Objective: To evaluate the acute efficacy, safety, and tolerability of lisdexamfetamine dimesylate (LDX) vs placebo (PBO) in preschool-aged children with attention-deficit/hyperactivity disorder (ADHD).Method: This phase 3, double-blind, fixed-dose study randomly assigned children (aged 4-5 years) with ADHD to 6 weeks of LDX (5, 10, 20, 30 mg) or PBO. The prespecified primary (change from baseline at week 6 in ADHD Rating Scale IV, Preschool version, total score [ADHD-RS-IV-PS-TS]) and key secondary (Clinical Global Impression-Improvement [CGI-I] score at week 6) efficacy endpoints were assessed using linear mixed-effects models for repeated measures. Safety and tolerability assessments included treatment-emergent adverse events (TEAEs) and changes in pulse and blood pressure (BP).Results: The study comprised 199 participants randomly asigned 5:5:5:5:6 to receive 5, 10, 20, 30 mg LDX or PBO, respectively. Least squares (LS) mean (95% CI) treatment difference at week 6 between pooled LDX (10, 20, 30 mg) and PBO was statistically significant for ADHD-RS-IV-PS-TS change (-5.9 [-11.01, -0.78], p = .0242; effect size [ES], -0.43). CGI-I scores improved (ie, 1-2 on CGI-I) in 41.7% for pooled LDX and 24.3% for PBO (p = .0857). The LS mean (95% CI) treatment difference between pooled LDX and PBO for CGI-I score at week 6 was -0.6 (-1.03, -0.16; p = .0074; ES, -0.52). Frequency of TEAEs was 46.6% across all 4 LDX doses vs 42.2% with PBO; the most frequent TEAEs were decreased appetite (13.7% vs 8.9%, respectively) and irritability (9.6% vs 0%). Discontinuations because of TEAEs were 5.5% for all LDX doses and 4.4% for PBO. Mean & PLUSMN; SD pulse/BP changes from baseline at week 6/early termination were numerically greater with LDX vs PBO (pulse beats/min: 2.7 & PLUSMN; 10.79 vs 1.2 & PLUSMN; 9.90; systolic BP, mm Hg: 1.0 & PLUSMN; 7.51 vs 0.3 & PLUSMN; 6.06; diastolic BP, mm Hg: 1.7 & PLUSMN; 5.90 vs 0.0 & PLUSMN; 6.88).Conclusion: In children aged 4 to 5 years with ADHD, LDX was more efficacious than PBO in reducing symptoms. The observed ES for change in ADHD-RS-IV-PS-TS appears to be smaller in magnitude than has been reported for studies of LDX conducted in older children and adolescents. LDX was generally well tolerated, and no new safety signals were identified.Clinical trial registration information: Safety and Efficacy Study in Preschool Children Aged 4-5 Years With Attention-Deficit/Hyperactivity Disorder; http://www.clinicaltrials.gov; NCT03260205.
Objective: To evaluate the long-term safety and tolerability of lisdexamfetamine dimesylate (LDX) in preschool-aged children (4-5 years of age inclusive) diagnosed with attention-deficit/hyperactivity disorder (ADHD).Methods: This phase 3 open-label study (ClinicalTrials.gov registry: NCT02466386) enrolled children aged 4-5 years meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) criteria for a primary ADHD diagnosis and having baseline ADHD Rating Scale-IV Preschool version total scores (ADHD-RS-IV-PS-TS) >= 24 for girls or >= 28 for boys and baseline Clinical Global Impressions-Severity scores >= 4. Participants were directly enrolled or enrolled after completing one of two antecedent short-term LDX studies. Over 52 weeks of treatment, participants received once-daily dose-optimized LDX (5-30 mg). Safety and tolerability assessments included treatment-emergent adverse events (TEAEs) and vital sign changes. Clinical outcomes included ADHD-RS-IV-PS-TS changes from baseline.Results: Among 113 participants in the safety set, optimized LDX dose was 5, 10, 15, 20, and 30 mg in 1 (0.9%), 12 (10.6%), 21 (18.6%), 26 (23.0%), and 53 (46.9%) participants, respectively. Of the safety set, 69 participants (61.1%) completed the study. TEAEs were reported in 76.1% of participants; no serious TEAEs were reported. Only one type of TEAE was reported in >10% of participants (decreased appetite, 15.9%). Mean +/- standard deviation (SD) changes in vital signs and body weight from baseline to week 52/or early termination (ET; n = 101) were 1.9 +/- 7.73 mmHg for systolic blood pressure, 3.1 +/- 7.58 mmHg for diastolic blood pressure, 4.7 +/- 11.00 bpm for pulse, and 0.6 +/- 1.38 kg for body weight. Over the course of the study, mean +/- SD change in ADHD-RS-IV-PS-TS from baseline to week 52/ET was -24.2 +/- 13.34 (n = 87).Conclusions: In this long-term 52-week study of children aged 4-5 years with ADHD, dose-optimized LDX (5-30 mg) was well tolerated and associated with reductions from baseline in ADHD symptoms.
