Chest
Volume 121, Issue 2, February 2002, Pages 370-376
Journal home page for Chest

Clinical Investigations
COPD
Body Mass Index and the Risk of COPD

https://doi.org/10.1378/chest.121.2.370Get rights and content

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.

Design and 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 COPD.

Methods

Cox proportional-hazards regression models were used to assess the relationship between COPD diagnosis and baseline body mass index (BMI) in men.

Results

The 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 getting COPD.

Section snippets

Study Population

The BLSA was started in 1958 as a long-term multidisciplinary study of normal human aging conducted by the intramural research program of the National Institute on Aging. The open-panel study continuously recruits community-dwelling volunteers, predominantly from the Washington-Baltimore area.11 In 1978, women began enrolling in the BLSA. The BLSA study participants are generally well educated and in good health at entry into the study. All participants give written informed consent as approved

Participant Characteristics

Table 1 shows the characteristics of the final study group by gender. At baseline, the men ranged in age from 40 to 73.2 years (mean age, 53.1 years) and the women ranged in age from 40 to 73.5 years (mean age, 55.5 years). On average, the men had higher BMI, were better educated, and had a larger proportion of smokers than the women. After a mean follow-up of 10.2 years for the men and 6.4 years for the women, the proportion of participants with COPD was lower in women than in men (3.6% vs

Discussion

The major finding of this study is that middle-aged and older men with low body weight, as measured by BMI, are at a substantially higher risk of COPD developing even after adjusting for other potential risk factors, including cigarette smoking, age, FEV1 percent predicted, abdominal obesity, and educational status. The inverse relationship between baseline BMI and the incidence of COPD is in agreement with the results of Higgins et al19 from the Tecumseh Community Health Study, who reported

ACKNOWLEDGMENT

The authors thank Denis Muller, Susheel Patil, and Christopher Morrell for their comments; Neil Gittings for assistance with the data sets; and Melvyn Tockman and Edward Billips for help with the study.

References (40)

  • B Nemery et al.

    Smoking, lung function, and body weight

    Br Med J

    (1983)
  • NW Shock et al.

    Normal human aging: the Baltimore Longitudinal Study of Aging

    (1984)
  • MS Tockman et al.

    Rapid decline in FEV1: a new risk factor for coronary heart disease mortality

    Am J Respir Crit Care Med

    (1995)
  • RI Harik-Khan et al.

    Determinants of maximal inspiratory pressure: the Baltimore Longitudinal Study of Aging

    Am J Respir Crit Care Med

    (1998)
  • American Thoracic Society

    Standardization of spirometry, 1994 update (ATS Statement)

    Am J Respir Crit Care Med

    (1995)
  • RI Harik-Khan et al.

    The effect of gestational parity on FEV1 in a group of healthy volunteer women

    Respir Med

    (1999)
  • H Shimokata et al.

    Studies in the distribution of body fat: II. Longitudinal effects of change in weight

    Int J Obes Relat Metab Disord

    (1989)
  • BG Ferris

    Epidemiology standardization project

    Am Rev Respir Dis

    (1978)
  • DR Cox

    Regression models and life tables

    J R Stat Soc

    (1972)
  • MW Higgins et al.

    An index of risk for obstructive airways disease

    Am Rev Respir Dis

    (1982)
  • Cited by (104)

    View all citing articles on Scopus
    View full text