Diuretics use in the management of hypertension.

Diuretics have been used for decades in the treatment of hypertension. Its efficacy has been demonstrated in numerous clinical trials. It is well known that the reduction in cardiovascular risk is a consequence of the reduction in blood pressure levels regardless of the drug used, but thiazide diuretics continue to be first-line drugs, especially in low doses and combined with other drugs. The debate on the advantages of using chlorthalidone or hydrochlorothiazide continues, however hydrochlorothiazide is drug most used and for which there is greater availability. The association with potassium-sparing diuretics increases the effectiveness and reduces the adverse reactions of thiazides. A new group of drugs, close to potassium-sparing diuretics, that antagonise aldosterone synthase are showing promising results as antihypertensives. There are no significant differences between men and women regarding the antihypertensive effect of thiazide diuretics.

Hydrochlorothiazide and Prevention of Kidney-Stone Recurrence.

BACKGROUND: Nephrolithiasis is one of the most common conditions affecting the kidney and is characterized by a high risk of recurrence. Thiazide diuretic agents are widely used for prevention of the recurrence of kidney stones, but data regarding the efficacy of such agents as compared with placebo are limited. Furthermore, dose-response data are also limited. METHODS: In this double-blind trial, we randomly assigned patients with recurrent calcium-containing kidney stones to receive hydrochlorothiazide at a dose of 12.5 mg, 25 mg, or 50 mg once daily or placebo once daily. The main objective was to investigate the dose-response effect for the primary end point, a composite of symptomatic or radiologic recurrence of kidney stones. Radiologic recurrence was defined as the appearance of new stones on imaging or the enlargement of preexisting stones that had been observed on the baseline image. Safety was also assessed. RESULTS: In all, 416 patients underwent randomization and were followed for a median of 2.9 years. A primary end-point event occurred in 60 of 102 patients (59%) in the placebo group, in 62 of 105 patients (59%) in the 12.5-mg hydrochlorothiazide group (rate ratio vs. placebo, 1.33; 95% confidence interval [CI], 0.92 to 1.93), in 61 of 108 patients (56%) in the 25-mg group (rate ratio, 1.24; 95% CI, 0.86 to 1.79), and in 49 of 101 patients (49%) in the 50-mg group (rate ratio, 0.92; 95% CI, 0.63 to 1.36). There was no relation between the hydrochlorothiazide dose and the occurrence of a primary end-point event (P = 0.66). Hypokalemia, gout, new-onset diabetes mellitus, skin allergy, and a plasma creatinine level exceeding 150% of the baseline level were more common among patients who received hydrochlorothiazide than among those who received placebo. CONCLUSIONS: Among patients with recurrent kidney stones, the incidence of recurrence did not appear to differ substantially among patients receiving hydrochlorothiazide once daily at a dose of 12.5 mg, 25 mg, or 50 mg or placebo once daily. (Funded by the Swiss National Science Foundation and Inselspital; NOSTONE ClinicalTrials.gov number, NCT03057431.).

Comparison of Clinical Outcomes and Safety Associated With Chlorthalidone vs Hydrochlorothiazide in Older Adults With Varying Levels of Kidney Function.

