High normal urine albumin-to-creatinine ratio predicts development of hypertension in Korean men

Clinical Significance of Altered Vascular Morphology and Function in Normotension

PURPOSE OF REVIEW

To review current literature examining the presence of subclinical micro- and macrovascular alterations in normotensive individuals and their clinical significance in terms of hypertension prediction. Emphasis is placed on alterations that can be detected in peripheral vascular beds using non-invasive, easily applicable methodology, as these are in general easier to capture and evaluate in clinical practice compared to more complex invasive or functional tests.

RECENT FINDINGS

Arterial stiffness, increased carotid intima-media thickness, and altered retinal microvascular diameters predict the progression from the normotensive to the hypertensive state. By contrast, there is substantial lack of relevant prospective studies for skin microvascular alterations. Although conclusions regarding causality cannot be safely deduced from available studies, detection of morphological and functional vascular alterations in normotensive individuals emerges as a sensitive indicator of progression to hypertension and hence increased CVD risk. An increasing amount of evidence suggests that early detection of subclinical micro- and macrovascular alterations would be clinically useful for the early identification of individuals at high risk for future hypertension onset. Methodological issues and gaps in knowledge need to be addressed before detection of such changes could guide the development of strategies to prevent new-onset hypertension in normotensive individuals.

Longitudinal changes in blood pressure are preceded by changes in albuminuria and accelerated by increasing dietary sodium intake

BACKGROUND

Dietary sodium is a well-known risk factor for cardiovascular and renal disease; however, direct evidence of the longitudinal changes that occur with aging, and the influence of dietary sodium on the age-associated alterations are scarce.

METHODS

C57BL/6 mice were maintained for 13 months on a low (LS, 0.02 % Na+), normal (NS, 0.3 % Na+) or high (HS, 1.6 % Na+) salt diet. We assessed 1) the longitudinal trajectories for two markers of cardiovascular and renal dysfunction (blood pressure (BP) and albuminuria), as well as hormonal changes, and 2) end-of-study cardiac and renal parameters.

RESULTS

The effect of aging on BP and kidney damage did not reach significance levels in the LS group; however, relative to baseline, there were significant increases in these parameters for animals maintained on NS and HS diets, starting as early as month 7 and month 5, respectively. Furthermore, changes in albuminuria preceded the changes in BP relative to baseline, irrespective of the diet. Circulating aldosterone and plasma renin activity displayed the expected decreasing trends with age and dietary sodium loading. As compared to LS - higher dietary sodium consumption associated with increasing trends in left ventricular mass and volume indices, consistent with an eccentric dilated phenotype. Functional and molecular markers of kidney dysfunction displayed similar trends with increasing long-term sodium levels: higher renovascular resistance, increased glomerular volumes, as well as higher levels of renal angiotensin II type 1 and mineralocorticoid receptors, and lower renal Klotho levels.

CONCLUSION

Our study provides a timeline for the development of cardiorenal dysfunction with aging, and documents that increasing dietary salt accelerates the age-induced phenotypes. In addition, we propose albuminuria as a prognostic biomarker for the future development of hypertension. Last, we identified functional and molecular markers of renal dysfunction that associate with long-term dietary salt loading.

Preoperative proteinuria may be a risk factor for postoperative acute kidney injury：a meta-analysis

Objective

To investigate the relationship between preoperative proteinuria and postoperative acute kidney injury (AKI).

Methods

We performed a search on databases included PubMed, Embase, the Cochrane Library, and Web of Science, from December 2009 to September 2020. Data extracted from eligible studies were synthesized to calculate the odds ratio (OR) and 95% confidence interval (CI). A fixed or random effects model was applied to calculate the pooled OR based on heterogeneity through the included studies.

