Microalbuminuria in essential hypertension: significance, pathophysiology, and therapeutic implications

Factors affecting serum PFAS concentrations among US females with surgically and naturally induced menopause: data from NHANES 2003-2018

Sex hormones influence excretion of the biopersistent per-and polyfluoroalkyl substances (PFAS) in rodents, but such influences in human studies are less clear. Data from National Health and Nutrition Examination Survey (NHANES) for 2003-2018 for US females aged ≥ 20 years who reported having hysterectomy (HYST, N=1064) and who reported being in natural menopause (MENOP, N=1505) were analyzed for associations of ever use of birth control pills, past pregnancies, live births, and other factors with serum concentrations of six per- and polyfluoroalkyl substances (PFAS). For both HYST and MENOP, PFAS concentrations computed as adjusted geometric means (AGM) were higher among those who took female replacement hormone therapy (HRT) compared to nonusers in multivariable adjusted models, for example PFOS in HRT takers (10.70 ng/mL; 95% C.I. 9.46-12.11) vs. 8.70 ng/mL (95% C.I. 8.07-9.37) in nonusers (p<0.01), and PFOA in HRT users was 2.85 ng/mL (95% C.I. 2.53-3.21) vs. 2.44 ng/mL (95% C.I. 2.32-2.36) in nonusers (p=0.01), with similar findings across race/ethnicity stratifications. HYST participants with retained ovaries sometimes had higher serum PFAS than those without ovaries in post-HYST participants not taking HRT, but results had overlapping confidence intervals in all cases and were inconsistent. PFASs were inversely associated with obesity and directly associated with higher SES as reflected in poverty income ratio (PIR) in most cases, yet HRT results for the entire population are robust to adjustments for obesity and PIR. The results suggest the hypothesis that exogenous hormone use, and specifically estrogen hormones, are associated with higher serum PFAS in postmenopausal women. We discuss potential explanations for the findings, including data from other populations that estrogens may delay the onset of kidney disease, a finding which might paradoxically increase serum PFAS among the HRT population to explain some or all of our findings in a menopausal population.

Impact of hypertension and diabetes on the onset of chronic kidney disease in a general Japanese population

Hypertension (HT) and diabetes mellitus (DM) are both major risk factors for chronic kidney disease (CKD); however, few studies have examined the impacts of the combination of HT and DM on CKD development in general populations. We aimed to explore whether HT or DM contributes more to CKD development in a Japanese community. A total of 5823 individuals without a history of CKD who underwent specific health checkups in fiscal year 2013 were monitored until the end of March 2018. Participants were categorized as having neither HT nor DM (none group), either HT or DM, and both (HT + DM). We calculated the hazard ratios (HRs) for developing CKD in each category using Cox proportional hazards models after adjusting for age, dyslipidemia, smoking, and alcohol drinking and with the none group as the reference. We also estimated the population attributable fraction (PAF) for CKD development in populations with either HT or DM or both. During a mean follow-up of 3.0 years, 759 individuals developed CKD, with HRs of 1.56 with a 95% confidence interval (CI) [1.33, 1.83], 1.22 with a 95% CI [0.86, 1.75], and 2.83 with a 95% CI [2.22, 3.63] for the HT only, DM only and HT + DM categories, respectively. Sex-specific analysis showed similar findings. The PAFs for CKD (14.1% and 17.2% for men and women, respectively) were the highest among participants with HT only. We concluded that in this Japanese community, HT contributed more than DM to CKD development; hence, managing hypertension is important to prevent CKD as well as diabetes.

Modulation Effects of Eugenol on Nephrotoxicity Triggered by Silver Nanoparticles in Adult Rats

The use of silver nanoparticles (AgNPs) is expanding. This study evaluates the modulator effect of eugenol (Eug) on AgNP-induced nephrotoxicity in rats. Sixty male rats were separated into six groups: control, Eug, AgNPs low-dose, AgNPs high-dose, Eug + AgNPs low-dose, and Eug + AgNPs high-dose. After 30 days, kidney function, antioxidative and proinflammatory status, histopathological, histomorphometrical, and immunohistochemical assessments were performed. AgNPs markedly induced oxidative stress in renal tissues, characterized by increased levels of blood urea nitrogen, creatinine, uric acid, kidney injury molecule-1, the total oxidant capacity, malondialdehyde, tumor necrosis factor-alpha (TNF-α), and interleukin-6, as well as decreased levels of the total antioxidant capacity, superoxide dismutase, catalase, reduced glutathione, and glutathione peroxidase. Moreover, the normal renal architecture was destroyed, and the thickness of the renal capsules, cortex, and medulla, alongside the diameter and quantity of the normal Malpighian corpuscles and the proximal and distal convoluted tubules were decreased. Immunoreactivity for P53, caspase-3, and TNF-α reactive proteins were significantly increased; however, Bcl-2 immunoreactivity was decreased. Eug reversed most biochemical, histological, histomorphometrical, and immunohistochemical changes in AgNP-treated animals. This study demonstrated that nephrotoxicity in AgNP-treated rats was mitigated by an Eug supplementation. Eug's antioxidant, antiapoptotic, and anti-inflammatory capabilities were the key in modulating AgNPs nephrotoxicity.

Chronic kidney disease and associated factors among adult population in Southwest Ethiopia

In Ethiopia, data on the burden and determinants of chronic kidney disease (CKD) in the general population is limited. This community-based study was conducted to assess the burden and associated factors of CKD among adults in Southwest Ethiopia. The study was conducted from August 23, 2018-October 16, 2018. Study participants were selected using a random sampling method. A structured questionnaire was used to collect relevant data. Blood pressure and anthropometric indices were measured following standard procedures. About 5 ml of urine sample was collected and the dipstick test was performed immediately. A blood sample of 3-5ml was collected for serum creatinine and blood glucose level determination. The three commonest estimators of glomerular filtration rate and the National Kidney Foundation Kidney Disease Outcomes Quality Initiative were used to define and stage CKD. Data were analyzed using SPSS 21. Multivariable logistic regression was employed and p-value <0.05 was used to indicate statistically significant results. A total of 326 participants with a mean age of 39.9(SD±11.2) years were enrolled in the study. The proportions of female participants (59.8%) were relatively higher than male participants (40.2%). The mean eGFR using CKD-EPI, CG and MDRD was 124.34 (SD±23.8) mL/min/1.73m², 110.67(SD±33.0) mL/min/1.73m² and 131.29 (SD±32.5) mL/min/1.73m² respectively. The prevalence of CKD was 7.4% using CKD-EPI & MDRD and 8% using CG. Similar finding using CKD-EPI & MDRD may indicate that either CKD-EPI or MDRD can be used to estimate GFR in this study area. In the age and sex-adjusted logistic regression model, hypertension was significantly associated with CKD using CKD-EPI & MDRD and age ≥40 years old was significantly associated with CKD using CG. Behavioral characteristics and other traditional risk factors were not significantly associated with CKD in the current study. The prevalence of CKD was high in the study area. Only hypertension and age ≥40 years old were significantly associated with CKD. More of the increased prevalence of CKD in the current study remained unexplained and deserves further study.

Association of microalbuminuria with metabolic syndrome: a cross-sectional study in Bangladesh

BACKGROUND AND AIMS

The objectives of this study were to estimate the prevalence of microalbuminuria and examine the association of microalbuminuria with metabolic syndrome (MetS) and its component in a Bangladeshi adult cohort.