Importance: Thiazide diuretics are commonly prescribed for the treatment of hypertension, a disease highly prevalent among older individuals and in those with chronic kidney disease. How specific thiazide diuretics compare in regard to safety and clinical outcomes in these populations remains unknown. Objective: To compare safety and clinical outcomes associated with chlorthalidone or hydrochlorothiazide use among older adults with varying levels of kidney function. Design, Setting, and Participants: This population-based retrospective cohort study was conducted in Ontario, Canada, from 2007 to 2015. Participants included adults aged 66 years or older who initiated chlorthalidone or hydrochlorothiazide during this period. Data were analyzed from December 2019 through September 2020. Exposures: New chlorthalidone users were matched 1:4 with new hydrochlorothiazide users by a high-dimensional propensity score. Time-to-event models accounting for competing risks examined the associations between chlorthalidone vs hydrochlorothiazide use and the outcomes of interest overall and within estimated glomerular filtration rate (eGFR) categories (≥60, 45-59, and <45 mL/min/1.73 m2). Main Outcomes and Measures: The outcomes of interest were adverse kidney events (ie, eGFR decline ≥30%, dialysis, or kidney transplantation), cardiovascular events (composite of myocardial infarction, coronary revascularization, heart failure, or atrial fibrillation), all-cause mortality, and electrolyte anomalies (ie, sodium or potassium levels outside reference ranges). Results: After propensity score matching, the study cohort included 12 722 adults (mean [SD] age, 74 [7] years; 7063 [56%] women; 5659 [44%] men; mean [SD] eGFR, 69 [19] mL/min/1.73 m2), including 2936 who received chlorthalidone and 9786 who received hydrochlorothiazide. Chlorthalidone use was associated with a higher risk of eGFR decline of 30% or greater (hazard ratio [HR], 1.24 [95% CI, 1.13-1.36]) and cardiovascular events (HR, 1.12 [95% CI, 1.04-1.22]) across all eGFR categories compared with hydrochlorothiazide use. Chlorthalidone use was also associated with a higher risk of hypokalemia compared with hydrochlorothiazide use, which was more pronounced among those with higher eGFR (eGFR ≥60 mL/min/1.73 m2: HR, 1.86 [95% CI, 1.67-2.08]; eGFR 45-59 mL/min/1.73 m2: HR, 1.57 [95% CI, 1.25-1.96]; eGFR <45 mL/min/1.73 m2: HR, 1.10 [95% CI, 0.84-1.45]; P for interaction = .001). No significant differences were observed between chlorthalidone and hydrochlorothiazide for dialysis or kidney transplantation (HR, 1.44 [95% CI, 0.88-2.36]), all-cause mortality (HR, 1.10 [95% CI, 0.93-1.29]), hyperkalemia (HR, 1.05 [95% CI, 0.79-1.39]), or hyponatremia (HR, 1.14 [95% CI, CI 0.98-1.32]). Conclusions and Relevance: This cohort study found that among older adults, chlorthalidone use was associated with a higher risk of eGFR decline, cardiovascular events, and hypokalemia compared with hydrochlorothiazide use. The excess risk of hypokalemia with chlorthalidone was attenuated in participants with reduced kidney function. Placed in context with prior observational studies comparing the safety and clinical outcomes associated with thiazide diuretics, these results suggest that there is no evidence to prefer chlorthalidone over hydrochlorothiazide.

Antihypertensive Class and Cardiovascular Outcomes in Patients With HIV and Hypertension.

[Figure: see text].

Acute interstitial nephritis and nephrogenic diabetes insipidus following treatment with sulfamethoxazole-trimethoprim and temozolomide.

We report a case of acute interstitial nephritis with associated nephrogenic diabetes insipidus in a patient treated with temozolomide and sulfamethoxazole-trimethoprim for glioblastoma multiforme. Kidney biopsy demonstrated focal tubulointerstitial change with tubular dilatation, epithelial change and interstitial inflammation. The patient's kidney function improved with cessation of sulfamethoxazole-trimethoprim and treatment with hydrochlorothiazide for nephrogenic diabetes insipidus. Recommencement of temozolomide did not result in further deterioration in kidney function. In this case report, we discuss the novel association between sulfamethoxazole-trimethoprim-induced acute interstitial nephritis and nephrogenic diabetes insipidus, and suggest possible mechanisms involved.

Treatment Patterns and Blood Pressure Control With Initiation of Combination Versus Monotherapy Antihypertensive Regimens.

