Racial/ethnic differences in microalbuminuria among adults with prehypertension and hypertension: National Health and Nutrition Examination Survey (NHANES), 1999-2006

Associations of dietary inflammatory index with low estimated glomerular filtration rate, albuminuria and chronic kidney disease in U.S adults: Results from the NHANES 2011-2018

BACKGROUND AND AIMS

Chronic Kidney Disease (CKD) is characterized by a high inflammation status with ever-increasing prevalence, and defined as low estimated glomerular filtration rate (eGFR) or albuminuria. Both low eGFR and albuminuria can have independent effects on the body. The dietary inflammatory index (DII) is a validated tool used to assess the inflammatory potential of the diet. We aim to explore not only the association between DII and CKD, but also the associations of DII with low eGFR and albuminuria, respectively. In addition, their associations in different subgroups remain to be explored.

METHODS AND RESULTS

18,070 participants from the 2011-2018 NHANES with complete data of dietary intake and laboratory data were involved in our study. The data of 24-hour dietary recall interview was used to calculate DII, CKD could be reflected by laboratory data of creatinine and albumin. Then weighted multivariate logistic regression models and subgroup analyses were performed. The prevalence of low eGFR, albuminuria and CKD were 6.8%, 9.8% and 14.5%, respectively. A positive association between DII and low eGFR was observed (OR=1.12, 95%CI: 1.05-1.21), Q2, Q3 and Q4 are positively associated with a significant 39%, 65% and 71% increased risk of low eGFR compared with Q1 (P for trend<0.05). DII was also associated with CKD (OR=1.06, 95%CI: 1.01-1.11).

CONCLUSION

Significant positive associations of DII with CKD and low eGFR were observed. But we didn't find such association between DII and albuminuria.

Hypertension-mediated organ damage and established cardiovascular disease in patients with hypertension: the China Hypertension Survey, 2012-2015

Hypertension is a major health burden worldwide. However, there is limited data on the status of hypertension-mediated organ damage (HMOD) and established cardiovascular (CV) disease in Chinese hypertensive patients. The aim of this study is to determine the prevalence of HMOD and established CV disease in a nationally representative population in China. A stratified multistage random sampling method was used in the China Hypertension Survey and 21,243 participants aged 35 or older were eligible for analysis in this study. For each participant, the demographic information and a self-reported medical history were acquired. Blood pressure was measured with the electronic device 3 times on the right arm, supported at heart level, after the participant was sitting at rest for 5 min. Samples of blood and urine were tested. 2-D and Doppler echocardiography were used to assess the heart's function and structures. Sampling weights were calculated based on the 2010 China population census data. Overall, the weighted prevalence of asymptomatic HMOD was 22.1%, 28.9%, 23.1%, 6.4%, and 6.2% for wide pulse pressure, left ventricular hypertrophy, microalbuminuria, chronic kidney disease, and abnormal ankle-brachial index, respectively. For the established CV disease, the weighted prevalence was 1.8%, 1.3%, 2.0%, and 1.1% for stroke, coronary artery disease, heart failure, and atrial fibrillation, respectively. The prevalence of asymptomatic HMOD and established CV disease was greater with higher blood pressure level (P < 0.05), rather than ankle-brachial index. Compared to those with uncontrolled hypertension, the prevalence of asymptomatic HMOD was lower in patients with controlled hypertension. In summary, the prevalence of HMOD in Chinese people aged 35 or older was very common, indicating a substantial future burden of both morbidity and mortality from hypertension in China. Clinical trial registration number: ChiCTR-ECS-14004641.

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.

