Association between Depressive Symptom Trajectory and Chronic Kidney Disease Progression: Findings from the Chronic Renal Insufficiency Cohort Study

Key Points

Depressive symptoms are largely stable over time among individuals with mild-to-moderate CKD Low educational attainment, cigarette smoking, and poor quality of life are associated with persistent depressive symptoms Persistent depressive symptoms are associated with nonlinear and rapid decline in kidney function

Background

Although depression is highly prevalent among individuals with CKD, little is known about the course of depressive symptoms over time. We characterized trajectories of depressive symptoms and CKD progression and evaluated the association between depressive symptoms trajectory and CKD progression.

Methods

Two thousand three hundred sixty-one individuals with mild-to-moderate CKD enrolled in the Chronic Renal Insufficiency Cohort Study were analyzed. The Beck Depression Inventory (BDI) was used to assess depressive symptoms at baseline and biennially. Higher BDI scores indicate worse depressive symptoms. eGFR was calculated using the 2021 CKD-EPI equation. Group-based trajectory models were used to determine trajectories of BDI score and eGFR change over time. Multinomial logistic regression was used to examine factors associated with BDI trajectories and to evaluate the association of BDI trajectories with eGFR change.

Results

Over 8 years of follow-up, three patterns of depressive symptoms were identified: persistently low BDI score (57.7%), persistently moderate BDI score (33.1%), and persistently high BDI score (9.2%). Three eGFR trajectory groups were identified: nonlinear, rapid eGFR decline (21.5%); linear, expected eGFR decline (54.8%); and stable eGFR (23.7%). Predictors of persistently moderate and high BDI trajectories included low educational attainment, smoking, and poor quality of life. Compared with those with a persistently low BDI score, the odds for nonlinear, rapid eGFR decline were higher for those with persistently moderate BDI scores (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.04 to 2.03) and persistently high BDI scores (OR, 1.90; 95% CI, 1.02 to 3.56). No association between moderate BDI score and linear, expected eGFR decline was observed.

Conclusions

Depressive symptoms remained largely stable among individuals with mild-to-moderate CKD, and persistently moderate and high BDI scores were associated with nonlinear, rapid eGFR decline. Future work is needed to better understand the interplay between depression and CKD progression.

Prospective associations of health literacy with clinical outcomes in adults with CKD: findings from the CRIC study

BACKGROUND

Limited health literacy is associated with significant morbidity and mortality in the general population but the relation of health literacy with long-term clinical outcomes among adults with chronic kidney disease (CKD) is less clear.

METHODS

Prospective data from the Chronic Renal Insufficiency Cohort (CRIC) Study (n = 3715) were used. Health literacy was assessed with the Short Test of Functional Health Literacy in Adults (dichotomized as limited/adequate). Cox proportional hazards models were used to separately examine the relations of health literacy with CKD progression, cardiovascular event (any of the following: myocardial infarction, congestive heart failure, stroke or peripheral artery disease), and all-cause, cardiovascular and non-cardiovascular mortality. Poisson regression was used to assess the health literacy-hospitalization association. Models were sequentially adjusted: Model 1 adjusted for potential confounders (sociodemographic factors), while Model 2 additionally adjusted for potential mediators (clinical and lifestyle factors) of the associations of interest.

RESULTS

In confounder-adjusted models, participants with limited (vs adequate) health literacy [555 (15%)] had an increased risk of CKD progression [hazard ratio (HR) 1.34; 95% confidence interval (CI) 1.06-1.71], cardiovascular event (HR 1.67; 95% CI 1.39-2.00), hospitalization (rate ratio 1.33; 95% CI 1.26-1.40), and all-cause (HR 1.54; 95% CI 1.27-1.86), cardiovascular (HR 2.39; 95% CI 1.69-3.38) and non-cardiovascular (HR 1.27; 95% CI 1.01-1.60) mortality. Additional adjustments for potential mediators (Model 2) showed similar results except that the relations of health literacy with CKD progression and non-cardiovascular mortality were no longer statistically significant.

CONCLUSIONS

In the CRIC Study, adults with limited (vs adequate) health literacy had a higher risk for CKD progression, cardiovascular event, hospitalization and mortality-regardless of adjustment for potential confounders.

Isolation, Characterization, and Autophagy Function of BECN1-Splicing Isoforms in Cancer Cells

Alternative splicing allows the synthesis of different protein variants starting from a single gene. Human Beclin 1 (BECN1) is a key autophagy regulator that acts as haploinsufficient tumor suppressor since its decreased expression correlates with tumorigenesis and poor prognosis in cancer patients. Recent studies show that BECN1 mRNA undergoes alternative splicing. Here, we report on the isolation and molecular and functional characterization of three BECN1 transcript variants (named BECN1-α, -β and -γ) in human cancer cells. In ovarian cancer NIHOVCAR3, these splicing variants were found along with the canonical wild-type. BECN1-α lacks 143 nucleotides at its C-terminus and corresponds to a variant previously described. BECN1-β and -γ lack the BCL2 homology 3 domain and other regions at their C-termini. Following overexpression in breast cancer cells MDA-MB231, we found that BECN1-α stimulates autophagy. Specifically, BECN1-α binds to Parkin and stimulates mitophagy. On the contrary, BECN1-β reduces autophagy with a dominant negative effect over the endogenous wild-type isoform. BECN1-γ maintains its ability to interact with the vacuolar protein sorting 34 and only has a slight effect on autophagy. It is possible that cancer cells utilize the alternative splicing of BECN1 for modulating autophagy and mitophagy in response to environmental stresses.

