The incremental effect of obstructive sleep apnea syndrome on right and left ventricular myocardial performance in newly diagnosed essential hypertensive subjects

Echocardiographic Findings in Healthy Elderly People with Unrecognized Sleep Disordered Breathing

OBJECTIVE

Sleep disordered breathing (SDB) is associated with cardiovascular disease such as hypertension and left ventricular hypertrophy in middle-aged patients; however, this association is not well described in the elderly. The aim of this study was to evaluate the impact of unrecognized SDB on cardiac function and remodeling in a population-based sample of healthy elderly without cardiac disease.

METHODOLOGY

A total of 405 healthy elderly (age ≥ 65 years) were examined by echocardiography and respiratory polygraphy. According to the apnea-hypopnea index (AHI), subjects were stratified in four categories: snorers (AHI < 5), mild (AHI: 5-15), moderate (AHI: 15-30), and severe (AHI > 30) cases.

RESULTS

Comparative analysis between snorers and SDB cases revealed that left atrial (LA) diameter and surface increased according to SDB severity (p < 0.05) without differences in LA mass index. In subjects with an AHI > 30, an increase was found for LV end-diastolic and end-systolic dimension (p < 0.001), as well as for LV mass (p < 0.03) and LV index (p < 0.05). The current study showed a weak but significant correlation between altered LA and LV measurements versus AHI and hypoxemia indices (p < 0.001). In the regression analysis, AHI and hypoxemia had a minimal effect, body mass index and male gender being the most significant predictors.

CONCLUSIONS

In a population of healthy elderly with SDB, slight changes in left atrial and ventricular measurements occur in severe cases (AHI > 30). Irrespective of the lack of a strong association between SDB and cardiac dysfunction, the presence of slight cardiac pathology in severe SDB cases might be considered.

CLINICAL TRIAL REGISTRATION

NCT 00759304 and NCT 00766584.

Respiratory medicine in China: progress, challenges, and opportunities

The past century witnessed a rapid development of respiratory medicine in China. The major burden of respiratory disease has shifted from infectious diseases to chronic noninfectious diseases. Great achievements have been made in improving the national standard of clinical management of various respiratory diseases and in smoking control. The specialty of respiratory medicine is expanding into pulmonary and critical care medicine. Nevertheless, respiratory diseases remain a major public health problem, with new challenges such as air pollution and nosocomial infections. This review describes the history, accomplishments, new challenges, and opportunities in respiratory medicine in China.