Prediabetes: A Worldwide Epidemic

Prediabetes, defined by blood glucose levels between normal and diabetic levels, is increasing rapidly worldwide. This abnormal physiologic state reflects the rapidly changing access to high-calorie food and decreasing levels of physical activity occurring worldwide, with resultant obesity and metabolic consequences. This is particularly marked in developing countries. Prediabetes poses several threats; there is increased risk of developing type 2 diabetes mellitus (T2DM), and there are risks inherent to the prediabetes state, including microvascular and macrovascular disease. Studies have helped to elucidate the underlying pathophysiology of prediabetes and to establish the potential for treating prediabetes and preventing T2DM.

Blood pressure is associated with the presence and severity of nonalcoholic fatty liver disease across the spectrum of cardiometabolic risk

OBJECTIVES

To determine the relationship between clinically relevant blood pressure (BP) groups and nonalcoholic fatty liver disease (NAFLD) presence and severity especially in the milieu of other metabolic risk factors.

PATIENTS AND METHODS

From a Brazilian cohort of 5362 healthy middle-aged men and women who presented for yearly physical examination and testing, the cross-sectional relationship between BP categories and NAFLD was assessed. BP groups were categorized as normal, prehypertension (PHT), and hypertension (HTN) according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure classification. NAFLD was ultrasound diagnosed, excluding persons with alcohol consumption more than 20 g/day. NAFLD severity was estimated using the Fibrosis-4 (FIB-4) risk score.

RESULTS

The prevalence of NAFLD was 36.2%. Participants with NAFLD were older (mean 46 vs. 42 years, P < 0.001) and had elevated BMI (mean 29.0 vs. 24.7 kg/m, P < 0.001). The prevalence of NAFLD among persons with normal BP, PHT, and HTN was 16.5, 37.5, and 59.3%, respectively. In multivariate analyses, PHT and HTN were associated with elevated odds of NAFLD (PHT-adjusted odds ratio 1.3, 95% confidence interval 1.1, 1.6; HTN-adjusted odds ratio 1.8, 95% confidence interval 1.4-2.3) compared with normal BP. Among nonobese hypertensive patients, BP control (BP < 140/90 mmHg) was independently associated with 40% lower odds of prevalent NAFLD. Compared with hypertensive patients, both normotensive individuals and prehypertensive patients were more likely to have a low fibrosis risk (FIB-4 ≥ 1.3).

CONCLUSION

Prevalent NAFLD may be seen early in the development of hypertension, even in the absence of other metabolic risk factors. Controlling BP among nonobese hypertensive patients may be beneficial in preventing or limiting NAFLD.

Estimated GFR or albuminuria: which one is really associated with resistant hypertension?

Patients with resistant hypertension belong to a very high cardiovascular risk group and have a high prevalence of target organ damage. Microalbuminuria and low estimated glomerular filtration rate are associated with resistant hypertension, and could be a cause and/or complication of hypertension. In this review, we explore the relationship between these 2 markers of kidney disease and the prevalence of resistant hypertension. We identified different phenotypes of resistant hypertension that associate with microalbuminuria and/or low estimated glomerular filtration rate. These phenotypes suggest that high sympathetic activity associated with fluid overload and endothelial dysfunction may contribute differently to the development of resistant hypertension.

Delayed heart rate recovery is strongly associated with early and late-stage prehypertension during exercise stress testing

BACKGROUND

Heart rate recovery (HRR) has been shown to predict cardiovascular disease mortality. HRR is delayed in hypertension, but its association with prehypertension (PHT) has not been well studied.

METHODS

The study population consisted of 683 asymptomatic individuals (90% men, aged 47±7.9 years). HRR was defined as peak heart rate minus heart rate after a 2-minute rest. PHT was categorized into stage I (systolic blood pressure (SBP) 120-129mm Hg or diastolic BP (DBP) 80-84mm Hg) or stage II (SBP 130-139mm Hg or DBP 85-89mm Hg). Logistic regression was used to generate odds ratios (ORs) for the relationship between HRR and PHT.

