Use of Plasma B-Type Natriuretic Peptide Level to Identify Asymptomatic Hypertensive Patients with Abnormal Diurnal Blood Pressure Variation Profiles: Nondippers, Extreme Dippers, and Risers

Associations of Ambulatory Blood Pressure Measurements With High-Sensitivity Troponin and Natriuretic Peptide Levels in SPRINT

BACKGROUND

Nighttime blood pressure (BP) has greater prognostic importance for cardiovascular disease (CVD) than daytime BP, but less is known about nighttime and daytime BP associations with measures of subclinical CVD.

METHODS

Among 897 Systolic Blood Pressure Intervention Trial Study (SPRINT) participants with 24-hour ambulatory BP monitoring obtained near the 27-month study visit, 849 (95%) had N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) measured at the 24-month study visit. Multivariable linear regression analyses were performed to evaluate the associations of nighttime and daytime BP with cardiac biomarker levels.

RESULTS

The mean age was 69 ± 12 years, 28% were African American, and mean nighttime and daytime SBP were 121 ± 16 mm Hg and 132 ± 14 mm Hg, respectively. In multivariable models, compared with the lowest tertile of nighttime systolic BP, the highest tertile was associated with 48% higher NT-proBNP levels (adjusted geometric mean ratio [GMR] = 1.48, 95% CI: 1.22, 1.79), and 19% higher hs-cTnT levels (adjusted GMR = 1.19, 95% CI: 1.07, 1.32). In contrast, the highest vs. lowest tertile of daytime systolic BP was not associated with NT-proBNP (adjusted GMR = 1.09, 95% CI: 0.88, 1.34), but was associated with 16% higher hs-cTnT levels (adjusted GMR = 1.16, 95% CI: 1.04, 1.30). Similar results were observed using diastolic BP.

CONCLUSIONS

In SPRINT, both higher nighttime and daytime BP were independently associated with higher hs-cTnT levels, but only higher nighttime BP was associated with higher NT-proBNP levels.

Maximum carotid intima-media thickness and NT-pro BNP in association with retinal vein occlusion

The purpose is to clarify the relationship between patients with retinal vein occlusion (RVO), maximal intima-media complex thickness (Max IMT), and N-terminal pro-brain natriuretic peptide (NT-proBNP), which is useful in assessing atherosclerosis. This was a retrospective observation, single center study. The patients were 86 RVO patients (male: female = 43:43, mean age 63.3 years), 25 with central retinal vein occlusion (CRVO) and 61 with branch retinal vein occlusion (BRVO), classified as ≧50 years old and <50 years old, Max IMT≧1.1 and less, NT-pro BNP≧55 and less. Results showed that Max IMT ≧1.1 was significantly more common in both the CRVO and BRVO groups at ≧50 years, and NT-pro BNP ≧55 was significantly more common in the CRVO group. Max IMT≧1.1 was seen in 80% of the BRVO group and in 85% of patients aged ≧50 years. Sixty-eight percent of patients in the CRVO group had Max IMT≧1.1, but none of those < 50 years had Max IMT≧1.1. Forty-eight percent of RVO patients had NT-pro BNP≧55, and significantly more patients had Max IMT≧1.1 than those who did not have NT-pro BNP more than 55 (p = 0.02). Multiple regression analysis with Max IMT as the dependent variable showed that age and NT-pro BNP were significantly associated with RVO (p = 0.015, 0.022). RVO patients were more likely to have a Max IMT≧1.1, which was associated with atherosclerosis. Max IMT and NT-pro BNP were also associated with RVO patients, so NT-pro BNP may be a marker of RVO.

Cardiac markers: Role in the pathogenesis of arterial hypertension

Cardiac biomarkers may play unique roles in the prognostic evaluation of patients with hypertension, as many cardiac biomarker levels become abnormal long before the onset of obvious cardiovascular disease (CVD). There are numerous cardiac markers. However, this review article only reported the roles of creatinine kinase-MB, cardiac troponins, lipoprotein a, osteopontin, cardiac extracellular matrix, C-reactive protein, cardiac matrix metalloproteinases, cardiac natriuretic peptides, myoglobin, renin, and dynorphin in the pathogenesis of hypertension. This article explained recent major advances, as well as discoveries, significant gaps, and current debates and outlined possible directions for future research. Further studies are required to determine the association between myoglobin and other cardiac markers in hypertension. Moreover, therapeutic approaches are required to determine the early control of these cardiac markers, which ultimately reduce the prevalence of CVDs.

