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

Abstract

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 (β₀) cross-sectionally and longitudinally in T2DM. We studied 753 adults with T2DM (DM+) and 436 adults without (DM-) at baseline (Phase 1), and 310 DM+ and 210 DM- adults at 3-yr follow-up (Phase 2). We measured carotid-femoral pulse wave velocity and used it to calculate β₀. In Phase 1, β₀ was significantly greater in DM+ 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 β₀ was significantly associated with hemoglobin A1c (r = 0.15 P < 0.001) and heart rate [(HR): r = 0.23 P < 0.001)] in DM+. In Phase 2, percentage-change in β₀ was significantly greater in DM+ 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 β₀. β₀ was greater in DM+ than DM- and increased much more in DM+ 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 β₀ in people with type 2 diabetes (T2DM) compared to those without, and also a greater change in β₀ 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.

Keywords: aging; aorta; blood pressure; ultrasound.

Graphical abstract

Figure 1.

Comparisons of β₀ between people with and without type 2 diabetes (A), and between people with and without type 2 diabetes stratified by a history of cardiovascular disease (B). A: data are shown as means (95% confidence intervals) after adjusting for age and sex. *Significantly different from DM+. DM+, people with type 2 diabetes; DM−, people without type 2 diabetes. B: data are shown as means (95% confidence intervals) after adjusting for age, sex, mean arterial pressure, and heart rate. *Significantly different from DMCVD. †Significantly different from DM. CVD, people with cardiovascular disease only (n = 200); CTRL, people with neither type 2 diabetes nor cardiovascular disease (n = 236); DM, people with type 2 diabetes only (n = 426); DMCVD, people with type 2 diabetes with cardiovascular disease (n = 327); Healthy, “healthy” people (n = 74).

Figure 2.

Comparisons of absolute and percentage-change in β₀ (A and C) and in CFPWV (B and D) over 3 years in people with and without type 2 diabetes. Data are shown as means (95% confidence intervals) after adjusting for age, sex, and baseline β₀ for the change in β₀ and for age, sex, and baseline CFPWV for the change in CFPWV. *Significantly different from DM+. Δβ₀, change in β₀; ΔCFPWV, change in carotid-femoral pulse wave velocity; DM+, people with type 2 diabetes; DM−, people without type 2 diabetes.