C-Reactive Protein Modifies the Relationship Between Blood Pressure and Microalbuminuria

Abstract

Abstract-C-reactive protein (CRP) and microalbuminuria reflect intimately related components of the atherosclerotic disease process. Epidemiological studies found only modest associations between CRP and microalbuminuria. Blood pressure, one of the components of the metabolic syndrome in the general population, is the main determinant of microalbuminuria in diabetes and hypertension. We questioned whether CRP modifies the relationship of blood pressure and other cardiovascular risk factors with microalbuminuria in a cross-sectional study in 8592 inhabitants from Groningen, The Netherlands. The crude data showed an increase in the prevalence of microalbuminuria with increasing CRP quartiles (4.8, 9.6, 14. Key Words: cardiovascular diseases Ⅲ blood pressure Ⅲ risk factors Ⅲ kidney Ⅲ albuminuria C -reactive protein (CRP), a sensitive marker of (sub)clinical inflammation, is thought to represent the state of chronic low-grade inflammation of the arterial vessel wall at atherosclerotic sites. 1 CRP consistently predicts cardiovascular (CV) outcome. [2][3][4] Microalbuminuria is also an established risk marker for future cardiovascular events in various populations. 5,6 The appearance of low levels of albumin in the urine is thought to be the consequence of generalized endothelial damage along the vascular tree, including the glomerulus. 7 Blood pressure has been shown to be the main determinant of microalbuminuria in diabetes and hypertension. 8 Many other CV risk factors, which cluster within the metabolic syndrome, have been shown to relate to microalbuminuria in the population. 9,10 Because CRP and microalbuminuria reflect closely related components of the same disease processes, one might anticipate a strong relationship between them. However, studies that investigated this relationship in large populations only found weak associations. 11,12 Interdependence between CRP and other cardiovascular risk factors with the risk of microalbuminuria may have been overlooked.We questioned whether elevated serum CRP levels modify the relation of blood pressure and other CV risk factors with microalbuminuria. Methods Study DesignThis study is part of the PREVEND study (Prevention of REnal and Vascular ENdstage Disease) in Groningen, The Netherlands. PREVEND investigates the natural course of microalbuminuria in relation to renal and cardiovascular morbidity and mortality in the general population. All inhabitants aged 28 to 75 years (nϭ85 421) were asked to send in a morning urine sample and to complete a brief questionnaire on demographics and renal and cardiovascular morbidity. A total of 40 856 subjects responded. Pregnant women and subjects using insulin were excluded. All subjects with an albumin concentration of Ͼ10 mg/L in their morning urine sample plus a random sample of the population with a morning urine albumin excretion Ͻ10 mg/L were invited to our outpatient clinic. A detailed overview of this protocol is described elsewhere. 13 All subjects completed an extensive questionnaire on demographics, renal and cardio...

Dietary salt intake is related to inflammation and albuminuria in primary hypertensive patients

“…However, it has been proposed that low-grade inflammation seen in hypertensive subjects may increase the likelihood of increased glomerular leakage of albumin in response to BP. 35,39 This glomerular leakage may involve either increased transmission of systemic BP or decreased barrier function of the glomerulus due to inflammatory involvement. [38][39][40] In our study, regarding the near-normal BP levels of the patients under treatment in three salt-intake groups, serum CRP and urinary albumin levels were still higher in patients with high dietary salt intake.…”

Albumin excretion in diabetic patients in the setting of acute myocardial infarction: association with 3-year mortality

“…Therefore, it is conceivable that the inflammatory injury and haemodynamic changes related to AMI [12] caused a greater leakage of urinary albumin in subjects with diabetes and associated glomerular damage. A recent study has demonstrated an association between C-reactive protein (a sensitive marker of inflammation) and microalbuminuria [30], and previous results from our laboratory indicate that C-reactive protein is a strong independent predictor of mortality in subjects with AMI [31]. The negative interaction between diabetes and ACR with respect to mortality suggests that microalbuminuria is the overriding factor in the setting of AMI because it reflects a heavily compromised clinical situation, and microalbuminuria was more common among the diabetic individuals than the non-diabetic individuals.…”

Microalbuminuria in Type 2 Diabetes and Hypertension

“…In a crosssectional study conducted in the large Groningen cohort, Stuveling et al (26) observed that increasing C-reactive protein values from 0.2 to 10 mg/l resulted in a remarkable steepening of the slope of the relationship of albuminuria versus mean arterial pressure, with a potentiating effect of C-reactive protein that became significant for mean arterial pressures Ͼ90 mmHg.…”