Many patients with hypertension require 2 or more drug classes to achieve their blood pressure (BP) goal. We compared antihypertensive medication treatment patterns and BP control between patients who initiated combination therapy versus monotherapy. We identified adults with hypertension enrolled in a US integrated healthcare system who initiated antihypertensive medication between 2008 and 2014. Patient demographics, clinical characteristics, antihypertensive medication, and BP were extracted from electronic health records. Antihypertensive medication patterns and multivariable adjusted prevalence ratios (PRs) of achieving the 2017 American College of Cardiology/American Heart Association guideline-recommended BP <130/80 mm Hg were evaluated for 2 years following treatment initiation. Of 135 971 patients, 43% initiated antihypertensive combination therapy (35% ACE [angiotensin converting enzyme] inhibitor (ACEI)-thiazide diuretics; 8% with other combinations) and 57% initiated monotherapy (22% ACEIs; 16% thiazide diuretics; 11% ß blockers; 8% calcium channel blockers). After multivariable adjustment including premedication BP levels, patients who initiated ACEI-thiazide diuretic combination therapy were more likely to achieve BP <130/80 mm Hg compared with their counterparts who initiated monotherapy with ACEI (PR, 1.10 [95% CI, 1.08-1.12]), thiazide diuretic (PR, 1.21 [95% CI, 1.18-1.24]), ß blocker (PR, 1.17 [95% CI, 1.14-1.20]), or calcium channel blocker (PR, 1.25 [95% CI, 1.22-1.29]). Compared with initiating monotherapy, patients initiating ACEI-thiazide diuretic combination therapy were more likely to achieve BP goals.

Electrolyte Abnormalities in Patients Presenting With Ventricular Arrhythmia (from the LYTE-VT Study).

Electrolyte abnormalities are a known trigger for ventricular arrhythmia, and patients with heart disease on diuretic therapy may be at higher risk for electrolyte depletion. Our aim was to determine the prevalence of electrolyte depletion in patients presenting to the hospital with sustained ventricular tachycardia or ventricular fibrillation (VT/VF) versus heart failure, and identify risk factors for electrolyte depletion. Consecutive admissions to a tertiary care hospital for VT/VF were identified between July 2016 and October 2018 using the electronic medical record and compared with an equal number of consecutive admissions for heart failure (CHF). The study included 280 patients (140 patients in each group; mean age 63, 60% male, 59% African American). Average EF in the VT/VF and CHF groups was 30% and 33%, respectively. Hypokalemia (K < 3.5 mmol/L) and severe hypokalemia (K < 3.0 mmol/L) were present in 35.7% and 13.6%, respectively, of patients with VT/VF, compared to 12.9% and 2.7% of patients with CHF (p < 0.001 and p = 0.001, respectively, between groups). Hypomagnesemia was found in 7.8% and 5.8% of VT/VF and CHF patients, respectively (p = 0.46). Gastrointestinal illness and recent increases in diuretic dose were strongly associated with severe hypokalemia in VT/VF patients (odds ratio: 11.1 and 21.9, respectively; p < 0.001). In conclusion, hypokalemia is extremely common in patients presenting with VT/VF, much more so than in patients with CHF alone. Preceding gastrointestinal illness and increase in diuretic dose were strongly associated with severe hypokalemia in the VT/VF population, revealing a potential opportunity for early intervention and arrhythmia risk reduction.

Treatment strategies for isolated systolic hypertension in elderly patients.

INTRODUCTION: Hypertension is a major and modifiable risk factor for cardiovascular disease. Its prevalence is rising as the result of population aging. Isolated systolic hypertension mostly occurs in older patients accounting for up to 80% of cases. AREAS COVERED: The authors systematically review published studies to appraise the scientific and clinical evidence supporting the role of blood pressure control in elderly patients with isolated systolic hypertension, and to assess the influence of different drug treatment regimens on outcomes. EXPERT OPINION: Antihypertensive treatment of isolated systolic hypertension significantly reduces the risk of morbidity and mortality in elderly patients. Thiazide diuretics and dihydropyridine calcium-channel blockers are the primary compounds used in randomized clinical trials. These drugs can be considered as first-line agents for the management of isolated systolic hypertension. Free or fixed combination therapy with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers and calcium-channel blockers or thiazide-like diuretics should also be considered, particularly when compelling indications such as coronary artery disease, chronic kidney disease, diabetes, and congestive heart failure coexist. There is also hot scientific debate on the optimal blood pressure target to be achieved in elderly patients with isolated systolic hypertension, but current recommendations are scarcely supported by evidence.

Renin-Angiotensin-Aldosterone System Inhibitors and Risk of Covid-19.