Deoxycholic Acid and Coronary Artery Calcification in the Chronic Renal Insufficiency Cohort

Background Deoxycholic acid (DCA) is a secondary bile acid that may promote vascular calcification in experimental settings. Higher DCA levels were associated with prevalent coronary artery calcification (CAC) in a small group of individuals with advanced chronic kidney disease. Whether DCA levels are associated with CAC prevalence, incidence, and progression in a large and diverse population of individuals with chronic kidney disease stages 2 to 4 is unknown. Methods and Results In the CRIC (Chronic Renal Insufficiency Cohort) study, we evaluated cross-sectional (n=1057) and longitudinal (n=672) associations between fasting serum DCA levels and computed tomographic CAC using multivariable-adjusted regression models. The mean age was 57±12 years, 47% were women, and 41% were Black. At baseline, 64% had CAC (CAC score >0 Agatston units). In cross-sectional analyses, models adjusted for demographics and clinical factors showed no association between DCA levels and CAC >0 compared with no CAC (prevalence ratio per 1-SD higher log DCA, 1.08 [95% CI, 0.91-1.26). DCA was not associated with incident CAC (incidence per 1-SD greater log DCA, 1.08 [95% CI, 0.85-1.39]) or CAC progression (risk for increase in ≥100 and ≥200 Agatston units per year per 1-SD greater log DCA, 1.05 [95% CI, 0.84-1.31] and 1.26 [95% CI, 0.77-2.06], respectively). Conclusions Among CRIC study participants, DCA was not associated with prevalent, incident, or progression of CAC.

Transfluthrin Spatial Repellent on US Military Materials Reduces Culex tarsalis Incursion in a Desert Environment

Standard residual pesticides applied to US military materials such as camouflage netting can reduce mosquito biting pressure in the field but may contribute to the evolution of resistance. However, residual applications of a spatial repellent such as transfluthrin could allow mosquitoes the opportunity to escape, only inducing mortality if insects linger, for example after becoming trapped in a treated tent. In this study we investigated the capability of transfluthrin on 2 types of US military material to reduce natural populations of disease vector mosquitoes in a cool-arid desert field environment in southern California. We found that transfluthrin could reduce Culex tarsalis incursion into protected areas by up to 100% upon initial treatment and up to 45% for at least 16 days posttreatment, showing that this compound could be an effective element in the US Department of Defense integrated vector management system appropriate for further study.

Single Measurements of Carboxy-Terminal Fibroblast Growth Factor 23 and Clinical Risk Prediction of Adverse Outcomes in CKD

RATIONALE & OBJECTIVE

An elevated fibroblast growth factor 23 (FGF-23) level is independently associated with adverse outcomes in populations with chronic kidney disease, but it is unknown whether FGF-23 testing can improve clinical risk prediction in individuals.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Participants in the Chronic Renal Insufficiency Cohort (CRIC) Study (n = 3,789).

EXPOSURE

Baseline carboxy-terminal FGF-23 (cFGF-23) level.

OUTCOMES

All-cause and cardiovascular (CV) mortality, incident end-stage renal disease (ESRD), heart failure (HF) admission, and atherosclerotic events at 3, 5, and 8 years.

ANALYTICAL APPROACH

We assessed changes in model performance by change in area under the receiver operating characteristic curve (ΔAUC), integrated discrimination improvement (IDI), relative IDI, and net reclassification index (NRI) above standard clinical factors. We performed sensitivity analyses, including an additional model comparing the addition of phosphate rather than cFGF-23 level and repeating our analyses using an internal cross-validation cohort.

RESULTS

Addition of a single baseline value of cFGF-23 to a base prediction model improved prediction of all-cause mortality (ΔAUC, 0.017 [95% CI, 0.001-0.033]; IDI, 0.021 [95% CI, 0.006-0.036]; relative IDI, 32.7% [95% CI, 8.5%-56.9%]), and HF admission (ΔAUC, 0.008 [95% CI, 0.0004-0.016]; IDI, 0.019 [95% CI, 0.004-0.034]; relative IDI, 10.0% [95% CI, 1.8%-18.3%]), but not CV mortality, ESRD, or atherosclerotic events at 3 years of follow-up. The NRI did not reach statistical significance for any of the 3-year outcomes. The incremental predictive utility of cFGF-23 level diminished in analyses of the 5- and 8-year outcomes. The cFGF-23 models outperformed the phosphate model for each outcome.

