Association between body mass index and patient-reported-outcome questionnaire scores (CAT™, ACT™, mMRC dyspnoea scale, IPAQ) in Ukraine, Kazakhstan and Azerbaijan: results of the CORE study

Background: The overweight/obese population (evaluated by a body mass index, BMI) represents a global health problem and contributes to the development of various chronic diseases. In this epidemiological study we evaluated this relationship by analyzing patient-reported questionnaires related to respiratory function, physical activity and BMI. Methods: In 2013-2015, adult residents of selected cities were enrolled to this study in: Ukraine (M/F: 403/561), Kazakhstan (M/F =348/597) and Azerbaijan (M/F: 389/544). Height was measured using a vertical measuring board, and body weight was measured by using portable digital scales. All participants were interviewed using CAT (TM), mMRC scale and IPAQ; respondents who also reported wheezing or whistling chest sounds during the previous 12 months additionally ACT (TM). Results: 45.4% of respondents in Ukraine, 47.6% in Kazakhstan and 54.9% of respondents in Azerbaijan were found to be overweight/obese (BMI >= 25 kg/m(2)). The mean CAT (TM) total score among this population versus those respondents with a normal weight was 5.2 versus 3.6 (Ukraine, p < 0.001), 4.2 versus 2.9 (Kazakhstan, p < 0.001) and 5.9 versus 4.3 (Azerbaijan, p < 0.001). The number of respondents without airflow limitations (mMRC score 0) among overweight/obese respondents versus normal weight respondents was 298 (68.2%) versus 456 (86.7%) in Ukraine, 261 (58.1%) versus 387 (78.2%) in Kazakhstan and 343 (67.1%) versus 345 (82.3%) in Azerbaijan. The ACT TM total score between overweight/obese respondents and normal weight respondents was not statistically different. IPAQ showed a tendency towards a higher proportion of "low activity" results (compared to "moderate" and "high") in the overweight/obese subgroup (24.7% vs. 23.8% in Kazakhstan, 18.5% vs. 14.6% in Azerbaijan), and in Ukraine this difference was significant (12.4% vs. 5.2%, p < 0.001). Conclusion: CAT (TM) and mMRC are widely used tools for respiratory function assessment. Despite CAT (TM) scores being close to a normal value (<5), the relationship of both CAT (TM) and mMRC scores with being overweight/obese was demonstrated in the general adult population of three CIS countries. IPAQ may also be a useful instrument for measuring activity level however, more objective studies are required to evaluate the relationship between BMI and physical activity.