Glycated hemoglobin A1c, lung function, and hospitalizations among adults with asthma.

Abstract Background Insulin resistance and metabolic dysfunction have been associated with asthma risk and asthma severity. Objective To examine the association between glycated hemoglobin A1c (HbA1c), asthma-related hospitalizations, and lung function measures among adults in the United Kingdom (U.K.). Methods Cross-sectional study of 47,606 adults aged 40 to 69 years old who participated in the UK Biobank and had asthma but no diagnosis of diabetes mellitus. HbA1c level was analyzed as a continuous measure and also categorized as normal ( Results Both HbA1c level (odds ratio [OR] = 1.03, 95% confidence interval [CI] = 1.01 to 1.04) and a HbA1c in the pre-diabetic or diabetic range (OR = 1.68, 95% CI = 1.18 to 2.41) were associated with ≥1 asthma hospitalization. Moreover, both HbA1c level and a HbA1c in the prediabetic/diabetic range were significantly and inversely associated with FEV1 and FVC. Conclusions HbA1c is linked to asthma-related hospitalizations and small decrements in FEV1 and FVC among British adults with asthma but no diagnosis of diabetes mellitus.