METHODS

This cross-sectional study included 175 subjects (84 males and 91 females; aged 19-59 years), recruited from the outdoor Department of Medicine and Endocrinology of a medical college hospital in Dhaka, Bangladesh. Lipid profile and fasting blood glucose (FBG) were measured in serum and albumin and creatinine were determined in urine samples. Microalbuminuria was defined as the urinary albumin-to-creatinine ratio (ACR) of 30 to 300 mg/g. The MetS was defined according to the criteria of the National Cholesterol Education Program (NECP). The association of microalbuminuria with MetS and its components was evaluated by multivariate logistic regression analysis.

RESULTS

Among the study subjects, 66.3% were hypertensive and 70.3% were diabetic individuals. Overall, the prevalence of microalbuminuria was 29.7% with 31% in males and 28.6% in females. Microalbuminuria was 2.6 fold higher in hypertensive and diabetic adults than in the non-hypertensive or non-diabetic adults. The prevalence of microalbuminuria was much more frequent in persons with the MetS (36.0%) than the persons without the MetS (5.4%). The levels of FBG, systolic blood pressure (SBP), diastolic blood pressure (DBP) and triglycerides were significantly higher (p < 0.01 for all cases) in subjects with microalbuminuria. In regression analysis, after adjusting for sex, age, and body mass index, microalbuminuria was strongly correlated with MetS followed by elevated BP and FBG (p < 0.01 for all cases).

CONCLUSIONS

Microalbuminuria was strongly associated with MetS in Bangladeshi adults. Elevated BP and FBG were the most predominant components of MetS among the study subjects. Comprehensive management of MetS at its early stage can be effective to prevent and reduce the progression of kidney injury and cardiovascular complications.

Past Sodium Intake, Contemporary Sodium Intake, and Cardiometabolic Health in Southwest Coastal Bangladesh

Background We compared the relationship of past and contemporary sodium (Na) intake with cardiometabolic biomarkers. Methods and Results A total of 1191 participants' data from a randomized controlled trial in coastal Bangladesh were analyzed. Participants provided 24-hour urine Na (24UNa) data for 5 monthly visits. Their fasting blood glucose, total cholesterol, triglycerides, high-density lipoprotein, blood pressure, and 24-hour urine protein were measured at the fifth visit. Participants' mean 24UNa over the first 4 visits was the past Na, and 24UNa of the fifth visit was the contemporary Na intake. We estimated the prevalence ratios of elevated cardiometabolic biomarkers and metabolic syndrome across 24UNa tertiles by multilevel logistic regression using participant-, household-, and community-level random intercepts. Models were adjusted for age, sex, body mass index, smoking, physical activity, alcohol consumption, sleep hours, religion, and household wealth. Compared with participants in tertile 1 of past urine Na, those in tertile 3 had 1.46 (95% CI, 1.08-1.99) times higher prevalence of prediabetes or diabetes mellitus, 5.49 (95% CI, 2.73-11.01) times higher prevalence of large waist circumference, and 1.60 (95% CI, 1.04-2.46) times higher prevalence of metabolic syndrome. Compared with participants in tertile 1 of contemporary urine Na, those in tertile 3 had 1.93 (95% CI, 1.24-3.00) times higher prevalence of prediabetes or diabetes mellitus, 3.14 (95% CI, 1.45-6.83) times higher prevalence of proteinuria, and 2.23 (95% CI, 1.34-3.71) times higher prevalence of large waist circumference. Conclusions Both past and contemporary Na intakes were associated with higher cardiometabolic disease risk.

Association of High Levels of Spot Urine Protein with High Blood Pressure, Mean Arterial Pressure and Pulse Pressure with the Development of Diabetic Chronic Kidney Dysfunction or Failure among Diabetic Patients. Statistical Regression Modeling to Predict Diabetic Proteinuria

INTRODUCTION

In research elevated Blood Pressure (BP) has been demonstrated to be a risk for the development of nephropathy and chronic renal disease (CKD) Or Diabetic Kidney Disease (DKD) among diabetics. However, no study has find correlation for the spot urine protein (UPr) excretion with elevated BP, Pulse Pressure (PP) and mean arterial pressure MAP). This technique was invented in the current study.

METHODS

10,270 were recruited for more than 12 years. Demographically, 43%, 38%, and 16% showed hypertension, nephropathy and chronic renal disease, respectively. UPr demonstrated significant correlations with systolic BP (SBP) and diastolic BP (DPB), MAP and PP (p < 0.0001 for all). SBP, DBP, PP and MAP, UPr were observed to be higher among the groups with nephroaphty and CKD/DKD with highly significant p-values (all p < 0.05). With logistic regression, odds ratio of hypertension (HTN) with nephropathy was observed to be 2.99 (95% CI 2.44 to 3.7; p < 0.0001); and odds ratio of HTN with CKD/DK was 7.1 (95% CI 4.3 to 11.84; p<0.0001), indicating that HTN significantly contributes to the development of nephropathy and CKD/DKD in diabetics.

RESULTS

Invented regression models for the excretion of UPr from the kidney with elevated SBP, DBP, MAP and PP were highly significant (p < 0.0001 for all); UPr = -138.6 + [1.347 × SBP] ; UPr = -93.4 + [1.62 × DBP] ; UPr = -149.5 + [1.922 × MAP] ; UPr = -41.23 +[1.541 × PP].

CONCLUSION

Current study is the first one to introduce this technique. These invented new equations can be used by physicians to estimate protein excretion in urine at bedside and outpatients departments for monitoring proteinuria and CKD/DKD.

Genetic Association of Albuminuria with Cardiometabolic Disease and Blood Pressure

Excretion of albumin in urine, or albuminuria, is associated with the development of multiple cardiovascular and metabolic diseases. However, whether pathways leading to albuminuria are causal for cardiometabolic diseases is unclear. We addressed this question using a Mendelian randomization framework in the UK Biobank, a large population-based cohort. We first performed a genome-wide association study for albuminuria in 382,500 individuals and identified 32 new albuminuria loci. We constructed albuminuria genetic risk scores and tested for association with cardiometabolic diseases. Genetically elevated albuminuria was strongly associated with increased risk of hypertension (1.38 OR; 95% CI, 1.27-1.50 per 1 SD predicted increase in albuminuria, p = 7.01 × 10-14). We then examined bidirectional associations of albuminuria with blood pressure which suggested that genetically elevated albuminuria led to higher blood pressure (2.16 mmHg systolic blood pressure; 95% CI, 1.51-2.82 per 1 SD predicted increase in albuminuria, p = 1.22 × 10-10) and that genetically elevated blood pressure led to more albuminuria (0.005 SD; 95% CI 0.004-0.006 per 1 mmHg predicted increase in systolic blood pressure, p = 2.45 × 10-13). These results support the existence of a feed-forward loop between albuminuria and blood pressure and imply that albuminuria could increase risk of cardiovascular disease through blood pressure. Moreover, they suggest therapies that target albuminuria-increasing processes could have antihypertensive effects that are amplified through inhibition of this feed-forward loop.

