Microalbuminuria is an early marker of target organ damage in essential hypertension

Current management and screening of peripheral and coronary artery disease in people with diabetes mellitus in Europe. The PADDIA/CADDIA survey

AIMS

This survey aimed to evaluate the current management and screening of coronary artery disease and peripheral artery disease in people with type 2 diabetes mellitus (T2DM) in Europe, utilizing the 2013 ESC/EASD (European Society of Cardiology/European Association for the Study of Diabetes) guidelines as a benchmark.

METHODS

The PADDIA/CADDIA survey is a European medical research collaboration targeting cardiologists, vascular physicians, diabetologists and general practitioners from Austria, Belgium, France, Germany, Italy, Netherlands and United Kingdom.

RESULTS

The questionnaire was completed by sixty-three physicians, of whom 75% declared assessing the cardiovascular risk of people with T2DM mostly without using a risk score (59%). More than 90% of the panel, check HbA1c, blood pressure and low-density lipoprotein cholesterol targets in their patients with T2DM and coronary or peripheral artery disease. For 94% the presence of T2DM influence their patients' management, by optimizing blood glucose, blood pressure and low-density lipoprotein cholesterol control. Only 37% considered screening for lower extremity peripheral artery disease among their T2DM patients and 35% among those with cardiovascular disease.

CONCLUSIONS

Physicians mostly follow the ESC/EASD 2013 guidelines, but when it comes to screening for additional conditions including coronary artery disease or peripheral artery disease, or intensifying the antithrombotic regimen there is need for better guidance.

Hypertension in Women: A South-Asian Perspective

Introduction

Hypertension is an important contributor to cardiovascular disease related morbidity and mortality. Despite the magnitude of its negative impact on cardiovascular outcomes, treatment and control of hypertension remain suboptimal in both men and women.

Materials and Methods

Numerous databases, i.e., PubMed, ScienceDirect, etc., were searched using keywords to identify relevant studies to our narrative review. The findings from the most pertinent articles were summarized and integrated into our narrative review on hypertension in women.

Results

The pathophysiology of essential hypertension is still being delineated in both men and women; there are multiple sex specific factors in association with the development of hypertension in women, including age, combined oral contraceptives (COCs), polycystic ovarian syndrome (PCOS), preeclampsia, etc. There are several sex specific considerations in antihypertensives drug choices.

Discussion

Despite the magnitude of its negative impact on cardiovascular outcomes, treatment and control of hypertension remain suboptimal in women. Medical treatment and adherence is uniquely challenging for South Asian women due to a variety of socio-cultural-economic factors. Further research is warranted to identify optimal sex-specific treatment options that will improve the control of hypertension and decrease the risk of subsequent cardiovascular disease in both genders.

The association between EKG abnormalities and the development of microalbuminuria in type 2 diabetes

Microalbuminuria is associated with both with chronic kidney disease and various cardiovascular abnormalities. Given the common use of electrocardiograms (EKGs) in diagnosing cardiovascular dysfunction, this study is analyzing the relationship between EKG abnormalities and diabetic nephropathy in type 2 diabetes mellitus (DM) patients. The enrollments of this study were from the 10-year follow-up data (2003-2012) of the Diabetes Management through an Integrated Delivery System project. All study subjects underwent at least 1 EKG measurement. The urinary microalbuminuria was recorded annually. The logistic regression model was used to evaluate the association between EKG abnormalities and the occurrence of diabetic nephropathy in type 2 DM patients. The total of 1189 patients with type 2 DM are included in this study and a total of 552 patients had microalbuminuria during a 10-year follow-up. A significantly higher odds ratio of microalbuminuria occurrence (4.85) was found in the patients with premature supraventricular contraction or tachycardia compared to those without EKG abnormalities. The odds ratios of microalbuminuria occurrence were 1.00, 2.43, 2.64, and 2.98, respectively, for patients with insulin resistance in the Q (quartile) 1(as the reference), Q2, Q3, and Q4, respectively. Our findings can serve as a reference for the association between EKG abnormalities and the development of microalbuminuria in type 2 diabetes.

Association of microalbuminuria and adverse outcomes in hypertensive patients: a meta-analysis

BACKGROUND

Studies on the association of microalbuminuria with adverse outcomes in patients with hypertension remain controversial. This meta-analysis aimed to assess the predictive value of microalbuminuria in hypertensive patients.

METHODS

PubMed and Embase databases were comprehensively searched for studies that published from their inceptions to July 10, 2020. Observational studies reporting the association of microalbuminuria (defined as urinary albumin excretion 30 and 300 mg/24 h urine or albumin/creatinine ratio 30-300 mg/g from a spot urine or equivalent value) with all-cause mortality or major adverse cardiovascular events (MACEs) in hypertensive patients were selected.

RESULTS

Nine studies with a total of 19,893 hypertensive patients were included. When compared with those without microalbuminuria, hypertensive patients with microalbuminuria had an increased risk of all-cause mortality (risk ratio [RR] 1.68; 95% confidence interval [CI] 1.46-1.93) and MACEs (RR 1.40; 95% CI 1.22-1.62), respectively. Gender-specific analysis indicated that microalbuminuria was significantly associated with an increased risk of all-cause mortality (RR 1.61; 95% CI 1.17-2.21) in men but not in women (RR 1.18; 95% CI 0.78-1.80).

CONCLUSION

This meta-analysis suggests that microalbuminuria is independently associated with higher risk of MACEs and all-cause mortality in hypertensive patients. Determination of microalbuminuria has potential to improve the risk classification of hypertension.

Relationship between renal volume and atherosclerosis in nondiabetic hypertensive patients with normal glomerular filtration rate

Background: The association between cystatin C (CysC) and atherosclerosis has been shown in numerous studies in hypertensive patients and in various patient groups with high cardiovascular risk. The study examining the association between renal volume and atherosclerosis is very limited. This study aimed to investigate whether there is an association between the presence of atherosclerosis with CysC and renal volume in hypertensive patients.Methods: 133 hypertensive patients and 80 healthy volunteers were evaluated. CysC level was studied in the blood sample taken from all participants. Carotid intima media thickness (CIMT) and renal volume were measured with ultrasound always by the same radiologist. Laboratory findings, CysC, CIMT, and renal volume measurements of the groups were compared statistically.Results: There was no significant difference in mean renal volume values between hypertension and control groups. There was no significant correlation between renal volume with albuminuria and proteinuria. CIMT was significantly higher in hypertension group than in control group (p = .003). There was a significant correlation between renal volume and CIMT, which is an indicator of subclinical atherosclerosis (r = 0.213, p = .001). Renal volume was found to be an independent predictor of CIMT when corrected with variables such as age, BMI, serum LDL-cholesterol level, creatinine, CysC, and albumin-to-creatinine ratio.Conclusion: Ultrasonographic renal volume measurement, which is easy to perform and does not take a long time, can be a useful method for predicting the presence of atherosclerosis in hypertensive patients with GFR >60 ml/min.

Serum endocan levels, carotid intima-media thickness and microalbuminuria in patients with newly diagnosed hypertension

Background: Endocan is a particular protein of endothelial cells. The purpose of this study was to determine the relationship of serum endocan levels with carotid intima-media thickness (cIMT), inflammation, and microalbuminuria in patients with newly-diagnosed hypertension.Materials-Methods: This prospective study included 61 patients with newly-diagnosed hypertension (HT) and 30 controls. Endocan, microalbuminuria and cIMT measurements were taken from all patients.Results: The serum endocan levels, the mean cIMT and microalbuminuria levels of patients with HT were significantly higher than those of the control group (p < .0001, p = .015 and p < .001, respectively).Conclusion: We found that endocan levels were increased in our study. This increase in endocan levels shows a relation with cIMT and microalbuminuria, which are associated with endothelial dysfunction.

