Simple, accurate, precise, and cost-effective chemometric techniques for the measurement of candesartan cilexetil and hydrochlorothiazide in synthetic mixtures were improved and validated. H-point standard addition, Q-absorption ratio, and correction absorbance spectrophotometric techniques were utilized for the simultaneous determination of both medicines in real pharmaceutical formulations. A new calibration approach was implemented based on chemical H-point standards. This approach was developed to resolve significantly overlapping spectra of two analytes and provide direct correction of both proportional and constant errors caused by the matrix of the sample. The first method of simultaneous determination of candesartan cilexetil and hydrochlorothiazide was carried out using the H-point standard addition method at wavelengths 239 and 283. For the ratio of the absorption at two selected wavelengths, one of which is the isoabsorptive point and the other being the maximum of one of the two components, the second method absorption ratio method was utilized. In distilled water, the isoabsorptive point of candesartan cilexetil and hydrochlorothiazide occurs at 258 nm. λ max of hydrochlorothiazide is 273 nm, which is the second wavelength used. Lastly, the absorbance correction method was implemented. This approach is based on absorbance correction equations and uses distilled water as the solvent for the examination of both medicines. In NaOH/EtOH solvent, the absorbance maxima of candesartan cilexetil and hydrochlorothiazide are 250 nm and 340 nm, respectively. For both wavelengths, candesartan cilexetil and hydrochlorothiazide exhibited linearity over a concentration range of 1-46 μg/ml and 1-44 μg/ml, respectively, for H-point standard addition. The Q-absorption ratio approach provides linearity over the concentration ranges of 1-46 μg/ml at 273 nm for candesartan cilexetil and 1-29 μg/ml for hydrochlorothiazide, 1-46 μg/ml at 258 nm for candesartan cilexetil, and 1-44 μg/ml for hydrochlorothiazide. For hydrochlorothiazide, the linearity for the correction absorbance method was obtained throughout a concentration range of 1-46 μg/ml at wavelengths 250 and 340 nm and 1-44 μg/ml at wavelength 250 nm. The results of the analysis have been statistically and empirically supported by recovery studies. All methods yielded recoveries in the range of 96 -102% for both medications. The LOD ranged from 0.46 -0.94 μg/mL for hydrochlorothiazide and from 1.26 -2.40 μg/mL for candesartan cilexetil. The approaches were then used to quantify candesartan cilexetil and hydrochlorothiazide in pharmaceutical tablets.

Blood pressure control remains an unmet clinical need. Only about half of patients achieve their blood pressure (BP) targets and of these, the majority require combination and double or triple therapies. International guidelines recommend the association of drugs with complementary mechanisms of action and, in particular, the combination of renin-angiotensin system (RAS) inhibitors, calcium channel blockers (CCBs), and diuretics. Among the various angiotensin receptor blockers, olmesartan (OM) is available as a monotherapy and in dual and triple single-pill combinations (SPCs) with amlodipine (AML) and/or hydrochlorothiazide (HCTZ). Several phase III and IV studies, together with real-world studies, have demonstrated the additional benefits of combining OM either with AML or with HCTZ in terms of BP control and target BP achievements both in the general population and in special subgroups of hypertensive patients, such as the elderly, diabetic, chronic kidney disease or obese patients. Ambulatory BP monitoring studies assessing 24h BP have also demonstrated that dual, as well as triple, OM-based SPCs induce a more sustained and smoother BP reduction than placebo and monotherapy. Furthermore, triple OM-based SPC has been shown to improve therapeutic adherence in hypertensive patients compared to free combinations. The availability of OM combined with HCTZ, AML or both at different dosages makes it a valuable option to customize therapy based on the levels of BP and the clinical characteristics of hypertensive patients.

