Reference values of MostGraph measures for middle-aged and elderly Japanese individuals who participated in annual health checkups

BackgroundThe forced oscillation technique (FOT) can measure respiratory system resistance and reactance under tidal volume respiration. MostGraph is a device that incorporates the FOT and enables the immediate, three-dimensional visualization of resistance and reactance parameters. The aim of this study was to establish MostGraph reference values for middle-aged and elderly Japanese individuals.MethodsFrom 2004 to 2006, 3253 subjects living in Takahata, Yamagata underwent spirometry. Of these, 872 again underwent spirometry in 2011, and 784 (368 men, ages 46–89 years; 416 women, ages 47–90 years) underwent FOT examinations using MostGraph-01.ResultsIn this study population, 19.0% of the men and 91.5% of the women were life-long never smokers. Abnormal spirometric findings were observed in 30.2% of the men and 14.6% of the women. Although the respiratory system resistance and reactance parameters obtained using MostGraph were not distributed normally, normal distribution was achieved via natural logarithm (R5, R20, Fres, and ALX), square root (R5-R20), or exponential (X5) transformation. Furthermore, the transformed values were converted back to the actual values after determining the values representing one and two standard deviations from the mean.ConclusionRespiratory system resistance and reactance reference values were determined using MostGraph in middle-aged and elderly Japanese individuals who participated in annual health checkups.