Abnormal Circadian Blood Pressure Profile as a Prognostic Marker in Patients with Nonischemic Dilated Cardiomyopathy

OBJECTIVES

An abnormal circadian blood pressure (BP) profile is considered a risk factor for cardiovascular disease. However, its significance in heart failure patients with nonischemic etiology is unknown. Herein, we investigated the prognostic value of a circadian BP profile in patients with nonischemic dilated cardiomyopathy (NIDCM).

METHODS

We enrolled 114 NIDCM patients (76 males, mean age 53.1 years). The percent nighttime BP fall (%NBPF) was defined using ambulatory BP monitoring as a percent decrease in mean systolic BP in nighttime from daytime. All patients were divided into three groups: dipper (%NBPF ≥10), non-dipper (0 ≤ %NBPF < 10), and riser (%NBPF <0).

RESULTS

Riser patients had the highest serum creatinine levels (dipper, 0.78 ± 0.20 mg/dl; non-dipper, 0.85 ± 0.21 mg/dl; riser, 0.99 ± 0.23 mg/dl; p = 0.006). In survival analysis, riser patients had the highest cumulative cardiac-related deaths (log-rank, p = 0.001), which was an independent predictor of cardiac-related deaths (hazard ratio, 12.6; 95% confidence interval, 1.76-253; p = 0.01). Multivariate analysis revealed that the norepinephrine level at 24-hour collected urine (24 h U-NE) and the serum creatinine level were independent determinants of %NBPF (adjusted R2 = 0.20; 24 h U-NE, p = 0.0001; serum creatinine, p = 0.04).

CONCLUSIONS

The riser profile was associated with poor prognosis of NIDCM, which may reflect impaired sympathetic nervous system activity. Evaluating the circadian BP profile may be useful for risk stratification in NIDCM patients.

Amino-Terminal Pro-B-Type Natriuretic Peptide Improves Discrimination for Incident Atherosclerotic Cardiovascular Disease Beyond Ambulatory Blood Pressure in Elderly Men

Improvement of risk prediction for atherosclerotic cardiovascular disease (ASCVD) is needed. Both ambulatory blood pressure (ABP) and biomarkers amino-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein and cystatin C improve risk prediction but they have not been evaluated in relation to each other. We analyzed whether NT-proBNP, high-sensitivity C-reactive protein, or cystatin C improved risk prediction beyond traditional ASCVD risk factors combined with 24-hour systolic BP (SBP). Secondary aim was to evaluate whether ABP improved risk prediction when compared with models with the biomarkers. We followed up 907 70-year-old men, free of baseline disease, for incident ASCVD defined as fatal or nonfatal myocardial infarction or fatal or nonfatal stroke for a median of 10 years. Cox regression was used to estimate the association between variables in the models and incident ASCVD. Biomarkers were added to a model containing both traditional risk factors and ABP and the models were compared on C-statistics and net reclassification improvement. Twenty-four hour SBP improved discrimination for incident ASCVD when compared with office SBP in a traditional risk factor model (area under the receiver-operating characteristic curve, +2.4%). NT-proBNP further improved reclassification (+18.7%–19.9%; P <0.01) when added to ABP models, whereas high-sensitivity C-reactive protein and cystatin C did not. Twenty-four hour SBP significantly improved net reclassification when added to a traditional risk factor model that included NT-proBNP. The combination of 24-hour SBP and NT-proBNP improved discrimination and net reclassification for incident ASCVD when compared with office SBP in elderly men. NT-proBNP, but not high-sensitivity C-reactive protein or cystatin C, improved risk prediction and discrimination when added to a model that included ABP.

