Review from JAMA — Are β-Blockers Efficacious as First-line Therapy for Hypertension in the Elderly? — A Systematic Review — Objective.—To assess antihypertensive efficacy of β-blockers and their effects on cardiovascular morbidity and mortality and all-cause morbidity compared with diuretics in elderly patients with hypertension.Data Source.—A MEDLINE search of English-language articles published between January 1966 and January 1998 using the terms hypertension (drug therapy) and elderly or aged or geriatric, and cerebrovascular or cardiovascular diseases, and morbidity or mortality. References from identified articles were also reviewed.Data Selection.—Randomized trials lasting at least 1 year, which used as first-line agents diuretics and/or β-blockers, and reported morbidity and mortality outcomes in elderly patients with hypertension.Data Synthesis and Results.—Ten trials involving a total of 16164 elderly patients (≥60 years) were included. Two thirds of the patients assigned to diuretics were well controlled on monotherapy, whereas less than a third of the patients assigned to β-blockers were well controlled on monotherapy. Diuretic therapy was superior to β-blockade with regard to all end points and was effective in preventing cerebrovascular events (odds ratio [OR], 0.61; 95% confidence interval [CI], 0.51-0.72), fatal stroke (OR, 0.67; 95% CI, 0.49-0.90), coronary heart disease (OR, 0.74; 95% CI, 0.64-0.85), cardiovascular mortality (OR, 0.75; 95% CI, 0.64-0.87), and all-cause mortality (OR, 0.86; 95% CI, 0.77-0.96). In contrast, β-blocker therapy only reduced the odds for cerebrovascular events (OR, 0.75; 95% CI, 0.57-0.98) but was ineffective in preventing coronary heart disease, cardiovascular mortality, and all-cause mortality (ORs, 1.01, 0.98, and 1.05, respectively).Conclusions.—In contrast to diuretics, which remain the standard first-line therapy, β-blockers, until proven otherwise, should no longer be considered appropriate first-line therapy of uncomplicated hypertension in the elderly hypertensive patient.

Emerging data indicate a correlation between gut microbial composition and cardiovascular disease including hypertension. The host’s diet greatly affects microbial composition and metabolite production. Short chain fatty acids (SCFAs) are products of microbial fermentation, which can be utilized by the host. It has been suggested that SCFAs play a pivotal role as mediators in a microbiome host: microbial interactions occur in health and disease. The aim of this study was to evaluate the effect of a high salt diet (HSD) on microbial variation and to determine whether this effect is accompanied by an alteration in fecal SCFAs. To this end, Dahl salt-sensitive rats were divided into two groups (n = 10 each): (A) Control: fed regular chow; and (B) Fed HSD. High-throughput pyrosequencing of the 16S rRNA amplicon sequencing was used for microbiome characterizing. Chromatography-mass spectrometry was used to measure the levels of SCFAs: acetic acid, propionic acid, butyric acid, and isobutyric acid in fecal samples. Differences in microbial composition were noted between groups. Principal Coordinate Analysis (PCoA) principal coordinate 1 (PC1) primarily separated controls from the HSD. Four taxa displayed significant differences between HSD and controls. Taxa from the Erwinia genus, the Christensenellaceae and Corynebacteriaceae families, displayed an increased abundance in HSD versus control. In contrast, taxa from the Anaerostipes genus displayed a decreased abundance in HSD. We were able to identify seven unique taxa that were significantly associated with blood pressure. There was a significant difference in fecal acetic acid, as well as propionic and isobutyric acid, but not in the butyric acid composition between groups. Adding salt to a diet impacts the gut’s microbial composition, which may alter fecal SCFA production.