Patients with grade 2-3 essential hypertension and postplacebo mean clinic systolic blood pressure (SBP) 160-190 mm Hg and 24-hour SBP 140-175 mm Hg by ambulatory blood pressure monitoring (ABPM) received 40 mg azilsartan medoxomil (AZL-M) monotherapy for 4 weeks. "Nonresponders" were then randomized to 8 weeks of double-blind treatment with AZL-M 40 mg, AZL-M/chlortalidone (CLD) 40/25, or AZL-M/CLD 40/12.5 mg. After 8 weeks, mean clinic SBP change was-21.1 (+/- 1.04) mm Hg for AZL-M/CLD 40/25 mg, -15.8 (+/- 1.08) mm Hg for AZL-M/CLD 40/12.5 mg, and -6.4 (+/- 1.05) mm Hg for AZL-M 40 mg (P < 0.001 for both AZL-M/CLD vs AZL-M, ANCOVA). Drug discontinuation rates were 8.9% (AZL-M/CLD 40/25 mg), 7.5% (AZL-M 40 mg), and 3.9% (AZL-M/CLD 40/12.5 mg). Creatinine increased in 8.1% (AZL-M/CLD 40/25), 3.1% (AZL-M/CLD 40/12.5 mg), and 3.0% (AZL-M 40 mg) of patients. AZL-M/CLD was effective and well tolerated in patients not achieving blood pressure targets with AZL-M.
An open-label, long-term study evaluated safety and tolerability of azilsartan medoxomil/chlorthalidone (AZL-M/CLD) vs olmesartan/hydrochlorothiazide (OLM/HCTZ) in hypertensive participants with stage 3 chronic kidney disease. Initial therapy was AZL-M/CLD 20/12.5mg (n=77) or OLM/HCTZ 20/12.5mg (n=76), but could be up-titrated (AZL-M/CLD to 40/25mg; OLM/HCTZ to 40/25mg [US] or 20/25mg [Europe]) with other agents added during weeks 4-52. Primary endpoint was proportion of participants with 1 adverse event (AE) through week 52. Baseline demographics were similar. AEs did not differ between groups (88.3%, AZL-M/CLD vs 76.3%, OLM/HCTZ; P=.058). AZL-M/CLD showed greater systolic BP reductions after initial dosing (P=.037) but not during long-term follow-up (P=.588). A greater proportion of participants up-titrated to the highest dose with OLM/HCTZ (48.7%) vs AZL-M/CLD (29.9%) (P=.021) and were taking additional antihypertensive medications (26.3% vs 16.9%). Both AZL-M/CLD and OLM/HCTZ showed similar efficacy and tolerability.
