Relationship between elevated morning blood pressure surge, uric acid, and cardiovascular outcomes in hypertensive patients

Assessing levels of uric acid and other cardiovascular markers in prehypertensive and hypertensive adults

INTRODUCTION

Although some studies have reported the association between uric acid (UA) and hypertension, evidence on prehypertension is still lacking. Therefore, the objective of this study was to determine the levels of UA and other cardiovascular markers among prehypertensive and hypertensive patients and assess their risk for developing arterial hypertension.

METHODS

157 individuals were recruited: 67 normotensive, 23 pre-hypertensive and 67 hypertensive. Blood samples were collected to measure biochemical parameters and anthropometric measurements and blood pressure were evaluated. We calculated the product of lipid accumulation and the visceral adiposity index to assess cardiovascular risk.

RESULTS

Our data showed an increase in UA levels in normotensives (4.9±1.3mg/dL), prehypertensives (5.2±1.3mg/dL) and hypertensives (5.9±1.6mg/dL) (p=0.004). We found a higher frequency of hyperuricemia in the hypertensive group (34.3%) than in the normotensive group (13.4%, p<0.05). Hypertensive volunteers had lower levels of HDL-C (p=0.004 and p=0.003) and higher body mass indexes (p<0.001 and p=0.007), glucose (p<0.001 and p=0.033), triglycerides (p=0.001 and p=0.005), visceral adiposity index (p<0.001 and p=0.002) and lipid accumulation product (p<0.001 and p=0.007) than normotensive and prehypertensive participants. We also observed that individuals with UA≥6.2mg/dL had an increased risk of hypertension of 4.77 (p=0.003) compared to individuals with levels≤4.3mg/dL.

CONCLUSION

Our results showed that UA is associated with increased blood pressure and unfavorable changes in anthropometric and biochemical parameters, which represent risk factors for hypertension and cardiovascular diseases.

Different Factors Associated with Morning Blood Pressure Surge in Antihypertensive-Naïve Dipper and Non-Dipper Subjects

The relationship between the morning blood pressure surge (MBPS) and cardiovascular risk is inconclusive. Previous studies have not taken into consideration dipping status in examining the MBPS and its associated factors. The aim was to examine factors associated with the MBPS in dippers and non-dippers. The MBPS was calculated by data obtained from ambulatory blood pressure monitoring, using the definition of sleep-trough morning surge. Dipping systolic blood pressure (DipSBP) was defined as [1 - (SBPsleeping/SBPawake)] × 100%. The value in milliseconds of standard deviation of normal-to-normal RR interval after waking up (SDNNaw) was calculated during the 2 h period after waking up. A total of 140 eligible subjects were divided into dippers (n = 62) and non-dippers (n = 78). Multiple regression analysis on data for all subjects revealed different correlations with the MBPS: positive in age, body mass index (BMI), and DipSBP, and inverse in cholesterol/high density lipoprotein-cholesterol (HDL-C) ratio, fasting blood glucose, and 2 h SDNNaw. When dippers were examined separately, age, female gender, and BMI correlated positively with MBPS, while cholesterol/HDL-C ratio and 2 h SDNNaw correlated negatively. For non-dippers, only age was associated with the MBPS. The factors associated with the MBPS were different for dippers and non-dippers. The MBPS seems to be a physiological response in this dipper group because age and BMI correlated positively with the MBPS, while parasympathetic neural activity after waking up and cholesterol/HDL-C ratio showed inverse correlations.

The assessment of hypertension in kidney transplant patients: time to change our approach?