Results

This meta-analysis of 11 observational studies included 203,987 participants, of whom 21,621 patients suffered from postoperative AKI and 182,366 patients did not suffer from postoperative AKI. The combined results demonstrated that preoperative proteinuria is an independent risk factor for postoperative AKI (adjusted OR = 1.65, 95%CI:1.44–1.89, p < 0.001). Subgroup analysis showed that both preoperative mild proteinuria (adjusted OR = 1.30, 95%CI:1.24–1.36, p < 0.001) and preoperative heavy proteinuria (adjusted OR = 1.93, 95%CI:1.65–2.27, p < 0.001) were independent risk factors for postoperative AKI. The heterogeneity was combined because its values were lower. Further subgroup analysis found that preoperative proteinuria measured using dipstick was an independent risk factor for postoperative AKI (adjusted OR = 1.48, 95%CI:1.37–1.60, p < 0.001). Finally, preoperative proteinuria was an independent risk factor for postoperative AKI in the non-cardiac surgery group (adjusted OR = 2.06, 95%CI:1.31–3.24, p = 0.002) and cardiac surgery group (adjusted OR = 1.69, 95%CI:1.39–2.06, p < 0.001)

Conclusion

Preoperative proteinuria is an independent risk factor for postoperative AKI and in instances when proteinuria is detected using dipsticks.

Urine albumin-to-creatinine ratio within the normal range and risk of hypertension in the general population: A meta-analysis

Inconsistent findings on the association between urine albumin‐to‐creatinine ratio (UACR) and risk of hypertension have been reported. This meta‐analysis sought to evaluate the association between the elevated level of UACR within the normal range and incident hypertension in the general population. We comprehensively searched PubMed and Embase databases until July 31, 2020. All longitudinal observational studies that assessed the association of elevated baseline level of UACR within the normal range with incident hypertension in the general population were included. The predictive value was estimated by pooling risk ratio (RR) with 95% confidence intervals (CI) for the highest versus the lowest category of UACR level. Nine articles (10 studies) involving 27 771 individuals were identified and analyzed. When compared with the lowest category of UACR, individuals with the highest UACR had a 1.75‐fold (RR 1.75; 95% CI 1.47–2.09; p < .001) higher risk of hypertension in a random effect model. Gender‐specific analysis indicated that the impact of UACR on the development of hypertension seemed to be stronger in women (RR 2.47; 95% CI 1.10–5.55; p = .029) than in men (RR 1.88; 95% CI 1.35–2.61; p < .001). An increased UACR within the normal range is independently associated with a higher risk of hypertension in the general population. Baseline UACR can be served as a predictor of incident hypertension in the general population.

A novel predicted model for hypertension based on a large cross-sectional study

Hypertension is a global public health issue and leading risk for death and disability. It is urgent to search novel methods predicting hypertension. Herein, we chose 73158 samples of physical examiners in central China from June 2008 to June 2018. After strict exclusion processes, 33570 participants with hypertension and 35410 healthy controls were included. We randomly chose 70% samples as the train set and the remaining 30% as the test set. Clinical parameters including age, gender, height, weight, body mass index, triglyceride, total cholesterol, low-density lipoprotein, blood urea nitrogen, uric acid, and creatinine were significantly increased, while high-density lipoprotein was decreased in the hypertension group versus controls. Nine optimal markers were identified by a logistic regression model, and achieved AUC value of 76.52% in the train set and 75.81% in the test set for hypertension. In conclusions, this study is the first to establish predicted models for hypertension using the logistic regression model in Central China, which provide risk factors and novel prediction method to predict and prevent hypertension.

Relationship between subtle urinary albumin excretion and risk of incident hypertension: modification by glomerular filtration rate

It has been reported that an increase in urinary albumin excretion (UAE) within the normal range could be a risk factor for incident hypertension. However, it remains unclear how the subtle increases in UAE and renal function interact in the development of hypertension. We examined the modification of UAE as a risk factor for incident hypertension by glomerular filtration rate (GFR) in the Japanese population. We prospectively followed 1281 normotensive individuals from Watari town (34.3% men; mean age, 58.0±12.3 years old) whose UAE was <30 mg g⁻¹· Cr. Hypertension was diagnosed as a systolic blood pressure (BP)⩾140 mm Hg and/or a diastolic BP⩾90 mm Hg, or antihypertensive medication use. The relationship between sex-specific quartiles of UAE and incident hypertension was examined with Cox proportional hazard analysis. During a mean follow-up of 3.7 years, 315 individuals developed hypertension. Multivariate Cox proportional hazard analysis revealed that a subtle increase in UAE was a risk factor for incident hypertension, but there was a significant interaction between UAE and estimated GFR (eGFR) (P=0.018). The risk of incident hypertension dose dependently increased in the highest eGFR quartile (⩾90 ml min⁻¹ per 1.73 m²). Decline in renal function alone increased the risk of incident hypertension but the increased risk with a subtle increase in UAE became smaller and less clear in the lower eGFR quartiles. The present data suggest that UAE as a risk factor for incident hypertension is largely dependent on eGFR levels.