BACKGROUND: There is concern about the potential of an increased risk related to medications that act on the renin-angiotensin-aldosterone system in patients exposed to coronavirus disease 2019 (Covid-19), because the viral receptor is angiotensin-converting enzyme 2 (ACE2). METHODS: We assessed the relation between previous treatment with ACE inhibitors, angiotensin-receptor blockers, beta-blockers, calcium-channel blockers, or thiazide diuretics and the likelihood of a positive or negative result on Covid-19 testing as well as the likelihood of severe illness (defined as intensive care, mechanical ventilation, or death) among patients who tested positive. Using Bayesian methods, we compared outcomes in patients who had been treated with these medications and in untreated patients, overall and in those with hypertension, after propensity-score matching for receipt of each medication class. A difference of at least 10 percentage points was prespecified as a substantial difference. RESULTS: Among 12,594 patients who were tested for Covid-19, a total of 5894 (46.8%) were positive; 1002 of these patients (17.0%) had severe illness. A history of hypertension was present in 4357 patients (34.6%), among whom 2573 (59.1%) had a positive test; 634 of these patients (24.6%) had severe illness. There was no association between any single medication class and an increased likelihood of a positive test. None of the medications examined was associated with a substantial increase in the risk of severe illness among patients who tested positive. CONCLUSIONS: We found no substantial increase in the likelihood of a positive test for Covid-19 or in the risk of severe Covid-19 among patients who tested positive in association with five common classes of antihypertensive medications.

Efficacy of chlorthalidone and hydrochlorothiazide in combination with amiloride in multiple doses on blood pressure in patients with primary hypertension: a protocol for a factorial randomized controlled trial.

BACKGROUND: Thiazide diuretics have demonstrated favorable blood pressure lowering efficacy, but the equivalent doses of their more common agents, chlorthalidone and hydrochlorothiazide, are still unclear. Further, concerns exist regarding adverse metabolic effects, which may be attenuated with the concomitant administration of a potassium-sparing diuretic, such as amiloride. This trial aims to investigate the efficacy of chlorthalidone and hydrochlorothiazide, in combination with amiloride at different doses, for initial management of patients with primary hypertension. METHODS/DESIGN: This is a factorial (2 × 2) randomized double-blinded clinical trial comparing the association of a thiazide diuretic (chlorthalidone 25 mg/day or hydrochlorothiazide 50 mg/day) with a potassium-sparing diuretic (amiloride 10 mg/day or amiloride 20 mg/day) in patients with primary hypertension. The primary outcome will be the mean change from baseline in 24-h systolic and diastolic blood pressure measured by ambulatory blood pressure monitoring. The secondary outcomes will be the mean change from baseline in daytime and nighttime systolic and diastolic blood pressure measured by ambulatory blood pressure monitoring, mean change from baseline in systolic and diastolic blood pressure measured by office blood pressure, incidence of adverse events, variation of laboratory parameters, and proportion of patients who achieved blood pressure control. The follow-up will last 12 weeks. For a P alpha of 0.05, power of 80%, standard deviation of 9 mmHg, and absolute difference of 6 mmHg on systolic blood pressure on 24-h ambulatory blood pressure monitoring, it will be necessary to study a total of 76 patients. The sample size will be increased by 10% to compensate for losses, resulting in 84 patients being randomized. DISCUSSION: Diuretics are pivotal drugs for the treatment of hypertension. Chlorthalidone and hydrochlorothiazide, in combination with amiloride in multiple doses, will be tested in terms of blood pressure lowering efficacy and safety. Since the intensity of blood pressure reduction is the major determinant of reduction in cardiovascular risk in hypertensive patients, this study will help to determine which combination of diuretics represents the most appropriate treatment for this population. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03928145. Registered on 25 April 2019. Last update on 29 April 2019.

A review of the prescribing trend of thiazide-type and thiazide-like diuretics in hypertension: A UK perspective.