Kidney transplantation (KT) is an increasingly utilized treatment for end-stage kidney disease. Hypertension either as a cause of kidney disease or as a complication of chronic kidney disease is the most frequently encountered comorbidity of KT patients. Hence, the management of hypertension in KT patients is crucial to prolong patient and graft survival. Ambulatory blood pressure monitoring (ABPM) appeared as a promising technique that has superiority over office and home blood pressure (BP) monitoring to correctly diagnose and manage hypertension. A recent meta-analysis by Pisano et al. including 42 studies with 4115 participants provided strong data for the comparison of ABPM with office BP monitoring in KT patients. In addition to the current literature knowledge, the findings of Pisano et al. filled the long-awaited evidence gap to suggest ABPM as a first-line BP monitoring technique for KT patients. Despite its disadvantages, such as patient discomfort, cost–effectiveness and limited availability, ABPM has crucial advantages in the management of hypertension including the detection of abnormal circadian BP patterns, the assessment of effects of physical activity and short-term variability of BP, and the exclusion of masked and white-coat hypertension.

Characterizing and Evaluating Diurnal Salivary Uric Acid Across Pregnancy Among Healthy Women

Uric acid levels during pregnancy have been examined as a potential indicator of risk for gestational diabetes mellites, hypertension, and related adverse birth outcomes. However, evidence supporting the utility of serum uric acid levels in predicting poor maternal and fetal health has been mixed. The lack of consistent findings may be due to limitations inherent in serum-based biomeasure evaluations, such as minimal repeated assessments and variability in the timing of these assessments. To address these gaps, we examined repeated measurements of diurnal salivary uric acid (sUA) levels in a sample of 44 healthy women across early-mid and late pregnancy. We assessed potential covariates and confounds of sUA levels and diurnal trajectories, as well as associations between maternal weight gain and blood pressure during pregnancy and sUA concentrations. Using multilevel linear models, we found sUA increased across pregnancy and displayed a robust diurnal pattern with the highest concentrations at waking, a steep decline in the early morning, and decreasing levels across the day. Maternal pre-pregnancy BMI, age, prior-night sleep duration, and fetal sex were associated with sUA levels and/or diurnal slopes. Maternal blood pressure and gestational weight gain also showed significant associations with sUA levels across pregnancy. Our results expand upon those found with serum UA measurements. Further, they demonstrate the feasibility of using at-home, minimally-invasive saliva sampling procedures to track UA levels across pregnancy with potential applications for the long-term monitoring of maternal cardiometabolic risk.

Morning blood pressure surge in the early stage of hypertensive patients impacts three-dimensional left ventricular speckle tracking echocardiography

BACKGROUND

The aim of this study was to examine left ventricular (LV) function in untreated, newly diagnosed hypertensive patients with morning blood pressure surge (MBPS) status using three-dimensional (3D) speckle tracking echocardiography (STE).

METHODS

In this study, 163 newly diagnosed hypertensive patients were included, and all patients underwent 24-h ambulatory blood pressure monitoring (ABPM). According to ABPM, participants were divided into a MBPS group and a non-MBPS group. The entire study population was examined by complete two-dimensional (2D) transthoracic echocardiography (TTE) and 3D STE.

RESULT

The results of this study showed that 3D LV longitudinal strain was significantly decreased in the MBPS group compared with the non-MBPS group (- 30.1 ± 2.0 vs. -31.1 ± 2.7, p = 0.045). Similar trends were observed for 3D twist (9.6 ± 6.1 vs. 12.1 ± 4.8, p = 0.011) as well as for 3D torsion (1.23 ± 0.78 vs. 1.49 ± 0.62, p = 0.042). The LV principal strain was decreased in the MBPS group (- 33.9 ± 1.7 vs. -35.5 ± 2.8, p < 0.001). The 3D LV global longitudinal strain (GLS) and principal strain were significantly associated with quartile of MBPS as measured by systolic blood pressure (SBP).

CONCLUSION

The 3D STE revealed that LV mechanics were more impaired in the MBPS group than in the non-surge newly diagnosed, untreated hypertensive patients; even the 2D TTE parameters showed no difference.

Association between Serum Uric Acid and Pre-hypertension and Hypertension among Chinese Adults

Fundamento

O ácido úrico (AU), produto final do metabolismo dos nucleotídeos das purinas, participa dos processos de doenças metabólicas e cardiovasculares. Evidências experimentais sugerem que o ácido úrico é um mediador importante na resposta fisiológica ao aumento da pressão arterial.