A β-class carbonic anhydrase (CA, EC 4.2.1.1) present in the genome of the Monogenean platyhelminth Gyrodactylus salaris, a fish parasite, GsaCAβ, has been investigated for its inhibitory effects with a panel of sulphonamides and sulfamates, some of which in clinical use. Several effective GsaCAβ inhibitors were identified, belonging to simple heterocyclic sulphonamides, the deacetylated precursors of acetazolamide and methazolamide (KIsof 81.9-139.7 nM). Many other simple benezene sulphonamides and clinically used agents, such as acetazolamide, methazolamide, ethoxzolamide, dorzolamide, benzolamide, sulthiame and hydrochlorothiazide showed inhibition constants <1 µM. The least effective GsaCAβ inhibitors were 4,6-disubstituted-1,3-benzene disulfonamides, with KIs in the range of 16.9-24.8 µM. Although no potent GsaCAβ-selective inhibitors were detected so far, this preliminary investigation may be helpful for better understanding the inhibition profile of this parasite enzyme and for the potential development of more effective and eventually parasite-selective inhibitors.

This study aimed to probe the effects of low-dose irbesartan and hydrochlorothiazide in combination with levamlodipine at different times on the circadian rhythm of blood pressure, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs) levels in patients with non-dipper hypertension (NDH). In this prospective randomized controlled trial, 124 patients with NDH who visited our hospital between August 2018 and July 2021 were enrolled and divided into morning (62 patients) and night (62 patients) medication groups according to the random number table method. All patients received low-dose irbesartan and hydrochlorothiazide combined with levamlodipine, with the morning medication group taking the medication between 7:00 and 10:00 and the night medication group taking the medication between 19:00 and 22:00 for 24 weeks. The effect of antihypertensive medication in both groups was measured, and changes in ambulatory blood pressure, blood pressure circadian rhythm, left ventricular structure, vascular endothelial function, MMPs, and TIMPs levels were observed before treatment initiation and after 24 weeks of treatment in both groups. The percentage of the dipper type was higher in the night medication group than in the morning medication group, while the percentage of the non-dipper type was lower in the morning medication group (p < .05). Low-dose irbesartan and hydrochlorothiazide combined with levamlodipine at different times can effectively treat NDH, but bedtime dosing is more beneficial in reducing nocturnal blood pressure, reversing NDH, improving the circadian rhythm of blood pressure, left ventricular structure, regulating vascular endothelial function, increasing MMPs levels, and reducing TIMP levels.

Hesperidin (HSP) is a major flavanone glycoside in citrus fruits, including sweet oranges and lemons. It demonstrates numerous pharmacological activities, such as antihypertensive effects and cardiac and kidney tissue protection. However, its effect on modulating renal function has yet to be properly explored. Female and male Wistar spontaneously hypertensive rats (SHR) were used to test the effect of HSP on renal function. The rats were divided into different groups, treated orally, and placed in metabolic cages for urine collection for 8 h. HSP, at doses of 0.3-3 mg/kg, led to an increase in urine volume in both female and male SHR. This effect was associated with increased Na+ elimination (3 mg/kg) without causing any change in K+ excretion or pH and conductivity values. When given HSP in combination with hydrochlorothiazide (HCTZ) or amiloride (AMLR), urine volume and Na+ elimination were significantly increased compared to the group that received only HSP. In relation to K+ excretion, the depleting effect of HCTZ and the sparing of AMLR prevailed in both groups. Pre-treatment with a non-selective cholinergic receptor antagonist, atropine, partially prevented HSP-induced diuresis and natriuresis in male SHR, but this effect was not demonstrated with the non-selective inhibitor of the enzyme cyclooxygenase, indomethacin. This study shows the diuretic action of HSP in hypertensive rats, an activity probably associated with the cholinergic pathway. Although various biological actions have already been defined for HSP, this pioneering research reveals its potential as a diuretic medicine.

Summarize selected late-breaking science on cardiovascular (CV) disease prevention presented at the 2022 scientific session of the American Heart Association (AHA).