Thiazide diuretics have been the cornerstone of hypertension treatment for >5 decades. Most recent European and American guidelines recommend both thiazide-type and thiazide-like diuretics as first-line drugs for all patients with hypertension. In contrast, diuretics are not regarded as first-line treatment in the UK and in patients who are to be initiated on a diuretic treatment, thiazide-like molecules, such as chlortalidone and indapamide are the preferred option. This review examines the prescribing trend of the 4 most commonly prescribed thiazide diuretics for the treatment of hypertension in the UK. Prescription cost analysis data were obtained for both 2010 and 2016/2017 for each region of the UK to analyse the impact of the 2011 National Institute for Health and Care Excellence hypertension guidelines on the trend in thiazide diuretic prescribing. Overall, the prescriptions of thiazide diuretics declined over the years. Bendroflumethiazide is the most commonly prescribed diuretic in the UK and despite some geographical differences, thiazide-type diuretics are more widely used than thiazide-like. The use of indapamide increased significantly between 2010 and 2016/2017 while chlortalidone was rarely employed. Of the many factors affecting trends in prescriptions, clinical inertia, treatment adherence, availability of the products and the lack of fixed dose combinations may play a role.

Blood pressure and low-density lipoprotein cholesterol control status in Chinese hypertensive dyslipidemia patients during lipid-lowering therapy.

ᅟ: The present study comprised 17,096 Chinese hypertensive dyslipidemia patients who received lipid-lowering treatment for > 3 months in order to investigate blood pressure (BP) as well as low-density lipoprotein cholesterol (LDL-C) goal attainment rates in Chinese hypertensive dyslipidemia patients on antidyslipidemia drugs. The factors that interfered with BP, or BP and LDL-C goal attainment rates and antihypertensive treatment patterns, were analyzed. In total, 89.9% of the 17,096 hypertensive dyslipidemia patients received antihypertensive medications mainly consisting of a calcium channel blocker (CCB) (48.7%), an angiotensin receptor antagonist (ARB) (25.4%) and an angiotensin-converting enzyme inhibitor (ACEI) (15.1%). In cardiology departments, usage rates of ß-blockers (19.2%) were unusually high compared to other departments (4.0-8.3%), whereas thiazide diuretics were prescribed at the lowest rate (0.3% vs 1.2-3.6%). The overall goal attainment rates for combined BP and LDL-C as well as BP or LDL-C targets were 22.9, 31.9 and 60.1%, respectively. The lowest BP, LDL-C and BP combined with LDL-C goal attainment rates were achieved in endocrine departments (19.9, 48.9 and 12.4%, respectively). Combination therapies showed no benefit particularly for BP goal achievement. A multivariate logistic regression analysis showed that age < 65 years, alcohol consumption, diabetes, coronary heart disease (CHD), cerebrovascular disease (CVD), chronic kidney disease (CKD), body mass index (BMI) ≥ 28 kg/m2 and not achieving total cholesterol goals were independent predictors for achieving BP, LDL-C or combined BP and LDL-C goals. In summary, the BP and LDL-C goal achievement rates in Chinese dyslipidemia outpatients with hypertension were low, especially in endocrine departments. Combination therapies were not associated with improvement of the goal achievement rates. TRIAL REGISTRATION: Clinical trial registration number NCT01732952.

Conventional Treatment of Hypoparathyroidism.

The treatment of hypoparathyroidism depends on the severity of hypocalcemia, how rapidly the hypocalcemia developed, and the symptomatology. Chronic hypoparathyroidism is usually treated with oral supplementations, including calcium, calcitriol, or other active vitamin D analogs, and at times, thiazide diuretics. Although the standard therapy can adequately control patients with this disease, sometimes very high doses are required to maintain serum calcium levels in the normal range, with poor compliance and risk of long-term complications.

Short-term treatment of irbesartan and hydrochlorothiazide decreases plasma N-terminal pro-brain natriuretic peptide levels in subjects with acute exacerbations of COPD.

