Associations of daytime, nighttime, and 24-hour heart rate with four distinct markers of inflammation in hypertensive patients: the Styrian Hypertension Study

Resting Heart Rate as a Cardiovascular Risk Factor in Hypertensive Patients: An Update

A large body of evidence has shown that resting heart rate (RHR) holds important prognostic information in several clinical conditions. In the majority of the general population studies, a graded association between RHR and mortality from all causes, cardiovascular (CV) disease, ischemic heart disease, and stroke has been observed. These associations appeared even stronger and more consistent in hypertensive patients. Studies performed with 24-hour ambulatory recording have shown that an elevated nighttime heart rate may confer an additional risk on top of office RHR. The mechanisms by which tachycardia alone or in association with sympathetic overactivity induces CV damage are well understood. Fast RHR is a strong predictor of future hypertension, metabolic disturbances, obesity, and diabetes. Several experimental lines of research point to high RHR as a main risk factor for the development of atherosclerosis, large artery stiffness, and CV disease. Elevated RHR is a common feature in patients with hypertension. Thus, there is a large segment of the hypertensive population that would benefit from a treatment able to decrease RHR. Improvement of unhealthy lifestyle should be the first goal in the management of the hypertensive patient with elevated RHR. Most clinical guidelines now recommend the use of combination therapies even in the initial treatment of hypertension. Although no results of clinical trials specifically designed to investigate the effect of RHR lowering in human beings without CV diseases are available, in hypertensive patients with high RHR a combination therapy including a cardiac slowing drug at optimized dose seems a sensible strategy. Tachycardia can be considered both as a marker of sympathetic overactivity and as a risk factor for cardiovascular events. In this sketch, the main cardiovascular and metabolic effects of increased sympathetic tone underlying high heart rate are shown. The link between tachycardia and cardiovascular events can be explained also by the direct hemodynamic action of heart rate on the arteries and the left ventricular (LV) wall.

Bidirectional Prospective Associations Between Cardiac Autonomic Activity and Inflammatory Markers

OBJECTIVE

Autonomic nervous system (ANS) imbalance has been cross-sectionally associated with inflammatory processes. Longitudinal studies are needed to shed light on the nature of this relationship. We examined cross-sectional and bidirectional prospective associations between cardiac autonomic measures and inflammatory markers.

METHODS

Analyses were conducted with baseline (n = 2823), 2-year (n = 2099), and 6-year (n = 1774) data from the Netherlands Study of Depression and Anxiety. To compare the pattern of results, prospective analyses with ANS (during sleep, leisure time, and work) and inflammation were conducted in two data sets from the Netherlands Twin Register measured for 4.9 years (n = 356) and 5.4 years (n = 472). Autonomic nervous system measures were heart rate (HR) and respiratory sinus arrhythmia (RSA). Inflammatory markers were C-reactive protein (CRP) and interleukin (IL)-6.

RESULTS

The Netherlands Study of Depression and Anxiety results showed that higher HR and lower RSA were cross-sectionally significantly associated with higher inflammatory levels. Higher HR predicted higher levels of CRP (B = .065, p < .001) and IL-6 (B = .036, p = .014) at follow-up. Higher CRP levels predicted lower RSA (B = -.024, p = .048) at follow-up. The Netherlands Twin Register results confirmed that higher HR was associated with higher CRP and IL-6 levels 4.9 years later. Higher IL-6 levels predicted higher HR and lower RSA at follow-up.

CONCLUSIONS

Autonomic imbalance is associated with higher levels of inflammation. Independent data from two studies converge in evidence that higher HR predicts subsequent higher levels of CRP and IL-6. Inflammatory markers may also predict future ANS activity, but evidence for this was less consistent.

Effects of Vitamin D3 on asymmetric- and symmetric dimethylarginine in arterial hypertension

BACKGROUND AND AIMS

Accumulating evidence has proposed a correlation between vitamin D (25(OH)D) insufficiency and cardiovascular (CV) disease. Vitamin D associated effects on endothelial function have been suggested to be a possible culprit. The present study investigated the association of vitamin D3 treatment on markers of endothelial dysfunction in patients with arterial hypertension.

METHODS AND RESULTS

The Styrian Vitamin D Hypertension Trial is a double-blind, placebo-controlled, single-centre study conducted at the Medical University of Graz, Austria. A total of 200 study participants with arterial hypertension and 25(OH)D levels below 30ng/mL were enrolled. The study participants were randomized to receive 2800 IU of vitamin D3 per day as oily drops (n=100) or placebo (n=100) for a duration of eight weeks. The present study uses an analysis of covariance (ANCOVA) to investigate the effect of vitamin D3 treatment on symmetric (SDMA) and asymmetric dimethylarginine (ADMA). A total of 187 participants (mean [SD] age 60.0 [11.3] years; 47% women; 25(OH)D 21.2 [5.6]ng/mL; mean systolic blood pressure of 131.4 [8.9] mmHg on a median of 2 antihypertensive drugs) completed the trial. Mean treatment effect was -0.004 (95%CI [-0.03 to 0.04]; P=0.819) on ADMA and 0.001 (95%CI [-0.05 to 0.05]; P=0.850) on SDMA. In the subgroup analysis patients with a 25(OH)D concentration <20ng/mL had a significant increase in their log l-arginine/ADMA ratio (mean treatment effect 18.4 95%CI [1.84-34.9]μmol/L/μmol/L; P=0.030). ClinicalTrials.gov Identifier: NCT02136771 EudraCT number: 2009-018125-70 CONCLUSIONS: Vitamin D3 supplementation in hypertensive patients with low 25-hydroxyvitamin D has no significant effect on ADMA and SDMA.