Background:Azilsartan medoxomil (AZL-M), an angiotensin II receptor blocker, has been developed in fixed-dose combinations (FDCs) with chlorthalidone (CTD).Objective/methods:We compared FDCs of AZL-M/CTD 20/12.5mg once daily titrated to 40/25mg if needed or AZL-M/CTD 40/12.5mg once daily titrated to 80/25mg if needed with an olmesartan medoxomil (OLM)-hydrochlorothiazide (HCTZ) 20/12.5mg FDC once daily titrated to 40/25mg if needed in a randomized, double-blind, 8-week study of 1085 participants with clinic SBP 160-190mmHg and DBP 119mmHg or less. Titration to higher doses occurred at week 4 if BP was at least 140/90mmHg (130/80mmHg if diabetes or chronic kidney disease). The primary endpoint was change from baseline in clinic SBP; 24-h ambulatory BP monitoring was also measured.Results:Greater reductions in clinic SBP from a baseline of 165mmHg were observed (P<0.001) in both AZL-M/CTD arms (-37.6 and -38.2mmHg) versus OLM/HCTZ (-31.5mmHg), despite greater dose titration in the OLM/HCTZ group. At 8 weeks, both AZL-M/CTD FDCs reduced 24-h SBP more than OLM/HCTZ (-26.4 and -27.9 versus -20.7mmHg; both P<0.001), and higher proportions in both AZL-M/CTD groups achieved target BP compared with the OLM/HCTZ group (69.4 and 68.9 versus 54.7%, both P<0.001). Adverse events leading to drug discontinuation occurred in 6.2, 9.5, and 3.1% with the AZL-M/CTD lower and higher doses, and OLM/HCTZ, respectively.Conclusion:This large, titration-to-target BP study demonstrated AZL-M/CTD FDCs to have superior antihypertensive efficacy compared with the maximum approved dose of OLM/HCTZ.
Two post hoc analyses in self-identified black and white patients with hypertension evaluated the angiotensin II receptor blocker azilsartan medoxomil (AZL-M) and the fixed-dose combination of AZL-M with chlorthalidone (AZL-M/CLD) versus the ARB olmesartan (OLM) and the OLM fixed-dose combination with hydrochlorothiazide (OLM/HCTZ). One analysis pooled 1,610 patients from two 6-week randomized controlled trials to compare once daily AZL-M 40 mg, AZL-M 80 mg, OLM 40 mg, and placebo. The second analysis included 1,020 patients from a 12-week randomized controlled trial to compare once daily AZL-M/CLD 40/25 mg, AZL-M/CLD 80/25 mg, and OLM/HCTZ 40/25 mg. Efficacy end points were 24-hour mean ambulatory and clinic systolic and diastolic blood pressure (SPB/DBP) and the percentage of patients achieving clinic SBP/DBP targets. Treatment with AZL-M 80 mg lowered mean clinic SBP by 12.5 mm Hg (p <0.01 vs OLM), treatment with AZL-M/CLD 40 mg/25 mg lowered mean ambulatory SBP by 31.0 mm Hg and mean clinic SBP by 39.3 mm Hg (both p <0.05 vs OLM/HCTZ), and treatment with AZL-M/CLD 80 mg/25 mg lowered mean ambulatory SBP by 34.4 mm Hg (p <0.01 vs OLM/HCTZ) and mean clinic SBP by 39.2 mm Hg (p <0.05 vs OLM/HCTZ). Target BP goals were achieved more frequently with AZL-M versus OLM and with AZL-M/CLD versus OLM/HCTZ. In conclusion, in both black and white patients, BP was lowered more effectively with AZL-M versus OLM and with AZL-M/CLD versus OLM/HCTZ. The AZL-M/CLD 40 mg/25 mg combination resulted in a statistically significant reduction in BP in both black and white patients.
Objective— Increasing evidence suggests that contractile dysfunction in smooth muscle cells (SMCs) plays a critical role in aortic biomechanical dysfunction and aortic aneurysm and dissection (AAD) development. However, the mechanisms underlying SMC contractile dysfunction in sporadic AAD are poorly understood. In this study, we examined the role of the NLRP3 (nucleotide oligomerization domain–like receptor family, pyrin domain containing 3)–caspase-1 inflammasome, a key inflammatory cascade, in SMC contractile dysfunction in AAD. Approach and Results— We observed significant SMC contractile protein degradation in aortas from patients with sporadic thoracic AAD. The contractile protein degradation was associated with activation of the NLRP3–caspase-1 inflammasome cascade. In SMCs, caspase-1 bound and directly cleaved and degraded contractile proteins, leading to contractile dysfunction. Furthermore, Nlrp3 or caspase-1 deficiency in mice significantly reduced angiotensin II–induced contractile protein degradation, biomechanical dysfunction, and AAD formation in both thoracic and abdominal aortas. Finally, blocking this cascade with the inflammasome inhibitor, glyburide (an antidiabetic medication), reduced angiotensin II–induced AAD formation. Conclusions— Inflammasome-caspase-1–mediated degradation of SMC contractile proteins may contribute to aortic biomechanical dysfunction and AAD development. This cascade may be a therapeutic target in AAD formation. In addition, glyburide may have protective effects against AAD development.