Association of Treatment for Hyperlipidemia with Decreased Total Mortality in Japanese Individuals: the Yamagata (Takahata) Study

AIM

To evaluate the effects of treatment for hyperlipidemia on total mortality, we examined the association with adjustments for multiple factors, including those related to general health, such as blood hemoglobin and serum levels of albumin, adiponectin, brain natriuretic peptide, and lipids, using a prospective cohort study of a general Japanese population.

METHODS

The population-based, longitudinal Takahata study enrolled 3,291 Japanese individuals (1515 male, 1776 female; age: 62.5 ± 10.3 years) between 2004 and 2006. The incidence and causes of death were annually monitored until January 10, 2012 (median follow-up period: 2,655 days).

RESULTS

During the follow-up period, there were 169 deaths. The Cox proportional hazard regression model analysis used to adjust for factors related to general health condition, cardiovascular disease risks, and serum lipid levels showed a significant association between treatment for hyperlipidemia and decreased total mortality compared with no treatment for hyperlipidemia [hazard ratio (HR): 0.24; 95% confidence interval (CI): 0.08-0.69) and subjects without hyperlipidemia (HR: 0.34;95%CI: 0.12-0.96). The Cox proportional hazard regression model analysis with adjustments for factors related to general health conditions showed a significantly lower total mortality in subjects without hyperlipidemia than that in subjects with untreated hyperlipidemia (HR: 0.70; 95%CI: 0.50-0.99).

CONCLUSIONS

Not only antihyperlipidemic drugs used but also selection bias and non-evaluated factors, such as socio-economic status, educational level, health literacy, and daily nutrition, affected the results. Subjects taking treatment for hyperlipidemia were found to have reduced total mortality, which was independent of serum lipid levels.

Swimming training promotes cardiac remodeling and alters the expression of mRNA and protein levels involved in calcium handling in hypertensive rats

AIM

The aim of this study was to identify the effects of swimming training on the mRNA expression and protein levels of the calcium handling proteins in the hearts of renovascular hypertensive rats submitted to swimming protocol during 6 weeks.

MAIN METHODS

Fischer rats with renovascular hypertension 2-kidney 1-clip (2K1C) and SHAM groups were divided among sedentary and exercised groups. The exercise protocol lasted for 6 weeks (1 h/day, 5×/week), and the mean arterial pressure, cardiomyocytes hypertrophy parameters, mRNA expression and protein levels of some calcium handling proteins in the left ventricle were evaluated.

KEY FINDINGS

Swimming training was able to reduce the levels of mean arterial pressure in the hypertensive group compared to 2K1C SED, and to promote cardiac hypertrophy in SHAM EX and 2K1C EX groups in comparison to the respective control groups. The mRNA levels of B-type natriuretic peptide were reduced in the 2K1C EX when compared to 2K1C SED. The mRNA and protein levels of the sarcoplasmic reticulum Ca2 +-ATPase increased after the swimming training in SHAM and 2K1C groups. The mRNA and protein levels of phospholamban, displayed an increase in their levels in the exercised SHAM and in hypertensive rats in comparison to their respective controls; while mRNA levels of Na+/Ca2 + exchanger was reduced in the left ventricle comparing to the sedentary hypertensive rats.

SIGNIFICANCE

Taken altogether, we provide evidence that the aerobic training may lead to cardiac remodeling, and modulate the calcium handling proteins expression in the heart of hypertensive rats.

Cross-sectional study of indices of dynamic components of ambulatory blood pressure and cardiac damage in elderly male patients with essential hypertension

BACKGROUND AND AIMS

Blood pressure control is closely related to target organ damage in elderly patients with hypertension. The aim of this study was to determine the relationship between ambulatory blood pressure monitoring (ABPM) indices and cardiac damage in elderly male patients with treated essential hypertension (EH).

METHOD

This study included 998 Chinese men (mean age, 78.44 ± 12.02 years) with EH. Participants underwent cardiac function assessment, laboratory testing, and ABPM, including ABP, BP variability, BP circadian rhythms, and hypertensive or hypotensive time indices. The relationships between ABPM indices and cardiac damage (expressed by shape and function) were assessed using ridge regression analysis.