RESULTS

The mean HRR was lower in the PHT groups than in those who were normotensive (60 bpm and 58 bpm in stages I and II PHT vs. 65 bpm in normal BP; P <0.01). Persons with PHT were more likely to be in the lowest quartile of HRR compared with those with normal BP (adjusted OR, 3.80 and 95% confidence interval [CI], 1.06, 13.56 for stage II PHT and adjusted OR, 3.01 and 95% CI 1.05, 8.66 for stage I PHT). In a fully adjusted model, HRR was still significantly associated with both stages of PHT.

CONCLUSION

Among asymptomatic patients undergoing stress testing, delayed HRR was independently associated with early and late stages of PHT. Further studies are needed to determine the usefulness of measuring HRR in the prevention and management of hypertension.

Prevalence of microalbuminuria among middle-aged population of China: a multiple center cardiovascular epidemiological study

We assessed the prevalence of microalbuminuria (MAU) and the relationships with other cardiovascular (CV) risk factors among a middle-aged Chinese population. Data from 10 313 participants were included in our cross-sectional survey. Microalbuminuria was defined as the urine albumin to creatinine ratio of 30:300 mg/g from a single-spot morning urine sample. Microalbuminuria was found to be common in males and females (15.04% vs 10.09%) aged 35 to 64 years in this Chinese general population, especially in those with obesity, hypertension, and diabetes. Multivariate analysis found that body mass index, triglyceride, high-sensitivity C-reactive protein, alcohol consumption, hypertension, and diabetes were independently associated with MAU. Microalbuminuria may be a useful indicator for risk of CV disease in general populations.

Microalbuminuria, macroalbuminuria and uncontrolled blood pressure among diagnosed hypertensive patients: the aspect of racial disparity in the NHANES study

Accumulating evidence reveals that albuminuria may exacerbate uncontrolled blood pressure (BP) in hypertensive patients. However, racial differences in the associations of albuminuria with uncontrolled BP among diagnosed hypertensives have not been evaluated. A total of 6147 diagnosed hypertensive subjects aged ≥ 18 years were collected from the National Health and Nutrition Examination Survey 1999-2008 with stratified multistage sampling designs. Odds ratios (ORs), relative ORs and 95% confidence intervals (CIs) in uncontrolled BP, and the different effects of microalbuminuria and macroalbuminuria on continuous BP were estimated using weighted logistic models and linear regression models. Hypertensive subjects with microalbuminuria and macroalbuminuria were more likely to have uncontrolled BP and higher average systolic BP (SBP) in all individual racial groups. Microalbuminuria was associated with isolated uncontrolled SBP in non-Hispanic blacks and whites, and macroalbuminuria was associated with isolated uncontrolled SBP and diastolic BP (DBP) and high average DBP only in non-Hispanic blacks. Compared with non-Hispanic whites, non-Hispanic blacks and Mexicans had lower associations of microalbuminuria with uncontrolled BP (relative OR = 0.68, 95% CI = 0.48-0.97 for blacks vs whites; relative OR = 0.62, 95% CI = 0.42-0.93 for Mexicans vs. whites) and isolated uncontrolled SBP (relative OR = 0.62, 95% CI = 0.43-0.90 for blacks vs. whites; relative OR = 0.45, 95% CI = 0.29-0.71 for Mexicans vs. whites). The association of microalbuminuria with uncontrolled BP was lower in non-Hispanic blacks and Mexicans than in non-Hispanic whites. Health providers need to improve care for mildly elevated albumin excretion rates in non-Hispanic white hypertensive patients while maintaining the quality of care in non-Hispanic blacks and Mexicans.

Hypertension-associated expenditures for medication among US adults

BACKGROUND

We sought to estimate how much the presence of hypertension adds to annual per capita and total expenditures for medication among US adults.

METHODS

The sample included 21,782 civilian noninstitutionalized adults aged ≥ 18 years who participated in the 2007 Medical Expenditure Panel Survey. Hypertension was defined as having a diagnosis of high blood pressure (except during pregnancy) or taking a blood pressure medication. We used a 2-part model to examine all-cause medication expenditure associated with hypertension.