This 52‐week, randomized, open‐label study evaluated long‐term safety/tolerability of fixed‐dose combination azilsartan medoxomil/chlorthalidone (AZL‐M/CLD) vs fixed‐dose combination olmesartan medoxomil/hydrochlorothiazide (OLM/HCTZ) in patients with essential hypertension (stage 2; clinic systolic blood pressure 160–190 mm Hg). Initial AZL‐M/CLD 40/12.5 mg/d (n=418) or OLM/HCTZ 20/12.5 mg/d (n=419) could be uptitrated during weeks 4 to 52 (AZL‐M/CLD to 80/25 mg; OLM/HCTZ to 40/25 mg [United States] or 20/25 mg [Europe]) to meet blood pressure targets. Treatment‐emergent adverse events/serious adverse events occurred in 78.5%/5.7% of patients taking AZL‐M/CLD vs 76.4%/6.2% taking OLM/HCTZ. The most frequent adverse events were dizziness (16.3% vs 12.6%), blood creatinine increase (21.5% vs 8.6%), headache (7.4% vs 11.0%), and nasopharyngitis (12.2% vs 11.5%). Hypokalemia was uncommon (1.0% vs 0.7%). Greater blood pressure reductions with AZL‐M/CLD by week 2 were maintained throughout the study, despite less uptitration (32.3% vs 48.9% with OLM/HCTZ). Fixed‐dose combination AZL‐M/CLD showed an encouraging benefit‐risk profile when used per standard clinical practice in a titrate‐to‐target strategy.
This 56-week phase 3, open-label, treat-to-target study, involving 2 consecutive, non-randomized cohorts, evaluated the safety and tolerability of azilsartan medoxomil (AZL-M) in essential hypertension (mean baseline blood pressure [BP] 152/100 mmHg). All subjects (n = 669) initiated AZL-M 40 mg QD, force-titrated to 80 mg QD at week 4, if tolerated. From week 8, subjects could receive additional medications, starting with chlorthalidone (CLD) 25 mg QD (Cohort 1) or hydrochlorothiazide (HCTZ) 12.5-25 mg QD (Cohort 2), if required, to reach BP targets. Adverse events (AEs) were reported in 75.9% of subjects overall in the two cohorts (73.8% Cohort 1, 78.5% Cohort 2). The most common AEs were dizziness (14.3%), headache (9.9%) and fatigue (7.2%). Transient serum creatinine elevations were more frequent with add-on CLD. Clinic systolic/diastolic BP (observed cases at week 56) decreased by 25.2/18.4 mmHg (Cohort 1) and 24.2/17.9 mmHg (Cohort 2). These results demonstrate that AZL-M is well tolerated over the long term and provides stable BP improvements when used in a treat-to-target BP approach with thiazide-type diuretics.
Background:Angiotensin receptor blockers (ARBs) are preferred antihypertensive therapies in patients with type 2 diabetes mellitus (T2DM). Azilsartan medoxomil (AZL-M) is a potent ARB for the treatment of stages 1-2 hypertension. We compared the efficacy, safety, and metabolic effects of AZL-M to both valsartan (VAL) and olmesartan (OLM), separately in patients with impaired fasting glucose (prediabetes mellitus) and T2DM.Methods:A pooled analysis of 3821 patients from three separate randomized placebo-controlled trials comparing the effects of AZL-M (40 and 80mg), OLM (40mg), VAL (320mg), and placebo on changes in ambulatory and clinic blood pressure (BP) among patients with hypertension and prediabetes mellitus or T2DM was performed. Two analysis pools were created to facilitate comparisons: Pool A included patients who received placebo, AZL-M or OLM and Pool B included those who received AZL-M or VAL. Within each pool, patients were stratified by glycemic subgroups (normoglycemic, prediabetes mellitus, or T2DM) based on hemoglobin A1c values. Changes from baseline in both 24-h and clinic SBP were the primary efficacy assessments.Results:Baseline 24-h mean SBPs were approximately 145 and 146mmHg in the prediabetes mellitus and T2DM subgroups, respectively; corresponding clinic SBPs were approximately 158 and 159mmHg. Baseline hemoglobin A1c values for each subgroup (both pools) were normoglycemic, 5.3%; prediabetes mellitus, 6.0%; and T2DM, 6.9%. Changes from baseline in 24-h or clinic SBP were significantly greater with AZL-M, 80mg compared with either OLM 40mg or VAL 320mg in all subgroups in each pool. Safety and tolerability were similar among the active treatment and placebo subgroups.Conclusion:These analyses indicate that AZL-M, 80mg/day lowers SBP by a greater magnitude than OLM or VAL at maximally approved doses in patients with prediabetes mellitus and T2DM. These findings have important clinical implications for this high-risk patient group.
