Study protocol

The “CHronic diabetes complications and All-cause Mortality in Pisa from 1999 ONwards” (CHAMP1ON) study is a single-center, observational study involving 497 consecutive outpatients referred to the University Hospital of Pisa for dysglycemia between 1999 and 2000 [9]. Inclusion criteria were age between 18 and 75 years, both women and men, history of diabetes or prediabetes (either impaired fasting glucose or impaired glucose tolerance). Most patients presented at baseline with comorbidities commonly associated with diabetes, including obesity and dyslipidemia. Exclusion criteria were concomitant acute or chronic diseases associated with a reduction in life expectancy, including ESKD, lung, hepatic, neoplastic or inflammatory diseases, and CVD events in the previous 12 months. At enrollment, all participants underwent a physical examination by a trained physician and a full clinical history was obtained. Patients were extensively characterized via biochemical and clinical exams and were thoroughly screened for the presence of major MVC, namely CKD, CAN, DPN, and DR.

After enrollment, participants periodically attended the clinic in relation to their clinical needs and were treated according to the best clinical practice relevant to that time for the control of major cardiovascular risk factors. The vital status of study participants was retrieved in April 2021 from the Italian Health Care database, which provides updated information on current Italian residents. In this retrospective longitudinal study, we analyzed data of CHAMP1ON study participants with diabetes who were screened for at least two MVC and had available survival data (Fig. 1).

Flow diagram of patients’ selection

The study was approved by the local Human Ethics Committee and conducted in accordance with the principles expressed in the Declaration of Helsinki. All subjects provided written informed consent prior to enrollment.