Objetivo

Avaliar a associação entre os níveis séricos de AU e pré-hipertensão e hipertensão em uma população chinesa.

Métodos

Conduziu-se um estudo transversal entre março e setembro de 2017, e 1.138 participantes com idades entre 35 e 75 anos foram incluídos neste estudo, onde 223 normotensos, 316 pré-hipertensos e 599 hipertensos foram selecionados para avaliar a associação entre níveis séricos de AU e hipertensão. Considerou-se um valor de p<0,05 estatisticamente significativo.

Resultados

Os níveis séricos de AU foram significativamente maiores no grupo pré-hipertensão e hipertensão em comparação com o grupo controle em toda a população (p<0,05 para todos). A análise quantitativa das características indicou níveis séricos de AU (2,92±0,81, 3,06±0,85, 3,22±0,98 mg/d) linearmente aumentados em mulheres normotensas, pré-hipertensas e hipertensas, com um valor de p de 0,008. Os níveis séricos de AU nos quartis correlacionaram-se positivamente com a PAD (p<0,05), principalmente em mulheres. Após o ajuste para idade, sexo, índice de massa corporal (IMC), glicose (GLI), colesterol total (CT), triglicerídeos (TG), colesterol HDL (lipoproteína de alta densidade), as razões de chances ( odds ratios — ORs) e intervalos de confiança (IC) de 95% da pré-hipertensão, dos níveis séricos de AU mais baixos (referentes) aos mais altos foram 1,718 (1,028–2,872), 1,018 (0,627–1,654) e 1,738 (1,003–3,010). Além disso, o segundo quartil dos níveis séricos de AU esteve significativamente associado à hipertensão, com uma OR (IC 95%) de 2,036 (1,256–3,298).

Conclusões

O presente estudo sugere que níveis séricos mais elevados de AU estão positivamente associados à pré-hipertensão e hipertensão entre adultos chineses.

Association of serum uric acid with mortality and cardiovascular outcomes in patients with hypertension: a meta-analysis

Studies on the association of uric acid with mortality and cardiovascular outcomes in patients with hypertension have produced contradictory results. The objective of this meta-analysis was to evaluate the prognostic utility of uric acid in hypertensive patients. We comprehensively searched PubMed and Embase databases (until July 31, 2020) to identify eligible studies that reported the association of uric acid with mortality and cardiovascular outcomes in hypertensive patients. Outcome measures included cardiovascular or all-cause mortality, coronary artery disease (CAD), stroke, and major adverse cardiovascular events (MACEs). Eleven eligible studies of 49,800 hypertensive patients were identified. For patients with the highest than those with reference lower group of uric acid level, the pooled hazard ratio (HR) was 1.51 (95% confidence interval [CI] 1.12-2.02) for all-cause mortality, 1.68 (95% CI 1.28-2.20) for cardiovascular mortality, 1.31 (95% CI 1.10-1.55) for CAD, and 1.48 (95% CI 1.28-1.70) for MACEs. However, there was no significant association between elevated uric acid level and incident stroke in hypertensive patients. This meta-analysis indicates that elevated uric acid level is significantly associated with an increased risk of cardiovascular or all-cause mortality, CAD and MACEs in hypertensive patients. Hypertensive patients with highest uric acid level exhibited a tendency for reduced risk of stroke, but the difference is not significant.

Cardiovascular events in hyperuricemia population and a cardiovascular benefit-risk assessment of urate-lowering therapies: a systematic review and meta-analysis

BACKGROUND

Hyperuricemia and gout have become public health concerns; many important guidelines have recommended xanthine oxidase inhibitors (XOIs) as the first-line urate-lowering therapies (ULTs) to treat chronic gout with hyperuricemia. However, whether treating hyperuricemia and gout with ULTs modifies cardiovascular risks remains controversial. The aim of this study was to assess the incident risk of cardiovascular (CV) events (CVE) in hyperuricemia population, assess the cardiovascular benefit-risk of ULTs in hyperuricemia patients with or without gout in diverse cardiovascular risk sub-groups, and specify the safety of different ULTs.

