Cilnidipine inhibits the sympathetic nerve activity and improves baroreflex sensitivity in patients with hypertension

Management of intradialytic hypertension: current evidence and future perspectives

Intradialytic hypertension (IDH), that is, a paradoxical rise in blood pressure (BP) during or immediately after a hemodialysis session, affects approximately 10-15% of the hemodialysis population. It is currently recognized as a phenomenon of major clinical significance as recent studies have shown that BP elevation extends to the whole interdialytic interval and associates with increased cardiovascular and all-cause mortality. The pathophysiology of IDH is complex involving volume and sodium overload, endothelial dysfunction, excess renin-angiotensin-aldosterone system and sympathetic nervous system activation, and other mechanisms. For several years, there was a scarcity of studies regarding IDH treatment; recently, however, several attempts to examine the effect of nonpharmacological and pharmacological measures on BP levels in IDH are made. This review attempts to summarize this latest evidence in the field of management of IDH and discuss areas for future research.

Efficacy of Cilnidipine (L/N-type Calcium Channel Blocker) in Treatment of Hypertension: A Meta-Analysis of Randomized and Non-randomized Controlled Trials

INTRODUCTION

 Hypertension is one of the most common cardiovascular diseases, and the prevalence of hypertension continues to rise across the globe. National and international guidelines recommend angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs), calcium channel blockers (CCBs), diuretics, and beta-blockers for the management of hypertension. CCBs are among the most used antihypertensive medications and Cilnidipine is a newer dihydropyridine CCB shown to have a prolonged antihypertensive property.

OBJECTIVE

 This meta-analysis of comparative randomized and non-randomized clinical trials evaluated the effect of Cilnidipine monotherapy or combination therapy on systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse rate (PR) over 48 weeks of therapy.

STUDY DESIGN

 PubMed (MEDLINE) and Google scholar databases were searched to identify studies designed to evaluate the effects of Cilnidipine in the treatment of hypertensive patients. The study criteria for inclusion into the meta-analysis were all prospective, randomized, and non-randomized clinical studies published till March 2021, studies published in a peer-reviewed journal, the inclusion of patients with hypertension, assessment of blood pressure and heart rate, and a follow-up of four weeks or longer. The initial search identified 82 potential articles; of these, 24 met the inclusion criteria. Studies with <4 weeks treatment period and those not having a CCB were excluded.

OUTCOMES

 Change in SBP, DBP, and PR from baseline at the end of therapy compared between the Cilnidipine and other CCB's.

RESULTS

Cilnidipine caused a significant reduction (p<0.05) in SBP, DBP, and PR at end of therapy, whereas the reduction in SBP, DBP, and PR with Cilnidipine was similar to other CCB's (p>0.05). The results of this meta-analysis revealed that there were no significant differences in the efficacy in the treatment of hypertensive patients with Cilnidipine and the other therapies.

CONCLUSION

 Cilnidipine has similar anti-hypertensive effects compared with other first-line antihypertensive drugs commonly used in practice. We recommend Cilnidipine as a novel first-line CCB for the management of hypertension either as a monotherapy or as a combination therapy.

Clinical Implications of Baroreflex Sensitivity in Type 2 Diabetes

The evaluation of baroreflex sensitivity (BRS), which maintains systemic circulatory homeostasis, is an established tool to assess cardiovascular autonomic neuropathy in type 2 diabetes mellitus (T2DM). As BRS plays an important function in blood pressure regulation, reduced BRS leads to an increase in blood pressure variability, which further leads to reduced BRS. This sequence of events becomes a vicious cycle. The major risk factors for reduced BRS are T2DM and essential hypertension, but many other risk factors have been reported to influence BRS. In recent years, reports have indicated that glycemic variability (GV), such as short- and long-term GV that are considered important risk factors for macrovascular and microvascular complications, is involved in reductions in BRS independently of blood glucose levels. In this review, we discuss reduced BRS in T2DM, its features, and the potential for its reversal.

