Prevalence and Prognostic Impact of Diabetes in Takotsubo Syndrome: Insights from the Tokyo Cardiovascular Care Unit Network Registry.

Diabetes is a major risk factor for cardiovascular diseases. However, some reports have shown that diabetes has a low prevalence and is associated with favorable outcomes in takotsubo syndrome (TTS). This phenomenon, known as the "diabetes paradox," in which diabetes plays a protective role in the development of TTS, remains controversial. Therefore, we investigated the prevalence of diabetes and the prognostic impact of diabetes and glycemic control in patients with TTS. Using the Tokyo Cardiovascular Care Unit Network registry between 2015 and 2021, we identified 1,226 eligible patients with TTS (median age 77 years, male proportion 21%). The prevalence of diabetes, its clinical characteristics, and its association with in-hospital mortality were assessed. The prevalence of diabetes was 17.0% in TTS and 15.8% in the general population, with no significant difference (p = 0.445). Patients with diabetes were older and had higher body mass index, brain natriuretic peptide, and C-reactive protein levels than patients without diabetes. Patients with diabetes tended to have a higher in-hospital mortality rate than those without (6.3% vs 3.4%, p = 0.057). The multivariable analysis revealed that neither diabetes (odds ratio 1.83, 95% confidence interval 0.88 to 3.80, p = 0.106) nor hemoglobin A1c level was significantly associated with in-hospital mortality. In conclusion, diabetes is not uncommon and not a good prognostic factor in this multicenter registry. Our observations do not support a protective effect of diabetes on the emergence and outcomes of TTS.