Unsweetening the Heart: Possible Pleiotropic Effects of SGLT2 Inhibitors on Cardio and Cerebrovascular Alterations in Resistant Hypertensive Subjects

Resistant hypertension (RH) is a multifactorial disease associated with several target organ damage, such as microalbuminuria, left ventricular hypertrophy, and arterial stiffness. These subjects have high cardiovascular complications, especially when associated with diabetes condition. Sodium glucose cotransporter 2 (SGLT-2) inhibitors represent a new class of oral antidiabetic drugs that have shown positive effects in diabetics and even hypertensives subjects. Several studies demonstrated positive outcomes related to blood pressure levels, body weight, and glycemic control. Also found a reduction on microalbuminuria, cardiac and arterial remodeling process, and decrease in hospitalization care due heart failure. Despite these positive effects, the outcomes found for stroke were conflicted and tend neutral effect. Based on this, we sought to assess the pleiotropic effects of SGLT-2 inhibitors and the possible impact in RH subjects. In order to analyze the prospects of SGLT-2 inhibitors as a possible medication to complement the therapy manage of this high-risk class of patients.

Stepped-wedge cluster-randomised controlled trial to assess the cardiovascular health effects of a managed aquifer recharge initiative to reduce drinking water salinity in southwest coastal Bangladesh: study design and rationale

INTRODUCTION

Saltwater intrusion and salinisation have contributed to drinking water scarcity in many coastal regions globally, leading to dependence on alternative sources for water supply. In southwest coastal Bangladesh, communities have few options but to drink brackish groundwater which has been associated with high blood pressure among the adult population, and pre-eclampsia and gestational hypertension among pregnant women. Managed aquifer recharge (MAR), the purposeful recharge of surface water or rainwater to aquifers to bring hydrological equilibrium, is a potential solution for salinity problem in southwest coastal Bangladesh by creating a freshwater lens within the brackish aquifer. Our study aims to evaluate whether consumption of MAR water improves human health, particularly by reducing blood pressure among communities in coastal Bangladesh.

METHODS AND ANALYSIS

The study employs a stepped-wedge cluster-randomised controlled community trial design in 16 communities over five monthly visits. During each visit, we will collect data on participants' source of drinking and cooking water and measure the salinity level and electrical conductivity of household stored water. At each visit, we will also measure the blood pressure of participants ≥20 years of age and pregnant women and collect urine samples for urinary sodium and protein measurements. We will use generalised linear mixed models to determine the association of access to MAR water on blood pressure of the participants.

ETHICS AND DISSEMINATION

The study protocol has been reviewed and approved by the Institutional Review Boards of the International Centre for Diarrheal Disease Research, Bangladesh (icddr,b). Informed written consent will be taken from all the participants. This study is funded by Wellcome Trust, UK. The study findings will be disseminated to the government partners, at research conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02746003; Pre-results.

Association of microalbuminuria with diabetes is stronger in people with prehypertension compared to those with ideal blood pressure

AIM

Microalbuminuria (MA) has been demonstrated as a biomarker for microvascular dysfunction. This study is aimed to evaluate the association of glycaemic status with MA in prehypertensive and ideal BP subjects and to evaluate the interaction between glycaemic and blood pressure status as risk factors for MA prevalence.

METHODS

1059 subjects aged 40-70 with non-hypertension who were recruited from six districts of Tianjin were divided into a prehypertensive group (622 cases) and an ideal blood BP group (437 cases). Subjects of the prehypertensive group and the ideal BP group were divided respectively into three subgroups: normoglycaemia subgroup, prediabetes subgroup and diabetes subgroup. The prevalence of MA in the above three subgroups of subjects with prehypertension and ideal BP were assessed. We performed a statistical analysis for interaction test between glycaemia and BP status on microalbuminuria in the overall study sample by a multivariate logistic regression model. The association of glycaemic status (defined as normoglycaemia, prediabetes, and diabetes) with MA was evaluated separately in prehypertensive and ideal BP subjects.

RESULTS

Results showed that the prevalence of MA in both prehypertensive and ideal BP groups rose with the increasing of classification of glycaemic level of subgroups (32.6%, 18.3%, 14.8% vs. 23.1%, 16.2%, 13.4%), the differences in prehypertensive group were statistically significant (Pearson χ² = 15.24, P < 0.001). The ORs (95% CI) of MA were 1.25 (0.86-1.83) for prediabetes and 2.56 (1.62-4.03) for diabetes in the fully adjusted model. There was no interaction between prediabetes and BP status regarding MA (P = 0.237) but we found a significant interaction between diabetes and BP status (P < 0.001). In the prehypertensive group, multivariate logistic regression models showed that the diabetes subgroup had a significant association with MA, and the adjusted odds ratio of the diabetes subgroup to the normoglycaemia subgroup was 2.68 (95%CI 1.54-4.67) (P < 0.001). However, there was no significant association of glycaemic status with MA in the ideal BP group. Stratified analysis by a multivariate logistic regression model in the whole study population showed that people with both prehypertension and diabetes had the highest risk of MA (adjusted OR = 2.50, 95%CI 1.16-5.36; P = 0.019), compared with those with ideal BP and normoglycaemia (reference group).

CONCLUSIONS

Our findings suggest that there was a statistically significant association between diabetes and microalbuminuria only in prehypertensive subjects. In addition, our study highlights the interaction between prehypertension and diabetes as a risk factor for MA.

The prevalence of hypertension in relation with the normal albuminuria range in type 2 diabetes mellitus within the South Korean population: The Korean National Health and Nutrition Examination Survey, 2011-2012

AIMS

The coexistence of hypertension (HTN) and diabetes mellitus (DM) increases the risk of cardiovascular disease. In some studies, normal albuminuria has also been associated with cardiovascular disease and HTN. Therefore, we examined the relationships between albuminuria and the prevalence of HTN and its control rate in type 2 DM patients.

RESULTS

We analyzed data from the 2011-2012 Korea National Health and Nutrition Examination Survey, and 1188 subjects with type 2 DM were included in the study. We divided albuminuria into 3 albuminuria tertiles (T): T1: <4.82mg/g; T2: 4.82-17.56mg/g; and T3: ≥17.56mg/g. The systolic and diastolic blood pressure were positively correlated with the albumin to creatinine ratio (ACR) after adjusting for all covariates (P<0.001). Type 2 DM subjects with hypertension had more ACR T3 (odds ratio=2.018, 95% confidence interval=1.445-2.818) than subjects without HTN. Subjects with controlled HTN had less ACR T3 than subjects without controlled HTN (odds ratio=0.566, 95% confidence interval=0.384-0.836). When, we redivided albuminuria by <10, 10-30 (high normal albuminuria), 30-300mg/g (microalbuminuria), and 300mg/g≤(macroalbuminuria), the odds ratio for high normal albuminuria and microalbuminuria was 1.52 and 2.24, respectively in the presence of HTN, however, high normal albuminuria was not associated with HTN control.

CONCLUSIONS

In conclusion, albuminuria within the high normal range was associated with the prevalence of HTN in South Korean patients with type 2 DM.