METHODS

We searched PubMed, Embase, the Cochrane Library, Wanfang, Chongqing VIP (CQVIP, en.cqvip.com), and China National Knowledge Infrastructure Database for prospective cohort studies and randomized controlled trials (RCTs) in English and Chinese. Potential medications included XOIs, and uricosurics. RCTs were divided into sub-groups analysis based on blinding status and patients' history of CV diseases. Risk ratios (RRs) were calculated and were reported with corresponding 95% confidence intervals (CIs) by fixed-effects or random-effects model.

RESULTS

Seven prospective cohort studies and 17 RCT studies were included. The risks of both major adverse cardiovascular events (MACE) (RR = 1.72, 95% CI 1.28-2.33) and CVE (RR = 1.35, 95% CI 1.12-1.62) were higher in the hyperuricemia population than non-hyperuricemia one. In seven RCT studies where XOIs were compared with no-treatment or placebo, the results of five low CV risk studies showed that XOIs lowered the risks of both MACE (RR = 0.35, 95% CI 0.20-0.62) and CVE (RR = 0.61, 95% CI 0.44-0.85); whereas two high CV risk studies showed that XOIs lowered the risk of CVE (RR = 0.69, 95% CI 0.54-0.88) rather than MACE (RR = 0.62, 95% CI 0.29-1.35). In nine RCT studies where the cardiovascular safety between febuxostat and allopurinol were compared, no statistical difference was found in the risk of MACE or CVE.

CONCLUSIONS

The hyperuricemia population does have a higher incidence of CVE, and the results suggested that XOIs might reduce the incidence of MACE and total CVE. In addition, from the perspective of cardiovascular safety, febuxostat equaled allopurinol in our meta-analysis.

Prognostic value of daytime and nighttime blood pressure in treated hypertensive patients according to age and sex

The authors assessed the prognostic value of daytime and nighttime blood pressure (BP) in adult (≤65 years) or old (> 65 years) women or men with treated hypertension. Cardiovascular outcomes were evaluated in 2264 patients. During the follow-up (mean 10 years), 523 cardiovascular events occurred. After adjustment for covariates, both daytime and nighttime systolic BP were always associated with outcomes, that is, hazard ratio (95% confidence interval per 10 mm Hg increment) 1.22 (1.04-1.43) and 1.20 (1.04-1.37), respectively, in adult women, 1.30 (1.18-1.43) and 1.21 (1.10-1.33), respectively, in adult men, 1.21 (1.10-1.33) and 1.18 (1.07-1.31), respectively, in old women, and 1.16 (1.01-1.33) and 1.28 (1.14-1.44), respectively, in old men. When daytime and nighttime systolic BP were further and mutually adjusted, daytime and nighttime BP had comparable prognostic value in adult and old women, daytime BP remained associated with outcomes in adult men (hazard ratio 1.40, 95% confidence interval 1.13-1.74 per 10 mm Hg increment), and nighttime BP remained associated with outcomes in old men (hazard ratio 1.35, 95% confidence interval 1.11-1.64 per 10 mm Hg increment). Daytime and nighttime systolic BP have similar prognostic impact in adult and old women with treated hypertension, whereas daytime BP is a stronger predictor of risk in adult men and nighttime BP is a stronger predictor of risk in old men.

The association of urinary uric acid excretion with ambulatory blood pressure values in patients with chronic kidney disease

BACKGROUND

To analyze the association between hypertension and urinary uric acid excretion in patients with chronic kidney disease (CKD).

METHODS

We screened 87 patients who had been admitted at the Dept of Nephrology, Huadong hospital between April 2017 to April 2019 who had completed 24-h ambulatory blood pressure monitoring and retained 24-h urine biochemical test specimens, thirty adult patients (age ≤ 65 years) with CKD 1-2 stages were recruited in the study. Pearson's correlation analysis and multiple linear regression analysis were used to study the correlation of urinary uric acid excretion with ambulatory blood pressure values and the association of morning mean diastolic pressure (mMDP), night mean diastolic pressure (nMDP) and CV of dMSP (coefficient of variation of day mean systolic pressure) with fractional excretion of uric acid (FEua) and uric acid clearance rate (Cur). Independent T test was used to compare the differences of blood pressure values in FEua1 (FEua< 6.0%) and FEua2 (FEua≥6.0%) or Cur1 (Cur < 6.2 ml/min/1.73 m2) and Cur2 (Cur ≥ 6.2 ml/min/1.73m2) groups according to the median of FEua or Cur, respectively.