Modified Sequence Method to Assess Baroreflex Sensitivity in Rats

Baroreceptors respond to fluctuations in blood pressure (BP) by modifying physiology in order to maintain a homeostatic set point. Baroreflex sensitivity (BRS) is used to quantify baroreceptor function and is a useful metric for tracking cardiovascular disease state and treatment effects. Pathological conditions such as hypertension (HTN) alter baroreflex function and reduce BRS. Traditionally, the sequence method is used to measure BRS, in which the linear slope of concomitant changes in BP and RR intervals are assessed. However, in rats, a high respiratory rate reduces the reliability of the sequence method. Here, we present a modified sequence method that captures BRS at lower frequencies and decreases the variability of the BRS estimate. This method was demonstrated using ECG and BP data from two groups of HTN rats: Sham rats and rats treated with vagus nerve stimulation. The modified sequence method resulted in lower BRS estimates than the traditional sequence technique when applied to the same data sets. Additionally, the modified sequence method resulted in lower BRS estimate variability.

The effect of an L/N-type calcium channel blocker on intradialytic blood pressure in intradialytic hypertensive patients

BACKGROUND

Intradialytic hypertension (HTN), which is one of the poor prognostic markers in patients undergoing hemodialysis, may be associated with sympathetic overactivity. The L/N-type calcium channel blocker, cilnidipine, has been reported to suppress sympathetic nerves activity in vivo. Therefore, we hypothesized that cilnidipine could attenuate intradialytic systolic blood pressure (SBP) elevation.

METHODS

Fifty-one patients on chronic hemodialysis who had intradialytic-HTN (SBP elevation ≥10 mmHg during hemodialysis) and no fluid overload were prospectively randomized into two groups: control and cilnidipine groups. Cilnidipine group patients took cilnidipine (10 mg/day) for 12 weeks. The primary endpoint was the change in the intradialytic SBP elevation before and after the 12-week intervention.

RESULTS

Before the intervention, no differences were observed in age, sex or pre-dialytic SBP (148.5 ± 12.9 vs. 148.3 ± 19.3 mmHg) between the two groups. Intradialytic SBP elevation was unchanged in the control group. Cilnidipine significantly lowered the post-dialytic SBP with an attenuation of the intradialytic SBP elevation from 12.0 ± 15.4 mmHg to 4.8 ± 10.1 mmHg. However, the observed difference in the intradialytic SBP elevation by cilnidipine did not reach statistical significance (group×time interaction effect p = 0.25). Cathecolamine levels were unaffected by the intervention in both groups.

CONCLUSION

Cilnidipine lowers both the pre- and post-dialytic SBP and might attenuate intradialytic SBP elevation. Therefore, cilnidipine may be effective in lowering SBP during HD in patients with intradialytic-HTN.

Variations of perioperative baroreflex sensitivity in hypertensive and normotensive patients

BACKGROUND

Impaired baroreflex sensitivity (BRS) is a marker of autonomous dysfunction, which may play an important role in the long-term development of hypertension. Perioperative patients with hypertension are rapidly increasing in all populations worldwide.

OBJECTIVE

To estimate the value of BRS for hypertension in a surgery cohort.

METHODS

An observational and cross-sectional study was performed, involving 96 patients who underwent video-assisted thoracoscopic pulmonary lobectomy or segmentectomy. Invasive blood pressure and heart rate before and after giving nitroglycerin were measured in 48 normotensive patients and 48 hypertensive patients (25 and 23 undergoing regular treatment hypertensive [HR] and irregular treatment hypertensive [HI], respectively) while entering the operation room, 30 minutes after skin incision, and 10 minutes after skin suture.

RESULTS

BRS_preoperative of hypertensive group (Group H) was lower than normotensive group (Group N) (3.49 ± 1.55 vs. 5.75 ± 4.15 ms/mmHg; P < 0.05). BRS_{intraoperative} of Group H was lower than Group N (1.70 ± 1.18 vs. 2.84 ± 1.11 ms/mmHg; P < 0.05). BRS_preoperative of patients in irregular-treated group (Group HI) was lower than regular-treated group (Group HR) (2.92 ± 1.36 vs. 4.31 ± 1.87 ms/mmHg; P < 0.05). BRS_{intraoperative} of Group HI was lower than Group HR (1.45 ± 0.90 vs. 2.08 ± 1.82 ms/mmHg; P < 0.05). BRS_{intraoperative} and BRS_{postoperative} were lower than BRS_preoperative in each group (P < 0.01).