Effects of acupuncture on the urinary metabolome of spontaneously hypertensive rats

BACKGROUND

The mechanism of action underlying the putative effects of acupuncture in essential hypertension remains unknown but neuronal mechanisms have been explored most extensively to date. We aimed to explore the effects of manual acupuncture (MA) with manual stimulation on blood pressure (BP) and urine metabolites in the spontaneously hypertensive rat (SHR) model of hypertension.

METHODS

After adaptive feeding (with a standard laboratory diet and distilled water) for 1 week, five normotensive Wistar Kyoto (WKY) rats with normal BP formed the control group. Ten SHRs were randomised into two groups (n=5 each), one of which received MA at ST9 for a total of 14 days (SHR+MA group). The other (SHR group) and the WKY control group underwent needle insertion without manual stimulation. BP was measured pre- and post-acupuncture in all groups and urinary metabolic profiles were investigated using metabonomics methods based on ¹H nuclear magnetic resonance (NMR) spectroscopy coupled with principal component analysis, partial least squares discriminant analysis, and orthogonal to partial least squares discriminant analysis.

RESULTS

A total of 46 metabolites were clearly separated in the urine by ¹H NMR. Loading plots showed significant changes in urinary metabolite contents after acupuncture treatment as well as significant differences between SHR and WKY rats. Acupuncture at ST9 in SHRs increased urine metabolites including α-ketoglutaric acid, N-acetyl glutamic acid, and betaine. Furthermore, systolic and diastolic BP, mean arterial pressure and heart rate were significantly reduced after acupuncture.

CONCLUSIONS

Acupuncture may decrease BP in SHRs by improving the metabolic disorder associated with hypertension.

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.

Association between Urine Albumin-to-Creatinine Ratio within the Normal Range and Incident Hypertension in Men and Women

PURPOSE

There have been few studies on gender difference in the impact of a urine albumin-to-creatinine ratio (UACR) within the normal range on the risk of hypertension. We evaluated whether the association between the UACR below the microalbuminuria range and the incident risk of hypertension is different between men and women.

MATERIALS AND METHODS

A total of 1173 individuals (442 men and 731 women) aged 40 to 70 years without hypertension was examined at baseline (2005-2008) and followed (2008-2011). We defined the UACR as the amount of albumin (mg/dL) divided by creatinine (g/dL) in randomly voided urine. The subjects were classified according to UACR tertile.

RESULTS

During an average of 2.6 years of follow-up, 57 men (12.9%) and 66 women (9.0%) developed hypertension. In multivariable-adjusted models, the odds ratio for new-onset hypertension comparing the highest and lowest tertiles of UACR was 1.83 [95% confidence interval (CI) 0.85-3.94] in men and 2.69 (95% CI 1.27-5.73) in women. In stratified analyses by menopausal status, higher tertiles of UACR were associated with an increased risk of incident hypertension in postmenopausal women.

CONCLUSION

Higher normal UACR levels were associated with an increased risk of incident hypertension in women. The UACR could have a clinical role in predicting the development of hypertension.

Association of Estimated Glomerular Filtration Rate and Proteinuria With Lipid-Rich Plaque in Coronary Artery Disease

BACKGROUND

Estimated glomerular filtration rate (eGFR) and proteinuria are both important determinants of the risk of cardiovascular disease and mortality. The aim of the present study was to investigate the independent and combined effects of eGFR and proteinuria on tissue characterization of the coronary plaques of culprit lesions.

