326 Lung Age/Chronological Age Index as Indicator of Clinical Improvement or Severity in Asthma Patients

BACKGROUND: Spirometry is a very useful clinical test to evaluate pulmonary function in asthma. However pulmonary function could be affected by the sex, time of clinical evolution, lung age (LA) and chronological age (CA). The aim of this study was to evaluate LA/CA as index of clinical improvement or severity in asthma patients. METHODS: The tenets of the Declaration of Helsinki were followed, and all patients gave their informed consent to participate in this study. Asthma severity was evaluated according with GINA classification. Spirometry was performed at the beginning of this study, at 46 days, 96 days, 192 days and after 8 months. Statistical analysis was performed using t test, 2-way ANOVA test, correlation and multiple regression models as well as ROC curves were also performed, a P < 0.05 was considered as significant. RESULTS: 70 asthma patients were included (22 male and 48 female), mean CA was 35-years old; mean LA was 48-years with a LA/CA index = 1.4, time of clinical evolution was 13 years. A LA/CA index = 1 (range 0.5 to 0.9) was observed in asymptomatic patients. LA/CA index over 1 were related with airway inflammation, and a LA/CA index more than 2 correlated with GINA step 3. Interestingly when we analyzed CA and LA, we observed that in female group more than 10 years of difference between CA and LA, (GINA Step2 and 3); while in male we observed (GINA Step1, Step2 and Step3). LA/CA index ≤ 1 was considered as normal. CONCLUSIONS: LA/CA index is a good as clinical indicator of clinical improvement or severity in asthma patients in with excellent correlation of pulmonary function and age.