Respiratory Function in Different Subtypes of Prediabetes and Its Relationship With Insulin Resistance and Hand Grip Strength
Yeonsook Moon, Noriyoshi Fujii, Tatsuyoshi Fujii, Jong Weon ChoiBackground
Lung function is reduced in patients with diabetes. However, few studies have examined pulmonary function and spirometric patterns in prediabetes (PDM) subtypes. This study investigated the differences in respiratory function among PDM subtypes and their relationship with insulin resistance and muscle strength in patients with PDM.
Methods
Data obtained from 2560 participants, including 1480 patients with PDM and 1080 healthy individuals, were evaluated. Spirometric indices, such as forced vital capacity (FVC), forced expiratory volume in 1 s (FEV 1 ), FEV exhaled in 6 s (FEV 6 ), peak expiratory flow rate, and percentage of predicted FVC (%pFVC) and FEV 1 (%pFEV 1 ), were measured. Muscle strength was evaluated by measuring hand grip strength (HGS). PDM was categorized into three subtypes: impaired fasting glucose (IFG), hemoglobin A1c (HbA1c)‐defined PDM (A‐PDM), and combined IFG and A‐PDM (GA‐PDM). The homeostasis model assessment of insulin resistance (HOMA‐IR) was used to estimate insulin resistance.
Results
Patients with PDM had significantly lower %pFVC and FEV 6 than healthy individuals, with a 1.4‐fold higher prevalence of restrictive spirometric patterns. GA‐PDM was more prevalent in individuals with low FVC than in those with high FVC. However, no significant difference was observed in the prevalence of IFG between the two groups. HOMA‐IR and HbA1c levels were closely correlated with %pFVC and %pFEV 1 . A‐PDM and GA‐PDM increased the risk of low FVC by 1.2‐ and 1.3‐fold, respectively (odds ratios: 1.274, 95% CI, 1.012–1.604, p = 0.039 and 1.311, 95% CI, 1.042–1.648, p = 0.021, respectively). Patients with A‐PDM had significantly lower HGS than those with IFG, particularly in men. After adjusting for potential confounders, HGS was significantly associated with %pFVC and %pFEV 1 values.
Conclusion
Respiratory function is more significantly reduced in patients with A‐PDM or GA‐PDM than in those with IFG, particularly in relation to insulin resistance and decreased muscle strength.