Systolic hypertension in the elderly program (SHEP). The first three months

The evolution, evolvability and engineering of gene regulatory DNA

Mutations in non-coding regulatory DNA sequences can alter gene expression, organismal phenotype and fitness^1-3. Constructing complete fitness landscapes, in which DNA sequences are mapped to fitness, is a long-standing goal in biology, but has remained elusive because it is challenging to generalize reliably to vast sequence spaces^4-6. Here we build sequence-to-expression models that capture fitness landscapes and use them to decipher principles of regulatory evolution. Using millions of randomly sampled promoter DNA sequences and their measured expression levels in the yeast Saccharomyces cerevisiae, we learn deep neural network models that generalize with excellent prediction performance, and enable sequence design for expression engineering. Using our models, we study expression divergence under genetic drift and strong-selection weak-mutation regimes to find that regulatory evolution is rapid and subject to diminishing returns epistasis; that conflicting expression objectives in different environments constrain expression adaptation; and that stabilizing selection on gene expression leads to the moderation of regulatory complexity. We present an approach for using such models to detect signatures of selection on expression from natural variation in regulatory sequences and use it to discover an instance of convergent regulatory evolution. We assess mutational robustness, finding that regulatory mutation effect sizes follow a power law, characterize regulatory evolvability, visualize promoter fitness landscapes, discover evolvability archetypes and illustrate the mutational robustness of natural regulatory sequence populations. Our work provides a general framework for designing regulatory sequences and addressing fundamental questions in regulatory evolution.

Pharmacotherapy for hypertension in adults 60 years or older

BACKGROUND

This is the second substantive update of this review. It was originally published in 1998 and was previously updated in 2009. Elevated blood pressure (known as 'hypertension') increases with age - most rapidly over age 60. Systolic hypertension is more strongly associated with cardiovascular disease than is diastolic hypertension, and it occurs more commonly in older people. It is important to know the benefits and harms of antihypertensive treatment for hypertension in this age group, as well as separately for people 60 to 79 years old and people 80 years or older.

OBJECTIVES

Primary objective• To quantify the effects of antihypertensive drug treatment as compared with placebo or no treatment on all-cause mortality in people 60 years and older with mild to moderate systolic or diastolic hypertensionSecondary objectives• To quantify the effects of antihypertensive drug treatment as compared with placebo or no treatment on cardiovascular-specific morbidity and mortality in people 60 years and older with mild to moderate systolic or diastolic hypertension• To quantify the rate of withdrawal due to adverse effects of antihypertensive drug treatment as compared with placebo or no treatment in people 60 years and older with mild to moderate systolic or diastolic hypertension SEARCH METHODS: The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to 24 November 2017: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We contacted authors of relevant papers regarding further published and unpublished work.

SELECTION CRITERIA

Randomised controlled trials of at least one year's duration comparing antihypertensive drug therapy versus placebo or no treatment and providing morbidity and mortality data for adult patients (≥ 60 years old) with hypertension defined as blood pressure greater than 140/90 mmHg.

DATA COLLECTION AND ANALYSIS

Outcomes assessed were all-cause mortality; cardiovascular morbidity and mortality; cerebrovascular morbidity and mortality; coronary heart disease morbidity and mortality; and withdrawal due to adverse effects. We modified the definition of cardiovascular mortality and morbidity to exclude transient ischaemic attacks when possible.