We have recently shown that a linear current-to-voltage (I-V) relationship of membrane conductance (passive conductance) reflects the intrinsic property of K+ channels in mature astrocytes. While passive conductance is known to underpin a highly negative and stable membrane potential (VM) essential for the basic homeostatic function of astrocytes, a complete repertoire of the involved K+ channels remains elusive. TREK-1 two-pore domain K+ channel (K2P) is highly expressed in astrocytes, and covalent association of TREK-1 with TWIK-1, another highly expressed astrocytic K2P, has been reported as a mechanism underlying the trafficking of heterodimer TWIK-1/TREK-1 channel to the membrane and contributing to astrocyte passive conductance. To decipher the individual contribution of TREK-1 and address whether the appearance of passive conductance is conditional to the co-expression of TWIK-1/TREK-1 in astrocytes, TREK-1 single and TWIK-1/TREK-1 double gene knockout mice were used in the present study. The relative quantity of mRNA encoding other astrocyte K+ channels, such as Kir4.1, Kir5.1, and TREK-2, was not altered in these gene knockout mice. Whole-cell recording from hippocampal astrocytes in situ revealed no detectable changes in astrocyte passive conductance, VM, or membrane input resistance (Rin) in either kind of gene knockout mouse. Additionally, TREK-1 proteins were mainly located in the intracellular compartments of the hippocampus. Altogether, genetic deletion of TREK-1 alone or together with TWIK-1 produced no obvious alteration in the basic electrophysiological properties of hippocampal astrocytes. Thus, future research focusing on other K+ channels may shed light on this long-standing and important question in astrocyte physiology.
We tested the hypothesis that apneas during the sleep cycle exacerbate hypertension and accelerate changes that occur with cerebral small vessel disease. Obstructive sleep apnea was modeled by intermittent inflations of a chronically implanted tracheal balloon to occlude the airway during the sleep cycle (termed OSA) in spontaneously hypertensive stroke-prone (SHRSP) rats, a model of cerebral small vessel disease. SHRSP rats and their parent strain, Wistar Kyoto (WKY) rats, were exposed to OSA for 2 weeks (from 9 to 11 or from 18 to 20 weeks). At 9 weeks, hypertension was developing in the SHRSP rats and was firmly established by 18 weeks. OSA exposure increased systolic blood pressure in SHRSP rats by ≈30 mm Hg in both age groups compared with shams that were surgically prepared but not exposed to OSA ( P <0.05). OSA exposure also increased systolic blood pressure in WKY rats by 20 and 37 mm Hg at 11 and 20 weeks, respectively ( P <0.05). OSA exposure in SHRSP rats compromised blood–brain barrier integrity in white matter at both 11 and 20 weeks of age when compared with SHRSP sham rats ( P <0.05). Microglia were activated in SHRSP rats exposed to OSA but not in sham rats at 11 weeks ( P <0.05). At 20 weeks, microglia were activated in sham SHRSP rats ( P <0.05) compared with WKY sham rats and were not further activated by OSA. Neither was blood–brain barrier integrity altered nor microglia activated in any of the WKY groups. We conclude that OSA accelerates the onset of the cerebral pathologies associated with cerebral small vessel disease in SHRSP, but not WKY, rats.
