Phenotyping Individuals With Neo-diagnosed Type 2 Diabetes at Risk for All-cause Mortality

Overview

Prevalence of type 2 diabetes (T2D) is increasing worldwide over the last two decades; in these patients the rate of all-cause and cardiovascular (CV) mortality is several folds higher than in the general population, configuring a major public health problem. The clinical phenotype is the main determinant of such high mortality risk; however, a relevant role is played by the disease duration, with a significant interaction with metabolic control. However, for T2D the diagnosis does not correspond to the true onset of the disease, and a high lethality rate also in patients with recent onset of the disease cannot be excluded. Robust evidence supports this hypothesis, showing as in subjects with new-onset T2D, the mortality risk is superimposable, and even higher, than that observed in people with overt and long-term T2D. In this complex scenario, it would be desirable an early identification of high-risk patients, in which an accurate estimation of risk of complications, coupled with appropriate and timely interventions, might help in reducing the risk of encountering premature mortality. The present study was design to address this specific issue.

Patients referring for the first time to the outpatient diabetes clinic in the department of Internal Medicine between January 2008 and December 2015 and matching the inclusion criteria were recruited. Diagnosis was confirmed on the basis of the Oral Glucose Tolerance Test (OGTT) or HbA1c ≥6.5% plus fasting blood glucose ≥126 mg/dl. Anthropometric measurements were recorded, arterial pressure and vital parameters were registered, and blood samples were collected for routine analyses. Complete blood count, glucose, HbA1c, Serum Glutamic Oxaloacetic Transaminase (sGOT), Serum Glutamic Pyruvic Transaminase (sGPT), uric acid, were determined by standard techniques. Total and HDL cholesterol and triglycerides were assayed through the automated spectrophotometer, enzymatic colorimetric method, COBAS INTEGRA using commercial kits (Roche Diagnostics). Serum creatinine was measured by Jaffe' method, and estimated glomerular filtration rate (eGFR) was calculated according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula. Previous major acute CV events, including myocardial infarction, stroke, foot ulcer/gangrene/amputation and coronary, carotid and lower limb revascularisation, were adjudicated based on hospital discharge records. At the end of the baseline visit, patients were treated according to the good clinical practice recommended by the international guidelines, and followed a six-month or an yearly calendar of follow-up visits, until death or until 31 December 2018. All-cause mortality was assessed by checking the vital status of study participants on 31 December 2018; to this aim, investigators interrogated the Italian Health Card database, which provides updated information on all current Italian residents. Incident major acute cardiovascular events were registered on the basis of clinical records every year; retinopathy onset was assessed by fundoscopy on a yearly basis.