MAIN RESULTS

This update includes one additional trial (MRC-TMH 1985). Sixteen trials (N = 26,795) in healthy ambulatory adults 60 years or older (mean age 73.4 years) from western industrialised countries with moderate to severe systolic and/or diastolic hypertension (average 182/95 mmHg) met the inclusion criteria. Most of these trials evaluated first-line thiazide diuretic therapy for a mean treatment duration of 3.8 years.Antihypertensive drug treatment reduced all-cause mortality (high-certainty evidence; 11% with control vs 10.0% with treatment; risk ratio (RR) 0.91, 95% confidence interval (CI) 0.85 to 0.97; cardiovascular morbidity and mortality (moderate-certainty evidence; 13.6% with control vs 9.8% with treatment; RR 0.72, 95% CI 0.68 to 0.77; cerebrovascular mortality and morbidity (moderate-certainty evidence; 5.2% with control vs 3.4% with treatment; RR 0.66, 95% CI 0.59 to 0.74; and coronary heart disease mortality and morbidity (moderate-certainty evidence; 4.8% with control vs 3.7% with treatment; RR 0.78, 95% CI 0.69 to 0.88. Withdrawals due to adverse effects were increased with treatment (low-certainty evidence; 5.4% with control vs 15.7% with treatment; RR 2.91, 95% CI 2.56 to 3.30. In the three trials restricted to persons with isolated systolic hypertension, reported benefits were similar.This comprehensive systematic review provides additional evidence that the reduction in mortality observed was due mostly to reduction in the 60- to 79-year-old patient subgroup (high-certainty evidence; RR 0.86, 95% CI 0.79 to 0.95). Although cardiovascular mortality and morbidity was significantly reduced in both subgroups 60 to 79 years old (moderate-certainty evidence; RR 0.71, 95% CI 0.65 to 0.77) and 80 years or older (moderate-certainty evidence; RR 0.75, 95% CI 0.65 to 0.87), the magnitude of absolute risk reduction was probably higher among 60- to 79-year-old patients (3.8% vs 2.9%). The reduction in cardiovascular mortality and morbidity was primarily due to a reduction in cerebrovascular mortality and morbidity.

AUTHORS' CONCLUSIONS

Treating healthy adults 60 years or older with moderate to severe systolic and/or diastolic hypertension with antihypertensive drug therapy reduced all-cause mortality, cardiovascular mortality and morbidity, cerebrovascular mortality and morbidity, and coronary heart disease mortality and morbidity. Most evidence of benefit pertains to a primary prevention population using a thiazide as first-line treatment.

First-line drugs for hypertension

BACKGROUND

This is the first update of a review published in 2009. Sustained moderate to severe elevations in resting blood pressure leads to a critically important clinical question: What class of drug to use first-line? This review attempted to answer that question.

OBJECTIVES

To quantify the mortality and morbidity effects from different first-line antihypertensive drug classes: thiazides (low-dose and high-dose), beta-blockers, calcium channel blockers, ACE inhibitors, angiotensin II receptor blockers (ARB), and alpha-blockers, compared to placebo or no treatment.Secondary objectives: when different antihypertensive drug classes are used as the first-line drug, to quantify the blood pressure lowering effect and the rate of withdrawal due to adverse drug effects, compared to placebo or no treatment.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomized controlled trials up to November 2017: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We contacted authors of relevant papers regarding further published and unpublished work.

SELECTION CRITERIA

Randomized trials (RCT) of at least one year duration, comparing one of six major drug classes with a placebo or no treatment, in adult patients with blood pressure over 140/90 mmHg at baseline. The majority (over 70%) of the patients in the treatment group were taking the drug class of interest after one year. We included trials with both hypertensive and normotensive patients in this review if the majority (over 70%) of patients had elevated blood pressure, or the trial separately reported outcome data on patients with elevated blood pressure.

DATA COLLECTION AND ANALYSIS

The outcomes assessed were mortality, stroke, coronary heart disease (CHD), total cardiovascular events (CVS), decrease in systolic and diastolic blood pressure, and withdrawals due to adverse drug effects. We used a fixed-effect model to to combine dichotomous outcomes across trials and calculate risk ratio (RR) with 95% confidence interval (CI). We presented blood pressure data as mean difference (MD) with 99% CI.

