Association of restrictive ventilatory dysfunction with the development of prediabetes and type 2 diabetes in Koreans
This study was performed to investigate whether ventilatory dysfunction is a predictor for the development of prediabetes and type 2 diabetes in Koreans. We analyzed the clinical and laboratory data of 16,195 Korean adults (age 20–79 years) who underwent routine medical checkups with a mean 4.7-years (range 3.0–5.9 years) interval. Spirometry results were categorized into three patterns: normal, obstructive ventilatory dysfunction [OVD; forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.70], and restrictive ventilatory dysfunction (RVD; FVC < 80 % predicted, FEV1/FVC ≥ 0.70). Compared with subjects with normal ventilatory function, subjects with RVD had a higher incidence of type 2 diabetes (3.7 vs. 6.3 %; P < 0.001), whereas subjects with OVD did not (3.7 vs. 4.8 %; P = 0.119). On multivariate logistic regression analysis, the odds ratio (OR) of RVD for type 2 diabetes was significantly increased after adjusting for age, sex, and lifestyle factors (1.40; 95 % CI 1.10–1.78). However, further adjustment for body mass index (BMI), waist circumference, and baseline glucose level attenuated the OR to become insignificant (1.12; 95 % CI 0.86–1.47). Among the 9,461 participants who had normal fasting glucose and HbA1c levels at baseline, the OR for progression to prediabetes or diabetes in the RVD group was significantly increased (1.30; 95 % CI 1.12–1.51). The increased OR remained significant after adjusting for BMI, waist circumference, and baseline glucose level (1.26; 95 % CI 1.07–1.47). Our results indicate that restrictive, but not obstructive ventilatory dysfunction, is independently associated with development of prediabetes and precedes the development of type 2 diabetes.