Impact of Ambulatory Blood Pressure on Early Cardiac and Renal Dysfunction in Hypertensive Patients without Clinically Apparent Target Organ Damage

PURPOSE

Impaired left ventricular (LV) global longitudinal strain (GLS) and the presence of microalbuminuria indicate early cardiac and renal dysfunction. We aimed to determine the relationships among 24-h ambulatory blood pressure (BP) variables, LV GLS, and urine albumin creatinine ratio (UACR) in hypertensive patients.

MATERIALS AND METHODS

A total of 130 hypertensive patients (mean age 53 years; 59 men) underwent 24-h ambulatory BP monitoring, measurements of peripheral and central BPs, and transthoracic echocardiography. Patients with apparent LV systolic dysfunction (LV ejection fraction <50%) or chronic kidney disease were not included. LV GLS was calculated using two-dimensional speckle tracking, and UACR was analyzed from spot urine samples.

RESULTS

In simple correlation analysis, LV GLS showed the most significant correlation with mean daytime diastolic BP (DBP) (r=0.427, p<0.001) among the various BP variables analyzed. UACR revealed a significant correlation only with night-time mean systolic BP (SBP) (r=0.253, p=0.019). In multiple regression analysis, daytime mean DBP and night-time mean SBP were independent determinants for LV GLS (β=0.35, p=0.028) and log UACR (β=0.49, p=0.007), respectively, after controlling for confounding factors. Daytime mean DBP showed better diagnostic performance for impaired LV GLS than did peripheral or central DBPs, which were not diagnostic. Night-time mean SBP showed satisfactory diagnostic performance for microalbuminuria.

CONCLUSION

There are different associations for daytime and night-time BP with early cardiac and renal dysfunction. Ambulatory BP monitoring provides more relevant BP parameters than do peripheral or central BPs regarding early cardiac and renal dysfunction in hypertensive patients.

Serum ICAM-1 level and ICAM-1 gene 1462A>G (K469E) polimorphism on microalbuminuria in nondiabetic, nonhypertensive and normolipidemic obese patients: Genetical background of microalbuminuria in obesity

BACKGROUND

A growing body of evidence suggest that obese individuals are under risk of renal parenchymal disorders when compared to nonobese counterparts. Microalbuminuria is the early marker of renal involvement. Although most of obese patients carries multiple risk factors for microalbuminuria, some obese individuals without risk factor may progress to microalbuminuria. The present study was performed to examine the role of ICAM-1 gene 1462A>G (K469E) polymorphism on microalbuminuria in obese subjects without diabetes mellitus, hypertension, hiperlipidemia and older age.

METHODS

Ninety eight obese and 96 nonobese individuals without a comorbidity enrolled into the study. Serum ICAM-1 level was measured by enzyme linked immunoabsorbent assay (ELISA) method. ICAM-1 gene 1462A>G (K469E) polymorphism was examined by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR). Nepholometric method was used to examine urinary albumin loss, and microalbuminuria was measured by albumin to creatinine ratio.

RESULTS

Obese individuals had significantly higher microalbuminuria and proteinuria level compared to nonobese subjects (p: 0.043 and p: 0.011; respectively). GG genotype of ICAM-1 carriers have significantly higher microalbuminuria compared to individuals with AA or AG genotype carriers (p: 0.042). Serum ICAM-1 level was significantly correlated with creatinine and microalbuminuria (p: 0.002 and p: 0.03; respectively). Logistic regression analysis indicated a 7.39 fold increased risk of microalbuminuria in individuals with GG genotype of ICAM-1 gene 1462A>G (K469E) polymorphism.

CONCLUSIONS

GG genotype of ICAM-1 gene K469E polymorphism is associated with increased microalbuminuria in obese individuals without another metabolic risk factor.

Microalbuminuria in primary hypertension: a guide to optimal patient management?

Accurate assessment of the global risk profile is considered a prerequisite for the optimal management of hypertensive patients. In particular, the evaluation of subclinical organ damage, namely left ventricular hypertrophy, peripheral atherosclerosis and renal function, plays a key role in optimizing therapeutic targets and strategy in individual patients. Urine albumin excretion is a low-cost, easy-to-use test and a powerful predictor of cardiovascular diseases. The search for albuminuria has, therefore, become routine in the evaluation of hypertensive patients. Moreover, albuminuria has been shown to be associated with early signs of extra-renal organ damage such as left ventricular hypertrophy, and carotid atherosclerosis. Under effective antihypertensive treatment, changes in subclinical organ damage over time, especially regression of left ventricular hypertrophy, are paralleled by modification of risk status and may serve as intermediate endpoints for treatment. More recently, changes in albuminuria have also been proposed to reflect changes in the risk of cardiovascular events. If this is confirmed by large well-designed studies, microalbuminuria may not simply be regarded as a risk predictor but become itself an independent target for treatment.

Identifying the determinants of microalbuminuria in obese patients in primary care units: the effects of blood pressure, random plasma glucose and other risk factors

OBJECTIVE

The objective of this study is to evaluate the demographic characteristics, blood pressure and blood glucose and the other related factors that affect the microalbuminuria levels in the obese patients aged 40 and above who applied to the primary care for medical evaluation.

MATERIALS AND METHODS

The population of the research, which was a cross-sectional type, comprised obese patients aged 40 and above who had applied to the community health centers in the center of Malatya. A total of 422 obese patients consisting of 116 males and 306 females were included in the research. The anthropometric measurements of the participants were determined, their blood pressures and their random blood glucoses were evaluated, as well. A microalbuminuria measurement was performed in the urine samples taken from the patients using "Nycocard Reader II" device.

FINDINGS

The incidence of microalbuminuria in patients was found as 31.5%, whereas the incidence of macroalbuminuria was 6.6%. The incidence of microalbuminuria in female patients was 32.7%, while it was 28.4% in male patients; on the other hand, the incidence of macroalbuminuria in female patients was found as 6.8%, whereas this percentage was determined as 7.8 in male patients (p > 0.05). The probability of the incidence of microalbuminuria increased 2.8 times more in those with the diastolic blood pressure of 90 mmHg and above when compared to those without it (GA: 1.79-4.56), whereas the incidence increased 3.2 times more in those with the random blood glucose of 200 mg/l and above (GA: 1.32-7.84) (p < 0.001). In our study, among the variables predicting the microalbuminuria in obese patients; the cutoff values of the diastolic and systolic blood pressures, the waist circumference were found as >85 mmHg; >130 mmHg; >141 mg/dl, respectively, in male patients and found as >85 mmHg, >114 cm, and 109 cm, respectively, in female patients. The sensitivity and specificity of the tests indicating the cutoff values showed significance (p < 0.05). There was no statistically significant relevance between the microalbumin levels of the obese patients via the anthropometric criteria, except for their waist circumference (p > 0.05).

RESULT

In this study, the blood pressure and blood glucose levels of the patients along with their waist circumference that indicated a central obesity were specified as the determinants of microalbuminuria. While the obese patients are being evaluated in terms of proteinuria, the cutoff values of these variables can be taken into consideration.

Residual Cardiovascular Risk in Individuals on Blood Pressure-Lowering Treatment

BACKGROUND

Hypertensive individuals on blood pressure (BP)-lowering treatment with BP in the normal or high-normal range have higher cardiovascular risk than untreated persons with usual BP in the same range. This residual risk (relative and absolute) is not well quantified and may be attributable in part to the higher burden of subclinical disease in treated individuals.