Relationship Between Dyslipidemia and Albuminuria in Hypertensive Adults: A Nationwide Population-Based Study

This study aimed to estimate the relationship between various lipid abnormalities and albuminuria in hypertensive Korean adults. Data obtained from the Korea National Health and Nutrition Examination Survey in 2011 to 2012 were analyzed. The study included 2330 hypertensive participants. Total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels were measured. Dyslipidemia parameters were defined as high TG ≥200 mg/dL, low HDL-C as HDL-C <40 mg/dL, high TC/HDL-C as TC/HDL-C ratio ≥4, high TG/HDL-C as TG/HDL-C ratio ≥3.8, and high LDL-C/HDL-C as LDL-C/HDL-C ratio ≥2.5. Albuminuria was defined as a urine albumin to creatinine ratio (ACR) ≥30 mg/g. Women with albuminuria showed significantly higher levels of TG, TC/HDL-C, and TG/HDL-C and a lower level of HDL-C than women without albuminuria (all P < 0.05). LogTG, TC/HDL-C, and logTG/HDL-C were positively correlated with ACR in both men and women; however, HDL-C was negatively correlated with ACR in women and non-HDL-C was positively correlated with ACR in men. In men, there was no association between ACR and lipid parameters. However, in women, higher values for logTG, TC/HDL-C, and logTG/HDL-C were associated with an increased odds ratio (OR) for albuminuria (OR [95% confidence interval]: 1.53 [1.06-2.21], 1.21 [1.02-1.45], and 1.78 [1.21-2.63], respectively) and HDL-C with a decreased OR for albuminuria (0.78 [0.67-0.92]) after adjusting for all covariates. LogTG, TC/HDL-C, and logTG/HDL-C were associated with an increased prevalence of albuminuria in hypertensive women. Screening and treatment for dyslipidemia may be necessary for hypertensive women to address potential albuminuria.

Glycosylation patterns of kidney proteins differ in rat diabetic nephropathy

Diabetic nephropathy often progresses to end-stage kidney disease and, ultimately, to renal replacement therapy. Hyperglycemia per se is expected to have a direct impact on the biosynthesis of N- and O-linked glycoproteins. This study aims to establish the link between protein glycosylation and progression of experimental diabetic kidney disease using orthogonal methods. Kidneys of streptozotocin-diabetic and control rats were harvested at three different time points post streptozotocin injection. A panel of 12 plant lectins was used in the screening of lectin blots. The lectins UEAI, PHA-E, GSI, PNA, and RCA identified remarkable disease-associated differences in glycoprotein expression. Lectin affinity chromatography followed by mass spectrometric analyses led to the identification of several glycoproteins involved in salt-handling, angiogenesis, and extracellular matrix degradation. Our data confirm a substantial link between glycosylation signature and diabetes progression. Furthermore, as suggested by our findings on dipeptidyl peptidase-IV, altered protein glycosylation may reflect changes in biochemical properties such as enzymatic activity. Thus, our study demonstrates the unexplored potential of protein glycosylation analysis in the discovery of molecules linked to diabetic kidney disease.

Prevalence and control of hypertension and albuminuria in South Korea: focus on obesity and abdominal obesity in the Korean National Health and Nutrition Examination Survey, 2011-2012

BACKGROUND

Albuminuria is associated with cardiovascular disease, and the relationship between albuminuria and hypertension is well established in many studies. So the control of hypertension is critical for decreasing cardiovascular events and albuminuria. Obesity and abdominal obesity are also associated with hypertension and albuminuria. Therefore, we analyzed the relationship between albuminuria and the prevalence and control of hypertension in the general Korean population according to obesity status.

METHODS

We analyzed data from the 2011-2012 Korea National Health and Nutrition Examination Survey, and 9,519 subjects were included. Subjects were divided into four groups: non-obese/normal waist circumference, non-obese/high waist circumference, obese/normal waist circumference, and obese/high waist circumference.

RESULTS

Systolic blood pressure and diastolic blood pressure were positively associated with albumin-creatinine ratio in all groups (all p values <0.005). Non-obese/normal waist circumference group were more likely to have hypertension (odds ratios [95% confidential intervals (CIs)] were 3.20 [2.21-4.63] in microalbuminuria level and 3.09 [1.05-9.14] in macroalbuminuria level), and less likely to have controlled hypertension (odds ratios <1 for both albuminuria levels) after adjusting for all covariates. Obese/normal waist circumference group were also more likely to have hypertension (odds ratio [95% CI] were 3.10 [1.56-6.15] in microalbuminuria level and 21.75 [3.66-129.04] in macroalbuminuria level), and less likely to have controlled hypertension in macroalbuminuria level (odds ratio [95% CI], 0.04 [0.01-0.15]).

CONCLUSIONS

Non-obese and normal waist circumference subjects have an increased prevalence and decreased control of hypertension in microalbuminuria and macroalbuminuria levels. Screening for albuminuria may provide helpful information about hypertension and blood pressure control, particularly in the non-obese and normal waist circumference subjects.

Cumulative systolic BP and changes in urine albumin-to-creatinine ratios in nondiabetic participants of the multi-ethnic study of atherosclerosis

BACKGROUND AND OBJECTIVES

Cumulative exposure to elevated systolic BP (cumSBP) may affect progression of urine albumin excretion in the absence of diabetes. The objective of this study was to examine the association between cumSBP exposure and progression of spot urine albumin-to-creatinine ratio (UACR) in a multi-ethnic cohort of adults without diabetes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The analysis included 3789 participants without severely increased urine albumin excretion or diabetes in the Multi-Ethnic Study of Atherosclerosis, a cohort of 6814 adults aged 45-84 years. UACR was measured at baseline and approximately 1.6, 3.1, and 9.4 years after the baseline examination. cumSBP was calculated as the summed average systolic BP (SBP; mmHg) between two consecutive examinations multiplied by the time between the two examinations (mmHg × year) and categorized as ≤ 1128 (SBP<120 mmHg), 1129-1222 (SBP ≥ 120-129 mmHg), 1223-1316 (SBP ≥ 130-130 mmHg), and > 1316 (SBP ≥ 140 mmHg). Baseline UACR was categori zed as normal, mildly increased, or moderately increased, and definite progression of UACR was defined as a persistently higher UACR category at subsequent examinations. No UACR progression was defined as remaining in the same UACR category across all examinations or regressing.

RESULTS

In fully adjusted models, compared with cumSBP ≤ 1128 mmHg, cumSBP 1223-1316 and >1316 mmHg was associated with a 85% and 130% significantly higher odds of definite UACR progression (95% confidence interval, 24% to 178% and 56% to 243%, respectively) versus no UACR progression. Every 100-mmHg higher level of cumSBP was associated with a 1.23-fold higher odds of definite UACR progression (95% confidence interval, 1.13 to 1.34) versus no UACR progression.

CONCLUSION

Exposure to higher cumSBP was associated with increased UACR progression among adults without diabetes.

Assessment of dyslipidemia in pre-dialysis patients in south-west Nigeria

Background:

Majority of chronic kidney disease (CKD) patients are more likely to die of cardiovascular complications before reaching end stage renal disease. The Kidney Disease Outcomes Quality Initiative (K/DOQI) recommends that all CKD patients should be evaluated for dyslipidemia and for treatment to reduce the risk of cardiovascular events.

Patients and Methods:

A cross-sectional case control study to determine the frequency of occurrence of lipid abnormalities in patients with CKD and compare these abnormalities with that of normal controls. A total of 100 patients and 100 controls were recruited for the study. Demographic and clinical data were obtained using structured questionnaire. Weight, height and waist circumference, body mass index (BMI) and blood pressure were also obtained. Subjects had their fasting lipid profile and fasting plasma glucose assayed after overnight fast of 8-14 hours. Low-density lipoprotein (LDL) was obtained using Friedwald formula.