RESULTS

After adjusting for confounding factors, multiple linear regression analysis showed that FEua was positively associated with the mMDP and nMDP, Cur was positively associated with CV of dMSP. Levels of mMDP and nMDP in FEua1 group was lower than that in FEua2 group (both P < 0.05), level of CV of dMSP in Cur2 group were higher than that in Cur1 group (P < 0.01).

CONCLUSIONS

We demonstrated that there is a positive correlation of FEua with morning and night mean diastolic pressure separately and Cur is positively related to CV of dMSP in CKD population. Monitoring the trend of urinary uric acid, may have a role in the early detection for hypertension or relative risks in the population of CKD.

Protective role of melatonin in cardiac ischemia-reperfusion injury: From pathogenesis to targeted therapy

Acute myocardial infarction (MI) is a major cause of mortality and disability worldwide. In patients with MI, the treatment option for reducing acute myocardial ischemic injury and limiting MI size is timely and effective myocardial reperfusion using either thombolytic therapy or primary percutaneous coronary intervention (PCI). However, the procedure of reperfusion itself induces cardiomyocyte death, known as myocardial reperfusion injury, for which there is still no effective therapy. Recent evidence has depicted a promising role of melatonin, which possesses powerful antioxidative and anti-inflammatory properties, in the prevention of ischemia-reperfusion (IR) injury and the protection against cardiomyocyte death. A number of reports explored the mechanism of action behind melatonin-induced beneficial effects against myocardial IR injury. In this review, we summarize the research progress related to IR injury and discuss the unique actions of melatonin as a protective agent. Furthermore, the possible mechanisms responsible for the myocardial benefits of melatonin against reperfusion injury are listed with the prospect of the use of melatonin in clinical application.

Morning blood pressure monitoring in the management of hypertension

: The aim of the current article is to review the current evidence on the role of morning blood pressure (BP) in the management of hypertension. Morning BP surge had been and will continue to be a hot topic of hypertension research. However, more evidence is needed to prove its clinical usefulness in the management of hypertension. Masked morning hypertension, as the other forms of masked hypertension, requires more research. The concept of morning BP monitoring could be clinically relevant in the therapeutic management of hypertension and in the prevention of cardiovascular complications by defining and treating morning hypertension. Antihypertensive medication is usually taken in the morning. The presence of uncontrolled morning BP during trough effect hours could be a hallmark of inadequate antihypertensive regimen, such as, for instance, the use of short-acting or intermediate-acting drugs, under dosing of drugs, or no or low use of combination therapy. To improve the management of hypertension in general and morning hypertension in particular, long-acting antihypertensive drugs should be used in appropriate often full dosages and in proper combinations. The clinical usefulness of antihypertensive drugs of specific mechanisms against morning BP or split or timed dosing of long-acting drugs in controlling morning BP remains under investigation. In conclusion, there is some evidence that morning BP is critical in the incidence of cardiovascular complications. However, proving its clinical usefulness in the management of hypertension requires further research.

Effects of serum uric acid on blood-pressure lowering treatment

If hyperuricemia is an independent risk factor in blood-pressure control, urate-lowering therapy should be used to reduce cardiovascular risk. It may also act as a prognostic marker of other abnormalities. This review presents current evidence on the relationship between hyperuricemia and hypertension.

Prognostic Value of Nondipping and Morning Surge in Elderly Treated Hypertensive Patients With Controlled Ambulatory Blood Pressure

BACKGROUND

The independent prognostic significance of nondipping and morning surge (MS) of blood pressure (BP) in treated hypertensive patients with controlled ambulatory BP is not yet clear. We investigated the association between the aforesaid ambulatory BP parameters and cardiovascular risk in elderly treated hypertensive patients with normal achieved ambulatory BP.