RESULTS

The prevalence of hypertension was 32.2%. Overall, 66.7% of adults purchased prescribed medications, with this proportion higher among hypertensive (93.0%) than normotensive (54.4%) adults (P < 0.001). Hypertensive adults were more likely to have medication expenditures than were normotensive adults (odds ratio (OR) = 6.42; P < 0.001). Among hypertensive adults, those aged ≥ 45 years were more likely to incur medication expenditure than those aged 18-44 years (OR = 3.00, P < 0.001 for those aged 45-64 years; OR = 5.95, P < 0.001 for those aged ≥ 65 years), whereas women were 2.91 times as likely as men to have medication spending (P < 0.001). Hispanics were less likely than non-Hispanic whites to have such spending (OR = 0.51; P < 0.001). Among those purchasing medications, the average cost was $1,510 higher among hypertensive persons ($2,337) than normotensive persons ($827). Hypertension-associated expenditures for medication were estimated at $68 billion in the US civilian non-institutionalized population in 2007.

CONCLUSIONS

The presence of hypertension among US adults is associated with an increase of all-cause expenditures for medication, with this increase varying across groups by age and sex.

Meta-analysis of cohort studies of baseline prehypertension and risk of coronary heart disease

Prehypertension is a common condition, but the extent to which it increases the risk for coronary heart disease (CHD) is unclear. The aim of this study was to determine the association between baseline prehypertension and risk for CHD by performing a meta-analysis of prospective cohort studies. A systematic search of published research was conducted through January 2013, using electronic databases and bibliographies of retrieved reports. Studies were included if they reported multivariate-adjusted relative risks (RRs) and corresponding 95% confidence intervals (CIs) of CHD with respect to prehypertension. A random-effects model was used to combine the study-specific risk estimates. Eighteen studies, consisting of 934,106 participants and 14,952 cases, with a median follow-up period of 8.8 years, were included. Prehypertension was associated with a significantly elevated risk for CHD (RR 1.36, 95% CI 1.22 to 1.53). Eight studies consisting of 12 cohorts further provided risk estimates for low-range prehypertension (120/80 to 129/84 mm Hg) and high-range prehypertension (130/85 to 139/89 mm Hg) separately. The risk for CHD increased significantly in high-range prehypertensive populations (RR 1.53, 95% CI 1.19 to 1.97) but not in low-range prehypertensive populations (RR 1.16, 95% CI 0.96 to 1.42). In conclusion, prehypertension is associated with a significantly increased risk for developing CHD, particularly high-range prehypertension. Further well-designed randomized controlled trials are needed to clarify the efficacy of blood pressure reduction in subjects with prehypertension.

Association of racial disparities in the prevalence of insulin resistance with racial disparities in vitamin D levels: National Health and Nutrition Examination Survey (2001-2006)

We tested the hypothesis that racial differences in vitamin D levels are associated with racial disparities in insulin resistance between blacks and whites. Among 3628 non-Hispanic black and white adults in the National Health and Nutrition Examination Survey from 2001 to 2006, we examined the association between race and insulin resistance using the homeostasis assessment model for insulin resistance. We conducted analyses with and without serum 25-hydroxyvitamin D (25[OH]D). We adjusted for age, sex, educational level, body mass index, waist circumference, physical activity, alcohol intake, smoking, estimated glomerular filtration rate, and urinary albumin/creatinine ratio. Blacks had a lower mean serum 25(OH)D level compared with whites (14.6 [0.3] ng/mL vs 25.6 [0.4] ng/mL, respectively; P < .0001). Blacks had a higher odds ratio (OR) for insulin resistance without controlling for serum 25(OH)D levels (OR, 1.67; 95% confidence interval, 1.26-2.20). The association was not significant (OR, 1.28; 95% confidence interval, 0.90-1.82) after accounting for serum 25(OH)D levels. The higher burden of insulin resistance in blacks compared with whites may be partially mediated by the disparity in serum 25(OH)D levels.

