Objective: The number of patients with type 2 diabetes has increased in Japan, and type 2 diabetes has attracted attention as a risk factor for asthma. However, the risk factors for the development of asthma in patients with type 2 diabetes have not been determined. This study was performed to clarify whether visceral fat accumulation (VFA) and insulin resistance are risk factors for the development of asthma in patients with type 2 diabetes.
Materials and methods: A cross-sectional study was conducted. The study group comprised 15 patients with type 2 diabetes with asthma, and the control group comprised 145 patients with type 2 diabetes without asthma. Their fat distribution was evaluated by measuring the VFA by abdominal computed tomography at the umbilical level. Their glucose status was assessed by measuring the fasting plasma glucose (FPG) concentration, fasting immunoreactive insulin concentration, homeostasis model assessment (HOMA) index, and hemoglobin A1c concentration.
Results: Among patients with type 2 diabetes, VFA was significantly greater in patients with asthma than those without asthma (P < 0.0001). The FPG concentration, fasting immunoreactive insulin concentration, and HOMA index were higher in patients with asthma than those without asthma (P < 0.05, P < 0.0001, and P < 0.0001, respectively). Multiple logistic regression analysis showed that VFA and the HOMA index were significantly associated with asthma in patients with type 2 diabetes (odds ratio, 1.78; 95% confidence interval, 1.31-3.89; P = 0.0115 and odds ratio, 3.65; 95% confidence interval, 1.37-7.85; P = 0.0078, respectively).
Conclusions: Our data suggest that VFA and insulin resistance are associated with the development of asthma in patients with type 2 diabetes.