Effects of vitamin D supplementation on glycated haemoglobin and fasting glucose levels in hypertensive patients: a randomized controlled trial

AIM

To investigate the efficacy of vitamin D supplementation on glycaemic control.

METHODS

The Styrian Vitamin D Hypertension Trial was a single-centre, double-blind, placebo-controlled study conducted between 2011 and 2014 at the Medical University of Graz, Austria. We enrolled 200 people with arterial hypertension and 25-hydroxyvitamin D [25(OH)D] concentrations <30 ng/mL. Study participants were randomized to receive either 2800 IU of vitamin D or placebo per day for 8 weeks. The present study was a post hoc analysis that incorporated an analysis of covariance (ancova) approach, while adjusting for baseline differences.

RESULTS

A total of 185 participants [mean ± standard deviation age, 60.1 ± 11.3 years; 47% women; mean 25(OH)D 21.2 ± 5.6 ng/mL, mean glycated haemoglobin (HbA1c) 44.8 ± 11.8 mmol/mol and mean body mass index 30.4 ± 5.4 kg/m(2) ] completed the trial. ancova showed a mean treatment effect [95% confidence interval (CI)] on HbA1c of -3.52 (-6.7 to -0.34) mmol/mol (p = .045). There was no difference in fasting glucose -4.7 mg/dL (95% CI -16.3 to 6.9; p = .426).

CONCLUSIONS

Vitamin D supplementation in obese hypertensive patients with low 25(OH)D reduces HbA1c levels. This finding warrants further investigation into potential vitamin D effects on glucose homeostasis.

Effects of Vitamin D Supplementation on Plasma Aldosterone and Renin-A Randomized Placebo-Controlled Trial

Increasing evidence describes a possible interplay between vitamin D insufficiency with increased aldosterone. The authors sought to evaluate the effect of vitamin D supplementation on plasma aldosterone concentration (PAC) in patients with hypertension and 25-hydroxyvitamin D[25(OH)D] insufficiency. The Styrian Vitamin D Hypertension Trial was a single-center, double-blind, placebo-controlled randomized clinical trial conducted from 2011 to 2014. Two hundred patients with arterial hypertension and 25(OH)D levels <30 ng/mL were enrolled. Study participants were randomized to receive either 2800 IU of vitamin D3 or placebo. The present investigation is a post hoc analysis using analysis of covariance adjusting for baseline differences. A total of 188 participants (mean±standard deviation age, 60.1±11.3 years; 47% women; 25(OH)D, 21.2±5.6 ng/mL) completed the trial. Mean differences between baseline and follow-up PAC in the control and intervention arm were +3.3 ng/dL and +0.9 ng/dL, respectively (P=.04). The findings indicate that vitamin D3 supplementation significantly decreases PAC in patients with arterial hypertension and 25(OH)D insufficiency.

Aldosterone-to-Renin Ratio Is Associated With Reduced 24-Hour Heart Rate Variability and QTc Prolongation in Hypertensive Patients

Aldosterone is considered to exert direct effects on the myocardium and the sympathetic nervous system. Both QT time and heart rate (HR) variability (HRV) are considered to be markers of arrhythmic risk and autonomous dysregulation. In this study, we investigated the associations between aldosterone, QT time, and HRV in patients with arterial hypertension.We recruited 477 hypertensive patients (age: 60.2 ± 10.2 years; 52.3% females) with a mean systolic/diastolic 24-hour ambulatory blood pressure monitoring (ABPM) value of 128 ± 12.8/77.1 ± 9.2 mmHg and with a median of 2 (IQR: 1-3) antihypertensive agents. Patients were recruited from the outpatient clinic at the Department of Internal Medicine of the Medical University of Graz, Austria. Blood samples, 24-hour HRV derived from 24-hour blood pressure monitoring (ABPM) and ECG's were obtained. Plasma aldosterone and plasma renin concentrations were measured by means of a radioimmunoassay. Twenty-four-hour urine specimens were collected in parallel with ABPM.Mean QTc was 423.3 ± 42.0 milliseconds for males and 434.7 ± 38.3 milliseconds for females. Mean 24H-HR and 24H-HRV was 71.9 ± 9.8 and 10.0 ± 3.6 bpm, respectively. In linear regression analyses adjusted for age, sex, body mass index, ABPM, and current medication, aldosterone to active renin ratio (AARR) was significantly associated with the QTc interval, a marker for cardiac repolarization abnormalities (mean = 426 ± 42.4 milliseconds; β-coefficient = 0.121; P = 0.03) as well as with the 24-hour heart rate variability a surrogate for autonomic dysfunction (median = 9.67 [IQR = 7.38-12.22 bpm]; β-coefficient = -0.133; P = 0.01).In hypertensive patients, AARR is significantly related to QTc prolongation as well as HRV. Further studies investigating the effects of mineralocorticoid receptor blocker and aldosterone synthase inhibitors on QTc and HRV are warranted.