MAIN RESULTS

The 2017 updated search failed to identify any new trials. The original review identified 24 trials with 28 active treatment arms, including 58,040 patients. We found no RCTs for ARBs or alpha-blockers. These results are mostly applicable to adult patients with moderate to severe primary hypertension. The mean age of participants was 56 years, and mean duration of follow-up was three to five years.High-quality evidence showed that first-line low-dose thiazides reduced mortality (11.0% with control versus 9.8% with treatment; RR 0.89, 95% CI 0.82 to 0.97); total CVS (12.9% with control versus 9.0% with treatment; RR 0.70, 95% CI 0.64 to 0.76), stroke (6.2% with control versus 4.2% with treatment; RR 0.68, 95% CI 0.60 to 0.77), and coronary heart disease (3.9% with control versus 2.8% with treatment; RR 0.72, 95% CI 0.61 to 0.84).Low- to moderate-quality evidence showed that first-line high-dose thiazides reduced stroke (1.9% with control versus 0.9% with treatment; RR 0.47, 95% CI 0.37 to 0.61) and total CVS (5.1% with control versus 3.7% with treatment; RR 0.72, 95% CI 0.63 to 0.82), but did not reduce mortality (3.1% with control versus 2.8% with treatment; RR 0.90, 95% CI 0.76 to 1.05), or coronary heart disease (2.7% with control versus 2.7% with treatment; RR 1.01, 95% CI 0.85 to 1.20).Low- to moderate-quality evidence showed that first-line beta-blockers did not reduce mortality (6.2% with control versus 6.0% with treatment; RR 0.96, 95% CI 0.86 to 1.07) or coronary heart disease (4.4% with control versus 3.9% with treatment; RR 0.90, 95% CI 0.78 to 1.03), but reduced stroke (3.4% with control versus 2.8% with treatment; RR 0.83, 95% CI 0.72 to 0.97) and total CVS (7.6% with control versus 6.8% with treatment; RR 0.89, 95% CI 0.81 to 0.98).Low- to moderate-quality evidence showed that first-line ACE inhibitors reduced mortality (13.6% with control versus 11.3% with treatment; RR 0.83, 95% CI 0.72 to 0.95), stroke (6.0% with control versus 3.9% with treatment; RR 0.65, 95% CI 0.52 to 0.82), coronary heart disease (13.5% with control versus 11.0% with treatment; RR 0.81, 95% CI 0.70 to 0.94), and total CVS (20.1% with control versus 15.3% with treatment; RR 0.76, 95% CI 0.67 to 0.85).Low-quality evidence showed that first-line calcium channel blockers reduced stroke (3.4% with control versus 1.9% with treatment; RR 0.58, 95% CI 0.41 to 0.84) and total CVS (8.0% with control versus 5.7% with treatment; RR 0.71, 95% CI 0.57 to 0.87), but not coronary heart disease (3.1% with control versus 2.4% with treatment; RR 0.77, 95% CI 0.55 to 1.09), or mortality (6.0% with control versus 5.1% with treatment; RR 0.86, 95% CI 0.68 to 1.09).There was low-quality evidence that withdrawals due to adverse effects were increased with first-line low-dose thiazides (5.0% with control versus 11.3% with treatment; RR 2.38, 95% CI 2.06 to 2.75), high-dose thiazides (2.2% with control versus 9.8% with treatment; RR 4.48, 95% CI 3.83 to 5.24), and beta-blockers (3.1% with control versus 14.4% with treatment; RR 4.59, 95% CI 4.11 to 5.13). No data for these outcomes were available for first-line ACE inhibitors or calcium channel blockers. The blood pressure data were not used to assess the effect of the different classes of drugs as the data were heterogeneous, and the number of drugs used in the trials differed.

AUTHORS' CONCLUSIONS

First-line low-dose thiazides reduced all morbidity and mortality outcomes in adult patients with moderate to severe primary hypertension. First-line ACE inhibitors and calcium channel blockers may be similarly effective, but the evidence was of lower quality. First-line high-dose thiazides and first-line beta-blockers were inferior to first-line low-dose thiazides.

Blood pressure-lowering efficacy of monotherapy with thiazide diuretics for primary hypertension

BACKGROUND

Hypertension is a modifiable cardiovascular risk factor. Although it is established that low-dose thiazides reduce mortality as well as cardiovascular morbidity, the dose-related effect of thiazides in decreasing blood pressure has not been subject to a rigorous systematic review. It is not known whether individual drugs within the thiazide diuretic class differ in their blood pressure-lowering effects and adverse effects.