Achievement of cardiometabolic goals in aware hypertensive patients in Spain: a nationwide population-based study

Despite the importance of achieving cardiometabolic goals beyond blood pressure, in the health of hypertensives, no comprehensive assessment of these characteristics has been performed in whole countries. We studied in 2008-2010 a total of 11 957 individuals representative of the Spanish population aged≥18 years. Information on cardiometabolic characteristics was collected at the participants' homes, through structured questionnaires, physical examination, and fasting blood samples. A total of 3983 individuals (33.3%) had hypertension (≥140/90 mm Hg or current antihypertensive drug treatment), 59.4% were aware of their condition, 78.8% treated among those aware, and 48.5% controlled among those aware and treated (22.7% of all hypertensives). Of the aware hypertensives, 13.8% had a body mass index<25 kg/m2, 38.6% consumed <2.4 g/d of sodium, 19.3% were diabetic with 61% attaining goal hemoglobin A1c<6.5%, whereas 42.3% had hypercholesterolemia, with 38.1% reaching goal low-density lipoprotein<115 mg/dL. Only 30.7% of overweight patients received a prescription of specific method for weight loss, 17.4% of daily smokers were offered a smoking cessation strategy, and 15.8% of older patients were given a flu shot. Aware and unaware hypertensives showed a similar frequency of some lifestyle, such as adequate physical activity. In conclusion, in a European country with a well-developed, free-access healthcare system, achievement of many cardiometabolic goals among hypertensives is poor. Moreover, a serious deficiency in hypertension awareness and in the effectiveness of some lifestyle interventions among aware hypertensives is present. Greater effort is needed in the management of coexisting risk factors and on lifestyle medical advice to improve the cardiometabolic health of hypertensives.

Autonomic and hemodynamic origins of pre-hypertension: central role of heredity

OBJECTIVES

The purpose of this study is to better understand the origins and progression of pre-hypertension.

BACKGROUND

Pre-hypertension is a risk factor for progression to hypertension, cardiovascular disease, and increased mortality. We used a cross-sectional twin study design to examine the role of heredity in likely pathophysiological events (autonomic or hemodynamic) in pre-hypertension.

METHODS

Eight hundred twelve individuals (337 normotensive, 340 pre-hypertensive, 135 hypertensive) were evaluated in a sample of twin pairs, their siblings, and other family members. They underwent noninvasive hemodynamic, autonomic, and biochemical testing, as well as estimates of trait heritability (the percentage of trait variance accounted for by heredity) and pleiotropy (the genetic covariance or shared genetic determination of traits) by variance components.

RESULTS

In the hemodynamic realm, an elevation of cardiac contractility prompted increased stroke volume, in turn increasing cardiac output, which elevated blood pressure into the pre-hypertension range. Autonomic monitoring detected an elevation of norepinephrine secretion plus a decline in cardiac parasympathetic tone. Twin pair variance components documented substantial heritability as well as joint genetic determination for blood pressure and the contributory autonomic and hemodynamic traits. Genetic variation at a pathway locus also indicated pleiotropic effects on contractility and blood pressure.

CONCLUSIONS

Elevated blood pressure in pre-hypertension results from increased cardiac output, driven by contractility as well as heart rate, which may reflect both diminished parasympathetic and increased sympathetic tone. In the face of increased cardiac output, systemic vascular resistance fails to decline homeostatically. Such traits display substantial heritability and shared genetic determination, although by loci not yet elucidated. These findings clarify the role of heredity in the origin of pre-hypertension and its autonomic and hemodynamic pathogenesis. The results also establish pathways that suggest new therapeutic targets for pre-hypertension, or approaches to its prevention.