BACKGROUND: Plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) are elevated in subjects with COPD, and high plasma NT-proBNP levels are correlated with a poor prognosis. Thus, it is crucial to decrease the plasma NT-proBNP levels at the early stage of disease. We aimed to assess the effects of short-term treatment of irbesartan and hydrochlorothiazide on plasma NT-proBNP levels and health-related quality of life (HRQOL) in subjects with acute exacerbations of COPD (AECOPD). SUBJECTS AND METHODS: Eighty subjects with AECOPD and high plasma NT-proBNP levels, without any clinical evidence of cor pulmonale, were enrolled. The subjects were randomly allocated into two groups of 40 subjects. In addition to standard treatment for AECOPD, the subjects in group I were treated with irbesartan alone, and those in group II were treated with irbesartan and hydrochlorothiazide for a week. Forty subjects with stable COPD were enrolled as a control group. Plasma NT-proBNP concentrations were measured on admission and on the first, fourth, and seventh days. The subjects' health-related quality of life was evaluated applying the 36-item short-form questionnaire on the first day before treatment and on the seventh day after treatment. RESULTS: Treatment of irbesartan and hydrochlorothiazide significantly decreased plasma NT-proBNP levels in subjects with AECOPD, and this reduction was more significant in group II than that in group I. There were no significant differences in 36-item short-form domain scores between subjects with stable COPD and those with AECOPD who were treated with irbesartan and hydrochlorothiazide. CONCLUSION: Treatment of irbesartan and hydrochlorothiazide rapidly decreased plasma NT-proBNP levels in subjects with AECOPD, and the treatment did not impair their physical status.

Outcomes Associated With a Strategy of Adjuvant Metolazone or High-Dose Loop Diuretics in Acute Decompensated Heart Failure: A Propensity Analysis.

Background In acute decompensated heart failure, guidelines recommend increasing loop diuretic dose or adding a thiazide diuretic when diuresis is inadequate. We set out to determine the adverse events associated with a diuretic strategy relying on metolazone or high-dose loop diuretics. Methods and Results Patients admitted to 3 hospitals using a common electronic medical record with a heart failure discharge diagnosis who received intravenous loop diuretics were studied in a propensity-adjusted analysis of all-cause mortality. Secondary outcomes included hyponatremia (sodium <135 mE q/L), hypokalemia (potassium <3.5 mE q/L) and worsening renal function (a ≥20% decrease in estimated glomerular filtration rate). Of 13 898 admissions, 1048 (7.5%) used adjuvant metolazone. Metolazone was strongly associated with hyponatremia, hypokalemia, and worsening renal function ( P<0.0001 for all) with minimal effect attenuation following covariate and propensity adjustment. Metolazone remained associated with increased mortality after multivariate and propensity adjustment (hazard ratio=1.20, 95% confidence interval 1.04-1.39, P=0.01). High-dose loop diuretics were associated with hypokalemia and hyponatremia ( P<0.002) but only worsening renal function retained significance ( P<0.001) after propensity adjustment. High-dose loop diuretics were not associated with reduced survival after multivariate and propensity adjustment (hazard ratio=0.97 per 100 mg of IV furosemide, 95% confidence interval 0.90-1.06, P=0.52). Conclusions During acute decompensated heart failure, metolazone was independently associated with hypokalemia, hyponatremia, worsening renal function and increased mortality after controlling for the propensity to receive metolazone and baseline characteristics. However, under the same experimental conditions, high-dose loop diuretics were not associated with hypokalemia, hyponatremia, or reduced survival. The current findings suggest that until randomized control trial data prove otherwise, uptitration of loop diuretics may be a preferred strategy over routine early addition of thiazide type diuretics when diuresis is inadequate.

Clinical outcomes in hypertensive patients treated with a single-pill fixed-dose combination of renin-angiotensin system inhibitor and thiazide diuretic.

Two or more antihypertensive agents are required to achieve blood pressure control for the most hypertensive patients. However, comparison of clinical outcomes between fixed-dose combinations (FDC) and free-equivalent combinations of renin-angiotensin system (RAS) inhibitor and thiazide diuretic is lacking nowadays. Patients who were newly diagnosed with hypertension between July 1st, 2008 and December 31st, 2011 and prescribed with FDC (n = 13 176) or free combinations of RAS inhibitors and thiazide diuretic (n = 4392) were identified from the National Health Insurance Research Database of Taiwan and matched in 3:1 ratio using the propensity score method. The primary end point was major adverse cardiovascular events (MACE). The secondary end points were hospitalization of heart failure, new diagnosis of chronic kidney disease, and the initiation of dialysis. Compared with he FDC group was associated with better medication adherence compared with the free combination group. FDC of RAS inhibitor and thiazide diuretic reduced MACE (hazard ratio [HR]: 0.85; 95% confidence interval [CI]: 0.74-0.97; P = 0.017), hospitalization for heart failure and initiation of dialysis compared with the free combination regimens. The outcome benefits of FDC was mainly driven by reduced cardiovascular and renal events in the patients with proportion of days covered <80%. In this retrospective claims database analysis, compared with the free combination regimens, the use of FDC of RAS inhibitor and thiazide diuretic was associated with improved medication compliance and clinical outcomes in the management of hypertension, particularly in the patients with poor medication adherence.