Result:

The study revealed that total cholesterol (TC) was elevated above normal levels in 44% of cases compared with 6% in controls (P < 0.001), with the mean (SD) value of 5.82 ± 3.28 mmol/l for cases compared with 3.9 ± 1.0 mmol/l (P < 0.001) in controls. Low density lipoprotein was elevated in 48% of cases compared with 14% in controls (P < 0.001), with the mean (SD) values of 4.15 ± 2.74 mmol/l and 2.57 ± 0.95 mmol/l for cases and controls, respectively, (P < 0.001). Triglyceride (TG) was elevated above normal level in 26% of cases compared with none in the controls (P < 0.001), with the mean (SD) values of 1.41 ± 1.10 mmol/l and 0.64 ± 0.24 mmol/l for cases and controls, respectively (P < 0.001). All Lipid fractions except HDL also correlated significantly with levels of proteinuria TC (r = 0.345, P = 0.001), TG (r = 0.268, P = 0.011) LDL (r = 0.366, P = 0.001).

Conclusion:

Dyslipidemia is common among patients with CKD. Regular evaluation of all CKD patients for dyslipidemia and treatment need be instituted.

Urinary albumin excretion, blood pressure changes and hypertension incidence in the community: effect modification by kidney function

BACKGROUND

Both increased albuminuria and reduced kidney function may predict blood pressure (BP) progression in the community, while they exacerbate each other's effects. We investigated associations and interactions between these two risk factors, BP changes and hypertension incidence in community-dwelling elderly men.

METHODS

Observational study from the Uppsala Longitudinal Study of Adult Men, which included 1051 men (all aged 71 years) with assessments on urinary albumin excretion rate (UAER), 24-hour ambulatory BP monitoring (ABPM) and cystatin-C estimated glomerular filtration rate (eGFR). Of these, 574 men attended re-examination after 6 years, and ABPM measurements were again recorded to assess blood pressure changes and hypertension incidence.

RESULTS

UAER was found to be associated with ABPM measurements both at baseline and longitudinally. In longitudinal analysis, there were significant interactions between UAER and kidney function in its association with the changes of systolic BP, mean arterial pressure and pulse pressure. After stratification for renal function state, UAER independently predicted BP changes only in those who had eGFR <60 mL/min/1.73 m(2). At re-examination, 71 new cases of hypertension were recorded. In multivariable logistic models, similar interactions were observed on hypertension incidence: UAER was an independent predictor of incident hypertension only in those with reduced renal function. These associations were evident also in the subpopulation of non-diabetics and in participants with normal range UAER (<20 µg/min).

CONCLUSIONS

In community-dwelling elderly men, UAER associates with BP progression and hypertension incidence, even within the normal range. Concurrent reduction of renal function modifies and exacerbates these associations.

Progression of microalbuminuria in SHR is associated with lower expression of critical components of the apical endocytic machinery in the renal proximal tubule

Cumulative epidemiological evidence indicates that the presence of microalbuminuria predicts a higher frequency of cardiovascular events, peripheral disease, and mortality in essential hypertension. Microalbuminuria may arise from increased glomerular permeability and/or reduced proximal tubular reabsorption of albumin by receptor-mediated endocytosis. This study aimed to evaluate the temporal pattern of urinary protein excretion and to test the hypothesis that progression of microalbuminuria is associated with decreased protein expression of critical components of the endocytic apparatus in the renal proximal tubule of spontaneously hypertensive rats (SHR). We found that urinary albumin excretion increased progressively with blood pressure in SHR from 6 to 21 wk of age. In addition, SDS-PAGE analysis of urinary proteins showed that microalbuminuric SHR virtually excreted proteins of the size of albumin or smaller (<70 kDa), typical of tubular proteinuria. Moreover, the protein abundance of the endocytic receptors megalin and cubilin as well as of the chloride channel ClC-5 progressively decreased in the renal cortex of SHR from 6 to 21 wk of age. Expression of the vacuolar H⁺-ATPase B2 subunit was also reduced in the renal cortex of 21-wk-old compared with both 6- and 14-wk-old SHR. Collectively, our study suggests that enhanced urinary protein excretion, especially of albumin, may be due, at least in part, to lower expression of key components of the apical endocytic apparatus in the renal proximal tubule. Finally, one may speculate that dysfunction of the apical endocytic pathway in the renal proximal tubule may contribute to the development of microalbuminuria in essential hypertension.

Renal protective effects of α-calcitonin gene-related peptide in deoxycorticosterone-salt hypertension

Deoxycorticosterone salt (DOC-salt) hypertension-induced renal damage is enhanced in α-calcitonin gene-related peptide (α-CGRP) knockout (KO) compared with wild-type (WT) mice. However, since the α-CGRP KO mice have a 15-20 mmHg higher baseline mean arterial pressure (MAP) than WT mice, they also have a higher MAP than WT mice throughout the course of DOC-salt hypertension. To determine the mechanism by which the absence of α-CGRP enhances hypertension-induced renal damage, DOC-salt hypertension was induced in telemetry probe implanted α-CGRP KO and WT mice. To equalize the blood pressure (BP) to that of DOC-salt WT mice, an additional group of DOC-salt α-CGRP KO mice was given 0.025% hydralazine to drink. The DOC-salt protocol increased the final MAP in α-CGRP KO mice to 155 ± 6 mmHg and in WT mice to 140 ± 5 mmHg. The MAP of the hydralazine-treated DOC-salt α-CGRP KO mice was 139 ± 6 mmHg. Urinary excretion of microalbumin and isoprostane, a marker for oxidative stress, was increased, and creatinine clearance was decreased in DOC-salt α-CGRP KO compared with DOC-salt WT mice. Equalization of the MAP in DOC-salt α-CGRP KO to that of DOC-salt WT mice did not significantly improve these parameters. Renal macrophage infiltration; desmin, a marker of podocyte damage; and the inflammatory cytokines TNF-α and IFN-γ and the chemokines monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α) were increased in DOC-salt α-CGRP KO mice and were not reduced by hydralazine treatment. However, BP equalization did improve the renal histopathological damage, as determined by light microscopy. Therefore, in DOC-salt hypertension in mice, the mechanism(s) of the renal protective effects of α-CGRP are both BP independent and BP dependent.

The growing epidemic of hypertension among children and adolescents: a challenging road ahead

Currently, it is clear that primary hypertension begins in childhood and that it contributes to the early development of chronic kidney disease (CKD). Hypertension also increases the risk of cardiovascular morbidity and mortality, and that risk rises as blood pressure levels escalate. As among adult patients, overweight and obesity rates are on the rise among children and adolescents with primary hypertension and can develop target organ damage including left ventricular hypertrophy. An elevated level of C-reactive protein (CRP) and microalbuminuria are early manifestations of cardiovascular disease and CKD in hypertensive patients. Lifestyle interventions are recommended for all children with hypertension. Pharmacologic therapy should be added for symptomatic children, those with stage 2 hypertension, and children with prehypertension and stage 1 hypertension who exhibit an insufficient response to lifestyle modifications. Although the recommendations for choice of drugs generally are similar for children and adults, dosages for children should be lower, based on weight, and adjusted very carefully. Medications that are effective and safe for children and adolescents include thiazide diuretics, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, beta-blockers, and calcium channel-blockers. Hypertension is not being detected early enough for initiation of a treatment regimen to reduce death and disability. Initiatives should be undertaken to make health care providers and the general population more aware of the seriousness of hypertension in children and adolescents. This review focuses on the principles underlying the importance of a team approach for hypertension control, especially one that incorporates increased data sharing using enhanced health information technology for early detection and intervention.