METHODS

The occurrence of a composite end-point (stroke, coronary events, heart failure, and peripheral revascularization) was evaluated in 391 elderly treated hypertensive patients (age range 60-90 years) with controlled ambulatory BP (both daytime BP <135/85 mm Hg and nighttime BP <120/70 mm Hg). According to nighttime change and MS of systolic BP, subjects were divided in dippers with normal or high MS (>23 mm Hg) and nondippers.

RESULTS

During the follow-up (9.3 ± 4.6 years, range 0.5-20 years), 76 events occurred. The event-rate was 2.09 per 100 patient-years. After adjustment for age, gender, left ventricular (LV) hypertrophy, asymptomatic LV systolic dysfunction at baseline and left atrial enlargement, dippers with high MS (hazard ratio 2.45, 95% confidence interval 1.27-4.73, P = 0.007) and nondippers (hazard ratio 2.04, 95% confidence interval 1.18-3.53, P = 0.01) were at higher cardiovascular risk than dippers with normal MS.

CONCLUSIONS

In elderly treated hypertensive patients with normal achieved ambulatory BP, dippers with high MS and nondippers are at increased cardiovascular risk.

Morning Blood Pressure Surge as a Predictor of Outcome in Patients with Essential Hypertension

OBJECTIVE

To determine the usefulness of monitoring morning blood pressure surge (MBPS) to predict cardiovascular events in patients with essential hypertension.

MATERIALS AND METHODS

A total of 81 patients (43 males and 38 females) with a mean age of 55.9 ± 9.8 years with essential hypertension were included in the study. Twenty-four hour ambulatory blood pressure (BP) monitoring was carried out to record MBPS. All patients were followed up for 36 months for cardiovascular events.

RESULTS

Mean MBPS was 26.23 ± 10.17 mmHg. Nineteen patients (23%) who experienced a cardiovascular event during the follow-up period had higher MBPS than patients who did not experience a cardiovascular event (P < 0.0001). MBPS was positively correlated with interventricular septum thickness (r = +0.38 and P = 0.000), left atrial size (r = +0.39 and P = 0.000), 24-h mean systolic BP (r = +0.36 and P = 0.001) and total cholesterol level (r = +0.23 and P = 0.003). MBPS was negatively correlated with high-density lipoprotein-cholesterol (r = -0.37 and P = 0.001).

CONCLUSION

MBPS can be used as a biomarker for a cardiovascular disease event in hypertensive patients.

Serum uric acid and acute kidney injury: A mini review

Acute kidney injury causes great morbidity and mortality in both the community and hospital settings. Understanding the etiological factors and the pathophysiological principles resulting in acute kidney injury is essential in prompting appropriate therapies. Recently hyperuricemia has been recognized as a potentially modifiable risk factor for acute kidney injury, including that associated with cardiovascular surgery, radiocontrast administration, rhabdomyolysis, and associated with heat stress. This review discussed the evidence that repeated episodes of acute kidney injury from heat stress and dehydration may also underlie the pathogenesis of the chronic kidney disease epidemic that is occurring in Central America (Mesoamerican nephropathy). Potential mechanisms for how uric acid might contribute to acute kidney injury are also discussed, including systemic effects on renal microvasculature and hemodynamics, and local crystalline and noncrystalline effects on the renal tubules. Pilot clinical trials also show potential benefits of lowering uric acid on acute kidney injury associated with a variety of insults. In summary, there is mounting evidence that hyperuricemia may have a significant role in the development of acute kidney injury. Prospective, placebo controlled, randomized trials are needed to determine the potential benefit of uric acid lowering therapy on kidney and cardio-metabolic diseases.