Molecular circadian clock components oscillate in cells of the cardiovascular system. These clocks allow the cell to respond to a stimulus with proper timing and magnitude. Alterations in these rhythms are associated with and/or contribute to various cardiovascular diseases. We tested the hypothesis that obstructive sleep apnea (OSA) disrupts the normal rhythms of the cerebrovascular circadian clock and vascular function. OSA was produced in rats by remotely inflating a balloon placed in the trachea. Unanesthetized rats underwent 60 apneas/ hour for 8 hours/ day (sleep phase). Following 2 weeks of sham or OSA, cerebral arteries were isolated at; the transition from dark‐to‐light (i.e., zeitgeber time (ZT) 0), 6, 12, or 18. We identified significant diurnal rhythms in mRNA expression levels of the circadian clock genes period 1 (per1), period 2 (per2), and the clock controlled gene albumin d‐site binding protein (dbp) in cerebral vessels of sham rats, which were significantly attenuated following OSA (p<0.05 for each). Perfused posterior cerebral arteries from sham rats exhibit a significant diurnal rhythm in the sensitivity to ATP induced vasodilation, that was most responsive at the beginning of the awake phase (p<0.05). This rhythm was abolished in OSA arteries, which exhibit diminished ATP sensitivity independent of the time‐of‐day (p<0.05). In the presence of L‐NAME the diurnal rhythm in ATP sensitivity was abolished in sham vessels and not different from OSA, suggesting cerebral arteries exhibit a diurnal rhythm in nitric oxide induced vasodilation that is impaired following OSA. In conclusion, OSA significantly attenuates the diurnal rhythms of the cerebrovascular circadian clock and vascular function. Funded by 1R01NS080531
,Obstructive sleep apnea (OSA) is associated with cerebrovascular diseases. However, little is known regarding. the effects of OSA on the cerebrovascular wall. We tested the hypothesis that OSA augments endothelin-1 (ET-1) constrictions of cerebral arteries. Repeated apneas (30 or 60 per hour) were produced in rats during the sleep cycle (8 hours) by remotely inflating a balloon implanted in the trachea. Four weeks of apneas produced a 23-fold increase in ET-1 sensitivity in isolated and pressurized posterior cerebral arteries (PCAs) compared with PCAs from sham-operated rats (EC50=10(-92) mol/L versus 10-(10.6) mol/L; P<0.001). This increased sensitivity was abolished by the ET-B receptor antagonist, BQ-788. Constrictions to the ET-B receptor agonist, IRL-1620, were greater in PCAs from rats after 2 or 4 weeks of apneas compared with that from sham-operated rats (P=0.013). Increased IRL-1620 constrictions in PCAs from OSA rats were normalized with the transient receptor potential channel (TRPC) blocker, SKF96365, or the Rho kinase (ROCK) inhibitor, Y27632. These data show that OSA increases the sensitivity of PCAs to ET-1 through enhanced ET-B activity, and enhanced activity of TRPCs and ROCK. We conclude that enhanced ET-1 signaling is part of a pathologic mechanism associated with adverse cerebrovascular outcomes of OSA.
Cerebral small vessel disease (CSVD) and its pathological changes in small vessels in brain, is responsible for lacunar infarcts, white matter lesions, hemorrhages, microbleeds, and cognitive impairment. Although it has been suggested that OSA has a role in CSVD, there are no controlled studies relating OSA to CSVD and it pathological consequences. We tested the hypothesis that OSA in SHRsp rats, a model for CSVD, accelerates the development of associated brain pathologies. Chronic intermittent airway obstructions (termed OSA, 10 sec in duration, 60/hr, during 8 hr of the sleep cycle) were induced by remotely inflating balloons implanted in the tracheas of SHRsp and their parent strain, Wistar Kyoto rats (WKY). Studies were conducted at 12 and 20 weeks of age after being subjected to 14 days of OSA. Sham rats had balloons implanted but without inflations to occlude the airway. Systolic blood pressure was significantly increased in SHRsp with OSA by 58 ± 15 and 32 ± 7 mm Hg at 12 and 20 weeks respectively compared to SHRsp sham rats (n=7-10, p<0.05). Working memory as assessed by novel object recognition was impaired in the SHRsp with OSA at both 12 and 20 weeks (n=6, p<0.01). IgG extravasation, a measure of blood brain barrier integrity, was significantly increased (n=6, p<0.05) in small vessels of the 12 and 20 week SHRsp OSA groups. In the 12 week SHRsp OSA group the IgG extravasation was mainly present in the white matter small vessels, while in the 20 week SHRsp OSA group, which contained far greater (p<0.05, n=6) IgG positive small vessels, the majority of the IgG extravasation was found in the grey matter. Activation of microglia in the external capsule (as determined by morphometric analysis) was significantly greater in the SHRsp OSA group compared to all other groups of rats (n=6 each group, p<0.05). There was a significant loss of white matter as indicated by a 192 ± 10% increase (n=6, p<0.05) in the breakdown products of myelin basic protein in the SHRsp OSA group at 20 weeks but not at 12 weeks. We conclude that OSA in the SHRsp accelerates the onset of the cerebral pathologies associated with cerebral small vessel disease.