OBJECTIVES

To determine the dose-related decrease in systolic and/or diastolic blood pressure due to thiazide diuretics compared with placebo control in the treatment of patients with primary hypertension. Secondary outcomes included the dose-related adverse events leading to patient withdrawal and adverse biochemical effects on serum potassium, uric acid, creatinine, glucose and lipids.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 1), Ovid MEDLINE (1946 to February 2014), Ovid EMBASE (1974 to February 2014) and ClinicalTrials.gov.

SELECTION CRITERIA

We included double-blind, randomized controlled trials (RCTs) comparing fixed-dose thiazide diuretic monotherapy with placebo for a duration of 3 to 12 weeks in the treatment of adult patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two authors independently screened articles, assessed trial eligibility, extracted data and determined risk of bias. We combined data for continuous variables using a mean difference (MD) and for dichotomous outcomes we calculated the relative risk ratio (RR) with 95% confidence interval (CI).

MAIN RESULTS

We included 60 randomized, double-blind trials that evaluated the dose-related trough blood pressure-lowering efficacy of six different thiazide diuretics in 11,282 participants treated for a mean duration of eight weeks. The mean age of the participants was 55 years and baseline blood pressure was 158/99 mmHg. Adequate blood pressure-lowering efficacy data were available for hydrochlorothiazide, chlorthalidone and indapamide. We judged 54 (90%) included trials to have unclear or high risk of bias, which impacted on our confidence in the results for some of our outcomes.In 33 trials with a baseline blood pressure of 155/100 mmHg, hydrochlorothiazide lowered blood pressure based on dose, with doses of 6.25 mg, 12.5 mg, 25 mg and 50 mg/day lowering blood pressure compared to placebo by 4 mmHg (95% CI 2 to 6, moderate-quality evidence)/2 mmHg (95% CI 1 to 4, moderate-quality evidence), 6 mmHg (95% CI 5 to 7, high-quality evidence)/3 mmHg (95% CI 3 to 4, high-quality evidence), 8 mmHg (95% CI 7 to 9, high-quality evidence)/3 mmHg (95% CI 3 to 4, high-quality evidence) and 11 mmHg (95% CI 6 to 15, low-quality evidence)/5 mmHg (95% CI 3 to 7, low-quality evidence), respectively.Direct comparison of doses did not show evidence of dose dependence for blood pressure-lowering for any of the other thiazides for which RCT data were available: bendrofluazide, chlorthalidone, cyclopenthiazide, metolazone or indapamide.In seven trials with a baseline blood pressure of 163/88 mmHg, chlorthalidone at doses of 12.5 mg to 75 mg/day reduced average blood pressure compared to placebo by 12.0 mmHg (95% CI 10 to 14, low-quality evidence)/4 mmHg (95% CI 3 to 5, low-quality evidence).In 10 trials with a baseline blood pressure of 161/98 mmHg, indapamide at doses of 1.0 mg to 5.0 mg/day reduced blood pressure compared to placebo by 9 mmHg (95% CI 7 to 10, low-quality evidence)/4 (95% CI 3 to 5, low-quality evidence).We judged the maximal blood pressure-lowering effect of the different thiazides to be similar. Overall, thiazides reduced average blood pressure compared to placebo by 9 mmHg (95% CI 9 to 10, high-quality evidence)/4 mmHg (95% CI 3 to 4, high-quality evidence).Thiazides as a class have a greater effect on systolic than on diastolic blood pressure, therefore thiazides lower pulse pressure by 4 mmHg to 6 mmHg, an amount that is greater than the 3 mmHg seen with angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and renin inhibitors, and the 2 mmHg seen with non-selective beta-blockers. This is based on an informal indirect comparison of results observed in other Cochrane reviews on ACE inhibitors, ARBs and renin inhibitors compared with placebo, which used similar inclusion/exclusion criteria to the present review.Thiazides reduced potassium, increased uric acid and increased total cholesterol and triglycerides. These effects were dose-related and were least for hydrochlorothiazide. Chlorthalidone increased serum glucose but the evidence was unclear for other thiazides. There is a high risk of bias in the metabolic data. This review does not provide a good assessment of the adverse effects of these drugs because there was a high risk of bias in the reporting of withdrawals due to adverse effects.