CONCLUSION

The perioperative autonomic nerve function was significantly impaired in hypertensive patients. This effect was less pronounced for those who were on regular antihypertensive treatment. Attention should be paid to maintain the stability of cardiovascular function, to ensure patients can go through perioperative period safely.

Sympathomodulatory Effects of Antihypertensive Drug Treatment

BACKGROUND

An activation of sympathetic neural influences to the heart and peripheral circulation has been shown to represent a hallmark of the essential hypertensive state, adrenergic neural factors participating together with other variables at the development and progression of the high blood pressure state as well as of the hypertension-related target organ damage. This represents the rationale for employing in hypertension treatment drugs which combine the blood pressure-lowering properties with the modulatory effects on the sympathetic neural function.

METHODS AND RESULTS

Several studies published during the past 40 years have investigated the impact of antihypertensive drugs on the sympathetic target as assessed by indirect and direct approaches. In the present paper, the effects of different monotherapies or combination drug treatment used in hypertension to lower elevated blood pressure values on various adrenergic markers will be examined. This will be followed by a discussion of the (i) hemodynamic and nonhemodynamic consequences of employing antihypertensive drugs with sympathomodulatory or sympathoexcitatory properties and (ii) mechanisms potentially responsible for the adrenergic responses to a given antihypertensive drug. The final part of this review will address the questions still open related to the impact of antihypertensive drug treatment on sympathetic function. Two questions in particular will be examined, i.e., whether antihypertensive drugs with sympathomodulatory properties may be capable to fully restore a "normal" adrenergic drive and how far sympathetic activity should be reduced in hypertensive patients.

CONCLUSION

Future investigations aimed at answering these questions will be needed in order to improve cardiovascular protection in treated hypertensive patients.

Addition of a renin-angiotensin-aldosterone system inhibitor to a calcium channel blocker ameliorates arterial stiffness

BACKGROUND

The aim of controlling hypertension is to protect against arteriosclerosis. Calcium channel blockers (CCBs) and renin-angiotensin-aldosterone system (RAAS) inhibitors have been reported to have antihypertensive effects, but their effect on the progression of arteriosclerosis is not fully understood. The cardio-ankle vascular index (CAVI) was developed to estimate arterial stiffness, which reflects arteriosclerosis. In this study, we investigated the longer term effects of CCBs and RAAS inhibitors on the progression of arteriosclerosis by monitoring the CAVI.

METHODS

Our subjects were 115 consecutive, non-smoking hypertensive patients on oral treatment with a CCB and/or RAAS inhibitor for at least 3 years in whom the CAVI was measured on two occasions approximately 1 year apart during the period from January 2009 to December 2011. Changes in CAVI were evaluated in patients administered a CCB alone (group C), an RAAS inhibitor (group R) alone, or both drugs together (group B). Changes in laboratory findings, blood pressure, and ankle-brachial index were similarly evaluated.

RESULTS

No significant change in laboratory findings, blood pressure, or ankle-brachial index was noted in any of the groups. The CAVI decreased slightly in group R (first recording 8.80±1.03, second recording 8.57±0.97, P=0.517) and increased significantly in group C (first 8.45±0.92, second 8.95±1.04, P=0.038), but showed no significant change in group B (first 9.01±1.26, second 9.05±1.35, P=0.851).

CONCLUSION

Long-term administration of a CCB alone increased the CAVI, but this effect was offset by the concomitant use of a RAAS inhibitor, indicating that a RAAS inhibitor might protect against arteriosclerosis.

