Seasonal Changes in Incidence of Patients With Diabetes Undergoing Cardiac Surgery

Abstract

Background: To evaluate the monthly incidence rate of patients with diabetes requiring heart surgery at a tertiary-care university hospital in East-Central Europe with a temperate climate zone. We also assessed whether additional factors affecting small blood vessels (smoking, aging, and diabetes) modulate the seasonal variability of diabetes.Methods: Medical records were retrospectively analyzed for all 9837 consecutive adult patients who underwent surgery at our institution between 2007 and 2018. Individual seasonal variations of diabetes, smoking, and elderly patients were analyzed monthly. Potential additive or subtractive effects of the coexistence of these factors in seasonal changes in incidence rates were also examined. In the absence of a waiting list, incidence rates accurately reflect the frequency of exacerbation of cardiovascular symptoms requiring surgical intervention.Results: Significant seasonal variations in the monthly incidence rate of diabetes (p < 0.02), smoking (p < 0.001), and elderly (p < 0.001) patients were observed at the cardiac surgery unit. The peak incidence of non-elderly and smoking patients with diabetes was during winter, whereas heart surgery in elderly patients without diabetes and smoking was most frequently required in summer. Concomitant occurrence of diabetes and smoking had an additive effect on the relative incidence rate of requirement for cardiac surgery (p < 0.001), while the simultaneous presence of older age and diabetes or smoking eliminated seasonal variations.Conclusions: Scheduling regular cardiovascular control in accordance with periodicities in diabetes, elderly, and smoking patients more than once a year may improve patient health and social consequences.Trial registration: NCT03967639