Hypertension, Blood Pressure Variability, and Target Organ Lesion

Hypertensive patients have a higher risk of developing health complications, particularly cardiovascular (CV) events, than individuals with normal blood pressure (BP). Severity of complications depends on the magnitude of BP elevation and other CV risk factors associated with the target organ damage. Therefore, BP control and management of organ damage may contribute to reduce this risk. BP variability (BPV) has been considered a physiological marker of autonomic nervous system control and may be implicated in increased CV risk in hypertension. This review will present some evidence relating BPV and target organ damage in hypertension in clinical and experimental settings.

Morning Blood Pressure Surge as a Predictor of Development of Chronic Kidney Disease

Blood pressure (BP) usually increases upon awakening--a physiological mechanism called morning BP surge (MBPS). BP values above the MBPS threshold are associated with target organ damage, including left ventricular hypertrophy and proteinuria. Despite these data, there have been no studies that have investigated the association between elevated MBPS and the development of incident chronic kidney disease (CKD). In this study, patients with essential hypertension were included and underwent ambulatory BP measurements and MBPS. Patients were followed for a median of 3.33 years. In total, 622 patients were enrolled. The mean age of patients was 57.6±12.4 years, 54.0% were men, 16.7% had diabetes, and 10.6% had prevalent cardiovascular disease. During follow-up, 32 patients developed CKD. Higher MBPS, analyzed both as continuous and categorical variables, was associated with incident CKD in all models. Elevated MBPS is associated with kidney function deterioration and the development of CKD. Studies are needed to further examine underlying mechanisms regarding MBPS and these renal outcomes.

Uric Acid is a Useful Tool to Predict Contrast-Induced Nephropathy

Developing contrast-induced nephropathy (CIN) after primary percutaneous coronary intervention (pPCI) has a negative impact on survival and morbidity. We assessed the predictive value of serum uric acid (SUA) for the development of CIN in patients with ST-segment elevation myocardial infarction (STEMI) who underwent pPCI. Contrast-induced nephropathy was defined an increase of ≥25% or ≥0.5 mg/dL in creatinine concentrations within 72 hours after pPCI. Patients were divided into 2 groups according to admission median SUA level. Serum uric acid level was <5.4 mg/dL (group 1; n = 222) and ≥5.4 mg/dL (group 2; n = 228). Compared to group 1, development of CIN (12% vs 20%, P < .001) was significantly greater in group 2. Using a cut point of >5.45 mg/dL, the SUA level predicted development of CIN with a sensitivity of 70% and specificity of 67%. In multiple logistic regression analysis, SUA level, diabetes mellitus, left ventricular ejection fraction <50%, contrast volume, estimated glomerular filtration rate, and C-reactive protein level emerged as independent predictors of CIN. In conclusion, elevated SUA is an independent risk factor for the development of CIN after pPCI in patients with STEMI.

Morning Blood Pressure Surge, Dipping, and Risk of Coronary Events in Elderly Treated Hypertensive Patients

BACKGROUND

The independent prognostic significance of morning surge (MS) of blood pressure (BP) is not yet clear. We investigated the association between MS of systolic BP and risk of coronary events in elderly treated hypertensive patients.

METHODS

The occurrence of coronary events was evaluated in 1,191 elderly treated hypertensive patients (age range 60-90 years). Subjects were divided according to tertiles of MS of systolic BP of the population as a whole, by dipping status and by group-specific tertiles of MS of systolic BP in dippers and nondippers.

RESULTS

During the follow-up (9.1 ± 4.9 years, range 0.4-20 years), 120 coronary events occurred. In the population as a whole, coronary event risk was not significantly associated with tertiles of MS of systolic BP, whereas nondippers were at higher risk than dippers. When nondippers and dippers were analyzed separately, by group-specific tertiles of MS of systolic BP, coronary event risk was associated with MS of systolic BP in dippers but not in nondippers. After adjustment for various covariates, Cox regression analysis showed that dippers in the third tertile (>23 mm Hg) of MS of systolic BP (hazard ratio 1.912, 95% confidence interval 1.048-3.488, P = 0.03) and nondippers (hazard ratio 1.739, 95% confidence interval 1.074-2.815, P = 0.02) were at higher coronary event risk than dippers with MS of systolic BP <23 mm Hg .

