Characteristics of factors for decreased lung function in elderly patients with type 2 diabetes.

Chronic obstructive pulmonary disease (COPD) often accompanies type 2 diabetes mellitus (T2DM). However, background factors affecting these diseases in the elderly remain unclear. Eligible patients with T2DM were divided into two age groups-non-elderly (<65 years) and elderly (≥65 years); COPD, ratio of forced expiratory volume in one second to forced expiratory volume (FEV1/FVC ratio), and percent predicted forced expiratory volume in one second (FEV1% predicted) were examined, and factors related to reduced respiratory function according to age group were evaluated. In total, 371 patients with T2DM were analysed. COPD was found in 9 patients (5.3%) in the non-elderly group and 45 (22.5%) in the elderly group. In the elderly, male sex, low body mass index (BMI), insulin therapy, and high C-peptide immunoreactivity levels were factors related to COPD. In the non-elderly, age, female sex, high BMI were factors related to decreased FEV1% predicted. Female sex was factor related to decreased FEV1% predicted in both age groups. Low BMI was a factor related to reduced respiratory function in elderly patients and high BMI was a factor related to reduced respiratory function in non-elderly patients. Thus, BMI needs to be managed according to the age and general condition of T2DM patients.