Table 1 Major longitudinal studies about the association of chronic kidney disease and cognitive decline (modified after [34])
From: Kidney disease as a determinant of cognitive decline and dementia
Study | Participants | Mean age (years) | Follow-up (years) | Cognitive test | Assessment (1) and classification (2) of renal function | Adjustment for confounders | Result (risk for cognitive decline depending on renal function/proteinuria/albuminuria) |
|---|---|---|---|---|---|---|---|
Osteoporotic Fractures in Men Study [30] | 5,929 men | 74 | 5 | 3MS, Trails B | (1) MDRD | Age, education, race, health status, ADL impairment, alcohol, diabetes, hypertension, CHD, stroke, BMI, PAD | Not significant for both tests in both CKD groups |
(2) Mild CKD = eGFR 45 to 59, moderate CKD = eGFR <45 | |||||||
Rancho Bernardo Study [31] | 1,345 | 75 | 6.6 | MMSE, Trails B, Category Fluency Test | (1) MDRD | Age, hypertension, HbA1c, dyslipidemia, education, exercise, alcohol, estrogen, depression | Not significant for eGFR |
(2) Moderate-to-severe CKD = eGFR <60 | Significant only for men and baseline albuminuria | ||||||
Three C Study [32] | 7,839 | 74 | 7 | MMSE | (1) CKD-EPI | Age, sex, education, ApoE, hypertension, CHD, dyslipidemia, diabetes, smoking, BMI, stroke | Not significant except for eGFR decline over first 4 years and vascular dementia |
(2) CKD = eGFR <60 | Borderline risk for proteinuria | ||||||
Reasons for Geographic and Racial Differences in Stroke [33] | 19,399 | 64 | 3.8 | 6-Item Screener | (1) CKD-EPI | Age, sex, race, education, region, hypertension, diabetes, stroke, CHD, alcohol, smoking | Not significant for eGFR <60 |
(2) CKD = eGFR <60 | OR 1.30 (95% CI 1.02 to 1.66) for UACR <10 mg/g in eGFR <60 | ||||||
Cardiovascular Health Cognition Study [22] | 3,349 | 77 | 6 | Cognitive battery testing for dementia similar to DSM-IV criteria | (1) Inverse of creatinine | Age, sex, race, body weight, education, CHD, stroke, hypertension, diabetes, smoking, apoE genotype | 37% increased risk of dementia (95% CI 1.06 to 1.78) |
(2) Moderate CKD = SCr ≥1.3 mg/dl for women and ≥1.5 for men | |||||||
Health, Aging, and Body Composition Study [23] | 3,034 | 74 | 2, 4 | 3MS | (1) MDRD at baseline | Age, sex, race, education, diabetes, medication, hypertension, hyperlipidemia, CRP, interleukin-6, hematocrit, CHD, stroke | OR 1.32 (95% CI 1.03 to 1.69) for eGFR 45 to 59 |
(2) CKD = eGFR <60 with two subgroups (eGFR 45 to 59 and <45) | OR 2.43 (95% CI 1.38 to 4.29) for eGFR <45 | ||||||
INVADE study [24] | 3,697 | 68 | 2 | 6-Item Cognitive Impairment Test | (1) CG at baseline | Age, sex, smoking, CHD, stroke, hypertension, diabetes, BMI, hyperlipidemia, alcohol, physical activity, depression | Moderate-to severe CKD: OR 2.14 (95% CI 1.18 to 3.87) |
(2) Mild CKD = eGFR 45 to 59, moderate-to-severe CKD = eGFR <45 | |||||||
Rush and Memory Aging Project [26] | 886 | 81 | 3.4 | Battery of 19 tests with five cognitive systems | (1) MDRD at baseline | Age, sex, education, BMI, hemoglobin, physical activity, social activity, hypertension, diabetes, smoking, CHD, stroke, PAD, depression | Each GFR reduction of 15 = increased rate of global cognitive decline of being 3 years older |
(2) CKD = eGFR <60 | |||||||
Northern Manhattan Study [25] | 2,172 | 72 | 2.9 | TICS | (1) CG + MDRD at baseline | Age, sex, race, education, insurance, hypertension, diabetes, alcohol, smoking, CHD, stroke homocysteine, hematocrit, psychoactive medication | Decline by 0.3 TICS points/year for eGFR <60 |
(2) Mildly reduced renal function = eGFR 60 to 90, eGFR <60 | Decline by 0.2 TICS points/year for eGFR = 60 to 90 | ||||||
Osaka-Tajiri Project [27] | 497 | 74 | 5 | Clinical Dementia Rating | (1) Not described | Age, sex, education, hypertension, diabetes, dyslipidemia, CHD, anemia | Conversion to dementia OR 5.3 (95% CI 1.7 to 16.2) |
(2) CKD = eGFR <60 or albuminuria | |||||||
Maine-Syracuse Longitudinal Study [28] | 590 | 62 | 5 | Composite scores of VM, VSOM, ST and WM | (1) MDRD | Age, sex, education, race, diabetes, BMI, smoking, HDL cholesterol, hypertension | Global cognitive ability: b = 0.21 SD decline/unit ln(eGFR) (95% CI 0.04 to 0.38) |
(2) CKD = eGFR <60 | Verbal episodic memory: b = 0.28 SD decline per unit ln(eGFR) (95% CI 0.02 to 0.54) | ||||||
Abstract reasoning: b = 0.36 SD decline per unit ln(eGFR) (95% CI 0.04 to 0.67) | |||||||
Cardiovascular Health Study [29] | 3,907 | 75 | 5.3 | 3MS, DSST | (1) Cystatin C-based eGFR | Age, sex, race, education, smoking, BMI, diabetes, hypertension, CRP, ApoE, depression | Points/year faster decline: |
(2) CKD = eGFR <60 | OR 0.64 (95% CI 0.51 to 0.77) in 3MS | ||||||
OR 0.42 (95% CI 0.28 to 0.56) in DSST | |||||||
Osaka Follow-up Study for Carotid Atherosclerosis, Part 2 [8] | 600 | 68 | 7.5 | MMSE | (1) MDRD | Age, sex, ApoE, education, hypertension, diabetes, cerebrovascular events | HR 1.96 (95% CI 1.08 to 3.58) |
(2) CKD = eGFR <60 | brain atrophy, SVD |