AUTHORS' CONCLUSIONS

This systematic review shows that hydrochlorothiazide has a dose-related blood pressure-lowering effect. The mean blood pressure-lowering effect over the dose range 6.25 mg, 12.5 mg, 25 mg and 50 mg/day is 4/2 mmHg, 6/3 mmHg, 8/3 mmHg and 11/5 mmHg, respectively. For other thiazide drugs, the lowest doses studied lowered blood pressure maximally and higher doses did not lower it more. Due to the greater effect on systolic than on diastolic blood pressure, thiazides lower pulse pressure by 4 mmHg to 6 mmHg. This exceeds the mean 3 mmHg pulse pressure reduction achieved by ACE inhibitors, ARBs and renin inhibitors, and the 2 mmHg pulse pressure reduction with non-selective beta-blockers as shown in other Cochrane reviews, which compared these antihypertensive drug classes with placebo and used similar inclusion/exclusion criteria.Thiazides did not increase withdrawals due to adverse effects in these short-term trials but there is a high risk of bias for that outcome. Thiazides reduced potassium, increased uric acid and increased total cholesterol and triglycerides.

First-line drugs for hypertension

BACKGROUND

Sustained elevated blood pressure, unresponsive to lifestyle measures, leads to a critically important clinical question: What class of drug to use first-line? This review answers that question.

PRIMARY OBJECTIVE

To quantify the benefits and harms of the major first-line anti-hypertensive drug classes: thiazides, beta-blockers, calcium channel blockers, angiotensin converting enzyme (ACE) inhibitors, alpha-blockers, and angiotensin II receptor blockers (ARB).

SEARCH STRATEGY

Electronic search of MEDLINE (Jan. 1966-June 2008), EMBASE, CINAHL, the Cochrane clinical trial register, using standard search strategy of the hypertension review group with additional terms.

SELECTION CRITERIA

Randomized trials of at least one year duration comparing one of 6 major drug classes with a placebo or no treatment. More than 70% of people must have BP >140/90 mmHg at baseline.

DATA COLLECTION AND ANALYSIS

The outcomes assessed were mortality, stroke, coronary heart disease (CHD), cardiovascular events (CVS), decrease in systolic and diastolic blood pressure, and withdrawals due to adverse drug effects. Risk ratio (RR) and a fixed effects model were used to combine outcomes across trials.

MAIN RESULTS

Of 57 trials identified, 24 trials with 28 arms, including 58,040 patients met the inclusion criteria. Thiazides (19 RCTs) reduced mortality (RR 0.89, 95% CI 0.83, 0.96), stroke (RR 0.63, 95% CI 0.57, 0.71), CHD (RR 0.84, 95% CI 0.75, 0.95) and CVS (RR 0.70, 95% CI 0.66, 0.76). Low-dose thiazides (8 RCTs) reduced CHD (RR 0.72, 95% CI 0.61, 0.84), but high-dose thiazides (11 RCTs) did not (RR 1.01, 95% CI 0.85, 1.20). Beta-blockers (5 RCTs) reduced stroke (RR 0.83, 95% CI 0.72, 0.97) and CVS (RR 0.89, 95% CI 0.81, 0.98) but not CHD (RR 0.90, 95% CI 0.78, 1.03) or mortality (RR 0.96, 95% CI 0.86, 1.07). ACE inhibitors (3 RCTs) reduced mortality (RR 0.83, 95% CI 0.72-0.95), stroke (RR 0.65, 95% CI 0.52-0.82), CHD (RR 0.81, 95% CI 0.70-0.94) and CVS (RR 0.76, 95% CI 0.67-0.85). Calcium-channel blocker (1 RCT) reduced stroke (RR 0.58, 95% CI 0.41, 0.84) and CVS (RR 0.71, 95% CI 0.57, 0.87) but not CHD (RR 0.77 95% CI 0.55, 1.09) or mortality (RR 0.86 95% CI 0.68, 1.09). No RCTs were found for ARBs or alpha-blockers.