Hypertension is a multifactorial disease arising from complex pathophysiological pathways. Individual characteristics of patients result in different responses to various classes of antihypertensive medications. Therefore, evaluating the efficacy of therapy based on in silico predictions is an important task. This study is a continuation of research on the modular agent-based model of the cardiovascular and renal systems (presented in the previously published article). In the current work, we included in the model equations simulating the response to antihypertensive therapies with different mechanisms of action. For this, we used the pharmacodynamic effects of the angiotensin II receptor blocker losartan, the calcium channel blocker amlodipine, the angiotensin-converting enzyme inhibitor enalapril, the direct renin inhibitor aliskiren, the thiazide diuretic hydrochlorothiazide, and the β-blocker bisoprolol. We fitted therapy parameters based on known clinical trials for all considered medications, and then tested the model's ability to show reasonable dynamics (expected by clinical observations) after treatment with individual drugs and their dual combinations in a group of virtual patients with hypertension. The extended model paves the way for the next step in personalized medicine that is adapting the model parameters to a real patient and predicting his response to antihypertensive therapy. The model is implemented in the BioUML software and is available at https://gitlab.sirius-web.org/virtual-patient/antihypertensive-treatment-modeling.

The study's objective was to ascertain the results of sub-chronic therapy of various diuretics on the ischemia/reperfusion dysfunction of the heart in hypertensive rats by a global ischemia in an isolated rat heart model. The research included 40 spontaneously hypertensive male rats (Wistar Kyoto strain, body mass 250 ± 30 g, 8 weeks old) grouped into four groups. The animals were treated for 4 weeks with 10 mg/kg of hydrochlorothiazide, indapamide, or spironolactone per os. After a period of sub-chronic treatment, we analyzed hemodynamic measurements, echocardiography, and myocardial function according to the Langendorff retrograde perfusion method. The hearts were subjected to 20 min of global ischemia and then reperfused for 30 min (I20:R30). Cardiovascular parameters that depict the left ventricle functions were continuously monitored, while flowmetry was used to determine coronary flow values. Markers of oxidative stress were estimated from coronary venous effluent using spectrophotometry. All three examined diuretics (hydrochlorothiazide, spironolactone, indapamide) lowered the production of the majority of the detected prooxidants, reducing myocardial oxidative damage. The cardiological examination of heart function in vivo demonstrated that treatment with indapamide and spironolactone mitigates left ventricular hypertrophy but without significant lowering of blood pressure or increment in ejection fraction. Additionally, monitoring of cardiac function ex vivo indicated the cardiodepressant effect of spironolactone in spontaneously hypertensive rats.

Micropollutants (MPs), such as pharmaceuticals and antibiotics, are present in the environment at low concentrations (ng/L-μg/L). A constructed wetland (CW) is a nature-based wastewater treatment technology, which can be used to remove MPs from wastewater treatment plant effluent. This study aimed to improve MP removal of CWs by optimizing the design of batch-operated CW. Three pilot-scale CWs were built to study the effect of two design-features: the use of a support matrix (a mixture of bark and biochar) and continuous aeration. The use of bark-biochar as support matrix increased the removal of 11 of 12 studied MPs compared to the CW filled with conventional material sand. The highest improved removal by the addition of bark-biochar was more than 40% (median) for irbesartan, carbamazepine, hydrochlorothiazide and benzotriazole. Aerating the bed of the bark-biochar CW did not change MP removal. Besides, the presence of bark-biochar also enhanced the removal of total nitrogen during 10 months of operation, but no improvement was observed on the total organic carbon and total phosphorus removal. Considering the application in a batch-operated CW, MP removal can be greatly enhanced by replacing sand with bark-biochar that will act as MP adsorbing matrix.