METHODS AND RESULTS

We assigned 3024 Framingham Offspring Cohort participants to 5 categories based on systolic BP (SBP) and diastolic BP (DBP) and use of BP-lowering treatment: (1) untreated SBP/DBP <120/80 mm Hg; (2) untreated SBP/DB ≥120/80 to <140/90 mm Hg; (3) treated SBP/DBP <140/90 mm Hg; (4) untreated SBP/DBP ≥140/90 mm Hg; and (5) treated SBP/DBP ≥140/90 mm Hg. A composite subclinical disease score was constructed, including information on left ventricular hypertrophy, systolic dysfunction, carotid ultrasound abnormality, peripheral artery disease, and microalbuminuria. The prevalence of subclinical disease rose across BP groups, as did the event rates for incident cardiovascular disease (449 events, median follow-up of 11 years; group 1, 0.65 event per 100 person-years; group 5, 3.20 events per 100 person-years; P<0.0001 for trend). On multivariable adjustment, treated hypertensives in groups 3 and 5 had 50% (95% CI 13% to 99%) and 28% (95% CI -6% to 73%) higher hazards, respectively, of developing cardiovascular disease compared with their untreated counterparts with similar levels of BP (groups 1 and 2 and group 4, respectively). The increased risk of cardiovascular disease in treated hypertensives was attributable in part to greater subclinical disease burden.

CONCLUSIONS

Treated hypertensives have higher subclinical cardiovascular disease burden, which partly explains their higher cardiovascular disease risk compared with untreated persons with similar BP levels.

Premenopausal women have increased risk of hypertensive target organ damage compared with men of similar age

BACKGROUND

The impact of high blood pressure (BP) on target organs (TO) in premenopausal women is not well known. The purpose of this study was to describe gender differences in TO involvement in a cohort of young-to-middle-aged subjects screened for stage 1 hypertension and followed for 8.2 years.

METHODS

Participants were 175 women and 451 men with similar age (range 18-45 years). Ambulatory BP at entry was 127.5±12.5/83.7±7.2 mm Hg in women and 131.9±10.3/81.0±7.9 mm Hg in men. Ambulatory BP, albumin excretion rate (AER), and echocardiographic data (n=489) were obtained at entry, every 5 years, and before starting antihypertensive treatment.

RESULTS

Female gender was an independent predictor of final AER (p=0.01) and left ventricular mass index (LVMI) (p<0.001). At follow-up end, both microalbuminuria (13.7% vs. 6.2%, p=0.002) and left ventricular hypertrophy (LVH) (26.4% vs. 8.8%, p<0.0001) were more common among women than men. In a multivariable Cox analysis, after adjusting for age, lifestyle factors, body mass, ambulatory BP, heart rate, and parental hypertension, female gender was a significant predictor of time to development of microalbuminuria (p=0.002), with a hazard ratio (HR) of 3.06, (95% confidence interval [CI] 1.48-6.34) and of LVH (p=0.004), with an HR of 2.50 (1.33-4.70). Inclusion of systolic and diastolic BP changes over time in the models only marginally affected these associations, with HRs of 3.13 (1.50-6.55) and 3.43 (1.75-6.70), respectively.

CONCLUSIONS

These data indicate that premenopausal women have an increased risk of hypertensive TO damage (TOD) and raise the question about whether early antihypertensive treatment should be considered in these patients.

The relation between serotonin levels and insufficient blood pressure decrease during night-time in hypertensive patients

AIM

The serotonin levels in thrombocytes are decreased in hypertensive patients. The aim of our study was to investigate the relationship between serotonin levels and insufficient nocturnal blood pressure (BP) decrease (non-dipper) in hypertensive patients.

PATIENTS AND METHODS

Fifty-six hypertensive patients and 27 healthy control subjects were included in the study. Of the hypertensive patients, 28 were classified as dippers and 28 as non-dippers based on nocturnal BP drops of >10 mmHg and <10 mmHg, respectively. Thrombocyte serotonin levels, serum uric acid, and C-reactive protein (CRP), and urinary albumin/creatinine ratios were analysed. Thrombocyte serotonin levels were measured using an enzyme immunoassay.

RESULTS

The thrombocyte serotonin level was 378.9 +/- 69.5 ng/10(9) platelet in the non-dipper group, 424.7 +/- 58.6 ng/10(9) platelet in the dipper group, and 518.1 +/- 35.9 ng/10(9) platelet in the control group. Serotonin levels in the non-dipper group were significantly lower than in the dipper group. Serotonin levels negatively correlated with blood pressure (r = -0.6, p<0.001). CRP concentration in the non-dipper group was higher than in the dipper (4.8 +/- 1.4 vs 3.6 +/- 1.6, p<0.01) and control (2.4 +/- 0.9, p<0.001) groups, and microalbuminuria was significantly higher in the non-dipper group compared with dipper (24.9 +/- 8.6 vs 13.4 +/- 8.8, p<0.001) and control (9.6 +/- 4.8, p<0.001) groups. Serotonin level was negatively correlated with microalbuminuria (p<0.001, r = -0.3), uric acid (p<0.01, r = -0.3), and CRP (p<0.01, r = -0.35).

CONCLUSION

In non-dipper hypertensive patients, thrombocyte serotonin levels were significantly lower than in dipper and control groups. Serotonin levels may be related to insufficient nocturnal blood pressure decrease in hypertensive patients.

Proteinuria and clinical outcomes in hypertensive patients

This narrative review focuses on outcomes related to proteinuria in hypertension (HT), and also examines the role of current and future therapeutic strategies. Proteinuria is an independent marker of renal and cardiovascular (CV) disease in hypertensive populations, particularly in high-risk groups such as diabetic patients. Effective blood pressure (BP) control and proteinuria management are associated with significant improvements in the risk of key adverse outcomes, although a causative relationship needs careful assessment. Available antihypertensives have varying effects on proteinuria reduction. Drugs affecting the renin system offer antiproteinuric and renoprotective effects that are probably at least partially independent of their BP effects. Economic evaluations of these interventions confirm their cost-saving benefits relative to other antihypertensives, but outcomes-based research is needed in some settings.

Hypertension and microalbuminuria: the new detrimental duo

Excretion of albumin with urine (UAE) in small amounts, i.e. microalbuminuria (MAU), also referred to as "incipient nephropathy", has long been considered a marker of early nephropathy and increased cardiovascular risk in the specific setting of diabetes mellitus. However, numerous clinical studies found an association between MAU and other cardiovascular risk factors, target organ damage and risk of cardiovascular disease in clinical contexts different from diabetes and including arterial hypertension. The present article reviews the available evidence on the clinical value of MAU in subjects with primary hypertension. In these subjects, prevalence of MAU varied from about 4% to 46% across different studies and these differences may be explained by the huge intra-individual variability in UAE, discrepancies in the technique of measurement and different definitions of MAU. A direct and continuous association between UAE and blood pressure (BP) has been found in many studies. A continuous association between UAE and left ventricular mass has also been found in most studies. In contrast, it is not yet clear whether the association between UAE and other factors including age, gender, smoking, ethnicity, insulin resistance, lipids and obesity is independent or mediated by confounders, particularly BP. From a prognostic standpoint, several longitudinal studies showed an association between MAU and the risk of future cardiovascular disease. Of particular note, in some of these studies the incidence of major cardiovascular events progressively increased with UAE starting below the conventional MAU thresholds. Thus, besides being a direct risk factor for progressive renal damage, MAU can be considered a marker, which integrates and reflects the long-term level of activity of several other detrimental factors on cardiovascular system. Antihypertensive treatment reduces UAE and such effect may be detected after just a few days of treatment. Among available antihypertensive drugs, angiotensin-converting enzyme (ACE) inhibitors and the angiotensin II receptor antagonists seem to be superior to other antihypertensive drugs in reducing UAE. The dual blockade of the renin-angiotensin system with an ACE inhibitor and an angiotensin II receptor antagonist is a new and promising approach to control UAE in hypertensive patients. Determination of MAU is recommended in the initial work-up of subjects with primary hypertension.

