Miscellaneous
Comparison of Cardiac Structural and Functional Changes in Obese Otherwise Healthy Adults With Versus Without Obstructive Sleep Apnea

https://doi.org/10.1016/j.amjcard.2006.12.052Get rights and content

Obstructive sleep apnea (OSA) and obesity have been linked to systolic and diastolic dysfunction of the left ventricle. Right ventricular function is poorly understood in the 2 clinical conditions. Data from this study show that otherwise healthy obese patients with OSA had increased an left atrial volume index compared with similarly obese patients without OSA (16.3 ± 1.2 ml/m in obese patients without OSA vs 20.2 ± 1.0 ml/m in those with OSA, p = 0.02) and altered diastolic function reflected by changes in mitral annular late diastolic velocity (−5.7 ± 0.7 cm/s in obese patients without OSA vs −7.3 ± 0.7 cm/s in those with OSA, p = 0.007), mitral annular early diastolic velocity (−7.9 ± 0.6 cm/s in obese patients without OSA vs −6.4 ± 0.3 cm/s in those with OSA, p = 0.05), and early to late diastolic annular ratio >1 (82% of obese patients without OSA vs 26% of those with OSA, p = 0.001), which may be signs of early subclinical impairment of cardiac function. Importantly, healthy obese subjects had similarly increased left ventricular mass compared with obese patients with OSA but normal diastolic function and left atrial size. There was a trend toward abnormal right ventricular filling in patients with OSA, measured by altered superior vena cava diastolic velocity during expiration (−15 ± 2 cm/s in obese patients without OSA vs −10 ± 3 cm/s in those with OSA, p = 0.2) and a tendency toward diastolic dysfunction reflected by decreased lateral tricuspid annular early diastolic velocity (−7.2 ± 0.5 cm/s in obese patients without OSA vs −6.1 ± 0.5 cm/s in those with OSA, p = 0.1) beyond that seen in obesity alone. In conclusion, OSA independent of obesity may induce cardiac changes that could predispose to atrial fibrillation and heart failure.

Section snippets

Methods

We recruited community-dwelling healthy adult men with obesity (body mass index ≥30 kg/m2). We studied 23 otherwise healthy newly diagnosed patients with moderate to severe OSA (apnea-hypopnea index ≥15 events/hour) and 18 healthy obese subjects proved to be free of OSA on complete overnight polysomnography (apnea-hypopnea index <5 events/hour). Exclusion criteria were a history of myocardial ischemia or electrocardiographic changes suggestive of ischemia, a history of hypertension or systemic

Results

A total of 23 otherwise healthy patients with moderate to severe OSA and 18 healthy obese subjects without OSA were included in the study. All patients with OSA were diagnosed by overnight polysomnography as having moderate to severe OSA by an apnea-hypopnea index ≥15 events/hour for the exposure group and <5 events/hour for the controls. Baseline characteristics of the patients are listed in Table 1. The 2 groups had similar mean ages, body mass indexes, heart rates, and systolic and diastolic

Discussion

The novel and important findings of the present study are, first, that patients with newly diagnosed moderate to severe OSA have impaired LV diastolic function by tissue Doppler velocity and have increased left atrial size. Second, LV mass, although increased in OSA, is similar to that seen in obese controls without OSA. Patients with OSA also tended toward impaired RV diastolic function, as evidenced by attenuation in tissue Doppler lateral tricuspid annular diastolic velocity and superior

Acknowledgment

We thank Eileen McMahon, PhD, and Carolyn Duenwald, BS, for excellent technical support.

References (31)

  • S.R. Ommen et al.

    Usefulness of serial echocardiographic parameters for predicting the subsequent occurrence of atrial fibrillation

    Am J Cardiol

    (2001)
  • A. Kales et al.

    Sleep apnoea in a hypertensive population

    Lancet

    (1984)
  • G.F. Mureddu et al.

    Left ventricular filling pattern in uncomplicated obesity

    Am J Cardiol

    (1996)
  • M.E. Otto et al.

    Comparison of right and left ventricular function in obese and nonobese men

    Am J Cardiol

    (2004)
  • S. Ghio et al.

    Doppler velocimetry in superior vena cava provides useful information on the right circulatory function in patients with congestive heart failure

    Echocardiography

    (2001)
  • Cited by (179)

    • Lower heart rates and beta-blockers are associated with new-onset atrial fibrillation

      2023, International Journal of Cardiology: Cardiovascular Risk and Prevention
    • General Treatment of Heart Failure With Preserved Ejection Fraction and Randomized Trials

      2020, Diastology: Clinical Approach to Heart Failure with Preserved Ejection Fraction
    View all citing articles on Scopus
    1

    Drs. Otto, Svatikova, and Somers are supported by Grants HL-65176, HL-61560, HL-70602, HL-73211-01, and M01-RR00585 from the National Institutes of Health, Bethesda, Maryland.

    2

    Dr. Belohlavek is supported by Grant HL-68555 from the National Institutes of Health and Grant #0245016N from the American Heart Association, Dallas, Texas.

    3

    Dr. Otto was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior and Fundação E. J. Zerbini (InCor), São Paulo, Brazil.

    View full text