The impact of sleep duration in obstructive sleep apnea patients.

Purpose: Obstructive sleep apnea (OSA) is a risk factor for cardiovascular disease. Strong associations have been reported among sleep duration, hypertension, obesity, and cardiovascular mortality. The authors hypothesize that sleep duration may play a role in OSA severity.

Exercise capacity and obstructive sleep apnea in lean subjects.

Background: Conflicting data regarding exercise capacity and obstructive sleep apnea (OSA) have been published, which may be partially explained by the difficulty of controlling all of the confounding factors. The aim of this study is to evaluate the exercise, anthropometric, and blood parameters in lean, sedentary patients with OSA compared with controls.

Methods: Fifty-four lean subjects (including 27 patients with OSA and 27 controls) were selected.

Incremental shuttle and six-minute walking tests in the assessment of functional capacity in chronic heart failure.

Background: The incremental shuttle test presents some theoretical advantages over the six-minute walk test in chronic heart failure (CHF), including better standardization and less dependency on collaboration.

Objectives: The present study evaluated test-retest repeatability, test accuracy in predicting a peak oxygen consumption (VO(2)) of 14 mL/kg/min or less, as well as the prognostic value of both walking tests in stable CHF patients.

Methods: Sixty-three patients (44 men; New York Heart Association functional class II to IV) underwent an incremental treadmill exercise test and, on another day, the walk test in duplicate.

Clinical reliability of the 6 minute corridor walk test performed within a week of a myocardial infarction.

The 6 minute walk test (6 MWT) has been shown to provide a clinically useful index of functional capacity in chronic heart failure. We hypothesized that similar results would be found in patients who had a recent (ie, within a week) myocardial infarction (MI). Twenty-five patients (23 males, aged 43 to 72 years) who had undertaken an exercise stress test without complications underwent 3 consecutive 6 MWTs (1 hour apart).