Prevalence and Correlates of Left Ventricular Hypertrophy in the African American Study of Kidney Disease Cohort Study

African Americans with hypertensive renal disease represent a high-risk population for cardiovascular events. Although left ventricular hypertrophy is a strong predictor of adverse cardiac outcome, the prevalence and associated factors of left ventricular hypertrophy in this patient population are not well described. The African American Study of Kidney Disease Cohort Study is a prospective, observational study that is an extension of the African American Study of Kidney Disease randomized clinical trial that was conducted from 1994 to 2001 in African Americans with hypertension and mild-to-moderate renal dysfunction. Echocardiograms and 24-hour ambulatory blood pressure monitoring were performed at the baseline visit of the cohort. Of 691 patients enrolled in the cohort study, 599 patients had interpretable baseline echocardiograms and ambulatory blood pressure data. Left ventricular hypertrophy was defined using a cut point for left ventricular mass index >49.2 g/m 2.7 in men and >46.7 m/m 2.7 in women. The majority of patients had left ventricular hypertrophy (66.7% of men and 73.9% of women). In a multiple regression analysis, higher average day and nighttime systolic blood pressure, younger age, and lower predicted glomerular filtration rate were associated with left ventricular hypertrophy, but albuminuria was not. These data demonstrate a striking prevalence of left ventricular hypertrophy in the African American Study of Kidney Disease Cohort and identify potential targets for prevention and therapeutic intervention in this high-risk patient population.

Microalbuminuria, von Willebrand factor and fibrinogen levels as markers of the severity in COPD exacerbation

In COPD, the systemic effects of the disease reflect the structural and/or biochemical alterations occurring in the structures or organs other than the lungs in relation to the characteristics of the primary disease. The disorders of endothelial structures due to COPD may lead vascular pathologies, such as ischemic heart disease, stroke, to occur more commonly in those with COPD. On consideration of the fact that the vascular endothelium is a major site in which the systemic effect of the inflammation occurs, should von Willebrand Factor, a clotting factor of endothelium origin, and the plasma level of fibrinogen vary with the severity of the disease in COPD, the variability of arterial blood gas values, and the stability or exacerbation of the disease? Considering the fact that microalbuminuria is an indirect manifestation of the renal endothelial permeability and/or renal perfusion; should there be an association between microalbuminuria and the severity of COPD? Therefore, in order to assess the effect of the systemic inflammation in COPD on the vascular endothelium, we compared the levels of the plasma vWF, fibrinogen, 24-h urine microalbuminuria of those with stable COPD (33 patients) and exacerbation of COPD (26 patients) with those of the controls (16 healthy subjects). The mean age was 63.42 -/+ 10.29, 68.00 -/+ 9.77 and 59.63 -/+ 14.10 years in SCOPD, COPDAE, and CG, respectively. The level of microalbuminuria was found to increase significantly in COPDAE group, compared to that of the controls (P = 0.004). When we investigated the relation between smoking burden and microalbuminuria, vWF, fibrinogen levels, the amount of consumption and positive relationship were found significant. (r = 0.336, P = 0.003 between smoking pack-years and vWF, r = 0.403, P = 0.001 between smoking pack-years and fibrinogen, and r = 0.262, P = 0.02 between smoking pack-years and microalbuminuria). The levels of vWF and fibrinogen are AECOPD > SCOPD > CG, with the highest being in AECOPD, and the difference among the groups was statistically significant. The relationship between the level of hypoxemia and microalbuminuria, fibrinogen and vWF was found to be significant (r = -0.360, P = 0.005 between oxygen saturation and microalbuminuria, r = -0.359, P = 0.005 between the level of PaO(2) and fibrinogen, and r = -0.336, P = 0.009 between PaO(2) and vWF). In conclusion, the levels of plasma vWF, fibrinogen, and microalbuminuria may be helpful in grading the severity of COPD exacerbation. The related increase in these markers may represent a possible pathophysiological mechanism behind the increased vascular morbidity of patients with COPD and detecting indirectly the endothelial dysfunction as a manifestation of systemic outcomes due to COPD and in detecting earlier the cases in which the risk for developing the associated complications are higher. We suggest that further studies are necessary to investigate the impact of antithrombotic treatment on microalbuminuria, plasma vWF and fibrinogen as markers of endothelial dysfunction coexisting COPD exacerbation.

Inaccuracy in pediatric outpatient blood pressure measurement

OBJECTIVE

Hypertension is common in the pediatric population. There is increasing evidence for early hypertensive target organ damage that may lead to substantial long-term morbidity. Because a critical aspect of any screening program for hypertension is the ability to measure blood pressure accurately, we compared typical blood pressure measurements at a vital sign station with those that were obtained following recommendations set forth in "The Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents."

METHODS

We compared the blood pressure measurements that were obtained with standard practice vital sign station screening with those that were obtained by trained personnel in accordance with Fourth Task Force recommendations. A total of 390 children were evaluated at 580 visits to the Pediatric Hypertension Clinic at Texas Children's Hospital.

RESULTS

Seventy-four percent of the readings were higher at the vital sign station, and only 12% differed by <5 mm Hg for both systolic blood pressure and diastolic blood pressure. The mean difference between vital sign station and examination room was 13.2 +/- 8.9 mm Hg for systolic blood pressure and 9.6 +/- 7.6 mm Hg for diastolic blood pressure. Multiple regression analyses revealed that age, gender, race, obesity, first versus subsequent visit, essential versus secondary, or white coat hypertension and antihypertensive medications made no statistically significant difference in the lack of correlation of the readings.

CONCLUSION

These results suggest that if pediatricians use vital sign station screening for blood pressure, children with elevated initial measurements must be reevaluated in the examination room.

Microalbuminuria in treated hypertensives: only a mirror image of cardiovascular risk? The HUNT Study, Norway

OBJECTIVES

Microalbuminuria as an independent marker of cardiovascular morbidity and mortality in hypertensive individuals is under debate. The aim of this study was to study the possible associations between microalbuminuria on one hand and known cardiovascular risk factors and cardiovascular disease on the other hand, in a large, unselected population of treated hypertensives without diabetes.

DESIGN

Cross-sectional study.

SETTING

Participants of the HUNT Study, Norway (n = 65,258).

SUBJECTS

5,369 individuals (> or =20 years) with treated hypertension delivered three morning urine samples for microalbuminuria analysis.

MAIN OUTCOME MEASURES

Microalbuminuria expressed as albumin-to-creatinine ratio, cardiovascular risk factors and cardiovascular disease.

RESULTS

Increasing age, pulse pressure (systolic blood pressure-diastolic blood pressure), s-creatinine, cigarette pack years, cardiovascular disease, antihypertensive medication group, and years with antihypertensive medication were significantly associated with microalbuminuria in men. Increasing pulse pressure, cigarette pack years, and antihypertensive medication group were associated with microalbuminuria in women, adjusted for other cardiovascular risk factors. When excluding individuals of both sexes with self-reported cardiovascular disease and blood pressure > 160/90 mm Hg, no variable associated with cardiovascular risk factors registered was statistically associated with microalbuminuria.

CONCLUSION

The present study indicates that microalbuminuria mainly represents a mirror image of hypertension (BP > 160/90) and prior or present cardiovascular disease. We therefore question whether the treatment quality would improve if yet another risk factor, microalbuminuria, were introduced as a routine test in treated hypertensives.

[Proteinuria]

Several health organizations recommend that people be regularly checked for proteinuria to detect and treat kidney disease before it progresses. Proteinuria detected by a simple dipstick test should be confirmed by a quantitative measurement to assess persistent proteinuria. Most proteins are too big to pass through the kidneys' filters into the urine unless the kidneys are damaged. Markers of kidney damage in addition to proteinuria include abnormalities in the urine sediment, ultrasound of the kidneys and estimation of kidney function (creatinemia to calculate glomerular filtration rate). These assessments provide clues to the type (diagnosis) of chronic kidney disease and will the risk for developing progressive kidney failure. Thus, early detection of kidney disease will result in a more timely introduction of therapy that may slow the course of kidney disease. Microalbuminuria (albumin excretion above the normal range) that a marker of microvascular lesions in diabetes and hypertension is associated with a worth cardiovascular prognosis. Level of proteinuria in excess of 3,0 g/d in glomerular disease strongly determines the extent of kidney damage and renal prognosis.

