TABLE 1.
Baseline characteristics according to quartiles of digital pulse propagation index
| Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | |||
| Full cohort | <5.47 m/s | 5.47–5.81 m/s | 5.81–6.20 m/s | >6.20 m/s | P value | |
| Participants, n | 5487 | 1371 | 1372 | 1372 | 1372 | |
| DPPI (mean over 15 min) | 5.81 [5.47–6.20] | 5.22 [5.11–5.36] | 5.64 [5.56–5.72] | 5.98 [5.89–6.08] | 6.55 [6.34–6.90] | |
| Men (%) | 50.6 | 19.8 | 47.9 | 65.2 | 69.8 | <0.001 |
| Age (years) | 52.3 ± 11.8 | 47.1 ± 10.3 | 49.7 ± 11.1 | 52.9 ± 11.3 | 59.4 ± 11.0 | <0.001 |
| Waist circumference (cm) | 91.9 ± 12.6 | 86.3 ± 12.6 | 89.8 ± 11.7 | 93.9 ± 11.5 | 97.4 ± 11.8 | <0.001 |
| Length (m) | 1.73 ± 0.09 | 1.68 ± 0.08 | 1.73 ± 0.09 | 1.76 ± 0.09 | 1.75 ± 0.09 | <0.001 |
| Race (%) | <0.001 | |||||
| White | 96.1 | 94.3 | 95.8 | 97.1 | 97.1 | |
| Black | 1.0 | 1.0 | 0.8 | 0.6 | 1.4 | |
| Asian | 1.9 | 3.3 | 2.2 | 1.0 | 0.9 | |
| Other | 1.1 | 1.4 | 1.2 | 1.3 | 0.6 | |
| Family history of CVD (%) | 48.4 | 45.0 | 48.4 | 50.7 | 49.3 | <0.001 |
| History of CVD (%) | 6 | 3.3 | 4.1 | 6.4 | 10.2 | <0.001 |
| SBP (mmHg) | 125.5 ± 18.3 | 115.5 ± 14.8 | 122.7 ± 16.3 | 127.0 ± 16.0 | 136.7 ± 19.2 | <0.001 |
| DBP (mmHg) | 73.4 ± 9.1 | 67.0 ± 7.2 | 71.6 ± 7.5 | 75.1 ± 7.8 | 79.7 ± 9.0 | <0.001 |
| MAP (mmHg) | 92.2 ± 12.3 | 84.4 ± 9.6 | 90.0 ± 10.6 | 93.8 ± 10.3 | 100.6 ± 12.4 | <0.001 |
| Pulse pressure (mmHg) | 52.2 ± 13.0 | 48.5 ± 11.2 | 51.1 ± 12.5 | 52.2 ± 12.2 | 56.9 ± 14.3 | <0.001 |
| Heart rate (bpm) | 68.4 ± 10.0 | 65.0 ± 8.5 | 67.2 ± 9.5 | 69.3 ± 9.8 | 72.3 ± 10.6 | <0.001 |
| Use of AHD (%) | 20.9 | 14.1 | 16.2 | 19.9 | 32.7 | <0.001 |
| Smoking (%) | <0.001 | |||||
| Never | 29.6 | 37.6 | 32.9 | 28.9 | 20.0 | |
| Former | 41.8 | 39.2 | 40.7 | 41.7 | 47.2 | |
| Current | 27.3 | 21.7 | 26.3 | 29.4 | 32.8 | |
| Alcohol use (%) | <0.001 | |||||
| None/hardly ever | 23.0 | 25.5 | 22.7 | 20.8 | 23.4 | |
| 1–4/month | 15.8 | 18.7 | 17.0 | 13.9 | 13.8 | |
| 2–7/week | 35.2 | 37.2 | 35.2 | 36.2 | 32.7 | |
| 1–3/day | 20.2 | 15.5 | 21.0 | 22.5 | 22.2 | |
| >3/day | 5.2 | 2.6 | 4.1 | 6.6 | 7.8 | |
| Total cholesterol (mmol/l) | 5.42 ± 1.0 | 5.1 ± 1.0 | 5.39 ± 1.05 | 5.53 ± 1.05 | 5.59 ± 1.04 | <0.001 |
| HDL cholesterol (mmol/l) | 1.22 (1.04–1.43) | 1.33 (1.15–1.54) | 1.25 (1.06–1.47) | 1.17 (1.00–1.38) | 1.14 (0.97–1.35) | <0.001 |
| Triglycerides (mmol/l) | 1.10 (0.81–1.58) | 0.90 (0.67–1.28) | 1.06 (0.77–1.50) | 1.22 (0.90–1.72) | 1.30 (0.93–1.88) | <0.001 |
| Use of LLD (%) | 8.9 | 5.9 | 7.1 | 8.6 | 14.1 | <0.001 |
| History of diabetes mellitus (%) | 2.4 | 1.3 | 1.9 | 2.1 | 4.3 | <0.001 |
| Serum glucose (mmol/l) | 4.93 ± 0.92 | 4.72 ± 0.81 | 4.88 ± 0.91 | 4.94 ± 0.76 | 5.17 ± 1.10 | <0.001 |
| Serum kreatinine (μmol/l) | 73.7 ± 19.8 | 68.5 ± 13.5 | 72.6 ± 18.98 | 75.1 ± 15.2 | 78.6 ± 27.3 | <0.001 |
| eGFR (CKD-EPI) | 93.3 ± 15.8 | 96.5 ± 14.7 | 95.4 ± 15.3 | 93.7 ± 14.9 | 87.7 ± 74.5 | <0.001 |
| Urinary sodium excretion | 145 ± 54 | 134.3 ± 48.0 | 143.1 ± 51.8 | 151.5 ± 56.0 | 152.6 ± 59.3 | <0.001 |
| Urinary albumin excretion | 8.60 [6.06–15.1] | 7.09 [5.49–10.83] | 8.16 [5.95–13.3] | 9.11 [6.37–14.8] | 11.28 [7.06–26.92] | <0.001 |
Data presented as mean ± SD, or median [IQR] or percentage of the population for normally, skewed, or nominal data, respectively. Differences were tested using analysis of variance (ANOVA), or Kruskal–Wallis tests for continuous data and with χ2 tests for categorical data. AHD, antihypertensive drugs; CKD-EPI, Chronic Kidney Disease-Epidemiology collaboration; CVD, cardiovascular disease; DBP, diastolic blood pressure; DPPI, digital pulse propagation index; eGFR, estimated glomerular filtration rate; IQR, interquartile range; LLD, lipid lowering drugs; MAP, mean arterial pressure.