RESULTS

Ridge regression analysis revealed the following after adjustments for age, common cardiovascular risk factors, disease, and medications: N-terminal fragment pro-B-type natriuretic peptide was negatively correlated with the diastolic blood pressure nocturnal fall rate; the peak early/atrial velocity (E/A) ratio E/A ratio was negatively correlated with the 24 h mean systolic blood pressure (24 hmSBP), daytime SBP (dSBP), and nocturnal SBP (nSBP); and ejection fraction (EF) was negatively correlated with 24 h SBP percent time of elevation (24 hSBP PTE %) and 24 h DBP percent time of elevation (24 hDBP PTE %). Left ventricular mass (LVM) was positively correlated with the 24 hmSBP, dSBP, nSBP, 24 h mean pulse pressure (24 hmPP), day mean pulse pressure, and nocturnal mean arterial pressure, whereas LVM was negatively correlated with the NDBPF.

CONCLUSIONS

Our study showed that the ABPM indices associated with cardiac damage may be regarded as an early predictive marker for cardiac function impairment in elderly male patients with EH.

Adding "hemodynamic and fluid leads" to the ECG. Part I: the electrical estimation of BNP, chronic heart failure (CHF) and extracellular fluid (ECF) accumulation

OBJECTIVES

In primary care the diagnosis of CHF and ECF accumulation is no triviality. We aimed to predict plasma BNP, CHF and ECF accumulation with segmental impedance spectroscopy while using and extending the electrodes of the conventional electrocardiography.

METHODS

Three combined multiple electrodes were added to the 15 lead ECG for segmental impedance spectroscopy and for measuring the maximal rate of segmental fluid volume change with heart action at the thorax and the legs. The obtained signals were analyzed by partial correlation analyses in comparison with plasma BNP, CHF classes, ejection fraction by echocardiography and cardiac index by double gas re-breathing. 119 subjects (34 healthy volunteers, 50 patients with CHF, NYHA classes II to IV and 35 patients without CHF) were investigated.

RESULTS

The maximal rate of volume change with heart action at the thorax and at the legs, as well as the ECF/ICF ratio at the legs contribute equally and independently to the prediction of BNP and heart failure in an unknown test sample of 49 patients (multiple r=0.88, p<0.001). The ROC-curve for the predicted plasma BNP>400 pg/ml gave an AUC=0.93. The absence or the presence of heart failure could be predicted correctly by a binomial logistic regression in 92.9 and 87.5% of cases, respectively.

CONCLUSION

The methodology, which is based on inverse coupling of BNP release and of maximal blood acceleration and on sensitive detection of ECF overload, could enable the diagnosis of CHF with useful sensitivity and specificity while writing a routine-ECG.

The Value of N-Terminal Pro–B-Type Natriuretic Peptide in Determining Antihypertensive Benefit

We investigated 3 hypotheses: (1) N-terminal pro–B-type natriuretic peptide (NT-proBNP) predicts cardiovascular disease events in patients with hypertension, (2) NT-proBNP is associated with blood pressure variability, and (3) NT-proBNP predicts benefit from antihypertensive regimens. The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) randomized a subset of 6549 patients at risk with no history of coronary heart disease to either atenolol-based or amlodipine-based blood pressure–lowering treatment. During 5.5 years of follow-up, 485 cardiovascular disease cases accrued and were matched with 1367 controls. Baseline and 6-month in-trial NT-proBNP were measured. The results show that NT-proBNP improves cardiovascular disease risk prediction beyond established predictors, continuous net reclassification improvement of 22.3% ( P <0.0001). Furthermore, a 1-mm Hg increase in the SD of systolic blood pressure was associated with 2% higher baseline NT-proBNP in a multivariable regression analysis ( P <0.0001). However, NT-proBNP predicted cardiovascular disease risk independently of blood pressure variation (odds ratio per SD increase in log NT-proBNP 1.24; 95% confidence interval, 1.06–1.45; P =0.007). Atenolol-based treatment led to a 69.6% increase in NT-proBNP at 6 months ( P <0.0001). In contrast, amlodipine-based treatment reduced NT-proBNP by 36.5% ( P <0.0001). Amlodipine recipients who achieved a 6-month NT-proBNP below the median (61 pg/mL) were at lower risk of cardiovascular disease when compared with those who did not (odds ratio, 0.58; 95% confidence interval, 0.37–0.91) after adjustment for confounders inclusive of baseline NT-proBNP and achieved blood pressure. If confirmed, these novel results suggest that NT-proBNP, as well as aiding cardiovascular disease risk assessment, may also help assess the efficacy of specific antihypertensive regimens. Further relevant studies seem warranted.