AUTHORS' CONCLUSIONS

First-line low-dose thiazides reduce all morbidity and mortality outcomes. First-line ACE inhibitors and calcium channel blockers may be similarly effective but the evidence is less robust. First-line high-dose thiazides and first-line beta-blockers are inferior to first-line low-dose thiazides.

Differences in men and women in coronary artery disease, systemic hypertension and their treatment

Various studies have shown that women with coronary artery diseases are treated quite differently from men, although the reasons for these differences are not easily discernible and may be based on misconceptions. Furthermore, although the attributable risk percentage for cardiovascular complications of hypertension is higher in women than in men, little information on treating hypertension in women is available. There is cause for concern owing to some findings that white women may be harmed by antihypertensive treatment unless that treatment differs from that of men. Consensus on the importance of this finding has not been reached.

Systolic hypertension in the elderly: reasons not to treat

Isolated systolic hypertension in the elderly is associated with increased morbidity and mortality. Accurate measurement of blood pressure in older patients is difficult. Therapy can be associated with various complications, and the special problems of the elderly, such as orthostatic hypotension and hyperkalemia, should be carefully considered. Drugs should be used in low doses and changes in dosage should be made infrequently. Patients should be monitored frequently for untoward effects of therapy. The benefits of blood pressure reduction and the optimal degree of blood pressure reduction remain unknown.

Effects of treatment for isolated systolic hypertension on cognitive status and depression in the elderly

The Systolic Hypertension in the Elderly Program (SHEP) was designed as a feasibility study and in part dealt with the effects of the treatment of isolated systolic hypertension on cognitive status and depression. Subjects were 60 years of age or older with a systolic blood pressure of 160 mmHg or greater and diastolic of less than 90 mmHg; free of several specified illnesses or chronic conditions. These volunteers were randomly assigned to treatment (n = 443) and placebo (n = 108) groups. The behavioral assessments at baseline and 1 year later were the SHORT-CARE instrument for depression, cognitive impairment, and disability and other tests of cognitive status (Digit Symbol Substitution and the Trail Making tests). Although the treatment regime was highly successful in controlling the hypertension, it did not have a significant impact on changes in cognitive function or level of depression; a behavioral benefit was not evident but the results are consistent with the view that an effective treatment regime for isolated systolic hypertension in the elderly can be behaviorally safe.

Comparative evaluation of enalapril and hydrochlorothiazide in elderly patients with mild to moderate hypertension

Initial treatment of elderly hypertensive patients with an angiotensin-converting enzyme inhibitor is currently discouraged due to such patients' typical low-renin profile. To validate this principle, we studied 38 elderly males (aged greater than or equal to 65 years) with mild to moderate hypertension, comparing hemodynamic responses to and subjective impressions of enalapril or hydrochlorothiazide (HCTZ). After gradual withdrawal of existing antihypertensive therapy and a four-week, single-blind placebo period, each patient was randomized in a double-blind fashion to receive either enalapril 10-20 mg/d or HCTZ 12.5-25 mg/d for two to four weeks. Combination therapy with both agents was employed if either alone failed to reduce seated diastolic BP to less than or equal to 90 mm Hg. Equivalent proportions of patients receiving enalapril or HCTZ (8 of 19 and 10 of 19, respectively; p = ns) responded with significant reductions in systolic and diastolic BP in seated and standing positions. Combination therapy was most effective in patients receiving HCTZ prior to enalapril. In patients receiving enalapril before HCTZ, BP changes were minimal. No adverse effects were observed in the enalapril group but occurred in an equivalent fraction of patients in the other groups (4 of 10 HCTZ alone, 6 of 20 enalapril + HCTZ; p = ns). We conclude that enalapril may be considered a reasonable monotherapeutic antihypertensive agent in some elderly patients. Combination with HCTZ is beneficial in patients who fail to respond adequately to HCTZ alone.