RT Journal Article
SR Electronic
T1 Obesity Is Associated With a Lower Resting Oxygen Saturation in the Ambulatory Elderly: Results From the Cardiovascular Health Study
JF Respiratory Care
FD American Association for Respiratory Care
SP 831
OP 837
DO 10.4187/respcare.02008
VO 58
IS 5
A1 Vishesh K Kapur
A1 Anthony G Wilsdon
A1 David Au
A1 Mark Avdalovic
A1 Paul Enright
A1 Vincent S Fan
A1 Nadia N Hansel
A1 Susan R Heckbert
A1 Rui Jiang
A1 Jerry A Krishnan
A1 Kenneth Mukamal
A1 Sachin Yende
A1 R Graham Barr
YR 2013
UL http://rc.rcjournal.com/content/58/5/831.abstract
AB BACKGROUND: The contribution of obesity to hypoxemia has not been reported in a community-based study. Our hypothesis was that increasing obesity would be independently associated with lower SpO2 in an ambulatory elderly population. METHODS: The Cardiovascular Health Study ascertained resting SpO2 in 2,252 subjects over age 64. We used multiple linear regression to estimate the association of body mass index (BMI) with SpO2 and to adjust for potentially confounding factors. Covariates including age, sex, race, smoking, airway obstruction (based on spirometry), self reported diagnosis of emphysema, asthma, heart failure, and left ventricular function (by echocardiography) were evaluated. RESULTS: Among 2,252 subjects the mean and median SpO2 were 97.6% and 98.0% respectively; 5% of subjects had SpO2 values below 95%. BMI was negatively correlated with SpO2 (Spearman R = −0.27, P < .001). The mean difference in SpO2 between the lowest and highest BMI categories (< 25 kg/m2 and ≥ 35 kg/m2) was 1.33% (95% CI 0.89–1.78%). In multivariable linear regression analysis, SpO2 was significantly inversely associated with BMI (1.4% per 10 units of BMI, 95% CI 1.2–1.6, for whites/others, and 0.87% per 10 units of BMI, 95% CI 0.47–1.27, for African Americans). CONCLUSIONS: We found a narrow distribution of SpO2 values in a community-based sample of ambulatory elderly. Obesity was a strong independent contributor to a low SpO2, with effects comparable to or greater than other factors clinically associated with lower SpO2.