Unlike medications that contain fixed-dose combinations, such as those recommended by clinical guidelines for treating high blood pressure, the so-called polypills contain several drugs that simultaneously treat two or more cardiovascular conditions or risk factors. They were proposed 2 decades ago, both for primary and secondary prevention with the hypothesis that they could have wide dissemination and population penetration, improving the use of therapeutics with proven benefits individually, thanks to an increase in patient adherence by reducing the number of daily tablets and also by having an equal or lower cost. In this simple review, we present a look at risk stratification different from that posed by clinical scores and summarize the benefits of polypills in the treatment of risk factors and in the reduction of major cardiovascular events. Additionally, we review the clinical messages of the HOPE-3 trial, which aim to control two of the most prevalent conditions, such as high blood pressure and high cholesterol, through a combination of candesartan, hydrochlorothiazide and rosuvastatin. Finally, we propose its potential indication in a heterogeneous health system such as that of our country, both at the population level based on intermediate or low risk, determined intuitively or using a risk calculator, as well as in the personalized care that is practiced in many health scenarios.

Na+/K+-ATPases (NKA) in the basolateral membrane of the intestinal enterocytes create a Na+-gradient that drives both ion-coupled fluid uptake and nutrient transport. Being dependent on the same gradient as well as on the environmental salinity, these processes have the potential to affect each other. In salmonids, L-lysine absorption has been shown to be higher in freshwater (FW) than in seawater (SW) acclimated fish. Using electrophysiology (Ussing chamber technique), the aim was to explore if the decrease in L-lysine transport was due to allocation of the Na+-gradient towards ion-driven fluid uptake in SW, at the cost of amino acid transport. Intestinal NKA activity was higher in SW compared to FW fish. Exposure to ouabain, an inhibitor of NKA, decreased L-lysine transport. However, exposure to bumetanide and hydrochlorothiazide, inhibitors of Na+, K+, 2Cl--co-transporter (NKCC) and Na+, Cl--co-transporter (NCC) respectively, did not affect the rate of intestinal L-lysine transport. In conclusion, L-lysine transport is Na+-dependent in rainbow trout and the NKA activity and thus the available Na+-gradient increases after SW acclimation. This increased Na+-gradient is most likely directed towards osmoregulation, as amino acid transport is not compromised in SW acclimated fish.

Our understanding of hyponatremic conditions has undergone major alterations. There is a tendency to treat all patients with hyponatremia because of common subtle symptoms that include unsteady gait that lead to increased falls and bone fractures and can progress to mental confusion, irritability, seizures, coma and even death. We describe a new approach that is superior to the ineffectual volume approach. Determination of fractional excretion (FE) of urate has simplified the diagnosis of a reset osmostat, Addison's disease, edematous causes such as congestive heart failure, cirrhosis and nephrosis, volume depletion from extrarenal salt losses with normal renal tubular function and the difficult task of differentiating the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) from cerebral/renal salt wasting (C/RSW). SIADH and C/RSW have identical clinical and laboratory parameters but have diametrically opposite therapeutic goals of water-restricting water-loaded patients with SIADH or administering salt water to dehydrated patients with C/RSW. In a study of nonedematous patients with hyponatremia, we utilized FEurate and response to isotonic saline infusions to differentiate SIADH from C/RSW. Twenty-four (38%) of 62 hyponatremic patients had C/RSW with 21 having no clinical evidence of cerebral disease to support our important proposal to change cerebral to renal salt wasting (RSW). Seventeen (27%) had SIADH and 19 (31%) had a reset osmostat. One each from hydrochlorothiazide and Addison's disease. We demonstrated natriuretic activity in the plasma of patients with neurosurgical and Alzheimer diseases (AD) in rat clearance studies and have now identified the natriuretic protein to be haptoglobin related protein without signal peptide (HPRWSP). We introduce a new syndrome of RSW in AD that needs further confirmation. Future studies intend to develop HPRWSP as a biomarker to simplify the diagnosis of RSW in hyponatremic and normonatremic patients and explore other clinical applications that can improve clinical outcomes.