Essential hypertension: an approach to its etiology and neurogenic pathophysiology

Essential hypertension, a rise in blood pressure of undetermined cause, includes 90% of all hypertensive cases and is a highly important public health challenge that remains, however, a major modifiable cause of morbidity and mortality. This review emphasizes that, from an evolutionary point of view, we are adapted to ingest and excrete <1 g of sodium (2.5 g of salt) per day and that essential hypertension develops when the kidneys become unable to excrete the amount of sodium ingested, unless blood pressure is increased. The renal-mean arterial pressure set-point model is briefly described to explain that a shift of the pressure natriuresis relationship toward abnormally high pressure levels is a pathophysiological characteristic of essential hypertension. Evidence indicating that this anomaly in the pressure natriuresis relationship arises from a sympathetic nervous system dysfunction is briefly formulated, and the most widely accepted pathophysiologic proposal to explain the development of this sympathetic dysfunction is described, with commentaries about novel action mechanisms of some drugs currently used in essential hypertension treatment.

Comparison of the antialbuminuric effects of L-/N-type and L-type calcium channel blockers in hypertensive patients with diabetes and microalbuminuria: the study of assessment for kidney function by urinary microalbumin in randomized (SAKURA) trial

OBJECTIVE

To clarify whether the L-/N-type calcium channel blocker (CCB) cilnidipine is more renoprotective than the L-type CCB amlodipine in patients with early-stage diabetic nephropathy.

METHODS

In this prospective, multicenter, open-labeled, randomized trial, the antialbuminuric effects of cilnidipine and amlodipine were examined in renin-angiotensin system (RAS) inhibitor-treated patients with hypertension (blood pressure [BP]: 130-180/80-110 mmHg), type 2 diabetes, and microalbuminuria (urinary albumin to creatinine [Cr] ratio [UACR]: 30-300 mg/g).

RESULTS

Patients received cilnidipine (n = 179, final dose: 10.27 ± 4.13 mg/day) or amlodipine (n = 186, 4.87 ± 2.08 mg/day) for 12 months. Cilnidipine and amlodipine equally decreased BP. The UACR values for the cilnidipine and amlodipine groups were 111.50 ± 138.97 and 88.29 ± 63.45 mg/g, respectively, before treatment and 107.93 ± 130.23 and 89.07 ± 97.55 mg/g, respectively, after treatment. The groups showed similar changes for the natural logarithm of the UACR, serum Cr, and estimated glomerular filtration rate.

CONCLUSIONS

Cilnidipine did not offer greater renoprotection than amlodipine in RAS inhibitor-treated hypertensive patients with type 2 diabetes and microalbuminuria.

Inhibition of oxidative stress in rostral ventrolateral medulla improves impaired baroreflex sensitivity in stroke-prone spontaneously hypertensive rats

Reactive oxygen species (ROS) in rostral ventrolateral medulla (RVLM) of brainstem contribute to sympathoexcitation and are critically involved in the pathogenesis of hypertension. Baroreflex sensitivity (BRS) is a valuable prognostic parameter of the autonomic nervous system, and is impaired in hypertension. The aim of the present study was to determine whether or not a chronic reduction of ROS in the RVLM improves impaired BRS in hypertensive rats. We transfected adenovirus vectors encoding either manganese superoxide dismutase (AdMnSOD) or β-galactosidase (AdLacZ) into the RVLM of stroke-prone spontaneously hypertensive rats (SHRSP). We measured BRS using the spontaneous sequence method. BRS was significantly lower in SHRSPs than in Wistar-Kyoto rats. In the AdMnSOD-transfected SHRSP, blood pressure, heart rate, and sympathetic nervous system activation were significantly decreased from day 5 after the gene transfer. BRS in the AdMnSOD-transfected SHRSP was significantly increased from day 4 after the gene transfer with the reduction of ROS in the RVLM. Furthermore, in the AdMnSOD-transfected SHRSP, intravenous infusion of atropine dramatically decreased BRS. In contrast, in the AdLacZ-transfected SHRSP, atropine did not decrease BRS. These results suggest that chronic reduction of ROS in the local RVLM improves the impaired BRS in SHRSP through inhibition of the sympathetic component.

