Background: Previous studies have documented the
prognostic value of low body weight in patients with COPD and also in
general populations. However, it is not clear whether low body weight
is a risk factor for COPD or a consequence of established disease.
Study objective: To determine whether asymptomatic subjects
with low initial body mass were at a greater risk of having COPD
develop during subsequent follow-up.
subjects: Observational retrospective study of 458 male and 192
female participants (age range, 40 to 73 years) in the Baltimore
Longitudinal Study of Aging. At baseline, the participants did not have
COPD. After mean follow-up periods of 10.2 years for the men and 6.4
years for the women, 40 men and 7 women received a diagnosis of
Methods: Cox proportional-hazards regression
models were used to assess the relationship between COPD diagnosis and
baseline body mass index (BMI) in men.
risk of COPD developing in men varied inversely with baseline BMI, even
after adjusting for other risk factors, including cigarette smoking,
age, FEV1 percent predicted, abdominal obesity, and
educational status. In men, the relative risk of COPD developing for
the lowest BMI tertile relative to the highest tertile was 2.76 (95%
confidence interval, 1.15 to 6.59). The small number of women who had
COPD did not allow us to draw conclusions regarding BMI as a risk
factor for COPD.
Conclusion: After controlling for
confounding variables, men with low BMI are at increased risk for