Pulse Wave Analysis of HbA1C Categorized Prediabetes, Type 2 Diabetes and Normo-Glycemic Populations

Abstract

Arterial stiffness is a significant risk factor for cardiovascular events and early detection is key for intervention and monitoring. This pathophysiological process is accelerated in type 2 diabetes (T2D), yet the onset of this condition has a limited body of research. PURPOSE: To evaluate (1) arterial stiffness properties via pulse wave analysis (PWA) across a 4-group spectrum, and (2) determine whether waist-to-height-ratio (WHtR), waist circumference (WC) or body mass index (BMI) serves as the best predictor of early changes in PWA pathophysiology. METHODS: PWA was measured in 52 participants across four groups separated by HbA1c values: 13 normo-glycemic (N, 4.0-5.1), 14 high normal (HN, 5.2-5.6), 10 prediabetes (PD, 5.7-6.4) and 13 with T2D (T2D, ≥ 6.5). Brachial, central and peripheral pressures, central and peripheral augmentation index (AIx) data were collected via Sphygmocor using validated methods after overnight caffeine abstinence and a minimum 4-hr fast. Group differences were evaluated via MANCOVAs. HbA1C, WHtR, WC and BMI data were assessed through regression to determine the best predictor. RESULTS: Significant differences were found between N to T2D and HN to T2D for brachial systolic blood pressure (SBP) [F(3,46)=2.743, p<.05], brachial diastolic blood pressure (DBP) [F(3,46)=3.329, p<.028] and brachial mean pressures (MP) [F(3,46)=4.321, p<.009]. Central DBP and MP differed between N to T2D, and HN to PD and T2D groups [DBP:F(3,44)=3.874, p<.015; MP:F(3,44)=3.303, p<.029]. Central pulse pressure (PP) and CAIx showed no differences between groups. Peripheral pressures significantly differed between N and both PD and T2D; HN and both PD and T2D groups for peripheral SBP [F(3,44)=3.007, p<.040], peripheral DBP [F(3,44)=4.316, p<.009] and peripheral MP [F(3,44)=3.487, p<.023], but not PP or PAIx. WHtR and WC were identified as the best predictors of CAIx after adjusting for age and height [R2=.800, F(5,45)=16.023, p<.0005; adj. R2=.640], while PAIx had no significant predictor. CONCLUSIONS: PWA may be effective for identifying differences in multiple brachial, central and peripheral pressure measures across a novel, pre-defined HbA1C spectrum; however, more research needs to be executed to validate these findings. WHtR and WC, but not BMI, effectively predicts CAIx.