LIMITATIONS

Power to detect increased CV mortality likely limited by low event rate. The NRI is not generalizable without accepted prespecified risk thresholds.

CONCLUSIONS

Among individuals with CKD, single measurements of cFGF-23 improve prediction of risks for all-cause mortality and HF admission but not CV mortality, ESRD, or atherosclerotic events. Future studies should evaluate the predictive utility of repeated cFGF-23 testing.

Serum Bicarbonate and Structural and Functional Cardiac Abnormalities in Chronic Kidney Disease - A Report from the Chronic Renal Insufficiency Cohort Study

BACKGROUND

Heart failure (HF) is a frequent occurrence in chronic kidney disease (CKD) patients and predicts poor survival. Serum bicarbonate is associated with increased rates of HF in CKD; however, the mechanisms leading to this association are incompletely understood. This study aims to assess whether serum bicarbonate is independently associated with structural and functional cardiac abnormalities in CKD.

METHODS

The association between serum bicarbonate and left ventricular (LV) hypertrophy (LVH), LV mass indexed to height2.7, LV geometry, ejection fraction (EF) and diastolic dysfunction was assessed in 3,483 participants without NYHA class III/IV HF, enrolled in the Chronic Renal Insufficiency Cohort study.

RESULTS

The mean estimated glomerular filtration rate was 42.5 ± 17 ml/min/1.73 m2. The overall prevalence of LVH was 51.2%, with 57.8, 50.9 and 47.7% for bicarbonate categories <22, 22-26 and >26 mmol/l, respectively. Participants with low bicarbonate were more likely to have LVH and abnormal LV geometry (OR 1.32; 95% CI 1.07-1.64, and OR 1.57; 95% CI 1.14-2.16, respectively). However, the association was not statistically significant after adjustment for demographics, traditional cardiovascular risk factors, medications and kidney function (OR 1.07; 95% CI 0.66-1.72, and OR 1.27; 95% CI 0.64-2.51, respectively). No association was found between bicarbonate and systolic or diastolic dysfunction. During follow-up, no significant changes in LV mass or EF were observed in any bicarbonate strata.

CONCLUSIONS

In a large CKD study, serum bicarbonate was associated with LV mass and concentric LVH; however, this association was attenuated after adjustment for clinical factors suggesting that the observed cardiac effects are mediated through yet unknown mechanisms.

Race/Ethnicity and Cardiovascular Outcomes in Adults With CKD: Findings From the CRIC (Chronic Renal Insufficiency Cohort) and Hispanic CRIC Studies

BACKGROUND

Non-Hispanic blacks and Hispanics with end-stage renal disease have a lower risk for death than non-Hispanic whites, but data for racial/ethnic variation in cardiovascular outcomes for non-dialysis-dependent chronic kidney disease are limited.

STUDY DESIGN

Prospective cohort.

SETTING & PARTICIPANTS

3,785 adults with entry estimated glomerular filtration rates of 20 to 70mL/min/1.73m(2) enrolled in the CRIC (Chronic Renal Insufficiency Cohort) Study.

PREDICTORS

Race/ethnicity (non-Hispanic white, non-Hispanic black, and Hispanic).

OUTCOMES

Cardiovascular outcomes (atherosclerotic events [myocardial infarction, stroke, or peripheral arterial disease] and heart failure) and a composite of each cardiovascular outcome or all-cause death.

MEASUREMENTS

Multivariable Cox proportional hazards.

RESULTS

During a median follow-up of 6.6 years, we observed 506 atherosclerotic events, 551 heart failure events, and 692 deaths. In regression analyses, there were no significant differences in atherosclerotic events among the 3 racial/ethnic groups. In analyses stratified by clinical site, non-Hispanic blacks had a higher risk for heart failure events (HR, 1.59; 95% CI, 1.29-1.95), which became nonsignificant after adjustment for demographic factors and baseline kidney function. In contrast, Hispanics had similar risk for heart failure events as non-Hispanic whites. In analyses stratified by clinical site, compared with non-Hispanic whites, non-Hispanic blacks were at similar risk for atherosclerotic events or death. However, after further adjustment for cardiovascular risk factors, medications, and mineral metabolism markers, non-Hispanic blacks had 17% lower risk for the outcome (HR, 0.83; 95% CI, 0.69-0.99) than non-Hispanic whites, whereas there was no significant association with Hispanic ethnicity.

LIMITATIONS

Hispanics were largely recruited from a single center, and the study was underpowered to evaluate the association between Hispanic ethnicity and mortality.

CONCLUSIONS

There were no significant racial/ethnic differences in adjusted risk for atherosclerotic or heart failure outcomes. Future research is needed to better explain the reduced risk for atherosclerotic events or death in non-Hispanic blacks compared with non-Hispanic whites.