Project 462229

Type 1 diabetes mellitus (T1D) is the most common form of diabetes among children and youth. Importantly, T1D is strongly associated with heart diseases such as heart attacks and strokes, known as cardiovascular disease (CVD). While lifestyle habits can prevent CVD in adults, little is known on their role in youth with T1D. Our study builds on the CARDEA study of adolescents with T1D and without T1D (healthy controls), where we found worse CVD markers in youth with T1D and hints of differences between girls and boys. We aim to: 1) Determine sex and gender differences in terms of early CVD markers in youth with T1D and healthy controls; 2) Verify how lifestyle habits are related to early markers of CVD across groups and across sex and gender; 3) Understand how early markers of CVD risk evolve over time in both groups; 4) Understand how lifestyle habits predict early markers of CVD 5 years later. We will also explore the role of mental health in these associations, as suggested by our patient/parent partners. We will re-evaluate the 197 participants from the first phase of CARDEA, and recruit another 200 youth with T1D and 200 controls. Height, weight, waist circumference and blood pressure will be measured for each participant. Physical activity will be measured using a special device called an accelerometer worn at the waist for 7 days. Sedentary behavior and sleep will be measured using questionnaires and the accelerometer. Dietary intake will be assessed using 3 24-hr diet recalls. Cholesterol levels will be measured after a 12-hr fast. State-of-the-art methods will assess heart structure and vascular function, including a heart MRI. Our study provides a unique opportunity to detect the earliest changes of the heart and vessels heralding CVD in youth with T1D, and determine how these evolve over time, relate to lifestyle habits, and differ between boys and girls. This information is critical for the development of effective and targeted preventive strategies.