In the last years, major progress occurred in heart failure (HF) management. Quadruple therapy is now mandatory for all the patients with HF with reduced ejection fraction. Whilst verciguat is becoming available across several countries, omecamtiv mecarbil is waiting to be released for clinical use. Concurrent use of potassium-lowering agents may counteract hyperkalaemia and facilitate renin-angiotensin-aldosterone system inhibitor implementations. The results of the EMPagliflozin outcomE tRial in Patients With chrOnic heaRt Failure With Preserved Ejection Fraction (EMPEROR-Preserved) trial were confirmed by the Dapagliflozin in Heart Failure with Mildly Reduced or Preserved Ejection Fraction (DELIVER) trial, and we now have, for the first time, evidence for treatment of also patients with HF with preserved ejection fraction. In a pre-specified meta-analysis of major randomized controlled trials, sodium-glucose co-transporter-2 inhibitors reduced all-cause mortality, cardiovascular (CV) mortality, and HF hospitalization in the patients with HF regardless of left ventricular ejection fraction. Other steps forward have occurred in the treatment of decompensated HF. Acetazolamide in Acute Decompensated Heart Failure with Volume Overload (ADVOR) trial showed that the addition of intravenous acetazolamide to loop diuretics leads to greater decongestion vs. placebo. The addition of hydrochlorothiazide to loop diuretics was evaluated in the CLOROTIC trial. Torasemide did not change outcomes, compared with furosemide, in TRANSFORM-HF. Ferric derisomaltose had an effect on the primary outcome of CV mortality or HF rehospitalizations in IRONMAN (rate ratio 0.82; 95% confidence interval 0.66-1.02; P = 0.070). Further options for the treatment of HF, including device therapies, cardiac contractility modulation, and percutaneous treatment of valvulopathies, are summarized in this article.

Herein, a novel immunochromatographic assay (ICA) based on metal-organic framework-decorated polydopamine (MOF@PDA) was firstly developed for the determination of hydrochlorothiazide (HCTZ) adulteration in functional foods. The coupling rate of MOF@PDA carrier to HCTZ antibody was as high as 91.7 %. The detection limits of the developed MOF@PDA-ICA in functional tablets and capsules were 5.93 and 4.72 μg/kg, the linear ranges were 11.2-91.91 μg/kg and 9.11-86.78 μg/kg, respectively. The sensitivity was 27-fold higher than that of the reported ICA. The recovery was 82.5-116.6 %, and coefficient of variation was 6.9-14.2 %. The results can be achieved and analyzed in 8 min with the smartphone-based detection device. The parallel tests of 23 commercial functional tablets and capsules showed that the results of the MOF@PDA-ICA were consistent with that of the LC-MS/MS (R2 > 0.99). Therefore, our method is facile, sensitive, portable, and can provide a reliable technical mean for the detection of HCTZ adulteration in functional foods.

Malate regulates blood pressure via nitric oxide production in salt-sensitive rats, a genetic model of hypertension. This study investigated the possible contributions of malate to blood pressure regulation and renal haemodynamics in normotensive rats. Malate (0.1, 0.3 and 1 μg/kg, iv) was injected into rats or L-nitro-arginine methyl ester (L-NAME)-treated rats and mean arterial blood pressure (MABP), cortical blood flow (CBF), and medullary blood flow (MBF), was measured. The clearance study involved infusion of malate at 0.1 μg/kg/h into rats, and MABP, CBF, MBF, glomerular filtration rate (GFR), urine volume (UV) and sodium output (UNaV) were determined. Mechanistic studies to evaluate the role of renal sodium channels involved the treatment with malate (600 mg/kg, po), amiloride (2.5 mg/kg, po) or hydrochlorothiazide (HCTZ) (10 mg/kg, po), and UV and UNaV were determined. Malate elicited significant peak reductions in MABP (124 ± 6.5 vs 105 ± 3.1 mmHg) at 0.1 μg/kg), CBF (231 ± 18.5 vs 205 ± 10.9 PU). L-NAME did not reverse the effect of malate on MABP but tended to blunt the effect on CBF (40%) and MBF (87%) at 0.3 μg/kg. Infusion of malate reduced MABP, CBF, and MBF in a time-dependent manner (p<0.05). Malate exerted a three-fold decrease in GFR in a time-related fashion (p<0.05) as well as increased UV. UNaV increased by 86% in malate-treated-amiloride rats (p<0.05). These data indicate that malate modulates blood pressure and exerts vascular and tubular effects on renal function that may involve epithelial sodium channels (ENaC).

