Objective: It has been shown that the prevalence of asthma in obese people has increased in recent years. The aim of this study was to evaluate factors involved in the relationship between asthma and obesity in women.

Methods: We evaluated serum leptin levels, fractional exhaled nitric oxide (FENO), asthma control (using the Asthma Control Test [ACT]), and presence of atopy in 41 obese women with asthma and 40 non-obese women with asthma. We also compared the relationship between body mass index (BMI) and these parameters between the 2 groups.

Results: Serum leptin levels were significantly higher in obese asthmatics than in nonobese asthmatics (P<.05). In the obese group, leptin levels were positively correlated with FENO levels (r=0.439, P=.004). Uncontrolled asthma (ACT score <20) was detected in 61% of women in the obese group compared to just 38% of those in the nonobese group (P=.035). In atopic patients, total immunoglobulin E levels were positively correlated with leptin levels (r=0.329, P=.038). When the 81 women were classified according to asthma control, high BMI was found to be the only significant factor that contributed to poor asthma control.

Conclusion: We have shown that serum leptin levels might have a role in poor asthma control in obese patients, and can conclude that obesity is an important factor in uncontrolled asthma.

Key words: Asthma. Asthma control. Exhaled nitric oxide. Leptin. Obesity