Type 2 diabetes exacerbates changes in blood pressure-independent arterial stiffness: cross-sectional and longitudinal evidence from the SUMMIT study

Greater central artery stiffness is observed in people with type 2 diabetes (T2DM). Elevated blood pressure (BP) and altered arterial wall structure/composition in T2DM are generally considered as main drivers for this alteration. However, because conventional arterial stiffness measures are BP-dependent and as such an influence of BP remains in a measure, it is unclear if greater central artery stiffness is a function of greater BP, or due to changes in the structure and composition of the arterial wall. We aimed to measure BP-independent arterial stiffness (b ₀) cross-sectionally and longitudinally in T2DM. We studied 753 adults with T2DM (DM þ) and 436 adults without (DM-) at baseline (Phase 1), and 310 DM þ and 210 DM- adults at 3-yr follow-up (Phase 2). We measured carotid-femoral pulse wave velocity and used it to calculate b ₀. In Phase 1, b ₀ was significantly greater in DM þ than DM- after adjusting for age and sex [27.5 (26.6–28.3) vs. 23.6 (22.4–24.8) au, P < 0.001]. Partial correlation analyses after controlling for age and sex showed that b ₀ was significantly associated with hemoglobin A1c (r ¼ 0.15 P < 0.001) and heart rate [(HR): r ¼ 0.23 P < 0.001)] in DM þ . In Phase 2, percentage-change in b ₀ was significantly greater in DM þ than DM-[19.5 (14.9–24.0) vs. 5.0 (-0.6 to 10.6) %, P < 0.001] after adjusting for age, sex, and baseline b ₀. b ₀ was greater in DM þ than DM- and increased much more in DM þ than in DM- over 3 yr. This suggests that T2DM exacerbates BP-independent arterial stiffness and may have a complemental utility to existing arterial stiffness indices. NEW & NOTEWORTHY We demonstrate in this study a greater BP-independent arterial stiffness b ₀ in people with type 2 diabetes (T2DM) compared to those without, and also a greater change in b ₀ over 3 yr in people with T2DM than those without. These findings suggest that the intrinsic properties of the arterial wall may change in a different and more detrimental way in people with T2DM and likely represents accumulation of cardiovascular risk.