Retinal arteriolar caliber and urine albumin excretion: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Changes in retinal microvascular caliber, which occur prior to onset of retinopathy, may indicate presence of kidney damage.

METHODS

This study examined the association between retinal arteriolar [central retinal artery equivalent (CRAE)] and venular caliber [central retinal venule equivalent (CRVE)] and presence of albuminuria (micro- or macroalbuminuria) among participants of the Multi-Ethnic Study of Atherosclerosis (MESA), a cohort of adults aged 45-84 years without baseline clinical cardiovascular disease. During the second MESA exam, digital fundus photography was completed in 5897 participants who provided spot urine specimens. Albuminuria was defined by spot urine albumin/creatinine ratios ≥ 30 mg/g. Multivariable adjusted odds of albuminuria by quintiles of CRAE and CRVE were determined using logistic regression. Analyses were repeated after stratifying by presence of type 2 diabetes.

RESULTS

Albuminuria was noted in 11.5% (n = 675) and included 584 subjects with microalbuminuria and 91 with macroalbuminuria. A significant U-shaped pattern was seen with higher prevalence of albuminuria across quintile extremes in CRAE (15.7, 8.8 and 10.6% in CRAE Quintiles 1, 3 and 5, respectively; P <0.0001). After adjustment for covariates, both narrower CRAE [odds ratios (OR) 1.55; 95% confidence interval (CI) 1.17-2.04, Quintile 1 versus 3) and wider CRAE (OR 1.44; 95% CI 1.07-1.93, Quintile 5 versus 3) were significantly associated with albuminuria. Associations appeared substantially stronger in adults with than without type 2 diabetes but the interaction term for diabetes and CRAE on presence of albuminuria did not meet statistical significance (P = 0.3). No association was noted between CRVE quintiles and albuminuria.

CONCLUSIONS

Albuminuria is associated with narrower and wider arteriolar caliber. Future studies should determine whether variation in arteriolar caliber predicts incident albuminuria and whether associations are mediated by hypertension and diabetes. Such information could further clarify early microvascular processes in the pathogenesis of kidney disease.

Heart disease and stroke statistics--2011 update: a report from the American Heart Association

Each year, the American Heart Association (AHA), in conjunction with the Centers for Disease Control and Prevention, the National Institutes of Health, and other government agencies, brings together the most up-to-date statistics on heart disease, stroke, other vascular diseases, and their risk factors and presents them in its Heart Disease and Stroke Statistical Update. The Statistical Update is a valuable resource for researchers, clinicians, healthcare policy makers, media professionals, the lay public, and many others who seek the best national data available on disease morbidity and mortality and the risks, quality of care, medical procedures and operations, and costs associated with the management of these diseases in a single document. Indeed, since 1999, the Statistical Update has been cited more than 8700 times in the literature (including citations of all annual versions). In 2009 alone, the various Statistical Updates were cited ≈1600 times (data from ISI Web of Science). In recent years, the Statistical Update has undergone some major changes with the addition of new chapters and major updates across multiple areas. For this year’s edition, the Statistics Committee, which produces the document for the AHA, updated all of the current chapters with the most recent nationally representative data and inclusion of relevant articles from the literature over the past year and added a new chapter detailing how family history and genetics play a role in cardiovascular disease (CVD) risk. Also, the 2011 Statistical Update is a major source for monitoring both cardiovascular health and disease in the population, with a focus on progress toward achievement of the AHA’s 2020 Impact Goals. Below are a few highlights from this year’s Update.

Relationship between chronic kidney disease and silent cerebral infarction in patients with Type 2 diabetes

AIMS

Silent cerebral infarction (SCI) is an independent risk factor for future symptomatic stroke. Although the prevalence of SCI is closely related to kidney function in non-diabetic individuals, evidence is lacking whether albuminuria and/or reduced estimated glomerular filtration rate (eGFR) independently increase the risk of SCI in diabetic patients. We therefore examined the relationships between albuminuria, eGFR and SCI in patients with Type 2 diabetes mellitus (T2DM).

METHODS

We studied 786 T2DM patients with an eGFR > or = 15 ml/min 1.73/m(2), including 337 women and 449 men [mean (+/- sd), age 65 +/- 11 years]. All patients underwent cranial magnetic resonance imaging (MRI) to detect SCI. GFR was estimated using the modified three-variable equation for Japanese subjects. Albuminuria was defined as a first morning urinary albumin-to-creatinine ratio (ACR) > or = 30 mg/g.

RESULTS

SCI was detected in 415 (52.8%) of the subjects. The prevalence of SCI was significantly associated with both elevated ACR and decreased eGFR in univariate analysis. In multivariate logistic regression analysis, urinary ACR remained independently associated with SCI after adjusting for conventional cardiovascular risk factors [odds ratio (OR) of urinary ACR per logarithmical value: 1.89, 95% confidence interval (CI) = 1.41-2.51, P < 0.001]; however, eGFR was no longer significantly associated with SCI (OR per ml/min 1.73/m(2) = 0.99, 95% CI = 0.98-1.00, P = 0.095).

CONCLUSION

In conclusion, albuminuria but not decreased eGFR may be an independent predictor of prevalent SCI in patients with T2DM.

Impact of olmesartan on blood pressure, endothelial function, and cardiovascular outcomes

The vascular endothelium, the largest "organ" in the body, synthesizes and releases a wide spectrum of vasoactive substances into the circulation. Endothelial dysfunction links hypertension and other cardiovascular (CV) risk factors that promote the development of atherosclerotic plaque, CV disease, and fatal and nonfatal CV events. Blood pressure (BP) reduction is the most effective way to reduce CV risk in patients with hypertension, but it is unknown whether endothelial dysfunction is a cause or consequence of hypertension. Renin-angiotensin-aldosterone system blockers improve endothelial function and have favorable vascular, metabolic, cardiac, and renoprotective effects that are independent of BP reduction. Olmesartan effectively reduces BP and also has vasoprotective properties, including reductions in endothelial dysfunction and inflammation, prevention of microalbuminuria, and reversal of vascular remodeling. Large-scale, long-term studies are needed to confirm that olmesartan has vasoprotective effects that are independent of BP control and to determine whether these pleiotropic effects translate into improved CV disease outcomes.