Childhood hypertension is not a silent disease

Early hypertension has generally been considered to be an asymptomatic condition; however, recent data show that many hypertensive children have evidence of end organ damage. We sought to determine if a spectrum of common symptoms is associated with early hypertension and whether those symptoms resolve with lowered blood pressure. Four hundred and nine consecutive children, 7-18 years old, examined in the Texas Children's Hospital Hypertension Clinic for new-onset high blood pressure (BP) completed a questionnaire, including the self-reporting of 15 symptoms potentially attributed to high blood pressure. Subjects received anti-hypertensive treatment and repeated the questionnaire 4-6 months after initiation of therapy. One-hundred fifty healthy, normotensive children completed the questionnaire as controls. Of hypertensive children, 64% were symptomatic, compared with 26% of normotensive children (P<0.001). Fifty-one percent of hypertensive children reported 1-4 symptoms, 14% >4 symptoms. Following treatment only 28% of children remained symptomatic. The three most common symptoms in hypertensive patients, headache, 42%, difficulty initiating sleep, 27%, and daytime tiredness, 26%, were markedly reduced with treatment, to 6.2%, 1.5% and 10%, respectively (P<0.001). We conclude that newly diagnosed hypertensive children had a variety of non-specific symptoms, more prevalent than those of normotensive children, and most somatic complaints improved with 4-6 months of anti-hypertensive treatment.

Microalbuminuria in patients with previous myocardial infarction

Microalbuminuria (MA) is a cardiovascular risk factor. The aim of this study was to examine the relationship between MA and the intima-media complex of the carotid and brachial artery, endothelial function, glucose metabolism, haemostatic variables and cardiac hypertrophy in patients with coronary heart disease. A total of 123 patients, aged 31-80 years, with a history of previous myocardial infarction and without known diabetes mellitus were examined with B-mode ultrasound of common carotid and brachial arteries, flow-mediated dilatation of the brachial artery and echocardiography. A standard oral glucose tolerance test with 75 g of glucose was performed. MA was defined as excretion of 20-200 microg albumin/min. MA was present in 11% of patients. Patients with MA had significantly higher level of 2-h plasma glucose, a lower displacement of the atrioventricular plane, a thicker septum wall and a higher prevalence of impaired glucose tolerance test compared with patients with normoalbuminuria (P<0.05). Urinary albumin excretion (UAE) was significantly and positively associated with calculated intima-media area (cIMa) in both brachial and common carotid arteries as well as with age and interventricular septum thickness. In conclusion, UAE was significantly and positively associated with cIMa in both the common carotid and the brachial arteries as well as with left ventricular septum thickness and glucose intolerance in patients with a history of previous myocardial infarction without known diabetes mellitus.

Uric acid and hypertension in adolescents

Hypertension is the most common form of cardiovascular disease. Although it is less common in adolescents than in adults, hypertension and the associated organ damage can and often does begin early in life. Consequently, for many with high blood pressure (BP), measures directed at the long-term prevention of cardiovascular morbidity may need to be started in adolescence to achieve maximal effectiveness. This article discusses some of the problems unique to hypertension in the young, as well as recent discoveries regarding the likely role played by increases in serum uric acid level in the development of adolescent-onset essential hypertension.

Serum cystatin C level is a marker of end-organ damage in patients with essential hypertension

High urinary albumin excretion rate (AER) has been associated with the presence of atherosclerotic vascular damages and is an independent risk factor for all causes of death and cardiovascular morbidity and mortality in essential hypertensive patients. Serum cystatin C (s-CC) is a recently identified nonglycosylated 13-kD basic protein that has been suggested to be a useful marker of glomerular filtration rate. In the present study, we investigated the relationship between s-CC level and end-organ damages in the kidney, heart, and vessels of patients with essential hypertension. Sixty patients with essential hypertension participated in the present study. Patients with renal failure were excluded. Serum-CC level was measured by a particle-enhanced turbidimetric assay. Left ventricular mass index (LVMI) and intima media thickness (IMT) in the common carotid arteries were evaluated by ultrasound images. Twenty-four-hour blood pressure was measured by a cuff-oscillometric method. Serum-CC level was negatively correlated with creatinine clearance (r=-0.617, p<0.0001). It was also correlated with mean 24-h systolic blood pressure (24h-SBP) (r=0.308, p= 0.0167), LVMI (r=0.528, p<0.0001), and IMT (r=0.539, p<0.0001). Both AER and s-CC level were independently associated with mean 24h-SBP. AER but not s-CC level was associated with HDL-cholesterol. The present study was the first to demonstrate that s-CC level is a useful and convenient parameter of renal function, and may also prove to be an early marker of the severity of end-organ damage in patients with essential hypertension.

Microalbuminuria in diabetic and hypertensive patients and the general population--consequences of various diagnostic criteria--the Nord-Trøndelag Health Study (HUNT)

OBJECTIVE

The purpose of this paper was to study the prevalence of microalbuminuria (MA) in males and females of various ages by applying various diagnostic criteria. Three groups of subjects were studied: apparently healthy individuals; self-reported hypertensives; and diabetics.

MATERIAL AND METHODS

A total of 9255 individuals (age > or =20 years), all of whom were identified from the large (n = 65 258) population-based Nord-Trøndelag Health Study (HUNT) performed in Norway between 1995 and 1997, delivered three morning urine samples for MA analysis. Of these individuals, 651 reported both diabetes and treated hypertension, 944 diabetes only and 5547 treated hypertension only. The remaining 2113 subjects without diabetes or treated hypertension were randomly selected. The albumin:creatinine ratio (ACR) was used as an expression of urine albumin excretion.

RESULTS

Applying the classical definition of MA of ACR > or =2.5 mg/mmol in at least two out of three urine samples, the prevalence of MA in those with both diabetes and hypertension was 42.2% in males and 25.9% in females; corresponding values for those with diabetes only were 27.8% and 22.4%, for the hypertensives 19.3% and 11.5% and for the randomly selected sample 5.2% and 4.7%. The prevalence of MA increased strongly with increasing age for both genders in all subgroups. The prevalence of MA changed considerably when applying different cut-off values of ACR and at least one, two or three urine samples with ACRs above the cut-off value.

CONCLUSIONS

This study, one of the largest cross-sectional screening studies of MA ever performed, clearly illustrates the consequences of applying different diagnostic criteria. The optimal cut-off levels of MA for the prediction of cardiovascular disease still remain to be properly defined, and more follow-up studies are therefore needed.

Microalbuminuria and all-cause mortality in treated hypertensive individuals: does sex matter? The Nord-Trøndelag Health Study (HUNT), Norway

BACKGROUND

In hypertensive individuals, few prospective studies are available in which the association between microalbuminuria (MA) and all-cause mortality in the 2 sexes have been studied within the same population.

METHODS AND RESULTS

We conducted a 4.3-year follow-up of 2307 men and 3062 women (> or =20 years old) with self-reported treated hypertension, all identified in the Nord-Trøndelag Health Study (HUNT), Norway, 1995 to 1997 (n=65 258). The main outcome measures were relative risk (RR) of all-cause mortality according to increasing albuminuria, defined at different levels of albumin-to-creatinine ratio (ACR). There was a consistent positive association between increasing ACR and all-cause mortality in men. The adjusted RR for ACR in the fourth quartile (> or =1.70 mg/mmol) was 1.6 (95% CI, 1.0 to 2.6), compared with ACR in the first quartile (<0.55 mg/mmol). The corresponding RR in women was 1.5 (95% CI, 0.8 to 3.1). We found a positive association between mortality and increasing number of urine samples with ACR above different cutoff levels, especially in men. In 3 urine samples, the lowest ACR level associated with mortality in men was 0.86 mg/mmol, RR 1.6 (95% CI, 1.1 to 2.4). The sex differences persisted after exclusion of those who died during the first year of follow-up, those with hypertension not treated optimally, and those with known cardiovascular disease.