CONCLUSIONS

In elderly treated hypertensive patients, high MS of systolic BP predicts coronary events in dippers but not in nondippers. Nondippers, however, show higher risk of coronary events independently of MS in systolic BP.

Association of Serum Uric Acid Level With Blood Pressure Variability in Newly Diagnosed Essential Hypertension

Serum uric acid (UA) is independently associated with hypertension and blood pressure (BP) variability (BPV) is associated with cardiovascular events and mortality in hypertensive patients. The aim of the present study was to assess the association of serum UA with BPV in 300 untreated essential hypertension patients (mean age 57.3±13.6 years). BPV was quantified as the standard deviation (SD) of the 24-hour, daytime, and nighttime mean values obtained by using ambulatory BP monitoring. In correlation analysis, log UA values were found to be positively correlated with 24-hour systolic BPV and nighttime systolic and diastolic BPV (Pearson coefficients of 0.246, 0.280, and 0.353, respectively; P<.001 for all). In multivariate analysis, log UA had an independent association with 24-hour systolic BPV and nighttime systolic and diastolic BPV. This study show for the first time that increased serum UA is independently associated with BPV in untreated essential hypertension patients.

Modifiable risk factors for increased arterial stiffness in outpatient nephrology

Arterial stiffness, as measured by pulse wave velocity (PWV), is an independent predictor of cardiovascular events and mortality. Arterial stiffness increases with age. However, modifiable risk factors such as smoking, BP and salt intake also impact on PWV. The finding of modifiable risk factors may lead to the identification of treatable factors, and, thus, is of interest to practicing nephrologist. We have now studied the prevalence and correlates of arterial stiffness, assessed by PWV, in 191 patients from nephrology outpatient clinics in order to identify modifiable risk factors for arterial stiffness that may in the future guide therapeutic decision-making. PWV was above normal levels for age in 85/191 (44.5%) patients. Multivariate analysis showed that advanced age, systolic BP, diabetes mellitus, serum uric acid and calcium polystyrene sulfonate therapy or calcium-containing medication were independent predictors of PWV. A new parameter, Delta above upper limit of normal PWV (Delta PWV) was defined to decrease the weight of age on PWV values. Delta PWV was calculated as (measured PWV) - (upper limit of the age-adjusted PWV values for the general population). Mean±SD Delta PWV was 0.76±1.60 m/sec. In multivariate analysis, systolic blood pressure, active smoking and calcium polystyrene sulfonate therapy remained independent predictors of higher delta PWV, while age, urinary potassium and beta blocker therapy were independent predictors of lower delta PWV. In conclusion, arterial stiffness was frequent in nephrology outpatients. Systolic blood pressure, smoking, serum uric acid, calcium-containing medications, potassium metabolism and non-use of beta blockers are modifiable factors associated with increased arterial stiffness in Nephrology outpatients.

Serum Uric Acid, Gender, and Low Ankle Brachial Index in Adults With High Cardiovascular Risk

Uric acid (UA) has been reported to be associated with cardiovascular disease (CVD) in caucasians. However, it is unclear whether this association remains significant in a Chinese population. The present study aimed to investigate the association between UA and low ankle brachial index (ABI), a measurement of peripheral arterial disease, in Chinese patients. A total of 6262 hospital-based patients with high CVD risk were enrolled. Low ABI was defined as ABI ≤0.9 in either side. Low ABI was detected in 1390 (22.2%) patients. Higher UA was significantly associated with higher risk of low ABI and modified by gender (P = .0045). After adjusting for age, body mass index, total cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein, fasting glucose, hypertension, and smoking, participants in the highest quartile of UA exhibited 37% (odds ratio [OR]:1.37, 95% confidence interval [CI]: 1.03-1.82) higher risk of low ABI compared to those in the lowest quartile in men, while OR (95% CI) was 1.69 (1.29-2.22) for women. However, when kidney function was further adjusted, the associations were attenuated in both men and women and were significant only in women. The results were suggestive of higher UA associating with higher risk of low ABI in women, and the association was largely driven by kidney function, especially in men.