A phase 3, 26‐week, open‐label, titrate‐to‐target study (n=418) assessed the safety of azilsartan medoxomil (AZL‐M) alone and with chlorthalidone (CLD), followed by a 6‐week, double‐blind, placebo‐controlled reversal phase with change in clinic diastolic blood pressure (DBP) as the primary endpoint. Target blood pressure (BP) was <140/90 mm Hg (<130/80 mm Hg with diabetes/chronic kidney disease). AZL‐M was initiated at 40 mg once a day (QD), force‐titrated to 80 mg at week 4. CLD 25 mg QD could be added (weeks 8–22), if required, to reach target, followed by additional antihypertensives from week 12. At the end of the open‐label phase, mean change in systolic BP (SBP)/DBP from baseline was −23/−16 mm Hg. The most common adverse events, irrespective of treatment, were dizziness (8.9%) and headache (7.2%). Serious AEs were reported in eight patients (1.9%). Consecutive creatinine elevations ≥50% with values exceeding the upper limit of normal (ULN) were reported in nine (2.2%) patients. All returned to below the 50% threshold; most also returned to below the ULN after drug discontinuation. Mean DBP was maintained through the reversal phase in patients receiving AZL‐M, but increased with placebo (difference: −7.8 mm Hg, 95% confidence interval, −9.8 to −5.8; P <.001). AZL‐M alone or with CLD showed good long‐term safety and stable BP improvements in a titrate‐to‐target approach. BP improvements caused by AZL‐M therapy were safely reversible upon AZL‐M withdrawal.
TWIK-2 (KCNK6) is a member of the 2-pore domain (K2P) family of potassium channels, which are highly expressed in the vascular system. We tested the hypothesis that TWIK-2 deficiency leads to pulmonary hypertension. TWIK-2 knockout mice and their wildtype littermates at 8 weeks of age had similar mean right ventricular systolic pressures (24±3 and 21±3 mm Hg, respectively.) Significantly, by 20 weeks of age, the mean right ventricular systolic pressures in TWIK-2 knockout mice increased to 35±3 mm Hg (P≤0.036), whereas mean right ventricular systolic pressures in wildtype littermates remained at 22±3 mm Hg. Elevated mean right ventricular systolic pressures in the TWIK-2 knockout mice was accompanied by pulmonary vascular remodeling as determined by a 25% increase in the cross-sectional area of the vessels occupied by the vessel wall. Additionally, secondary branches of the pulmonary artery from 20-week-old TWIK-2 knockout mice showed an enhanced contractile response to U46619 (10(-6) moles/L), a thromboxane A2 mimetic, which was completely abolished with the Rho-kinase inhibitor, Y27632 (10(-6) and 10(-5) moles/L). Treatment of TWIK-2 knockout mice with the Rho-kinase inhibitor, fasudil, in the drinking water for 12 weeks, abolished the development of pulmonary hypertension and attenuated the vessel remodeling. We concluded that mice deficient in the TWIK-2 channel develop pulmonary hypertension between 8 and 20 weeks of age through a mechanism involving Rho-kinase. Our results suggest that downregulation of TWIK-2 in the pulmonary vasculature may be an underlying mechanism in the development of pulmonary hypertension.