Association of Kidney Function and Albuminuria With Cardiovascular Mortality in Older vs Younger Individuals

Abstract

Background:The cardiovascular risk implications of a combined assessment of reduced kidney function and microalbuminuria are unknown. In elderly persons, traditional cardiovascular risk factors are less predictive, and measures of end organ damage, such as kidney disease, may be needed for improved cardiovascular mortality risk stratification.Methods: The glomerular filtration rate was estimated from calibrated serum creatinine, and the urine albumincreatinine ratio (ACR) was measured in 3 urine samples in 9709 participants of the second Nord-Trøndelag Health Study (HUNT II), a Norwegian community-based health study, followed for 8.3 years with a 71% participation rate.Results: An estimated glomerular filtration rate (EGFR) at levels of less than 75 mL/min/1.73 m 2 was associated with higher cardiovascular mortality risk, whereas a higher ACR was associated with higher risk with no lower limit. Low EGFR and albuminuria were synergistic cardiovascular mortality risk factors. Compared with subjects with an EGFR greater than 75 mL/min/1.73 m 2 and ACR below the sex-specific median who were at the lowest risk, subjects with an EGFR of less than 45 mL/min/1.73 m 2 and microalbuminuria had an adjusted incidence rate ratio of 6.7 (95% confidence interval, 3.0-15.1; P Ͻ.001). The addition of ACR and EGFR improved traditional risk models: 39% of subjects with intermediate risk were reclassified to low-or high-risk categories with corresponding observed risks that were 3-fold different than the original category. Age-stratified analyses showed that EGFR and ACR were particularly strong risk factors for persons 70 years or older.Conclusions: Reduced kidney function and microalbuminuria are risk factors for cardiovascular death, independent of each other and traditional risk factors. The combined variable improved cardiovascular risk stratification at all age levels, but particularly in elderly persons where the predictive power of traditional risk factors is attenuated.

Clinical impact of albuminuria and glomerular filtration rate on renal and cardiovascular events, and all-cause mortality in Japanese patients with type 2 diabetes

“…In contrast, reduced eGFR was a high risk for developing cardiovascular endpoints (cardiovascular death, new admissions due to to angina, myocardial infarction, stroke, revascularization or heart failure) and all-cause mortality independent of UACR [15]. Interestingly, the Second Nord-Trøndelag Health (HUNT II) study [16] reported that reduced eGFR with higher UACR was associated with a higher risk for cardiovascular events. This discrepancy compared to our present study may be partly because the number of patients with cardiovascular events in the present study was relatively small as shown in Table 2.…”

Renal Resistive Index and Cardiovascular and Renal Outcomes in Essential Hypertension

“…[33][34][35] Albuminuria is subject to large within-individual variations, with reported coefficient of variation of 50%, 36 and the conclusion as to whether microalbuminuria is present should preferably be based on repeated measurements. On the other hand, RI evaluation is easier because the same probe is used for the heart, and it causes little physical stress to patients.…”

Chronic Kidney Disease Awareness Among Individuals with Clinical Markers of Kidney Dysfunction

“…with poor outcomes in this patient population (19,20). Unlike individuals who may never experience sequelae of their kidney disease, namely individuals with CKD defined solely by albuminuria and elderly patients with decreased eGFR from "natural aging" (21,22), patients who exhibit complications from their renal dysfunction may particularly benefit from being aware of their CKD.…”