Differences in the association of inflammation and tryptophan with depressive symptoms between white and non-white chronic dialysis patients

A systematic review and meta-analysis of the evidence on inflammation in depressive illness and symptoms in chronic and end-stage kidney disease

BACKGROUND

Depression affects approximately 27% of adults with chronic kidney disease (CKD) and end-stage kidney failure (ESKF). Depression in this population is associated with impaired quality of life and increased mortality. The extent of inflammation and the impact on depression in CKD/ESKF is yet to be established. Through a systematic literature review and meta-analysis, we aim to understand the relationship between depression and inflammation in CKD/ESKF patients.

METHODS

We searched nine electronic databases for published studies until January 2022. Titles and abstracts were screened against inclusion and exclusion criteria. Data extraction and study quality assessment was carried out independently by two reviewers. A meta-analysis was carried out where appropriate; otherwise a narrative review of studies was completed.

RESULTS

Sixty studies met our inclusion criteria and entered the review (9481 patients included in meta-analysis). Meta-analysis of cross-sectional associations revealed significantly higher levels of pro-inflammatory biomarkers; C-reactive protein; Interleukin 6 (IL-6) and tumour necrosis factor-alpha in patients with depressive symptoms (DS) compared to patients without DS. Significantly lower levels of anti-inflammatory cytokine IL-10 were found in patients with DS compared to patients without DS. Considerable heterogeneity was detected in the analysis for most inflammatory markers.

CONCLUSION

We found evidence for an association of higher levels of pro-inflammatory and lower anti-inflammatory cytokines and DS in patients with CKD/ESKF. Clinical trials are needed to investigate whether anti-inflammatory therapies will be effective in the prevention and treatment of DS in these patients with multiple comorbidities.

Dialysis withdrawal and symptoms of anxiety and depression: a prospective cohort study

BACKGROUND

An important aspect of end-of-life decisions in dialysis patients is elective withdrawal from dialysis therapy. Several studies have shown that clinical factors, such as comorbidity, play a role in dialysis withdrawal. The role of symptoms of anxiety and depression is largely unknown. The.

METHODS

A prospective multi-center study has been set up to investigate anxiety and depressive symptoms longitudinally in dialysis patients. Anxiety and depressive symptoms were investigated using the Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI) as baseline. Adverse events, including dialysis withdrawal and mortality were registered during follow-up. Multivariable cox proportional hazard models were used with anxiety and depression as the independent variable and dialysis withdrawal as the outcome variable. Models included age, sex, ethnicity and a set of clinical comorbidities.

RESULTS

A total of 687 patients were included between 2012 and 2017, with a median follow-up of 3.2 years. A total of 48 patients (7%) withdrew from dialysis therapy, and subsequently deceased. Anxiety and depressive symptoms at baseline showed an association with dialysis withdrawal with hazard ratios of 2.31 (1.09-4.88) for anxiety and 2.56 (1.27-5.15) for depressive symptoms, independent of somatic comorbidities.

DISCUSSION

Withdrawal from dialysis therapy is associated with anxiety and depressive symptoms. Dialysis patients with more severe depressive and anxiety symptoms were more vulnerable for dialysis withdrawal. Insight in factors that play a role in dialysis withdrawal could aid patients and clinicians making an informed decision and develop clinical guidelines.

Biological, Psychological, and Social Determinants of Depression: A Review of Recent Literature

Depression is one of the leading causes of disability, and, if left unmanaged, it can increase the risk for suicide. The evidence base on the determinants of depression is fragmented, which makes the interpretation of the results across studies difficult. The objective of this study is to conduct a thorough synthesis of the literature assessing the biological, psychological, and social determinants of depression in order to piece together the puzzle of the key factors that are related to this condition. Titles and abstracts published between 2017 and 2020 were identified in PubMed, as well as Medline, Scopus, and PsycInfo. Key words relating to biological, social, and psychological determinants as well as depression were applied to the databases, and the screening and data charting of the documents took place. We included 470 documents in this literature review. The findings showed that there are a plethora of risk and protective factors (relating to biological, psychological, and social determinants) that are related to depression; these determinants are interlinked and influence depression outcomes through a web of causation. In this paper, we describe and present the vast, fragmented, and complex literature related to this topic. This review may be used to guide practice, public health efforts, policy, and research related to mental health and, specifically, depression.

The Effect of the Hydroalcoholic Extract of Watercress on the Levels of Protein Carbonyl, Inflammatory Markers, and Vitamin E in Chronic Hemodialysis Patients

Introduction

Chronic kidney disorder is a main public health concern. Inflammatory processes and oxidative stress are common in end-stage renal disease patients. We aimed to evaluate the effect of the hydroalcoholic extract of watercress (WC) on the inflammatory cytokines and protein carbonyl (PCO) contents in chronic hemodialysis patients.