Antialbuminuric advantage of cilnidipine compared with L-type calcium channel blockers in type 2 diabetic patients with normoalbuminuria and microalbuminuria

We evaluated the antialbuminuric advantage of cilnidipine, an N/L-type calcium channel blocker (CCB), compared with L-type CCBs in diabetic patients with normoalbuminuria and microalbuminuria. The study was a multicenter, non-randomized crossover trial. Participants were 90 type 2 diabetic patients exhibiting either normo- or microalbuminuria, and undergoing CCB treatment for ≥6 months prior to study entry. The CCB at the time of entry was continued for the first 6 months (Period 1). Treatment was subsequently switched from cilnidipine to an L-type CCB, or vice versa, for the second 6-month observation period (Period 2). During Period 1, the L-type CCB group showed a significant increase of urinary albumin excretion (UAE) over time, while the cilnidipine group showed no significant elevation. During Period 2, switching of the treatment from the L-type CCB to cilnidipine resulted in significant reduction of the UAE, whereas switching from cilnidipine to the L-type CCB resulted in no significant change in the UAE. This study demonstrated that the antialbuminuric effect of Cilnidipine, but not the L-type CCBs, was sustained even in patients treated for a long time. In addition, the antialbuminuric effect can be anticipated after switching from an L-type CCB to cilnidipine, but not vice versa.

Azelnidipine attenuates glomerular damage in Dahl salt-sensitive rats by suppressing sympathetic nerve activity

Dihydropyridine-type calcium channel blockers (CCBs) exert potent antihypertensive effects. The CCB azelnidipine decreases heart rate by suppressing sympathetic nerve activity, which affects afferent and efferent arterioles in the glomeruli. We examined whether azelnidipine can improve progressive glomerular injury in comparison with amlodipine by suppressing renal sympathetic nerve activity in Dahl salt-sensitive rats. Glomerular circulation in Dahl salt-sensitive rats was monitored with a charge-coupled device camera before and after administration of amlodipine (0.5 mg kg(-1), bolus injection) or azelnidipine (0.1 mg kg(-1), bolus injection). Systemic sympathetic nerve activity was also compared by analysis of heart rate variability with a telemetry blood pressure monitoring system after crossover administration of amlodipine (1.0 mg kg(-1) per day) and azelnidipine (3.0 mg kg(-1) per day) for 1 week. To investigate renoprotective effects, rats were treated with amlodipine (1.0 mg kg(-1) per day) or azelnidipine (3.0 mg kg(-1) per day) for 3 weeks with or without renal denervation. The efferent arteriole contracted in response to acute amlodipine but not azelnidipine treatment. The low frequency/high frequency ratio, an index of parasympathetic nerve activity, decreased in response to azelnidipine but not amlodipine treatment. In response to chronic treatment, proteinuria and glomerular injury improved to a greater extent with azelnidipine compared with amlodipine. The renoprotective effects of azelnidipine were diminished by renal denervation. Azelnidipine decreased glomerular damage in Dahl salt-sensitive rats to a greater extent than amlodipine. Azelnidipine appeared to decrease intraglomerular pressure by suppressing sympathetic nerve activity.

Short-term aerobic exercise reduces nitroglycerin-induced orthostatic intolerance in older adults with type 2 diabetes

AIMS/HYPOTHESIS

Older adults are at a high risk for syncope due to orthostatic intolerance (OI), and this risk increases with comorbid type 2 diabetes and vasoactive medications. Despite many benefits, previous investigations have shown worsening OI with aerobic training. We examined whether aerobic exercise reduced OI in older adults with type 2 diabetes who were given a short-acting vasoactive agent (nitroglycerin).

METHODS

Forty older adults (25 males and 15 females, mean age 71.4 ± 0.7 years, ranging in age from 65 to 83 years) with type 2 diabetes were recruited. Subjects were randomized to each of 2 groups: an aerobic group (3 months of vigorous aerobic exercise) and a nonaerobic (no aerobic exercise) group. Exercise sessions were supervised by a certified exercise trainer 3 times per week. After being given 400 μg of sublingual nitroglycerin, each subject was placed in a 70° head-up tilt for 30 minutes.

RESULTS

When the 2 groups were compared using a Cox proportional hazards model, tilt table tolerance was significantly better in the aerobic group as compared to in the nonaerobic group (χ(2)(MC) = 7.271, P = 0.007).

CONCLUSIONS

Our findings indicate that a relatively short aerobic exercise intervention can improve postnitroglycerin orthostatic tolerance in older adults with type 2 diabetes.