CONCLUSIONS

The association between ACR and all-cause mortality was stronger in treated hypertensive men than in women. The persistent sex differences indicate that hypertensive women tolerate MA better than men and that MA in women should be interpreted differently than in men.

Hyperuricemia in childhood primary hypertension

Experimental animal models suggest that uric acid might have a pathogenic role in the early development of primary hypertension. We hypothesized that serum uric acid is correlated with blood pressure in children with new-onset, untreated, primary hypertension. We evaluated 125 consecutive children referred to the Baylor Pediatric Renal Program for evaluation of hypertension. None of the subjects had previously been evaluated or treated for hypertension. The children ranged in age from 6 to 18 years (mean, 13.4+/-3.3) and had normal renal function (creatinine clearance >80 mL x min(-1) x 1.73 m(-2)). Sixty-three children had primary hypertension, 40 had secondary hypertension, and 22 had white-coat hypertension. Forty controls with normal blood pressure were recruited from the renal clinic. Uric acid levels were directly correlated with systolic (r=0.80, P=0.0002) and diastolic (r=0.66, P=0.0006) blood pressure in controls and in subjects with primary hypertension and were independent of renal function. Serum uric acid concentrations >5.5 mg/dL were found in 89% of subjects with primary hypertension, in 30% with secondary hypertension, in 0% with white-coat hypertension, and in 0% of controls. We conclude that serum uric acid is directly correlated with blood pressure in untreated children and that a serum uric acid value >5.5 mg/dL in an adolescent being evaluated for hypertension strongly suggests primary hypertension as opposed to white-coat or secondary hypertension. These results are consistent with the hypothesis that uric acid might have a role in the early pathogenesis of primary hypertension.

Microalbuminuria in hypertension

A body of evidence indicates that microalbuminuria is a well-recognized marker of cardiovascular complications and increased cardiovascular risk in hypertension. However, the prognostic significance of microalbuminuria remains controversial because only the results of a few prospective studies performed in small groups of hypertensive subjects without diabetes mellitus are available. Several factors can affect the prevalence of microalbuminuria in hypertension including age, sex, race, severity of the disease, and concomitant risk factors. This accounts for the large differences in the prevalence of microalbuminuria that can be found in the literature, with prevalence rates going from a low of 4.7% to a high of 46%. The main determinant of albumin excretion rate in subjects with mild hypertension and no cardiovascular complications seems to be the hemodynamic load, whereas in subjects with more severe hypertension and associated target organ damage, the augmented urinary albumin leak is probably the consequence of glomerular damage. Inhibition of the renin-angiotensin system with angiotensin-converting enzyme inhibitors or angiotensin II receptor antagonists is particularly effective at reducing the albumin excretion rate, but whether these classes of drugs are more beneficial in patients with microalbuminuria remains to be determined. There is general consensus that evaluation of microalbuminuria is useful for the assessment of overall cardiovascular risk in hypertension, since albumin excretion rate appears to be a cost-effective way to identify patients at higher risk for whom additional preventive and therapeutic measures are advisable.

Association between Left Ventricular Diastolic Dysfunction and Renal Hemodynamic Change in Patients with Treated Essential Hypertension

The heart and kidneys are important target organs in hypertension. Early signs of hypertensive target organ damage can be detected by evaluating left ventricular (LV) diastolic function and intrarenal hemodynamics using Doppler ultrasonography. However, it has not been sufficiently clarified whether cardiac damage and renal impairment progress in parallel, especially from the early stage. In the present study, Doppler echocardiography and renal Doppler ultrasonography were performed in 99 patients with treated essential hypertension, and LV diastolic filling parameters, ie., the velocity ratio of atrial filling to early diastolic filling (A/E), and the deceleration time of the E wave (DcT) and renal Doppler parameters, i.e., the diastolic to systolic ratio (D/S) and resistance index (RI), were determined. D/S was negatively correlated and RI was positively correlated with A/E and DcT. These cardiac and renal Doppler parameters were also associated with age, diastolic blood pressure, creatinine clearance, and/or glucose levels. By multiple regression analysis, D/S was found to have a significant association with DcT, independent of other clinical parameters, including age. In subgroup analysis in which patients were divided by their glucose tolerance, a significant correlation between renal Doppler parameters and LV diastolic function was observed in subjects with normal glucose tolerance, but this correlation disappeared in those with impaired glucose tolerance and diabetes mellitus. The present findings show that there is a significant relation between LV diastolic function and renal Doppler parameters in treated hypertensive patients, and suggest that cardiac damage progresses in parallel with renal involvement in these patients from the early stage.

Microalbuminuria, cardiovascular, and renal risk in primary hypertension

Microalbuminuria is defined as abnormal urinary excretion of albumin between 30 and 300 mg/d. It can be measured accurately by several widely available and sensitive methods. This abnormality can be found in 8 to 15% of nondiabetic patients with primary hypertension, although its prevalence varies greatly in the literature, likely due to differences in the methods used to detect it and to the criteria applied in the selection of patients. The pathogenetic mechanisms leading to the development of microalbuminuria are still not completely known. BP load and increased systemic vascular permeability, possibly due to early endothelial damage, seem to play a major role. Increased urinary albumin excretion has been associated with several unfavorable metabolic and nonmetabolic risk factors and subclinical hypertensive organ damage. In fact, a higher prevalence of concentric left ventricular hypertrophy and subclinical impairment of left ventricular performance, as well as the presence of carotid atherosclerosis, have been reported in patients with microalbuminuria. These associations might per se justify a greater incidence of cardiovascular events. Long-term longitudinal studies have recently confirmed the unfavorable prognostic significance of microalbuminuria in hypertensive patients. It has also been hypothesized that microalbuminuria might be a forerunner of overt renal damage in primary hypertension. Clinical studies, however, have shown conflicting results, and this hypothesis has to be considered tempting but speculative at present. In conclusion, microalbuminuria is a specific, integrated marker of cardiovascular risk and target organ damage in primary hypertension and one that is suitable for identifying patients at higher global risk. A wider use of this test in the diagnostic work-up of hypertensive patients is recommended.

Microalbuminuria, cardiovascular disease and risk factors in a nondiabetic/nonhypertensive population. The Nord-Trøndelag Health Study (HUNT, 1995-97), Norway

OBJECTIVE

Microalbuminuria (MA) as an independent marker of cardiovascular morbidity and mortality in nondiabetic/nonhypertensive individuals is under international debate. The aim of this study was to investigate the associations between MA and known cardiovascular risk factors/markers and disease in a randomly selected nondiabetic/nonhypertensive sample.

DESIGN

Cross-sectional study.

SETTING

Participants in the population-based Nord-Trøndelag Health Study (HUNT), Norway (n = 65 258).

SUBJECTS

A total of 2113 individuals (> or =20 years), randomly selected without diabetes and treated hypertension, delivered three morning urine samples for MA analysis.

MAIN OUTCOME MEASURES

MA expressed as albumin-to-creatinine ratio (ACR), cardiovascular risk factors and disease.

RESULTS

Increasing age, pulse pressure, systolic (SBP) and diastolic blood pressure (DBP) and coronary heart disease (CHD) significantly predicted MA in men and increasing pulse pressure, SBP and DBP were associated with MA in women, adjusted for other cardiovascular risk factors/markers. After excluding individuals with known CHD and untreated hypertension (SBP > or = 140 mmHg, DBP > or = 90 mmHg) and hence a high total risk of cardiovascular disease (CVD), only increasing age was associated with ACR in men and increasing SBP and pulse pressure in women. Smoking, elevated lipid and glucose levels were strongly associated with MA in individuals with a high total risk of CVD than in individuals with a low total risk.