Nocturnal Blood Pressure Pattern Affects Left Ventricular Remodeling and Late Gadolinium Enhancement in Patients with Hypertension and Left Ventricular Hypertrophy

Background

Left ventricular hypertrophy (LVH) is an independent predictor of cardiac mortality, regardless of its etiology. Previous studies have shown that high nocturnal blood pressure (BP) affects LV geometry in hypertensive patients. It has been suggested that continuous pressure overload affects the development of LVH, but it is unknown whether persistent pressure influences myocardial fibrosis or whether the etiology of LVH is associated with myocardial fibrosis. Comprehensive cardiac magnetic resonance (CMR) including the late gadolinium enhancement (LGE) technique can evaluate both the severity of changes in LV geometry and myocardial fibrosis. We tested the hypothesis that the nocturnal non-dipper BP pattern causes LV remodeling and fibrosis in patients with hypertension and LVH.

Methods

Forty-seven hypertensive patients with LVH evaluated by echocardiography (29 men, age 73.0±10.4 years) were examined by comprehensive CMR and 24-h ambulatory blood pressure monitoring (ABPM).

Results and Conclusions

Among the 47 patients, twenty-four had nocturnal non-dipper BP patterns. Patients with nocturnal non-dipper BP patterns had larger LV masses and scar volumes independent of etiologies than those in patients with dipper BP patterns (p = 0.035 and p = 0.015, respectively). There was no significant difference in mean 24-h systolic BP between patients with and without nocturnal dipper BP patterns (p = 0.367). Among hypertensive patients with LVH, the nocturnal non-dipper blood pressure pattern is associated with both LV remodeling and myocardial fibrosis independent of LVH etiology.

Modest elevation in BNP in asymptomatic hypertensive patients reflects sub-clinical cardiac remodeling, inflammation and extracellular matrix changes

In asymptomatic subjects B-type natriuretic peptide (BNP) is associated with adverse cardiovascular outcomes even at levels well below contemporary thresholds used for the diagnosis of heart failure. The mechanisms behind these observations are unclear. We examined the hypothesis that in an asymptomatic hypertensive population BNP would be associated with sub-clinical evidence of cardiac remodeling, inflammation and extracellular matrix (ECM) alterations. We performed transthoracic echocardiography and sampled coronary sinus (CS) and peripheral serum from patients with low (n = 14) and high BNP (n = 27). Peripheral BNP was closely associated with CS levels (r = 0.92, p<0.001). CS BNP correlated significantly with CS levels of markers of collagen type I and III turnover including: PINP (r = 0.44, p = 0.008), CITP (r = 0.35, p = 0.03) and PIIINP (r = 0.35, p = 0.001), and with CS levels of inflammatory cytokines including: TNF-α (r = 0.49, p = 0.002), IL-6 (r = 0.35, p = 0.04), and IL-8 (r = 0.54, p<0.001). The high BNP group had greater CS expression of fibro-inflammatory biomarkers including: CITP (3.8±0.7 versus 5.1±1.9, p = 0.007), TNF-α (3.2±0.5 versus 3.7±1.1, p = 003), IL-6 (1.9±1.3 versus 3.4±2.7, p = 0.02) and hsCRP (1.2±1.1 versus 2.4±1.1, p = 0.04), and greater left ventricular mass index (97±20 versus 118±26 g/m², p = 0.03) and left atrial volume index (18±2 versus 21±4, p = 0.008). Our data provide insight into the mechanisms behind the observed negative prognostic impact of modest elevations in BNP and suggest that in an asymptomatic hypertensive cohort a peripheral BNP measurement may be a useful marker of an early, sub-clinical pathological process characterized by cardiac remodeling, inflammation and ECM alterations.

