Obese Women Have Higher Asthma Prevalence

Asthma prevalence among obese women in the United States is almost double that of normal-weight women, but the same association is not seen in men, according to a new study.

Researchers at the National Center for Health Statistics (NCHS; Atlanta, GA, USA), a part of the US Centers for Disease Control and Prevention (CDC; Atlanta, GA, USA), conducted a retrospective study that analyzed data from the National Health and Nutrition Examination Survey (NHANES) across all adult age groups, in order to examine asthma prevalence and demographic and ethnic associations between 2001–2014.

The results showed that obesity was significantly associated with higher asthma prevalence, and that overall asthma prevalence increased from 2001 (7.1%) to 2014 (9.2%). Obesity was associated with higher asthma prevalence rates among all age groups and racial groups, with the overall prevalence among adults at 8.8%, with 11.1% of obese adults, 7.8% of overweight adults, and 7.1% of normal-weight adults having asthma. Asthma prevalence rates increased during the study time period among overweight adults, but not among adults who were obese or whose weight was normal.

Demographically, the prevalence of current asthma among obese non-Hispanic whites was 10.9%, compared with 8.1% among normal-weight white adults. The prevalence among non-Hispanic black adults who were obese was 13.6%, compared with 6.6% in normal-weight blacks. And obese Hispanic adults had an asthma prevalence of 9.6%, versus 5.7% among normal-weight Hispanics. No significant differences in prevalence rates were seen between normal and overweight adults within any racial group.

When examined by sex, obese women had 14.6% prevalence for current asthma, versus 7.9% for normal-weight women and 9.1% for overweight women; but prevalence did not differ significantly by weight status for men. The researchers observed that it has been suggested that sex-related differences in fat distribution may at least partly explain the largely gender-specific asthma risk associated with obesity, and that hormones secreted by ectopic fat may contribute to asthma. The study was published in the March 2016 issue of NCHS Data Brief.

“Current asthma prevalence was higher among adults with obesity compared with adults in lower weight categories. This pattern was consistent across most demographic subgroups, except among men,” concluded lead author Lara Akinbami, MD, and colleagues. “The reasons for this are not clear; interestingly, asthma prevalence is higher in young boys than young girls, but this switches around the time of puberty. In adults, asthma prevalence is higher in women than men.”

Obese patients also often exhibit asthma-like symptoms, arising from the effects of increased body mass index (BMI) on lung volumes, an increased effort to breathe, and the increased release of adipokines. The resulting breathlessness is a common finding in both asthma and obesity, creating a potential for misdiagnosis.

Related Links:
National Center for Health Statistics
US Centers for Disease Control and Prevention