Targeted sequencing identifies a missense variant in the BEST3 gene associated with antihypertensive response to hydrochlorothiazide.

Chromosome 12q15 was identified in Genetic Epidemiology of Response Assessment (GERA) and replicated in Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) for its association with blood pressure (BP) response to hydrochlorothiazide (HCTZ). However, the functional variant is unknown and we aimed to identify the likely functional variants through targeted sequencing. The chromosome 12q15 region was sequenced in 397 best and worst responders to HCTZ in PEAR (N=199) and GERA (N=198) hypertensive study participants. Logistic regression was used for the association analysis adjusting for age, sex, race, and principal components 1 and 2. For validation, the significant single nucleotide polymorphism was tested for association with the change in systolic (ΔSBP) and diastolic BP (ΔDBP) post-treatment in the entire PEAR (N=370) and GERA (N=570) cohorts. A novel missense polymorphism (G>A, Pro383Leu) in BEST3, rs61747221, was significantly associated with better HCTZ response (P=0.0021, odds ratio=2.05). It was validated in the entire cohort of PEAR (ΔSBP: P=0.021, ß=-1.60, ΔDBP: P=0.023, ß=-1.08) and GERA (ΔSBP: P=0.028, ß=-1.95, ΔDBP: P=0.032, ß=-1.28). BEST3 encodes the calcium sensitive chloride channel in the vascular smooth muscle implicated in the regulation of BP, especially in response to vasoconstrictors like angiotensin II. These results suggest that BEST3 is involved in the chronic BP lowering mechanism of thiazides and highlight its importance as a genetic predictor of the BP response to thiazide diuretics.

Thiazide but not loop diuretics is associated with hypomagnesaemia in the general population.

PURPOSE: Hypomagnesaemia has been associated with various adverse outcomes. Loop and thiazide diuretics promote urinary magnesium excretion. However, it is unknown if this links to hypomagnesaemia. We study if loop or thiazide diuretic use affects serum magnesium levels and if it associates with hypomagnesaemia. In addition, we study the effect of combining a potassium-sparing diuretic with a thiazide diuretic on the presence of hypomagnesaemia. METHODS: The study performed a cross-sectional analysis within 9820 participants from the prospective Rotterdam Study. Hypomagnesaemia was defined as a serum magnesium level ≤0.72 mmol/L. Participants were categorized by defined daily dose (DDD), and all analyses were adjusted for age, sex, BMI, eGFR, serum potassium levels, proton pump inhibitor use, and comorbidities. RESULTS: Loop diuretic use was associated with higher serum magnesium levels (<1 DDD: 0.004 mmol/L 95% CI: -0.008; 0.017; 1 DDD: 0.023 mmol/L 95% CI: 0.013; 0.032; >1 DDD: 0.043 mmol/L 95% CI: 0.028; 0.057). Thiazide diuretic use was associated with lower serum magnesium levels (<1 DDD: -0.013 mmol/L 95% CI: -0.023; -0.002; ≥1 DDD: -0.018 mmol/L 95% CI: -0.028; -0.010), resulting in an increased odds ratio of hypomagnesaemia of 3.14 (95% CI: 1.67; 5.92) and 2.74 (95% CI: 1.57; 4.77), respectively. These effects were predominantly seen in participants using diuretics for more than 390 days. Combining thiazide diuretics with a potassium-sparing agent was not associated with lower serum magnesium levels or hypomagnesaemia. CONCLUSIONS: Thiazide diuretic use is associated with lower serum magnesium levels and an increased risk of hypomagnesaemia. This increased risk is not seen in participants using a combination of thiazide diuretics with a potassium-sparing agent. The use of loop diuretics is not associated with an increased risk of hypomagnesaemia.