Methods

This was a double-blind randomized clinical trial performed on 46 hemodialysis patients. The participants were randomly divided into two groups: intervention group (500 mg hydroalcoholic extract of WC every day for 4 weeks) and control group (500 mg of white flour every night for 4 weeks). The blood samples were taken to determine the levels of vitamin E, PCO, and inflammatory cytokines at baseline and the end of treatment.

Results

Forty-five patients completed the study (22 patients in the intervention group and 23 patients in the control group). There was a significant reduction in the PCO level (20.33 ± 4.40 vs. 15.06 ± 6.41, P=0.001) in the intervention group; also, this change was statistically significant relative to the control group. Furthermore, there were significant reductions in hs-CRP (8953.30 ± 5588.06 vs. 7249.86 ± 5091.62, P=0.007) and IL-6 (60.10 (55.99, 73.10) vs. 55.21 (53.39, 60.48), P=0.050) in the intervention group, but these changes were not significant in comparison with the control group.

Conclusion

We conclude that the hydroalcoholic extract of WC reduced the PCO content in hemodialysis patients via inhibition of protein oxidation. Although WC administration had caused a significant reduction in IL-6 and CRP levels, these differences were not statistically significant relative to the control group. Further research is needed to identify the antioxidant and anti-inflammatory effects of WC in hemodialysis patients.

Depression and the Effect of Sertraline on Inflammatory Biomarkers in Patients with Nondialysis CKD

Background

Inflammatory biomarkers are elevated in patients with CKD and associated with poor outcomes. Major depressive disorder (MDD) is prevalent in CKD and associated with inflammation. No studies investigated the effect of MDD treatment on plasma inflammatory biomarkers in patients with nondialysis CKD.

Methods

In a prespecified analysis of the randomized, double-blind CKD Antidepressant Sertraline Trial, we investigated whether treatment with sertraline versus placebo or response to treatment would affect plasma levels of albumin, prealbumin, IL-6, and high-sensitivity C-reactive protein (hsCRP), measured at baseline and after 12 weeks of treatment. We also explored whether somatic versus nonsomatic depressive symptoms, measured using the Quick Inventory of Depressive Symptomatology, and quality-of-life subscales, measured using the Kidney Disease Quality of Life Short Form, were associated with baseline levels of these inflammatory biomarkers.

Results

Of the 193 participants, mean age was 58.4 (SD 13) years and 58% were black, 42% were white, and 18% were Hispanic. Higher baseline hsCRP correlated with somatic depressive symptoms (r=0.21; P=0.01), fatigue (r=0.22; P=0.005), and poorer physical functioning (r=−0.26; P=0.001). There was no change in hsCRP in the sertraline group. hsCRP increased in placebo nonresponders from baseline (median, 3.7 mg/L; interquartile range [IQR], 1.7–10.0 mg/L) to exit (median, 4.9 mg/L; IQR, 1.8–8.8 mg/L; P=0.01). The change from baseline to exit differed between placebo responders (median, −0.4 mg/L; IQR, −9.3 to 0.2 mg/L) and nonresponders (median, 0.8 mg/L; IQR, −0.1 to 3.9 mg/L; P=0.008). There were no differences in changes in albumin, prealbumin, or IL-6 from baseline in any group.

Conclusions

Among patients with CKD and MDD, hsCRP correlated with somatic symptoms of depression and fatigue, but not with nonsomatic symptoms. Sertraline treatment was not associated with a longitudinal change in hsCRP from baseline regardless of treatment effect on depressive symptoms, but those who failed to respond to placebo had an increase in hsCRP over time. This area deserves further investigation.

Clinical Trial registry name and registration number:

CKD Antidepressant Sertraline Trial (CAST), NCT00946998.

Tryptophan in health and disease

Tryptophan (TRP), an essential amino acid in mammals, is involved in several physiological processes including neuronal function, immunity, and gut homeostasis. In humans, TRP is metabolized via the kynurenine and serotonin pathways, leading to the generation of biologically active compounds, such as serotonin, melatonin and niacin. In addition to endogenous TRP metabolism, resident gut microbiota also contributes to the production of specific TRP metabolites and indirectly influences host physiology. The variety of physiologic functions regulated by TRP reflects the complex pattern of diseases associated with altered homeostasis. Indeed, an imbalance in the synthesis of TRP metabolites has been associated with pathophysiologic mechanisms occurring in neurologic and psychiatric disorders, in chronic immune activation and in the immune escape of cancer. In this chapter, the role of TRP metabolism in health and disease is presented. Disorders involving the central nervous system, malignancy, inflammatory bowel and cardiovascular disease are discussed.