The waveform fluctuation and the clinical factors of the initial and sustained erythropoietic response to continuous erythropoietin receptor activator in hemodialysis patients

OBJECTIVES

Erythropoiesis-stimulating agents (ESA) are the main treatment for anemia in hemodialysis (HD) patients. We evaluated factors determining the response after treatment of a new ESA (continuous erythropoietin erythropoietin receptor activator (CERA)).

METHODS

61 HD patients were classified by their response at two different timings. First, patients whose hematocrit (Hct) increased 1.5% in the first week were defined as initial responders (IR, n = 16). We compared several parameters between IR and the rest of the study subjects (non-IR, n = 45). Second, patients whose Hct increased 2% in the 4th week were defined as sustained responders (SR, n = 12), and we did a similar comparison.

RESULTS

The Hct showed a waveform fluctuation. Compared with the rest, IR had significantly lower platelet counts and higher levels of ferritin, total protein, total bilirubin, and serum sodium, while SR had significantly lower levels of C-reactive protein and low-density lipoprotein (All P < 0.05). In comparison with the rest, higher Hct persisted for 10 weeks in SR but only for two separate weeks (the 1st and 7th week) in IR.

CONCLUSIONS

The initial and sustained erythropoietic responses are independent from each other and are associated with different factors. Treatment focusing on these factors may improve the response.

Microalbuminuria in children with primary and white-coat hypertension

Microalbuminuria serves as an early marker of hypertension-related renal damage in adults. However, data on the prevalence of microalbuminuria in paediatric hypertensive patients in general and in children with white-coat hypertension (WCH) specifically are lacking. The aim of our study was to investigate the prevalence of microalbuminuria in children with primary hypertension (PH) and WCH, respectively. This was a retrospective case review of children with PH and WCH treated at three paediatric nephrology centres. Untreated children with either form of hypertension for whom measurements of urinary albumin excretion (UAE) had been performed were enrolled in the study. The study cohort comprised 52 children (39 boys) with hypertension (26 children with PH, 26 with WCH). Microalbuminuria (>3.2 mg/mmol creatinine) was present in 20% of children with PH and none of the children with WCH (p < 0.01). Children with PH had a higher median UAE than those with WCH (1.27 ± 1.92 vs. 0.66 ± 0.46 mg/mmol creatinine, p < 0.05). Based on these results, we suggest that children with PH have an increased prevalence of microalbuminuria, while children with WCH show no signs of hypertension-related renal damage.

Hyperuricemia and microalbuminuria are separately and independently associated with prehypertension among Chinese Han women

BACKGROUND

Whether hyperuricemia and microalbuminuria are separately associated with prehypertension among Chinese Han women is controversial.

METHODS

Information was collected from physical examinations, personal interviews, and blood and urine samples. Associations of hyperuricemia and microalbuminuria with hypertension and prehypertension were analyzed by using multivariate nonconditional logistic regression models in 1,773 women aged ≥30 years.

RESULTS

Both average systolic and diastolic blood pressure increased with uric acid and urinary albumin-to-creatinine ratio levels (all trend P values<0.001). When subjects with microalbuminuria or using antihypertensive medication were excluded, individuals with a uric acid level in the 2(nd), 3(rd), and 4(th) quartiles of uric acid were more likely to have prehypertension than those with a uric acid level in the lowest quartile [odds ratio (OR)=1.50, 95% confidence interval (CI) 1.02-2.19; OR=1.69, 95% CI 1.12-2.56; OR=2.67, 95% CI 1.57-4.53). After exclusion of subjects with diabetes or hyperuricemia or using antihypertensive medication, compared with normotensives, individuals with high blood pressure status of prehypertension were more likely to have microalbuminuria (OR=1.83, 95% CI 1.12-2.99). Additionally, microalbuminuria was positively associated with blood pressure levels (trend P value<0.001).

CONCLUSIONS

Hyperuricemia and microalbuminuria are separately and independently associated with prehypertension among Chinese Han women.

