Inspiratory Muscle Strength is Correlated with Carnitine Levels in Type 2 Diabetes

Abstract

Introduction. Plasma carnitine insufficiency has been known to cause muscle weakness. Carnitine levels and pulmonary functions were lower in patients with diabetes. Patients and Methods. To determine whether pulmonary functions are correlated with carnitine levels in patients with type 2 diabetes. In this study, we evaluated pulmonary functions and carnitine concentrations in 49 patients with type 2 diabetes and 34 healthy controls. Results. Carnitine levels were lower in type 2 diabetes group than control group (52.56 ± 12.38 and 78.96 ± 10.66 hmol/mL, respectively, p < 0.0001). Pulmonary functions were not significantly different between groups. Carnitine levels were not correlated with age, duration of diabetes, fasting blood glucose levels, and glycemic control (HbA1c%) in patients with type 2 diabetes. However, carnitine levels in patient group were correlated with % forced vital capacity (FVC%) (r = 0.35, p = 0.016), % forced expiratory volume in 1 s (FEV1%) (r = 0.318, p= 0.029), FEV1/FVC (r= 0.302, p= 0.039), inspiratory muscle strength (PImax) (r = 0.407, p = 0.023), and PImax% (r = 0.423, p= 0.018). Conclusion. This study suggests that low carnitine levels may be associated with lower PImax and PImax% in type 2 diabetes.