CONCLUSION

MA was associated with increasing blood pressure in both genders, age and CHD in men. Other cardiovascular risk factors/markers might be more influential in predicting ACR variation in nondiabetic/nonhypertensive individuals with a high total risk of CVD than in individuals with a low total risk.

Risk factors for microalbuminuria in children with sickle cell anemia

PURPOSE

To determine the prevalence of microalbuminuria and to establish clinical characteristics associated with microalbuminuria in children with sickle cell anemia.

PATIENTS AND METHODS

Urine samples of all children (homozygous SS) followed in the Medical College of Georgia's Children's Medical Center Sickle Cell Clinic were screened for microalbuminuria. Random samples were obtained from continent patients at routine office visits between September 1996 and November 1999. A retrospective chart survey was performed to determine clinical correlates for microalbuminuria. Medical records were reviewed for age, sex, hemoglobin, and episodes of pneumonia, pain, aplasia, acute chest syndrome, priapism, and avascular necrosis. Demographic and clinical variables were compared with microalbuminuria by univariate and multivariate logistic regression.

RESULTS

One hundred forty-two patients ages 21 months to 20 years made up the study group. The prevalence of microalbuminuria was 19%. Both increasing age and a lower hemoglobin level were found to correlate with microalbuminuria. By multivariate analysis, boys with microalbuminuria were likely to have a lower hemoglobin level and girls with microalbuminuria were likely to be older. None of the following factors were significantly related to microalbuminuria: pain, pneumonia, acute chest syndrome, priapism, avascular necrosis, or aplastic episodes.

CONCLUSIONS

Microalbuminuria is strongly and directly related to age and strongly and inversely related to hemoglobin levels. Identification of risk factors for microalbuminuria may allow earlier intervention to prevent renal complications in patients with sickle cell disease.

A blood pressure independent association between glomerular albumin leakage and electrocardiographic left ventricular hypertrophy. The LIFE Study. Losartan Intervention For Endpoint reduction

In the Losartan Intervention For Endpoint reduction (LIFE) study left ventricular (LV) hypertrophy was associated with increased urine albumin/creatinine ratio (UACR) at baseline. To evaluate whether this association was due only to parallel blood pressure (BP)-induced changes we re-examined the patients after 1 year of antihypertensive treatment to investigate whether changes in LV hypertrophy and UACR were related independently of changes in BP. In 7,142 hypertensive patients included in the LIFE study, we measured UACR, LV hypertrophy by electrocardiography, plasma glucose and BP after 2 weeks of placebo treatment and again after 1 year of antihypertensive treatment with either an atenolol or a losartan based regime. At baseline and still after 1 year of treatment logUACR (R = 0.28, P < 0.001) was still correlated to LV hypertrophy (beta = 0.05) assessed by ECG independently of systolic BP (beta = 0.16), plasma glucose (beta = 0.19) and age (beta = 0.08). Change in logUACR (R = 0.19, P < 0.001) during treatment was correlated to change in LV hypertrophy (beta = 0.10) independently of reduction in systolic BP (beta = 0.13) and change in plasma glucose (beta = 0.06). After 1 year of antihypertensive treatment UACR was still related to LV hypertrophy independently of systolic BP, and the reduction in UACR during that first year of treatment was related to regression of LV hypertrophy independently of reduction in systolic BP. This suggests that the relationship between LV hypertrophy and glomerular albumin leakage is not just due to parallel BP-induced changes. As glomerular albumin leakage may represent generalised vascular damage we hypothesise a vascular relationship between cardiac and glomerular damage.

Microalbuminuria identifies overall cardiovascular risk in essential hypertension: an artificial neural network-based approach

BACKGROUND

Ultrasound (US) examination of heart and carotid arteries provides an accurate assessment of target organ damage (TOD) and may influence the stratification of the absolute cardiovascular risk profile. Microalbuminuria has recently proved to be a useful cost-effective marker of increased cardiovascular risk but is still too often neglected in clinical practice.

OBJECTIVE

To evaluate how well artificial neural networks (ANNs) predict cardiovascular risk stratification by means of routine data and urinary albumin excretion, as compared to prediction by the clinical work-up suggested by the International Society of Hypertension (ISH), with and without ultrasound-determined TOD.

METHODS

A group of 346 never previously treated essential hypertensives (212 men, 134 women, mean age 47 +/- 9 years) was studied. Risk was stratified according to the criteria suggested by the 1999 WHO/ISH guidelines; first, by routine procedures alone, and subsequently by reassessment, using data on cardiac and vascular structures obtained by US evaluation. The ANN was trained and tested to predict the overall cardiovascular risk on the basis of routine clinical data and urinary albumin excretion (UAE). The impact of these three approaches on the determination of cardiovascular risk profile was evaluated.

RESULTS

According to the first classification, 5.5% (n = 19) of patients were considered at low risk, 47.3% (n = 164) at medium, 26.7% (n = 92) at high and 20.6% (n = 71) at very high risk. A marked change in risk stratification, namely an increase in the prevalence of high- and very-high-risk patients (2.3% low, 29.8% medium, 42.8% high and 25.2% very high risk; chi(2) 15.201, P < 0.0001), was obtained when US examination of TOD was taken into consideration. On the basis of routine clinical data and UAE, the artificial neural network successfully predicted overall cardiovascular risk and allocated patients in different classes as accurately as the US-based evaluation.

CONCLUSIONS

The use of US techniques allows a more precise stratification of absolute cardiovascular risk in hypertensive patients as compared to routine clinical data. An ANN can accurately identify the patients' risk status by using low-cost routine data and UAE. These results further emphasize the value of UAE in the stratification of cardiovascular risk.

Relationship between microalbuminuria and cardiac structural changes in mild hypertensive patients

The aim of this study was to determine the relationship between urinary albumin excretion (UAE), cardiac structural changes upon echocardiography and 24-h ambulatory blood pressure (ABPM) levels. Twenty mild hypertensive patients (mean age 56.8 +/- 9.6 years) were evaluated. After 2 weeks of a washout period of all antihypertensive drugs, all patients underwent an echocardiographic evaluation, a 24-h ABPM and an overnight urine collection. Systolic and diastolic blood pressure during 24-h ABPM was 145 +/- 14/91 +/- 10 mmHg (daytime) and 130 +/- 14/76 +/- 8 mmHg (nighttime), respectively. Seven (35%) patients presented UAE > or = 15 microg/min, and for the whole group, the geometric mean value for UAE was 10.2 x// 3.86 microg/min. Cardiac measurements showed mean values of interventricular septum thickness (IVS) of 11 +/- 2.3 mm, left ventricular posterior wall thickness (PWT) of 10 +/- 2.0 mm, left ventricular mass (LVM) of 165 +/- 52 g, and left ventricular mass index (LVMI) of 99 +/- 31 g/m2. A forward stepwise regression model indicated that blood pressure levels did not influence UAE. Significant correlations were observed between UAE and cardiac structural parameters such as IVS (r = 0.71, P<0.001), PWT (r = 0.64, P<0.005), LVM (r = 0.65, P<0.005) and LVMI (r = 0.57, P<0.01). Compared with normoalbuminuric patients, those who had microalbuminuria presented higher values of all cardiac parameters measured. The predictive positive and negative values of UAE > or = 15 microg/min for the presence of geometric cardiac abnormalities were 75 and 91.6%. These data indicate that microalbuminuria in essential hypertension represents an early marker of cardiac structural damage.

