Racial and Gender Disparities in COPD Risk for Never-Smokers

A study on gender and racial inequalities in the prevalence of chronic obstructive pulmonary disease (COPD) among non-smokers found that black Americans and women are at higher risk. The research, published in the International Journal of Chronic Diseases, attributes this link to both biological and socioeconomic factors.

The study’s sample included 129,535 black and white Americans over the age of 50 who had never smoked. The main outcome measure was self-report of a medical diagnosis of COPD; the survey also recorded each participant’s gender, race, height, highest level of education, annual household income, age, health insurance coverage, household size, and marital status. The researchers used the education and income variables to determine socioeconomic position, and attempted to account for respondents living with a smoker by adjusting for household size and marital status.

Previous literature has shown that women and black Americans are more likely to be diagnosed with COPD. The increased prevalence in women can be attributed to both biological factors, such as shorter height and reduced lung size, and social factors, such as higher likelihood of exposure to secondhand smoke and air pollution due to women being more likely to live below the poverty line.

Similarly, black Americans have lower sitting heights and different metabolism of cigarette smoke, which can be associated with COPD. They are also disproportionately exposed to more secondhand smoke due to higher levels of poverty and increased likelihood of living in a multi-unit dwelling.

Consistent with their hypotheses, the researchers found that black women had the highest rate of self-reported COPD diagnosis at 7%, higher than the rate among white women at 5.2%, white men at 2.9%, and black men at 2.4%. The prevalence of COPD increased with respondent age and decreasing levels of income and education. Other factors linked to increased prevalence of COPD were shorter height, living alone, and having a health insurance plan.

The study’s most significant finding was that socioeconomic position could explain the difference in COPD prevalence across races. Controlling for socioeconomic position attenuated the risk of COPD for black women, resulting in no significant difference between COPD odds for black and white women. When socioeconomic position was controlled for among men, black men had lower odds of COPD than white men. According to the researchers, this indicates that “socioeconomic factors may be crucial in shaping racial inequalities in COPD,” but those factors do not explain the gender disparity in COPD prevalence.

“When we took into account height, a proxy for lung size, the odds of COPD among women compared to men were less elevated,” lead author Esme Fuller-Thomson, PhD, said in a press release. “However, we still found women had approximately 50% higher odds of COPD compared to white men even when we adjusted for height, education, income, and health care access."

This study finding on the importance of socioeconomic position, especially among women, “is consistent with knowledge that black women in the US are more likely to live in poverty than white women and, thus, face increased exposure to toxins, such as secondhand smoke and air pollution,” the study authors wrote, proposing that these inequities may make black women doubly vulnerable to COPD.

They concluded that although biological factors like sex and height are associated with COPD prevalence in nonsmokers, structural factors like race and socioeconomic position should also be considered in COPD research and policy development.