Nighttime blood pressure dipping in young adults and coronary artery calcium 10-15 years later: the coronary artery risk development in young adults study

Nighttime blood pressure (BP) dipping can be quantified as the ratio of mean nighttime (sleep) BP to mean daytime (awake) BP. People whose dipping ratio is ≥ 0.90 have been referred to as nondippers, and nondipping is associated with cardiovascular disease events. We examined the relationship between systolic nighttime BP dipping in young adults and the presence of coronary artery calcium (CAC) 10 to 15 years later using data from the ambulatory BP monitoring substudy of the Coronary Artery Risk Development in Young Adults Study. Among 239 participants with adequate measures of both nighttime and daytime readings and coronary artery calcium, the systolic BP dipping ratio ranged from 0.72 to 1.24 (mean, 0.88; SD, 0.06), and CAC was present 10 to 15 years later in 54 participants (22.6%). Compared with those whose systolic BP dipping ratio ranged from 0.88 to 0.92 (quartile 3), the 57 participants (23.9%) with less pronounced or absent dipping (ratio, 0.92-1.24; quartile 4) had an unadjusted odds ratio of 4.08 (95% CI, 1.48-11.2) for the presence of CAC. The 60 participants (25.1%) with a more pronounced dipping (ratio, 0.72-0.85; quartile 1) also had greater odds for presence of CAC (odds ratio, 4.76 [95% CI, 1.76-12.9]). When modeled as a continuous predictor, a U-shaped relationship between systolic BP dipping ratio and future CAC was apparent and persisted after adjustment for multiple potential confounders (P<0.001 for quadratic term). Both failure of systolic BP to dip sufficiently and "overdipping" during nighttime may be associated with future subclinical coronary atherosclerosis.

Evaluation of the Relationship between Circadian Blood Pressure Variation and Left Atrial Function Using Strain Imaging

Background

Non-dippers were reported as showing different left atrial function, compared to dippers, but no study to date investigated the changes in the left atrial function according to the diurnal blood pressure pattern, using tissue Doppler and strain imaging.

Methods

Forty never treated hypertensive patients between 30 and 80 years of age were enrolled in this study. Patients were classified as non-dippers when, during night time, they had a blood pressure decrease of less than 10%. Strain of the left atrium was measured during late systole, and peak strain rates of the left atrium were measured during systole, early and late diastolic periods.

Results

The left atrial expansion index, left atrial active emptying volume and left atrial active emptying fraction were all significantly increased in non-dippers. They also had increased values of mean peak left atrial strain (dippers = 21.26 ± 4.23% vs. non-dippers = 24.91 ± 5.20%, p = 0.02), strain rate during reservoir (dippers = 1.29 ± 0.23 s^-1 vs. non-dippers =1.52 ± 0.27 s^-1, p = 0.01) and contractile period (dippers = -1.38 ± 0.24 s^-1 vs. non-dippers = -1.68 ± 0.32 s^-1, p < 0.01).

Conclusion

Strain and strain rate acquired from color Doppler tissue imaging demonstrate exaggerated reservoir and booster pump function in never-treated, non-dipper hypertensive patients. These methods are simple and sensitive for the early detection of subtle changes in the left atrial function.

Proteomic analysis of coronary sinus serum reveals leucine-rich α2-glycoprotein as a novel biomarker of ventricular dysfunction and heart failure

BACKGROUND

Heart failure (HF) prevention strategies require biomarkers that identify disease manifestation. Increases in B-type natriuretic peptide (BNP) correlate with increased risk of cardiovascular events and HF development. We hypothesize that coronary sinus serum from a high BNP hypertensive population reflects an active pathological process and can be used for biomarker exploration. Our aim was to discover differentially expressed disease-associated proteins that identify patients with ventricular dysfunction and HF.