Microalbuminuria in the US population: third National Health and Nutrition Examination Survey

Microalbuminuria (MA) is associated with adverse health outcomes in diabetic and hypertensive adults. The prevalence and clinical significance of MA in nondiabetic populations is less clear. The purpose of this study was to generate national estimates of the prevalence of MA in the US population. Untimed urinary albumin concentrations (UACs) and creatinine concentrations were evaluated in a nationally representative sample of 22,244 participants aged 6 years and older. Persons with hematuria and menstruating or pregnant women were excluded from analysis. The percent prevalence of clinical proteinuria (UAC > or = 300 mg/L) was similar for males and females. However, the prevalence of MA (urinary albumin-creatinine ratio [ACR], 30 to 299 mg/g) was significantly lower in males (6.1%) compared with females (9.7%). MA prevalence was greater in children than young adults and increased continuously starting at 40 years of age. MA prevalence was greater in non-Hispanic blacks and Mexican Americans aged 40 to 79 years compared with similar-aged non-Hispanic whites. MA prevalence was 28.8% in persons with previously diagnosed diabetes, 16.0% in those with hypertension, and 5.1% in those without diabetes, hypertension, cardiovascular disease, or elevated serum creatinine levels. In adults aged 40+ years, after excluding persons with clinical proteinuria, albuminuria (defined as ACR > or = 30 mg/g) was independently associated with older age, non-Hispanic black and Mexican American ethnicity, diabetes, hypertension, and elevated serum creatinine concentration. MA is common, even among persons without diabetes or hypertension. Age, sex, race/ethnicity, and concomitant disease contribute to the variability of MA prevalence estimates.

Microalbuminuria, an integrated marker of cardiovascular risk in essential hypertension

This paper reviews the existing epidemiological and clinical evidence about the relationships of non-diabetic microalbuminuria with cardiovascular risk factors such as elevated blood pressure (BP), systolic particularly, cardiac hypertrophy, adverse metabolic status, smoking habits, elevated angiotensin II levels, endothelial dysfunction, acute and perhaps subclinical inflammation. Because of that unique property of reflecting the influence of so many clinically relevant parameters, microalbuminuria may legitimately be defined as an integrated marker of cardiovascular risk, an unique profile among the several prognostic predictors available to stratify risk in hypertensive patients. Recent cohort studies also showed associations with cardiovascular morbidity and mortality independently from conventional atherogenic factors. This behaviour, whose understanding still needs further elucidation, suggests to measure albuminuria and to screen patients at a higher absolute risk in whom preventive treatment is expected to be more beneficial than in those with a lower absolute risk.

Non-diabetic microalbuminuria, endothelial dysfunction and cardiovascular disease

Subclinical increases in albuminuria (microalbuminuria) predict morbid events, but the reasons for that are still not understood in full. This paper reviews the existing evidence regarding the relationships of non-diabetic microalbuminuria and cardiovascular disease, the underlying assumption being that endothelial dysfunction contributes both to atherosclerotic macrovascular disease and renal microvascular disease of which albuminuria is a marker. Much data support that concept, and suggest a preferential link with endothelial activation in response to acute and subclinical inflammatory stimulation, although further studies are needed to establish the exact cause-effect mechanisms. Epidemiological studies also show associations with cardiovascular events, and some recent prospective results also indicate the power of microalbuminuria to predict risk independently from conventional atherogenic factors. Thus, microalbuminuria might be considered as an integrated marker of cardiovascular risk sensitive to systemic vascular status in addition to other parameters such as blood pressure levels, glucose metabolism, smoking habits, a profile rather unique among the prognostic predictors available to stratify risk in hypertensive patients.

Spot urinary albumin-creatinine ratio predicts left ventricular hypertrophy in young hypertensive African-American men

Hypertensive patients with target organ damage are at increased cardiovascular risk, and should be treated most aggressively. The association between urinary albumin excretion and left ventricular hypertrophy (LVH) in prior studies is inconsistent, and has not been described using a single, random spot urine specimen. Therefore, we evaluated the association between the urinary albumin creatinine ratio (ACR) and left ventricular (LV) mass and also tested the hypothesis that a simple random, single-void urine ACR would identify high risk young, hypertensive, African-American men. We measured echocardiographic LV mass and a random spot urinary ACR in 109 untreated, hypertensive, young, inner city, African-American men. The mean age was 41 +/- 6 years and the mean blood pressure (BP) was 157 +/- 19/107 +/- 13 mm Hg. Microalbuminuria (ACR 30 to 300 mg/g) was present in 22% of subjects. The ACR is higher in the men with LVH than in the men without LVH (P < .05). Increased ACR is a predictor of increased LV mass index (P < .003) using multiple linear regression. An ACR >30 mg/g has a sensitivity of 33% and a specificity of 82% for the diagnosis of echocardiographic LVH. In conclusion, elevated random spot ACR is a marker of increased LV mass, independent of BP, in young urban African-American men with hypertension, and may help to determine the aggressiveness of antihypertensive therapy in this high-risk group.

Hypertension

The current JNC-VI criteria for diagnosis and classification of hypertension are discussed. The laboratory evaluation of both essential and secondary hypertension is examined, and recommendations are made in this regard. Finally, the complications and treatment of essential hypertension and the causes and management of resistant hypertension are discussed.

Low wall shear stress in carotid arteries in subjects with left ventricular hypertrophy

Left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular complications including atherosclerosis. The close linkage between LVH and carotid atherosclerosis has been the focus of much research. However, the underlying mechanism linking the two conditions is not fully understood. Low wall shear stress contributes to intimal thickening and atherosclerosis development as a local mechanism. In the present study, we investigated the relationship between wall shear stress and LVH in subjects with risk factors for atherosclerosis. Eighty subjects with at least one risk factor for atherosclerosis; ie, hypertension, diabetes mellitus, hyperlipidemia, or smoking, were enrolled. Intimal-medial thickness (IMT), number of plaques, internal dimensions, and blood flow velocity in the common carotid artery were evaluated. Wall shear stress was calculated using a Poiseuillean parabolic model of velocity distribution: shear stress = 4 x blood viscosity x central flow velocity/internal dimension. Subjects were divided into two groups; LVH(-) (n = 36) and LVH(+) (n = 44), according to their left ventricular mass index (LVMI). Mean shear stress and systolic peak shear stress were significantly lower in subjects with LVH compared with subjects without LVH. Furthermore, mean shear stress (r = -0.42, P < .0001) and peak shear stress (r = -0.31, P < 0.01) were significantly inversely related to LVMI. Stepwise regression analysis revealed that wall shear stress independently correlated with LVMI as well as IMT. These results indicate that low shear stress could function as a local factor in the development of atherosclerosis in subjects with LVH.

Clinical value of microalbuminuria in hypertension

Microalbuminuria (MA) is a well recognized marker of cardiovascular complications in hypertension, but whether MA can predict adverse outcome in this clinical condition is still a subject for debate. The fact that in hypertensive cohorts those patients who showed an increase in albumin excretion rate also manifested an increased incidence of morbid events indicates that the presence of MA in hypertension may carry an increased cardiovascular risk. However, the prognostic significance of MA remains controversial because no results of prospective studies performed in hypertensive subjects without diabetes mellitus are available. Several factors can affect the prevalence of MA in hypertension, including severity of the disease, selection procedures, concomitant risk factors, degree of obesity, age, and sex distribution. This accounts for the large differences in the prevalence of MA that can be found in the literature, with prevalence rates going from a low of 4.7% to a high of 40%. There is still conflict over whether MA in hypertension is due to increased intraglomerular pressure or to glomerular damage. The data from the literature suggest that in subjects with mild hypertension the main determinant of albumin excretion rate is the haemodynamic load. In subjects with more severe hypertension and hypertensive complications, the augmented urinary albumin leak is probably the consequence of a systemic microvascular disturbance which involves the glomeruli. In this respect, the insulin resistance state often associated to high blood pressure appears as one of the main pathogenetic factors. Whether management of hypertensive populations may be improved by monitoring of albumin excretion rate and whether antihypertensive drugs which are more effective in decreasing urinary albumin can be more beneficial in patients with MA remains to be determined.