Abstract TH973: Longitudinal Associations of Blood Pressure and Arterial Stiffness in Youth with Type 1 and Type 2 Diabetes: The SEARCH for Diabetes in Youth Study

Introduction: Increasing arterial stiffness and blood pressure (BP) are thought to contribute to cardiovascular disease risk in youth-onset type 1 (T1D) and type 2 (T2D) diabetes. Prior work in generally healthy youth found that arterial stiffness preceded changes in BP. Whether this temporal relationship exists in a youth-onset diabetes population, who have higher arterial stiffness and BP compared to healthy controls, is unknown. Further, which arterial stiffening mechanisms are most involved (load-dependent stiffening due to elevated BP or structural stiffening due to arterial wall thickening and remodeling) is unknown. Hypothesis: Our objective is to investigate the longitudinal bidirectional relationships between arterial stiffness (measured by carotid-femoral pulse wave velocity PWV CF ), and BP in youth-onset T1D or T2D. Additionally, we will use a recently-published modeling strategy to uncouple structural stiffness (PWV Structural ) and load-bearing stiffness (PWV Load ) components from measured PWV CF . We hypothesize that baseline PWV measures will predict future BP, as in generally healthy youth. Methods: Participants from the SEARCH for Diabetes in Youth Study (T1D, n=566; T2D, n=93; baseline age, 18.0 ± 4.6 years) had clinical, BP, and PWV CF assessed at two timepoints (mean follow-up time: 4.5 ± 1.1 years). Using a modeling approach which incorporates arterial mechanics, PWV CF , and BP, we calculated the PWV Structural and PWV Load components. We constructed separate multivariable linear regression models to quantify associations of (A) baseline PWV measures with follow-up BP, and (B) baseline BP with follow-up PWV. Results: In fully-adjusted models ( Image 1 ), a 1-SD higher baseline PWV Load was associated with a 4.03 (95%CI: 2.68-5.37) mmHg higher SBP at follow-up, but baseline PWV CF (ß: 1.15, 95%CI: -0.28-2.57) and PWV Structural (ß: 0.45, 95%CI: -0.95-1.85) were not associated. In the reverse analysis ( Image 2 ), a 10 mmHg higher SBP at baseline was associated with 0.08 (95%CI: 0.02-0.13) SD higher PWV CF , 0.32 (95%CI: 0.24-0.41) SD higher PWV Load , and 0.05 (95%CI: -0.01-0.11) SD higher PWV Structural . Bidirectional associations were largely consistent for DBP. Conclusions: In adolescents and young adults with youth-onset diabetes, BP may temporally precede changes in arterial stiffness, with load-dependent stiffening playing a larger role. This suggests BP control as a primary target for reducing arterial stiffness and CVD risk in youth-onset diabetes.