Table 1.
Participant characteristics and baseline cerebrovascular parameters
| Total |
Young |
Middle |
Older |
|||||
|---|---|---|---|---|---|---|---|---|
| Characteristics | Males | Females | Males | Females | Males | Females | Males | Females |
| n | 34 | 39 | 13 | 12 | 13 | 17 | 8 | 10 |
| Age, yr | 46.9 ± 18.5 | 50.6 ± 16.5 | 26.8 ± 2.9a,b | 27.2 ± 2.3a,b | 50.3 ± 8.4a,c | 54.7 ± 6.5a,c | 70.9 ± 3.3b,c | 70.0 ± 3.5b,c |
| Stature, cm | 175.7 ± 9.4* | 171.5 ± 7.9 | 179.4 ± 6.7 | 172.0 ± 7.9 | 170.2 ± 9.9 | 174.4 ± 7.5 | 178.4 ± 8.8 | 165.7 ± 5.5 |
| Weight, kg | 77.0 ± 13.7 | 73.7 ± 13.5 | 77.7 ± 13.0 | 79.0 ± 17.7 | 70.3 ± 11.1 | 72.1 ± 11.5 | 85.8 ± 14.0 | 70.2 ± 10.0 |
| BMI, kg·m2 | 21.8 ± 3.2 | 21.4 ± 3.3 | 21.6 ± 3.4 | 22.9 ± 4.3 | 20.6 ± 2.5 | 20.6 ± 2.7 | 24.0 ± 3.1 | 21.2 ± 2.9 |
| Normal weight, %Ω | 75 | 74 | 62 | 67 | 85 | 76 | 75 | 80 |
| PA, METmin/wk | 2,358 ± 1,590 | 2,029 ± 1,071 | 2,172 ± 829 | 2,309 ± 1,159 | 1,867 ± 1,076 | 1,944 ± 992 | 3,373 ± 2,579 | 1,859 ± 1,151 |
| MAP, mmHg | 96 ± 19 | 103 ± 17 | 87 ± 26a,b | 93 ± 11a,b | 97 ± 10a,c | 103 ± 15a,c | 108 ± 7b,c | 111 ± 13b,c |
| Intracranial cerebrovascular parameters (n = 73, females = 39) | ||||||||
| MCAv, cm/s | 63.7 ± 14.0* | 72.7 ± 15.9 | 70.8 ± 14.0b | 76.9 ± 10.9b | 62.8 ± 12.2c | 74.8 ± 15.0c | 53.7 ± 11.3b,c | 64.2 ± 20.2b,c |
| CVCi, cm/s/mmHg | 0.65 ± 0.19* | 0.74 ± 0.21 | 0.77 ± 0.18a,b | 0.88 ± 0.16a,b | 0.64 ± 0.15a,c | 0.73 ± 0.16a,c | 0.48 ± 0.14b,c | 0.58 ± 0.23b,c |
| CVRi, mmHg/cm/s | 1.6 ± 0.5 | 1.5 ± 0.5 | 1.3 ± 0.4a,b | 1.2 ± 0.2a,b | 1.6 ± 0.4a,c | 1.4 ± 0.3a,c | 2.1 ± 0.5b,c | 2.0 ± 0.6b,c |
| PI, AU | 0.76 ± 0.16† | 0.74 ± 0.12 | 0.82 ± 0.22 | 0.67 ± 0.10 | 0.69 ± 0.10c | 0.72 ± 0.10c | 0.78 ± 0.08c | 0.85 ± 0.11c |
| , mmHg | 41.7 ± 6.2 | 41.4 ± 8.8 | 44.6 ± 5.4 | 42.4 ± 4.6 | 42.9 ± 4.4 | 41.2 ± 4.6 | 36.7 ± 6.0 | 40.5 ± 4.9 |
| V̇e, L/min | 11.7 ± 4.2 | 10.8 ± 4.2 | 11.9 ± 4.1 | 11.4 ± 4.3 | 11.6 ± 5.2 | 11.4 ± 4.8 | 11.3 ± 2.7 | 9.2 ± 2.8 |
| Extracranial internal carotid artery parameters (n = 58, females = 31) | ||||||||
| ICA diameter, cm | 0.61 ± 0.11* | 0.52 ± 0.08 | 0.60 ± 0.10 | 0.49 ± 0.05 | 0.56 ± 0.03 | 0.54 ± 0.08 | 0.68 ± 0.16 | 0.53 ± 0.10 |
| Peak systolic velocity, cm/s | 30.9 ± 7.7 | 36.2 ± 12.5 | 29.8 ± 7.5 | 34.4 ± 9.9 | 31.4 ± 8.1 | 35.2 ± 10.6 | 31.9 ± 8.4 | 40.2 ± 18.5 |
| Mean blood flow, mL/min | 470.8 ± 235.8 | 417.1 ± 270.0 | 476.4 ± 267.2 | 266.4 ± 98.5 | 395.3 ± 221.0 | 535.7 ± 388.9 | 566.3 ± 200.8 | 412.3 ± 199.5 |
| Shear rate, s−1 | 213.1 ± 69.2* | 268.2 ± 86.5 | 207.7 ± 57.4 | 287.7 ± 104.0 | 222.4 ± 50.9 | 256.4 ± 80.6 | 206.9 ± 106.9 | 263.8 ± 78.0 |
Values are means ± SD. Data were compared using a two-way ANOVA with main effects of age (males and females) and sex (young, middle, and older). *Significant main effects of sex. When main effect of age is present, post hoc pairwise comparisons reveal where significant differences lie: ayoung vs. middle, byoung vs. older, cmiddle vs. older. †Significant age-by-sex interaction effect. ΩAccording to BMI classifications [Weir and Jan (34)], proportion of participants classified as normal weight are presented as a percentage. BMI, body mass index; CVCi, cerebrovascular conductance index; CVRi, cerebrovascular resistance index; MAP, mean arterial pressure; MCAv, Middle cerebral artery velocity; PA, physical activity; , end-tidal carbon dioxide; PI, pulsatility index; V̇e, minute ventilation.