Introduction The patient was a 72-year-old man with a history of hypertension, hyperlipidemia, benign prostatic hyperplasia, and oropharyngeal cancer. His home medications include amlodipine, atorvastatin, hydrochlorothiazide, and tamsulosin. He lives alone and eats a soft, bland, nutrient-poor diet. During his annual primary care visit, he is found to have a serum potassium level of 3.3 mEq/L (reference range 3.5-5.0). Assessment The use of hydrochlorothiazide, a thiazide diuretic, as well as his low consumption of dietary potassium, have likely contributed to his mild, asymptomatic hypokalemia. Outcome The patient's serum potassium normalizes following replenishment with a 10 mEq microencapsulated potassium chloride (KCl) extended release (ER) tablet three times a day with meals for one week. A registered dietitian was consulted to provide recommendations for a well-balanced diet, consistent with his dietary texture needs. Conclusions Hypokalemia is a commonly encountered electrolyte disorder, occurring in about 3 to 4% of community-dwelling elders.1 Though asymptomatic hypokalemia is often an incidental finding, it is associated with an increased risk of major adverse cardiovascular events if left untreated and thus should be promptly corrected when discovered.².

Despite being a developed country in the European Union (EU), knowledge of the nature and extent of contamination of water bodies with contaminants of emerging concern (CECs) in Ireland is limited. In this study, >140 CECs including pharmaceuticals, pesticides and personal care products were monitored in monthly samples of wastewater treatment plant (WWTP) influent, effluent and receiving surface waters at both an urban and a rural location (72 samples in total) in Ireland over a 12-month period in 2018-2019. In total, 58 CECs were detected, including several EU Water Framework Directive Watch List compounds. Of all classes, the highest concentrations were measured for pharmaceuticals across all media, i.e., propranolol in surface waters (134 ng·L-1), hydrochlorothiazide in effluent (1067 ng·L-1) and venlafaxine in influent wastewater (8273 ng·L-1). Overall, high wastewater treatment removal was observed and a further reduction in CEC occurrence and concentration was measured via dilution in the receiving river environment. Lastly, an environmental risk assessment (ERA) was performed using risk quotients (RQ), which revealed that in surface waters, total RQ for all CECs was an order of magnitude lower than in effluents. The majority of CECs in surface waters posed a lower risk except E2 and EE2 which presented a medium risk (RQs of 3.5 and 1.1, respectively) in the rural area. This work represents the most comprehensive CEC monitoring dataset to date for Ireland which allowed for an ERA prioritisation to be performed for the first time.

The tidal freshwater Potomac River (TFPR) in the metropolitan Washington, DC region receives wastewater discharge from eight major wastewater treatment plants with the potential to impact water quality. A total of 85 pharmaceutical chemicals and personal care products (PPCPs) were analyzed in surface water and sediments using solid-phase extraction and QuEChERS, respectively, in conjunction with liquid-chromatography tandem mass spectrometry-multiple reaction monitoring quantitation (LC-MS/MS-MRM). A total of 52 PPCPs were quantified in both surface water and sediment. The most frequently quantified PPCPs in water included caffeine, fexofenadine, nicotine, sulfamethoxazole, hydrochlorothiazide, MDA, desvenlafaxine, and metoprolol ranging from 10 to 360 ng/L, and in sediment included diphenhydramine, escitalopram, desvenlafaxine, fexofenadine, sertraline and triclocarban ranging from 20 to 120 ng/g (dry weight). Comparisons of PPCP constituents in WTP discharge and adjacent surface water showed altered compositions reflecting dispersal and transformation processes acted quickly following contact of effluent with surface water. Although the PPCPs were present at their greatest concentrations in surface water near the WTP discharge zones, PPCP concentrations rapidly attenuated yielding mainstem TFPR concentrations relatively consistent along the freshwater reach of the tidal range in the estuary. The PPCP concentrations in sediment maximized in the tributary shoals, but also decreased in the mainstem TFPR similarly to surface water. Compositional analysis showed sorption to geosolids was the most important factor in the loss of PPCPs following WTP discharge in the tributary embayments.

