Journal Article Annotations
2024, 2nd Quarter

Psychonephrology

Annotations by Shivali Patel, MD and Sahil Munjal, MD
July, 2024

Association of cognitive impairment with the interaction between chronic kidney disease and depression: findings from NHANES 2011-2014.

PUBLICATION #1 — Psychonephrology

Association of cognitive impairment with the interaction between chronic kidney disease and depression: findings from NHANES 2011-2014.

Tong Zhou, Jiayu Zhao, Yimei Ma, Linqian He, Zhouting Ren, Kun Yang, Jincheng Tang, Jiali Liu, Jiaming Luo, Heping Zhang.

Abstract: BMC Psychiatry. 2024 Apr 24;24(1):312. doi: 10.1186/s12888-024-05769-1.

Background:
Cognitive impairment (CoI), chronic kidney disease (CKD), and depression are prevalent among older adults and are interrelated, imposing a significant disease burden. This study evaluates the association of CKD and depression with CoI and explores their potential interactions.

Method:
Data for this study were sourced from the 2011-2014 National Health and Nutritional Examination Survey (NHANES). Multiple binary logistic regression models assessed the relationship between CKD, depression, and CoI while controlling for confounders. The interactions were measured using the relative excess risk of interaction (RERI), the attributable proportion of interaction (AP), and the synergy index (S).

Results:
A total of 2,666 participants (weighted n = 49,251,515) were included in the study, of which 700 (16.00%) had CoI. After adjusting for confounding factors, the risk of CoI was higher in patients with CKD compared to non-CKD participants (odds ratio [OR] = 1.49, 95% confidence interval [CI]:1.12-1.99). The risk of CoI was significantly increased in patients with depression compared to those without (OR = 2.29, 95% CI: 1.73-3.03). Furthermore, there was a significant additive interaction between CKD and depression in terms of the increased risk of CoI (adjusted RERI = 2.01, [95% CI: 0.31-3.71], adjusted AP = 0.50 [95% CI: 0.25-0.75], adjusted S = 2.97 [95% CI: 1.27-6.92]).

Conclusion:
CKD and depression synergistically affect CoI, particularly when moderate-to-severe depression co-occurs with CKD. Clinicians should be mindful of the combined impact on patients with CoI. Further research is needed to elucidate the underlying mechanisms and assess the effects specific to different CKD stages.

Annotation

The finding:
This cross-sectional study, using data from National Health and Nutritional Examination Survey (NHANES), demonstrated both moderate-to-severe depression and chronic kidney disease (CKD) have a synergistic effect on increasing the risk of cognitive impairment in individuals ages 60 or older.

Strength and weaknesses:
Strengths of the study include the use of a large nationally representative sample, adjusting for confounding factors, and the measurement of cognitive impairment via three scales commonly used for screening and epidemiological research. Weaknesses include inability to firmly establish causality secondary to its observational study design. Residual confounding could influence cognitive functioning due to history of traumatic brain injury or other neurological insult, pharmacologic agents like anticholinergics or benzodiazepines, cannabis use, exercise/physical activity, and metabolic and vitamin derangements. Also, most participants (80.33%) were non-Hispanic whites, which limits generalizability outside of the USA.

Relevance:
Depression and cognitive impairment have shown to independently increase the risk of cognitive impairment and this study adds to the literature by showing a synergistic effect. Given, treatment of cognitive impairment is challenging due to its multifactorial etiology, treating both entities- depression and CKD may support a patient’s cognitive functioning. Understanding this relationship is pertinent for C-L psychiatrists evaluating CKD patients for transplantation as cognitive impairment can negatively impact the pre- and post-transplantation courses. The study highlights the need for an integrated approach to managing patients with CKD and depression, emphasizing the importance of screening and formulation of individualized treatment strategies, encompassing psychopharmacology, psychotherapy and lifestyle adjustments.