METHODS AND RESULTS

Coronary sinus serum from 11 asymptomatic, hypertensive patients underwent quantitative differential protein expression analysis by 2-dimensional difference gel electrophoresis. Proteins were identified using mass spectrometry and then studied by enzyme-linked immunosorbent assay in sera from 40 asymptomatic, hypertensive patients and 105 patients across the spectrum of ventricular dysfunction (32 asymptomatic left ventricular diastolic dysfunction, 26 diastolic HF, and 47 systolic HF patients). Leucine-rich α2-glycoprotein (LRG) was consistently overexpressed in high BNP serum. LRG levels correlate significantly with BNP in hypertensive, asymptomatic left ventricular diastolic dysfunction, diastolic HF, and systolic HF patient groups (P≤0.05). LRG levels were able to identify HF independent of BNP. LRG correlates with coronary sinus serum levels of tumor necrosis factor-α (P=0.009) and interleukin-6 (P=0.021). LRG is expressed in myocardial tissue and correlates with transforming growth factor-βR1 (P<0.001) and α-smooth muscle actin (P=0.025) expression.

CONCLUSIONS

LRG was identified as a serum biomarker that accurately identifies patients with HF. Multivariable modeling confirmed that LRG is a stronger identifier of HF than BNP and this is independent of age, sex, creatinine, ischemia, β-blocker therapy, and BNP.

Postgraduate Symposium The MTHFR C677T polymorphism, B-vitamins and blood pressure

High blood pressure (BP) and elevated homocysteine are reported as independent risk factors for CVD and stroke in particular. The main genetic determinant of homocysteine concentrations is homozygosity (TT genotype) for the C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene, typically found in approximately 10% of Western populations. The B-vitamins folate, vitamin B12and vitamin B6are the main nutritional determinants of homocysteine, with riboflavin more recently identified as a potent modulator specifically in individuals with the TT genotype. Although observational studies have reported associations between homocysteine and BP, B-vitamin intervention studies have shown little or no BP response despite decreases in homocysteine. Such studies, however, have not considered the MTHFR C677T polymorphism, which has been shown to be associated with BP. It has been shown for the first time that riboflavin is an important determinant of BP specifically in individuals with the TT genotype. Research generally suggests that 24 h ambulatory BP monitoring provides a more accurate measure of BP than casual measurements and its use in future studies may also provide important insights into the relationship between the MTHFR polymorphism and BP. Further research is also required to investigate the association between specific B-vitamins and BP in individuals with different MTHFR genotypes in order to confirm whether any genetic predisposition to hypertension is correctable by B-vitamin intervention. The present review will investigate the evidence linking the MTHFR C677T polymorphism to BP and the potential modulating role of B-vitamins.

Does B-type natriuretic peptide predict the new onset of hypertension?

Increased B-type natriuretic peptide (BNP) expression precedes the development of hypertension in spontaneously hypertensive rats. We therefore tested the hypothesis that elevated plasma BNP levels predict the onset of hypertension in normotensive subjects. Japanese normotensive participants who were at our hospital for a yearly physical check-up (mean age 52.7 years, 35.9% women, n=5,026) were enrolled in the study. Blood pressure and BNP were measured at baseline and subjects were followed up for 5 years (median 1,114 d), with the endpoint being the development of hypertension. We evaluated the relationship between plasma BNP levels at baseline and the incidence of hypertension during the follow-up period. Hypertension was defined as systolic or diastolic blood pressure > or =140 or > or =90 mmHg, respectively, or the use of antihypertensive medications. During the follow-up period, hypertension developed in 23.4% (77.0 per 1,000 person-years) and 14.9% (51.0 per 1,000 person-years) of male and female subjects, respectively. Cox proportional hazard regression analysis demonstrated that after adjustment for known risk factors, the risk of hypertension was increased from the first to fourth quartiles of baseline BNP levels. However, after additional adjustment for baseline blood pressure, BNP did not predict the new onset of hypertension. Baseline BNP levels are closely associated with the risk of hypertension in individuals with normal blood pressure, but the prediction of hypertension with BNP is largely dependent on baseline blood pressure. Measurements of BNP may serve as a complementary method for the prediction or confirmation of hypertension.