September 4, 2009

CKD Associates with Cognitive Decline

Q: What is the clinical evidence from this study?

Study design: Cohort. Population: Chronic Kidney Disease and Cognitive Decline (n=2172). Intervention: Creatinine clearance <60 ml/min vs. Creatinine clearance ≥90 ml/min. Primary outcome: Annual change in modified Telephone Interview for Cognitive Status (TICS-m) score (Parameter estimate -0.365, 95% CI -0.511, -0.220, p=<0.001).

Key Result

Participants with a creatinine clearance <60 ml/min experienced significantly greater cognitive decline, losing an additional 0.365 points per year on the TICS-m compared to those with normal kidney function.

Study Design

Type

Cohort (n=2,172)

Multicenter

PICO

Population

Chronic Kidney Disease and Cognitive Decline (n=2,172)

Intervention / Comparator

Creatinine clearance <60 ml/min vs Creatinine clearance ≥90 ml/min

Primary Outcome

Annual change in modified Telephone Interview for Cognitive Status (TICS-m) score — Parameter estimate -0.365 (-0.511, -0.220), p=<0.001

Main Result

Effect estimate: Parameter estimate -0.365 (95% CI -0.511, -0.220)

p-value: p=<0.001

Limitations

Relied on only one serum creatinine measurement per subject without repeat measurements to assess change in kidney function
Lacked urine samples to identify participants with albuminuria as their only manifestation of CKD
MDRD and Cockcroft-Gault formulas are less accurate when the true GFR is ≥60 ml/min
Potential survivor bias as participants were healthier than those not included at baseline
Unmeasured confounding from insufficient data on the length of exposure to vascular risk factors or severity of underlying vascular disease

Abstract

Cognitive impairment and chronic kidney disease (CKD) will become increasingly prevalent in the aging US population. Although evidence exists that CKD is a risk factor for cognitive decline, longitudinal studies are limited and largely have excluded ethnically diverse populations. The Northern Manhattan Study includes a population-based, prospective, stroke-free cohort. We assessed global cognitive function annually using the modified Telephone Interview for Cognitive Status (TICS-m) and estimated kidney function using Cockcroft-Gault creatinine clearance (CCl), Modification of Diet in Renal Disease estimated GFR (eGFR), and serum creatinine (sCr). We examined the association between CKD and change in TICS-m scores over time, adjusting for sociodemographic and vascular risk factors. Of 2172 subjects (mean age 71.5 yr, mean follow-up 2.9 yr), 59% were Hispanic, 20% were black, and 63% were women. Participants with a CCl 90 ml/min, adjusting for potential confounders. Our results were similar when we used eGFR or sCr to estimate kidney function. In conclusion, decreased kidney function associates with greater cognitive decline, even in those with mild CKD. Kidney disease may represent a novel mechanism leading to cognitive impairment and a target for early intervention.

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Cite This Study

Khatri et al. (Fri,) conducted a cohort in Chronic Kidney Disease and Cognitive Decline (n=2,172). Creatinine clearance <60 ml/min vs. Creatinine clearance ≥90 ml/min was evaluated on Annual change in modified Telephone Interview for Cognitive Status (TICS-m) score (Parameter estimate -0.365, 95% CI -0.511, -0.220, p=<0.001). Participants with a creatinine clearance <60 ml/min experienced significantly greater cognitive decline, losing an additional 0.365 points per year on the TICS-m compared to those with normal kidney function.

synapsesocial.com/papers/6a09622287ad1657d2513edf https://doi.org/https://doi.org/10.1681/asn.2008101090