Influence of type 2 diabetes and central fat distribution on beat-to-beat blood pressure variability

Type 2 diabetes (T2D) is among the most prevalent diseases in the United States and is accompanied by an increased risk for cardiovascular disease. Resting beat-to-beat blood pressure variability (BPV) plays a predictive role in adverse cardiovascular outcomes, providing additional information over absolute blood pressure alone. Notably, the majority of patients with T2D are obese exhibiting an increased central fat distribution (CFD), which carries an independent cardiovascular risk. This raises the question as to how T2D and comorbid CFD contribute to beat-to-beat BPV in patients with T2D. Therefore, the purpose of this study was to test the hypothesis that patients with T2D have greater beat-to-beat BPV compared to body weight matched controls with CFD alone and lean controls. Beat-to-beat blood pressure (finger photoplethysmography) was measured continuously during a quiet, supine resting baseline in 26 T2D patients with CFD (T2D; Age: 55 ± 9 years, BMI: 32.5 ± 4.1 kg/m 2 ), 21 bodyweight matched controls with CFD (BWM; Age: 53 ± 12 years, BMI: 31.5 ± 4.7 kg/m 2 ), and 17 lean controls (Lean; Age: 54 ± 10 years, BMI: 22.2 ± 1.7 kg/m 2 ). CFD was determined by a waist circumference greater than 102 cm for obese (BMI ≥ 30.0 kg/m 2 ) men, 88 cm for obese women, 94 cm for overweight (BMI = 25.0 - 29.9 kg/m 2 ) men, and 80 cm for overweight women. Beat-to-beat BPV was quantified through calculations of standard deviation (SD), range, coefficient of variation (CV), and average real variability (ARV) for systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP). Absolute resting SBP, DBP, and MAP were determined by averaging 3 brachial blood pressure readings during the baseline. Resting absolute SBP (T2D: 130 ± 14 mmHg; BWM: 128 ± 15 mmHg; Lean: 113 ± 10 mmHg; P = 0.0004), DBP (T2D: 79 ± 7 mmHg; BWM: 79 ± 7 mmHg; Lean: 71 ± 7 mmHg; P = 0.0026), and MAP (T2D: 96 ± 10 mmHg; BWM: 97 ± 10 mmHg; Lean: 85 ± 7 mmHg; P = 0.0004) were greater in T2D and BWM than in lean controls. Beat-to-beat SD was greater in T2D than in lean controls for SBP (T2D: 6.9 ± 1.7 mmHg; BWM: 6.3 ± 2.0 mmHg; Lean: 5.1 ± 1.0 mmHg; P = 0.004) and MAP (T2D: 4.9 ± 1.2 mmHg; BWM: 4.5 ± 1.1 mmHg; Lean: 4.0 ± 0.8 mmHg; P = 0.027). Similarly, MAP ARV (T2D: 1.7 ± 0.6 mmHg; BWM: 1.5 ± 0.4 mmHg; Lean: 1.2 ± 0.5 mmHg; P = 0.003) was greater in T2D than in lean controls, while SBP ARV (T2D: 3.4 ± 1.5 mmHg; BWM: 2.8 ± 0.8 mmHg; Lean: 1.9 ± 0.6 mmHg; P = 0.0001) was greater in T2D and in BWM than in lean controls. There were no differences in CV for SBP, DBP, or MAP (P > 0.05). Range was greater for SBP (T2D: 40 ± 10 mmHg; BWM: 35 ± 12 mmHg; Lean: 31 ± 7 mmHg; P = 0.017) in T2D than in lean controls. These data suggest that beat-to-beat BPV for SBP and MAP is greater in those with T2D and CFD than in lean controls. Most of these differences were not observed between those with CFD alone and lean controls, suggesting that the combination of T2D and CFD drives these differences. Support or Funding Information: This work was supported by the College of Nursing and Health Innovation. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.