Why are we still using hydrochlorothiazide?

Genome Wide Association Study Identifies the HMGCS2 Locus to be Associated With Chlorthalidone Induced Glucose Increase in Hypertensive Patients

Background

Thiazide and thiazide‐like diuretics are first‐line medications for treating uncomplicated hypertension. However, their use has been associated with adverse metabolic events, including hyperglycemia and incident diabetes mellitus, with incompletely understood mechanisms. Our goal was to identify genomic variants associated with thiazide‐like diuretic/chlorthalidone‐induced glucose change.

Methods and Results

Genome‐wide analysis of glucose change after treatment with chlorthalidone was performed by race among the white (n=175) and black (n=135) participants from the PEAR‐2 (Pharmacogenomic Evaluation of Antihypertensive Responses‐2). Single‐nucleotide polymorphisms with P<5×10⁻⁸ were further prioritized using in silico analysis based on their expression quantitative trait loci function. Among blacks, an intronic single‐nucleotide polymorphism (rs9943291) in the HMGCS2 was associated with increase in glucose levels following chlorthalidone treatment (ß=12.5; P=4.17×10⁻⁸). G‐allele carriers of HMGCS2 had higher glucose levels (glucose change=+16.29 mg/dL) post chlorthalidone treatment compared with noncarriers of G allele (glucose change=+2.80 mg/dL). This association was successfully replicated in an independent replication cohort of hydrochlorothiazide‐treated participants from the PEAR study (ß=5.54; P=0.023). A meta‐analysis of the 2 studies was performed by race in Meta‐Analysis Helper, where this single‐nucleotide polymorphism, rs9943291, was genome‐wide significant with a meta‐analysis P value of 3.71×10⁻⁸. HMGCS2, a part of the HMG‐CoA synthase family, is important for ketogenesis and cholesterol synthesis pathways that are essential in glucose homeostasis.

Conclusions

These results suggest that HMGCS2 is a promising candidate gene involved in chlorthalidone and Hydrochlorothiazide (HCTZ)‐induced glucose change. This may provide insights into the mechanisms involved in thiazide‐induced hyperglycemia that may ultimately facilitate personalized approaches to antihypertensive selection for hypertension treatment.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00246519 and NCT01203852.

Type 2 Diabetes and Thiazide Diuretics

PURPOSE OF REVIEW

In patients with prediabetes or type 2 diabetes, the use of thiazides as antihypertensive agents has been challenged because associated metabolic adverse events, including new-onset diabetes.

RECENT FINDINGS

These metabolic disturbances are less marked with low-dose thiazides and, in most but not all studies, with thiazide-like diuretics (chlorthalidone, indapamide) than with thiazide-type diuretics (hydrochlorothiazide). In post hoc analyses of subgroups of patients with hypertension and type 2 diabetes, thiazides resulted in a significant reduction in cardiovascular events, all-cause mortality, and hospitalization for heart failure compared to placebo and generally were shown to be non-inferior to other antihypertensive agents. Benefits attributed to thiazide diuretics in terms of cardiovascular event reduction outweigh the risk of worsening glucose control in type 2 diabetes and of new-onset diabetes in non-diabetic patients. Thiazides still play a key role in the management of patients with type 2 diabetes and hypertension.

Triple combination therapy in hypertension: the antihypertensive efficacy of treatment with perindopril, amlodipine, and indapamide SR

BACKGROUND AND OBJECTIVE

The blood pressure (BP) of most patients on antihypertensive monotherapy or bitherapy remains uncontrolled. Our study evaluated the efficacy of triple therapy with perindopril, amlodipine, and indapamide sustained release (SR) in patients with uncontrolled hypertension on previous antihypertensive therapy.

METHODS

This 4-month, multicenter, prospective, observational, open-label study included patients switched from previous antihypertensive therapy to triple therapy with perindopril, amlodipine, and indapamide SR. The main outcome was change in office BP from baseline to 4 months, as well as changes in 24-h ambulatory BP monitoring (ABPM) parameters in a subgroup of patients.

RESULTS

Age was 62.8 ± 11.3 years in 6,088 patients (55 % were male). Office BP at baseline was 158.1 ± 13.0/92.6 ± 8.8 mmHg. By 4 months, office BP decreased by 26.7 ± 13.3/12.9 ± 9.4 mmHg (p < 0.001). ABPM was performed in 62 patients. In these patients, 24-h systolic BP decreased (from 138.7 ± 12.5 to 125.5 ± 12.8 mmHg), as did 24-h diastolic BP (from 77.5 ± 11.4 to 70.4 ± 8.7 mmHg) (both p < 0.0001). Heart rate remained unchanged. In patients previously on renin-angiotensin-aldosterone system (RAAS) inhibitor/amlodipine, 24-h ambulatory systolic and diastolic BP decreased from 136.9 ± 12.8 to 125.4 ± 13.3 mmHg (p = 0.0003) and from 76.3 ± 12.6 to 70.2 ± 9.5 mmHg (p = 0.0005). In those previously on RAAS inhibitor/hydrochlorothiazide, 24-h ambulatory systolic and diastolic BP decreased from 137.8 ± 12.7 to 122.7 ± 15.4 mmHg (p = 0.0039) and from 73.6 ± 9.4 to 65.7 ± 7.3 mmHg (p = 0.002). Most (74 and 80 %, respectively) patients reached target ABPM values (<130/80 mmHg).

CONCLUSION

A triple combination of perindopril, amlodipine, and indapamide SR controlled BP effectively in hypertensive patients uncontrolled by previous antihypertensive monotherapy or bitherapy, including RAAS inhibitor/amlodipine or RAAS inhibitor/hydrochlorothiazide combinations.

Hypertension: is it time to replace drugs with nutrition and nutraceuticals?

Many hypertension patients want to learn about ways to reduce reliance on pharmaceuticals, says functional medicine practitioner Mark Houston, who believes it is often possible to reduce or eliminate reliance on drugs using nutrition and nutraceuticals.

Patterns of nonadherence to antihypertensive therapy in primary care

Nonadherence to medications is an important cause of poor blood pressure control. Long-acting antihypertensive agents could theoretically be beneficial in partially adherent patients, who are commonly seen in contemporary practice. Little has been reported about the duration of drug holidays (DHs) in treated hypertensives outside of generally compliant patients in phase 4 clinical trials. The authors described patterns of nonadherence to single and multiple antihypertensives in a random sample of 120 primary care patients with uncontrolled hypertension. Adherence to up to 3 antihypertensives was measured by electronic monitoring. Frequencies of single-day omissions and DHs of 2 consecutive days (DH2), 3 days (DH3), or ≥4 days (DH≥4) for each drug were calculated. Overall, 89 (74%) of patients had at least a 1-day omission. A single day omission was found in 61.4% of the patients taking 1 drug, followed by DH≥4 (28.1%), DH2 (26.3%), and DH3 (8.8%). In patients using multiple drugs, single-day omissions were also most common, followed by DH≥4, DH2, and DH3. Omissions of ≤3 days comprise on average 74% of all omissions. Although encouraging full adherence remains important, it may be prudent to prescribe long-acting antihypertensive agents, which can compensate for the majority of dose omissions.