There is increasing awareness of seasonal variation in blood pressure (BP). In the present analysis, we investigated seasonal variation in the antihypertensive treatment effect of the irbesartan/hydrochlorothiazide combination in patients with stage 2 and 3 hypertension. The study participants were hypertensive patients enrolled in a 12-week therapeutic study. Antihypertensive treatment was initiated with irbesartan/hydrochlorothiazide 150/12.5 mg/day, with possible uptitration to 300/12.5 mg/day and 300/25 mg/day at 4 and 8 weeks of follow-up, respectively. The month of treatment commencement was classified as spring/summer (May to August) and autumn/winter (September to December). Of the 501 enrolled patients, 313 and 188 commenced antihypertensive treatment in spring/summer and autumn/winter, respectively. The mean changes in systolic/diastolic BP at 8 and 12 weeks of follow-up were greater in patients who commenced treatment in autumn/winter (-32.3/-16.5 and -34.2/-16.7 mmHg, respectively) than those who commenced treatment in spring/summer (-28.4/-13.9 and -27.1/-12.8 mmHg, respectively), with a between-season difference of 3.9 (95% confidence interval [CI], 1.4-6.4, P = 0.002)/2.6 (95% CI, 0.9-4.2, P = 0.002) mmHg and 7.0 (95% CI, 4.7-9.3, P < 0.0001)/3.9 (95% CI, 2.4-5.4, P < 0.0001) mmHg, respectively. Further subgroup analyses according to several baseline characteristics showed a greater between-season difference in the changes in systolic BP in patients aged ≥55 years than in those <55 years (n = 255, 12.6 mmHg vs. n = 246, 6.9 mmHg, P = 0.02), especially in patients who did not use antihypertensive medication at baseline (n = 94, 15.4 mmHg vs. n = 132, 5.4 mmHg, P = 0.006). In conclusion, there is indeed seasonality in the antihypertensive treatment effect, with a greater BP reduction in patients who commenced treatment in cold than warm seasons.

The dysfunction of Na+-Cl- cotransporter (NCC) caused by mutations in solute carrier family12, member 3 gene (SLC12A3) primarily causes Gitelman syndrome (GS). In identifying the pathogenicity of R158Q and G212S variants of SLC12A3, we evaluated the pathogenicity by bioinformatic, expression, and localization analysis of two variants from a patient in our cohort. The prediction of mutant protein showed that p.R158Q and p.G212S could alter protein's three-dimensional structure. Western blot showed a decrease of mutant Ncc. Immunofluorescence of the two mutations revealed a diffuse positive staining below the plasma membrane. Meanwhile, we conducted a compound heterozygous model-Ncc R156Q/G210S mice corresponding to human NCC R158Q/G212S. NccR156Q/G210S mice clearly exhibited typical GS features, including hypokalemia, hypomagnesemia, and increased fractional excretion of K+ and Mg2+ with a normal blood pressure level, which made NccR156Q/G210S mice an optimal mouse model for further study of GS. A dramatic decrease and abnormal localization of the mutant Ncc in distal convoluted tubules contributed to the phenotype. The hydrochlorothiazide test showed a loss of function of mutant Ncc in NccR156Q/G210S mice. These findings indicated that R158Q and G212S variants of SLC12A3 were pathogenic variants of GS.