A mathematical model to estimate the risk of microalbuminuria in an overweight adult male population

Being overweight or obese promotes microalbuminuria and increases the risk of chronic kidney disease. This study aimed to develop a mathematical model to estimate the risk of microalbuminuria in overweight Chinese men. Urine albumin/creatinine ratio and metabolic variables were assessed in 1179 subjects, randomly divided into estimation and validation groups that were comparable with respect to all variables. Regression analysis identified body mass index, systolic blood pressure, fasting plasma glucose and blood uric acid as significant variables; these were used to develop a mathematical model for estimating the risk of microalbuminuria. The model generated a receiver-operating characteristic curve indicative of strong predictive accuracy for microalbuminuria (area under the curve, 0.81). A probability cut-off point of 0.50 resulted in global predictive values for microalbuminuria of 86.4% and 84.1% in the validation group (n = 354) and in all subjects, respectively. This model provides a beneficial tool for identifying overweight Chinese men at risk of microalbuminuria; additional studies are required to examine the predictive ability of the model further.

Relationship between inflammation and microalbuminuria in prehypertension

Inflammation is a pathogenic factor for target-organ damage (TOD) in hypertension. This study examined the relationship between inflammatory parameters and urinary albumin excretion (UAE) in prehypertension. A total of 65 prehypertensive subjects (blood pressure (BP) 120-139/80-89 mm Hg) and 26 healthy volunteers with BP <120/80 mm Hg were included. High-sensitivity C-reactive protein (hs-CRP), and serum and urinary tumor necrosis factor-α (TNF-α) were measured as inflammatory markers. Prehypertensive individuals had higher levels of inflammatory parameters and UAE than healthy subjects. Analyses carried out in prehypertensive participants showed that BP was similar between individuals with normoalbuminuria or microalbuminuria (MAB) (UAE between 30 and 299 mg per day). However, serum hs-CRP and urinary TNF-α excretion were higher in prehypertensives with MAB. Multiple regression analysis showed that systolic blood pressure (r=0.29, P<0.01), hs-CRP (r=0.20, P<0.001), and urinary TNF-α (r=0.69, P<0.001) were independently correlated with UAE (adjusted R(2)=0.73, P<0.001). Finally, logistic regression analysis performed in the prehypertensive group with the absence or presence of MAB as the dependent variable demonstrated that hs-CRP (3.92 (1.45-10.58), P=0.007) and urinary TNF-α (1.69 (1.20-2.37), P=0.002) were independent risk factors for the presence of MAB. Inflammatory parameters are significantly and independently associated with UAE in prehypertensive subjects, suggesting that inflammation may be a pathogenic factor for the early vascular or TOD in these individuals.

Urinary albumin-to-creatinine ratio in a first-morning void urine and prehypertension among Chinese Han women

BACKGROUND

This study was operated to investigate the association between urinary albumin-to-creatinine ratio (ACR) and prehypertension among Chinese Han women.

METHODS

Information on blood pressure measurement and other variables were obtained, and blood and urine samples collected in 1796 women aged ≥30 years. The association between urinary ACR and prehypertension were analyzed by using multivariate non-conditional logistic regression models.

RESULTS

Average urinary ACR was higher in hypertensives than in prehypertensives (median: 15.54 vs 9.01 mg/g), and in prehypertensives than in normotensives (median: 9.01 vs 7.13 mg/g). Both systolic and diastolic blood pressures increased with urinary ACR. Compared with the lowest quartile of urinary ACR, multivariate adjusted odds ratios of prehypertension were 1.25 (95% confidence interval, 0.89-1.78), 1.95 (1.30-2.92) and 1.59 (1.02-2.48) for the second, third and fourth quartiles, respectively. After exclusion of subjects with diabetes or use of antihypertensive medication, the odds ratio of prehypertension still increased with urinary ACR levels.