METHODS AND RESULTS

Conventional intravascular ultrasound and 3-D integrated backscatter intravascular ultrasound (IB-IVUS) were performed in 555 patients undergoing elective percutaneous coronary intervention. They were divided into 2 groups according to the absence or presence of proteinuria (dipstick result ≥1+). Patients with proteinuria had coronary plaque with significantly greater percentage lipid volume compared with those without (43.6±14.8% vs. 48.6±16.1%, P=0.005). Combined analysis was done using eGFR and absence or presence of proteinuria. Subjects with eGFR 45-59 ml/min/1.73 m2 and proteinuria were significantly more likely to have higher percent lipid volume compared with those with eGFR >60 ml/min/1.73 m2 without proteinuria. After multivariate adjustment for confounders, the presence of proteinuria proved to be an independent predictor for lipid-rich plaque (OR, 1.85; 95% CI: 1.12-3.06, P=0.016).

CONCLUSIONS

The addition of proteinuria to eGFR level may be of value in the risk stratification of patients with coronary artery disease.

Normal range albuminuria and metabolic syndrome in South Korea: the 2011-2012 Korean National Health and Nutrition Examination Survey

Background

It is well-known that there is a close relationship between metabolic syndrome (MetS) and microalbuminuria. However, some recent studies have found that even normal range albuminuria was associated with MetS and cardiometabolic risk factors. The purpose of this study is to analyze the relationship between MetS and normal range albuminuria and to calculate the cutoff value for albuminuria that correlates with MetS in the representative fraction of Korean population.

Methods

Data were obtained from the 2011–2012 Korea National Health and Nutrition Examination Survey and included 9,650 subjects aged ≥19 years. We measured metabolic parameters: fasting blood glucose, waist circumference, blood pressure, and lipids, and albumin-to-creatinine ratio (ACR). The optimal ACR cutoff points for MetS were examined by the receiver operating characteristic curve. Multivariate logistic regression was used to obtain the prevalence of MetS and its components according to the ACR levels.

Results

The first cutoff value of ACR were 4.8 mg/g for subjects with ≥3 components of MetS. There was a graded association between ACR and prevalence of MetS and its components. If ACR was <4 mg/g, there was no significant increase in the prevalence of MetS or its components. From the ACR level of 4–5 mg/g, the prevalence of MetS significantly increased after adjusting for age, sex, body mass index, smoking, alcohol intake, exercise, and medications for diabetes mellitus and hypertension (odds ratio; 95% confidence intervals = 1.416; 1.041–1.926).

Conclusions

Albuminuria within the normal range (around 5 mg/g) was associated with prevalence of MetS in the Korean population.

An analysis of long-term occurrence of renal complications following pediatric pyeloplasty

OBJECTIVE

Few reports discuss post-pubertal renal complications after pyeloplasty. We analyzed long-term complications, such as decreased renal function (RF) measured by serum creatinine (SCr), hypertension (HTN), or proteinuria (protU) following pediatric pyeloplasty.

SUBJECTS AND METHODS

We retrospectively investigated 257 patients who underwent dismembered pyeloplasty due to ureteropelvic junction obstruction from January 1986 to December 2001. Medical history, preoperative and postoperative blood pressure, urinalysis, and SCr results were reviewed.

RESULTS

Fifty-five patients (47 male, 8 female) who were followed up for at least 10 years with post-pubertal follow-up data available were analyzed. Seven (12.7%) patients were diagnosed with HTN, and 10 (18.2%) with protU. The grade of hydronephrosis decreased, and the differential RF measured by MAG-3 renal scan significantly increased at final analysis (p<0.001). Presence of preoperative symptoms (p=0.034), and SCr elevation (p=0.018) showed correlation with HTN. HTN took 15.7 (±5.8) (7-25) years, and protU detection took 16.2 (±5.9) (6-23) years, with the highest incidence of both HTN and protU between 15 and 20 years postoperatively.

CONCLUSION

According to our investigation, a prudent evaluation of signs of RF decrease at 10 years after surgery, and then every 5 years, until 20 years should be recommended, although further studies are necessary.