We conducted this study to compare the risks of asthma development and exacerbation between metformin users and nonusers. Overall, 57,743 propensity score-matched metformin users and nonusers were identified from Taiwan’s National Health Insurance Research Database between 1 January 2000, and 31 December 2017. We used the Cox proportional hazards model with robust standard error estimates to compare the risks of asthma onset, exacerbation, and hospitalization for asthma in participants with type 2 diabetes (T2D). Compared with metformin nonuse, the aHRs (95% CI) for metformin use in asthma development, exacerbation, and hospitalization for asthma were 1.13 (1.06–1.2), 1.62 (1.35–1.95), and 1.5 (1.22–1.85), respectively. The cumulative incidences of asthma development, exacerbation, and hospitalization for asthma were significantly higher in metformin users than nonusers (p < 0.001). A longer cumulative duration of metformin use for more than 728 days was associated with significantly higher risks of outcomes than metformin nonuse. Our study demonstrated that metformin users showed significantly higher risks of asthma development, exacerbation, and hospitalization for asthma than metformin nonusers. Moreover, metformin use for more than 728 days was associated with higher risks of outcomes. A randomized control study is warranted to verify our results.

We conducted this study to compare the morbidity and mortality associated with UTI and sepsis, between metformin users and nonusers in patients with diabetes. As such, 40,774 propensity score-matched metformin users and nonusers were identified from Taiwan’s National Health Insurance Research Database, between 1 January 2000 and 31 December 2017. We adopted the Cox proportional hazards model with robust standard error estimates for comparing the risks of UTI, sepsis, and death due to UTI or sepsis, in patients with T2DM. Compared with the nonuse of metformin, the aHRs (95% CI) for metformin use in UTI, recurrent UTI, sepsis, and death due to UTI or sepsis were 1.06 (0.98, 1.15), 1.08 (0.97, 1.2), 1.01 (0.97, 1.06), and 0.58 (0.42, 0.8), respectively. The cumulative incidence of death due to UTI or sepsis was significantly lower in metformin users than in nonusers (p = 0.002). A longer cumulative duration of metformin use had a lower aHR in the risk of death due to UTI or sepsis than metformin nonuse. In patients with T2DM, metformin use showed no significant differences in the risks of UTI, recurrent UTI, or sepsis. However, it was associated with a lower risk of death due to UTI or sepsis than metformin nonuse.

Older adults are more likely to have influenza and respond less well to the flu vaccine. We conducted this study to investigate whether pre-influenza vaccination metformin use had an effect on influenza and relevant complications in older adults with type 2 diabetes mellitus. Propensity score matching was used to identify 28,169 pairs of metformin users and nonusers from Taiwan’s National Health Insurance Research Database from 1 January 2000 to 31 December 2018. We used Cox proportional hazards models to calculate the risks of hospitalization for influenza, pneumonia, cardiovascular disease, ventilation, and mortality between metformin users and nonusers. Compared with metformin nonusers, the aHRs (95% CI) for metformin users at risk of hospitalization for influenza, pneumonia, cardiovascular disease, invasive mechanical ventilation, death due to cardiovascular disease, and all-cause mortality were 0.60 (0.34, 1.060), 0.63 (0.53, 0.76), 0.41 (0.36, 0.47), 0.56 (0.45, 0.71), 0.49 (0.33, 0.73), and 0.44 (0.39, 0.51), respectively. Higher cumulative duration of metformin use was associated with lower risks of these outcomes than no use of metformin. This cohort study demonstrated that pre-influenza vaccination metformin use was associated with lower risks of hospitalizations for influenza, pneumonia, cardiovascular disease, mechanical ventilation, and mortality compared to metformin nonusers.

Acute exacerbations of chronic obstructive pulmonary disease (COPD) with severe hyperglycemia may require insulin to lower glucose levels in people with coexisting type 2 diabetes (T2D) and COPD. We conducted this study to examine the risk of hospitalization for COPD, pneumonia, ventilator use, lung cancer, hypoglycemia, and mortality with and without insulin use in people with T2D and COPD. We adopted propensity-score-matching to identify 2370 paired insulin users and non-users from Taiwan’s National Health Insurance Research Database between 1 January 2000 and 31 December 2018. Cox proportional hazards models and the Kaplan–Meier method were utilized to compare the risk of outcomes between study and control groups. The mean follow-up for insulin users and non-users was 6.65 and 6.37 years. Compared with no insulin use, insulin use was associated with a significantly increased risk of hospitalization for COPD (aHR 1.7), bacterial pneumonia (aHR 2.42), non-invasive positive pressure ventilation (aHR 5.05), invasive mechanical ventilation (aHR 2.72), and severe hypoglycemia (aHR 4.71), but with no significant difference in the risk of death. This nationwide cohort study showed that patients with T2D and COPD requiring insulin therapy may have an increased risk of acute COPD exacerbations, pneumonia, ventilator use, and severe hypoglycemia without a significant increase in the risk of death.

Migraines are common headache disorders and risk factors for subsequent strokes. Acupuncture has been widely used in the treatment of migraines; however, few studies have examined whether its use reduces the risk of strokes in migraineurs. This study explored the long-term effects of acupuncture treatment on stroke risk in migraineurs using national real-world data. We collected new migraine patients from the Taiwan National Health Insurance Research Database (NHIRD) from 1 January 2000 to 31 December 2017. Using 1:1 propensity-score matching, we assigned patients to either an acupuncture or non-acupuncture cohort and followed up until the end of 2018. The incidence of stroke in the two cohorts was compared using the Cox proportional hazards regression analysis. Each cohort was composed of 1354 newly diagnosed migraineurs with similar baseline characteristics. Compared with the non-acupuncture cohort, the acupuncture cohort had a significantly reduced risk of stroke (adjusted hazard ratio, 0.4; 95% confidence interval, 0.35–0.46). The Kaplan–Meier model showed a significantly lower cumulative incidence of stroke in migraine patients who received acupuncture during the 19-year follow-up (log-rank test, p < 0.001). Acupuncture confers protective benefits on migraineurs by reducing the risk of stroke. Our results provide new insights for clinicians and public health experts.