest WMH tertile ( P for interaction=0.04). Conclusions Participants with higher WMH burden appeared to experience greater benefit from intensive BP lowering in prevention of recurrent stroke. By contrast, intensive BP lowering increased the odds of kidney function decline, but WMH burden did not significantly distinguish this risk. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 00059306.

Post Hoc Analyses of Randomized Clinical Trial for the Effect of Clopidogrel Added to Aspirin on Kidney Function.

BACKGROUND AND OBJECTIVES: Despite the high burden of CKD, few specific therapies are available that can halt disease progression. In animal models, clopidogrel has emerged as a potential therapy to preserve kidney function. The effect of clopidogrel on kidney function in humans has not been established. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The Secondary Prevention of Small Subcortical Strokes Study randomized participants with prior lacunar stroke to treatment with aspirin or aspirin plus clopidogrel. We compared annual eGFR decline and incidence of rapid eGFR decline (≥30% from baseline) using generalized estimating equations and interval-censored proportional hazards regression, respectively. We also stratified our analyses by baseline eGFR, systolic BP target, and time after randomization. RESULTS: At randomization, median age was 62 (interquartile range, 55-71) years old; 36% had a history of diabetes, 90% had hypertension, and the median eGFR was 81 (interquartile range, 65-94) ml/min per 1 m2. Persons receiving aspirin plus clopidogrel had an average annual change in kidney function of -1.39 (95% confidence interval, -1.15 to -1.62) ml/min per 1.73 m2 per year compared with -1.52 (95% confidence interval, -1.30 to -1.74) ml/min per 1.73 m2 per year among persons receiving aspirin only (P=0.42). Rapid kidney function decline occurred in 21% of participants receiving clopidogrel plus aspirin compared with 22% of participants receiving aspirin plus placebo (hazard ratio, 0.94; 95% confidence interval, 0.79 to 1.10; P=0.42). Findings did not vary by baseline eGFR, time after randomization, or systolic BP target (all P values for interaction were >0.3). CONCLUSIONS: We found no effect of clopidogrel added to aspirin compared with aspirin alone on kidney function decline among persons with prior lacunar stroke.