Comparative effect of direct renin inhibition and AT1R blockade on glomerular filtration barrier injury in the transgenic Ren2 rat

Renin-angiotensin system (RAS) activation contributes to kidney injury through oxidative stress. Renin is the rate-limiting step in angiotensin (ANG II) generation. Recent work suggests renin inhibition improves proteinuria comparable to ANG type 1 receptor (AT1R) blockade (ARB). Thereby, we investigated the relative impact of treatment with a renin inhibitor vs. an ARB on renal oxidative stress and associated glomerular structural and functional changes in the transgenic Ren2 rat, which manifests hypertension, albuminuria, and increased tissue RAS activity. Young Ren2 and age-matched Sprague-Dawley (SD) controls (age 6-9 wk) were treated with a renin inhibitor (aliskiren), an ARB (irbesartan), or vehicle for 21 days. Ren2 rats exhibited increases in systolic pressure (SBP), albuminuria, and renal 3-nitrotyrosine content as well as ultrastructural podocyte foot-process effacement and diminution of the podocyte-specific protein nephrin. Structural and functional alterations were accompanied by increased renal cortical ANG II, AT1R, as well as NADPH oxidase subunit (Nox2) expression compared with SD controls. Abnormalities were attenuated to a similar extent with both aliskiren and irbesartan treatment. Despite the fact the dose of irbesartan used caused a greater reduction in SBP than aliskerin treatment (P < 0.05), the effects on proteinuria, nephrin, and oxidative stress were similar between the two treatments. Our results highlight both the importance of pressor-related reductions on podocyte integrity and albuminuria as well as RAS-mediated oxidant stress largely comparable between ARB and renin inhibition treatment.

Prehypertension: epidemiology, consequences and treatment

The term prehypertension was coined in 1939 in the context of early studies that linked high blood pressure recorded during physical examination for life insurance purposes to subsequent morbidity and mortality. These studies demonstrated that individuals with blood pressure >120/80 mmHg, but <140/90 mmHg--the accepted value for the lower limit of the hypertensive range--had an increased risk of hypertension, cardiovascular disease and early death from cardiovascular causes. The prehypertension classification of blood pressure was later used by the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure to define a group of individuals at increased risk of cardiovascular events because of elevated blood pressure, an increased burden of other risk factors such as obesity, diabetes mellitus, dyslipidemia, and inflammatory markers, and evidence of organ damage for example, microalbuminuria, retinal arteriolar narrowing, increased carotid arterial intima-media thickness, left ventricular hypertrophy and coronary artery disease. Nonpharmacological treatment with lifestyle modifications such as weight loss, dietary modification and increased physical activity is recommended for all patients with prehypertension as these approaches effectively reduce risk of cardiovascular events. Pharmacological therapy is indicated for some patients with prehypertension who have specific comorbidities, including diabetes mellitus, chronic kidney disease and coronary artery disease.

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.

Is a reduced estimated glomerular filtration rate a risk factor for stroke in patients with type 2 diabetes?

Although chronic kidney disease is a risk factor for cardiovascular disease it is unclear whether diabetic patients with a reduced glomerular filtration rate (GFR), independent of (micro)albuminuria, carry an increased risk of stroke. We therefore investigated the independent effect of estimated GFR (eGFR) on stroke events in patients with type 2 diabetes mellitus (T2DM). We studied T2DM patients with an eGFR >or=15 ml min(-1) per 1.73 m(2), who had no history of stroke. Patients were divided into four categories by the eGFR at baseline for comparison: >or=90, 60-89, 30-59 and 15-29 ml min(-1) per 1.73 m(2). The end point was an incident stroke event. The Cox proportional hazard model was used to calculate the hazard ratio (HR) and 95% confidence interval (CI). The study included a total of 1300 T2DM patients (546 women and 754 men) with a mean (+/-s.d.) age of 63+/-13 years. During a mean follow-up period of 3.7+/-1.4 years, 91 patients experienced an incident stroke event. Although a lower eGFR was associated with an increased stroke risk using a univariate model, statistical significance disappeared after adjusting for other risk factors including albuminuria. The HR (95% CI) was 0.75 (0.40-1.41, P=0.373), 0.99 (0.50-1.95, P=0.964) and 0.91 (0.36-2.28, P=0.844) for patients with eGFRs of 60-89, 30-59 and 15-29 ml min(-1) per 1.73 m(2), respectively, compared with patients with an eGFR >or=90. Clinical albuminuria remained a significant risk factor for stroke, and the adjusted HR compared with normoalbuminuria was 2.40 (1.46-3.95, P=0.001). In conclusion, the association between reduced GFR and stroke events in patients with T2DM is likely to be mediated by albuminuria.

Strain vessel hypothesis: a viewpoint for linkage of albuminuria and cerebro-cardiovascular risk

Albuminuria is closely associated with stroke and cardiovascular diseases (CVDs) as well as the salt sensitivity of blood pressure (BP). Although albuminuria may reflect generalized endothelial dysfunction, there may be more specific hemodynamic mechanisms underlying these associations. Cerebral hemorrhage and infarction occur most frequently in the area of small perforating arteries that are exposed to high pressure and that have to maintain strong vascular tone in order to provide large pressure gradients from the parent vessels to the capillaries. Analogous to the perforating arteries are the glomerular afferent arterioles of the juxtamedullary nephrons. Hypertensive vascular damage occurs first and more severely in the juxtamedullary glomeruli. Therefore, albuminuria may be an early sign of vascular damages imposed on 'strain vessels' such as perforating arteries and juxtamedullary afferent arterioles. Coronary circulation also occurs under unique hemodynamic conditions, in which the entire epicardial segments are exposed to very high pressure with little flow during systolic phases. From the evolutionary point of view, we speculate that such circulatory systems in the vital organs are mandatory for survival under the danger of hypoperfusion due to difficult access to salt and water as well as high risks of wound injuries. In addition, albuminuria would indicate an impairment of renal medullary circulation, downstream from the juxtamedullary glomeruli, and therefore an impaired pressure natriuresis, which would lead to salt sensitivity of BP. Our 'strain vessel hypothesis' may explain why hypertension and diabetes, unforeseen in the concept of evolution, preferentially affect vital organs such as the brain, heart and kidney.

A history of preeclampsia identifies women who have underlying cardiovascular risk factors

OBJECTIVE

The objective of this study was to prospectively assess physical and biochemical cardiovascular risk markers in women who had developed preeclampsia (PE) at 1 year postpartum.

STUDY DESIGN

Following an overnight fast, previously PE (n = 70) and normotensive women (n = 70) had weight and blood pressure recorded and levels of morning blood for insulin, glucose, C-reactive protein, lipids, cholesterol, and urine for microalbumin and creatinine measured. Body mass index, homeostatic model assessment index, and incidence of metabolic syndrome were determined.

RESULTS

At 1 year postpartum, markers of cardiovascular disease were different between the groups. There were also differences in the number of women with abnormal values. Mathematical modeling of cardiovascular event risk suggests that PE increases the risk by 2- to 3-fold; the risk was greatest for women with severe PE.

CONCLUSION

The development of PE is 1 of the earliest clinically identifiable markers of a woman's heightened risk of cardiovascular disease.

Blood pressure abnormalities in children with chronic kidney disease

OBJECTIVES

Disturbances of blood pressure (BP) rhythms have been demonstrated in patients with various degrees of renal impairment. The purpose of this study was to determine the prevalence of BP abnormalities in children with chronic kidney disease (CKD) and evaluate possible factors associated with nocturnal BP abnormalities.

METHODS

42 children between 2 and 19 years of age with CKD stages 2-5 completed 24-h ambulatory BP monitoring.

