Homeostatic Measure of Insulin Resistance Is Associated With Future Asthma Exacerbations: A 1-Year Prospective Cohort Study.

ABSTRACT

BACKGROUND: Recent evidence suggests that insulin resistance affects asthma outcomes. However, the effect of the homeostatic measure of insulin resistance (HOMA-IR) on airway inflammation and asthma exacerbations (AEs) is poorly understood. OBJECTIVE: To analyze the relationship between HOMA-IR and clinical and inflammatory characteristics in patients with asthma, and the association between HOMA-IR and AEs in the following year. METHODS: A prospective cohort study recruited participants with asthma, who were classified into the HOMA-IRhigh group and HOMA-IRlow group based on the cutoff value of 3.80 for HOMA-IR and were observed within 12 months. We evaluated the clinical and inflammatory features and conducted a 1-year follow-up to study the exacerbations. We used negative binomial regression models to analyze the association between HOMA-IR and AEs. RESULTS: Compared with patients in the HOMA-IRlow group (n = 564), those in the HOMA-IRhigh group (n = 61) had higher levels of body mass index, a higher waist circumference and waist-hip ratio, higher triglycerides, lower cholesterol high-density lipoproteins, more neutrophils in the peripheral blood, and elevated IL-5 levels in the induced sputum. Furthermore, patients in the HOMA-IRhigh group had a significantly increased risk for moderate to severe AEs (adjusted incidence rate ratio [aIRR] = 2.26; 95% CI, 1.38-3.70), severe AEs (aIRR = 2.42; 95% CI, 1.26-4.67), hospitalization (aIRR = 2.54; 95% CI, 1.20-5.38), and emergency visits (aIRR = 3.04; 95% CI, 1.80-8.53). CONCLUSIONS: The homeostatic measure of insulin resistance was associated with asthma-related clinical features and airway inflammation, and was an independent risk factor for future AEs. Therefore, insulin resistance may have important implications for managing asthma as a potential treatable trait.