CONCLUSION

Increased urinary ACR was significantly and positively associated with prehypertension among Chinese Han women.

Vitamin D and racial disparity in albuminuria: NHANES 2001-2006

Background

National data show unexplained racial disparity in albuminuria. We assessed whether low serum vitamin D status contributes to racial disparity in albuminuria.

Methods

We examined the association between race and albuminuria (spot urinary albumin/creatinine ratio (ACR) ≥30) among non-Hispanic black and white nonpregnant adults who were free of renal impairment in the National Health and Nutrition Examination Survey (NHANES) from 2001–2006. We conducted analyses without and with serum 25(OH)D. We adjusted for age, sex, education level, smoking, body mass index (BMI), diabetes, diagnosis of hypertension, and use of antihypertensive medication.

Results

Albuminuria was present in 10.0% of non-Hispanic blacks and 6.6% in non-Hispanic whites. Being black (odds ratio (OR) 1.46; 95% confidence interval (CI) 1.23–1.73) was independently associated with albuminuria. There was a graded, inverse association between 25(OH)D level and albuminuria. Notably, the association between race and albuminuria was no longer significant (OR 1.19; 95% CI 0.97–1.47) after accounting for participants' serum 25(OH)D. Similar results were observed when participants with macroalbuminuria (ACR ≥300 mg/g) or elevated parathyroid hormone (>74 pg/ml) were excluded or when a continuous measure of 25(OH)D was substituted for the categorical measure. There were no interactions between race and vitamin D status though racial disparity in albuminuria was observed among participants with the highest 25(OH)D levels.

Conclusion

Suboptimal vitamin D status may contribute to racial disparity in albuminuria. Randomized controlled trials are needed to determine whether supplementation with vitamin analogues reduces risk for albuminuria or reduce racial disparity in this outcome.

Effects of race on albuminuria and risk of cardiovascular and kidney disease

The literature describing the relationship between urinary protein excretion and risk of cardiovascular disease and renal disease is rapidly proliferating. Several studies have demonstrated racial differences in the relationship between albuminuria and associated disorders. The purpose of this article is to summarize the effects of race on the relationship between albuminuria and renal and cardiovascular disease risk, propose explanatory hypotheses, and suggest directions for future investigation.

Microalbuminuria in relation to the metabolic syndrome and its components in a Chinese population

BACKGROUND

We investigated the prevalence of microalbuminuria and its association with the metabolic syndrome and its components in a Chinese population.

METHODS

The study subjects were recruited from a newly established residential area in the suburb of Shanghai. We measured anthropometry, blood pressure (BP), fasting plasma glucose, and serum lipids, and collected spot urine samples for the determination of albumin-creatinine ratio. We defined microalbuminuria as a urinary albumin-to-creatinine ratio of 30 to 299 mg/g. The metabolic syndrome was defined according to the International Diabetes Federation criteria.

RESULTS

The 1079 participants included 410 (38.0%) hypertensive patients, and 66 (6.1%) diabetic patients. The prevalence of microalbuminuria (4.3%) was 3.2 times higher in 167 patients with the metabolic syndrome than 912 subjects without the metabolic syndrome (12.0% vs. 2.9%, P < 0.0001). In multiple regression adjusted for sex, age, body mass index, current smoking, alcohol intake and the use of antihypertensive drugs, and mutually adjusted for the components, microalbuminuria was significantly associated with diastolic BP (odds ratio 1.74 for +10 mmHg; 95% confidence interval [CI] 1.10-2.76; P = 0.02) and fasting plasma glucose (1.18; 95% CI 1.01-1.41; P = 0.04), but not with waist circumference, systolic BP, or serum HDL cholesterol and triglycerides (P > 0.10).

CONCLUSIONS

Microalbuminuria is common in the Chinese population, and much more prevalent in the presence of the metabolic syndrome, mainly attributable to elevated diastolic BP and plasma glucose.

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.