RESULTS

The percentage of patients with daytime hypertension was less than 10% but rates were higher at nighttime where 14% had systolic and 24% diastolic hypertension. A similar percentage of patients had a BP load >50%. BP abnormalities that were not evident in clinic BP readings were identified in 49% of the participants. The nocturnal BP dipping percentage tended to decrease as the estimated glomerular filtration rate decreased. Proteinuria was significantly associated with nocturnal BP nondipping.

CONCLUSION

24-h ambulatory BP monitoring may provide additional insight into hypertension in pediatric patients as early as CKD stage 2. Several BP abnormalities were identified that were not evident in casual BP measurements including nocturnal hypertension, elevated BP load, and nocturnal BP nondipping.

Nontraditional risk factors for cardiovascular disease in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) have a reduced lifespan, and a substantial proportion of these individuals die from cardiovascular disease. Although a large percentage of patients with CKD have traditional cardiac risk factors such as diabetes, hypertension and abnormalities in cholesterol, interventions to address these factors--which have significantly decreased cardiovascular mortality in the general population--have not shown such benefit in the CKD population. In addition, the severity and extent of cardiovascular complications in patients with CKD is disproportionate to the number and severity of traditional risk factors. This realization has focused attention on nontraditional cardiac risk factors that are particularly relevant to patients with CKD, including decreased hemoglobin levels, microalbuminuria, increased inflammation and oxidative stress, and abnormalities in bone and mineral metabolism. However, large prospective trials in patients with advanced CKD or in those requiring chronic dialysis have not shown that normalization of these nontraditional risk factors improves survival. Moreover, the mechanisms by which these nontraditional risk factors contribute to cardiovascular disease are unknown. Therefore, although current treatment of patients with CKD includes management of traditional and nontraditional risk factors, the value of modifying some nontraditional risk factors remains unclear.

What is the mechanism of microalbuminuria in diabetes: a role for the glomerular endothelium?

Microalbuminuria is an important risk factor for cardiovascular disease and progressive renal impairment. This holds true in the general population and particularly in those with diabetes, in whom it is common and marks out those likely to develop macrovascular disease and progressive renal impairment. Understanding the pathophysiological mechanisms through which microalbuminuria occurs holds the key to designing therapies to arrest its development and prevent these later manifestations. Microalbuminuria arises from the increased passage of albumin through the glomerular filtration barrier. This requires ultrastructural changes rather than alterations in glomerular pressure or filtration rate alone. Compromise of selective glomerular permeability can be confirmed in early diabetic nephropathy but does not correlate well with reported glomerular structural changes. The loss of systemic endothelial glycocalyx--a protein-rich surface layer on the endothelium--in diabetes suggests that damage to this layer represents this missing link. The epidemiology of microalbuminuria reveals a close association with systemic endothelial dysfunction and with vascular disease, also implicating glomerular endothelial dysfunction in microalbuminuria. Our understanding of the metabolic and hormonal sequelae of hyperglycaemia is increasing, and we consider these in the context of damage to the glomerular filtration barrier. Reactive oxygen species, inflammatory cytokines and growth factors are key players in this respect. Taken together with the above observations and the presence of generalised endothelial dysfunction, these considerations lead to the conclusion that glomerular endothelial dysfunction, and in particular damage to its glycocalyx, represents the most likely initiating step in diabetic microalbuminuria.

Usefulness of microalbuminuria versus the metabolic syndrome as a predictor of cardiovascular disease in women and men>40 years of age (from the Rancho Bernardo Study)

To examine the sex-specific contributions of the metabolic syndrome and microalbuminuria to cardiovascular disease (CVD) and coronary heart disease (CHD) mortality in community-dwelling older adults, 869 women and 575 men aged 40 to 96 years (mean age 71) completed questionnaires, physical examinations, and fasting laboratory tests between 1992 and 1995. Participants were followed over an average of 8 years. CVD and CHD mortality were analyzed using Cox proportional hazards models. At baseline, 267 participants had the Adult Treatment Panel III metabolic syndrome, 151 had microalbuminuria, and 34 had both. During follow-up, there were 180 CVD deaths, including 83 CHD deaths. In women, microalbuminuria was associated with a twofold increased risk of CVD and CHD mortality (p<or=0.01). Women with both microalbuminuria and the metabolic syndrome (n=18) had a threefold increased risk of CVD mortality and a fivefold increased risk of CHD mortality compared with women without either (n=657). A significant interaction existed between microalbuminuria and the metabolic syndrome in the prediction of both CVD and CHD (p=0.02). In men, neither the combination of the metabolic syndrome and microalbuminuria (n=16), nor either alone, significantly increased the risk of CVD or CHD mortality. In conclusion, in this cohort, microalbuminuria and the metabolic syndrome together were a more powerful predictor of CVD mortality than either alone in women but not in men. Screening for microalbuminuria in older women may identify women at high risk for CVD mortality beyond that conferred by risk factors included in the metabolic syndrome.

The frequency of elevated blood pressure in obese minority youth

In this study, 167 obese persons were recruited (45 African Americans, 122 Caribbean Hispanic persons), with a mean age of 14.6+/-2.1 years, a mean body mass index (BMI) of 38+/-7.5 kg/m(2), and mean BMI Z-score of 2.47+/-0.36; 31 nonobese youth were recruited as controls (7 African Americans, 24 Caribbean Hispanic persons), with a mean age of 14.6+/-2.1 years, a mean BMI of 20+/-2.8 kg/m(2), and a mean BMI Z-score of -0.08+/-0.87. The objective was to assess the frequency of elevated blood pressure in obese minority youth. Weight, height, blood pressure (BP), and various biochemical markers were measured in each participant. Overall, 31% of the obese patients had elevated BP, compared with 3% of the control participants. Obese persons with elevated BP had significantly higher BMI, BMI Z-scores, and hemoglobin A1c levels. The frequency of elevated BP and the degree of systolic BP elevation increased with increasing BMI Z-score. Elevated BP was 10 times more frequent in obese minority youth, emphasizing the importance of screening for hypertension in this high-risk population.

Effects of different ACE inhibitor combinations on albuminuria: results of the GUARD study

Clinical practice guidelines recommend blockers of the renin-angiotensin system alone or in combination with other agents to reduce blood pressure and albuminuria in patients with type 2 diabetes. Dihydropyridine calcium channel blockers, however, may lower blood pressure but not albuminuria in these patients. Here we tested the hypothesis that combining an ACE inhibitor with either a thiazide diuretic or a calcium channel blocker will cause similar reductions in blood pressure and albuminuria in hypertensive type 2 diabetics. We conducted a double blind randomized controlled trial on 332 hypertensive, albuminuric type 2 diabetic patients treated with benazepril with either amlodipine or hydrochlorothiazide for 1 year. The trial employed a non-inferiority design. Both combinations significantly reduced the urinary albumin to creatinine ratio and sitting blood pressure of the entire cohort. The percentage of patients progressing to overt proteinuria was similar for both groups. When we examined patients who had only microalbuminuria and hypertension we found that a larger percentage of the diuretic and ACE inhibitor normalized their albuminuria. We conclude that initial treatment using benzaepril with a diuretic resulted in a greater reduction in albuminuria compared to the group of ACE inhibitor and calcium channel blocker. In contrast, blood pressure reduction, particularly the diastolic component, favored the combination with amilodipine. The dissociation between reductions in blood pressure and albuminuria may be related to factors other than blood pressure.