Placebo effect in randomized controlled trials for Meniere's disease: A meta-analysis.

PURPOSE: Meniere's Disease is a condition known for its recurrent vertigo, fluctuating sensorineural hearing loss, aural fullness, and tinnitus. Previous studies have demonstrated significant influence of placebo treatments. Our objective was to quantify the magnitude of the placebo effect in randomized controlled trials for Meniere's Disease. MATERIALS AND METHODS: A systematic review was performed by searching PubMed, SCOPUS, CINAHL, and Cochrane databases from inception through September 27, 2022. Data extraction, quality rating, and risk of bias assessment were performed by two independent reviewers. A meta-analysis of mean differences with 95 % confidence interval, weighted summary proportions, and proportion differences were calculated using random and fixed effects models. RESULTS: A total of 15 studies (N = 892) were included in the review. Significant improvement was seen in the functional level scores of the pooled placebo groups, with a mean difference of -0.6 points, (95%CI: -1.2 to -0.1). There was no difference in pure tone audiometry, speech discrimination score, or vertigo frequency at 1 and 3 months for the placebo group. Patient-reported vertigo episodes were improved in 52.5 % (95%CI: 39.2 to 65.5) of the placebo group and was significantly less than the pooled experimental group (90.1 %, 95%CI: 39.2 to 65.5, p < 0.001). CONCLUSIONS: The placebo effect in Meniere's Disease trials is associated with some symptomatic improvement in subjective outcomes, such as patient reported vertigo episodes. However, the clinical significance is questionable across other outcomes measures, especially when analyzing objective data. The extent and strength of the placebo effect continues to be a hurdle in the search for better treatment options.

Angiotensin receptor blockade improves arterial distensibility and reduces exercise-induced pressor responses in obese hypertensive patients with the metabolic syndrome.

Patients with the metabolic syndrome have three or more of five cardiovascular risk factors and increased oxidative stress, arterial stiffness and pressor responses to exercise, which may contribute to their threefold greater risk for coronary heart disease. In addition to lowering basal blood pressure (BP), angiotensin receptor blockers (ARBs) may benefit metabolic syndrome patients by reducing oxidative stress, arterial stiffness, and pressor responses to exercise. Twelve patients, 7 women and 5 men, with the metabolic syndrome (aged 45 +/- 2 years, BP 145 +/- 5/85 +/- 2 mm Hg, waist girth 110 +/- 3 cm, triglycerides 186 +/- 23 mg/dL, HDL cholesterol 44 +/- 2 mg/dL, glucose 99 +/- 3 mg/dL) were studied off medications, while on modest sodium restriction ( approximately 100 mmol/d). Patients were randomized to the ARB losartan or placebo for 3 weeks then crossed over to the complement for 3 weeks. Studies were performed at the end of each phase following an overnight fast. Serum lipids and biomarkers of oxidative stress (F2-isoprostanes, thiobarbituric acid reacting substances) were unchanged by losartan, whereas large artery elasticity at rest, measured with the HDI PulseWave, increased from 13.6 +/- 0.7 on placebo to 16.2 +/- 1.1 mL/mm Hg on losartan, P <.05. Losartan lowered systolic BP pre-exercise from 142 +/- 3 to 131 +/- 3 mm Hg (P <.001) and systolic BP after 6 min of treadmill exercise from 192 +/- 6 to 169 +/- 5 mm Hg (P <.001). Losartan lowered systolic BP (-23 +/- 3 v -11 +/- 2 mm Hg, P <.05) and pulse pressure (-4 +/- 1 v -15 +/- 2 mm Hg, P <.05) more during exercise than rest. Losartan reduces the pressor response to exercise, perhaps by enhancing arterial compliance. In addition to lowering basal BP, angiotensin receptor blockade in patients with metabolic syndrome improves arterial compliance and reduces pressor reactivity to exercise.