Figure 2.

Relationship between end-tidal carbon dioxide (ETco₂) and middle cerebral artery blood velocity (MCAv) by early-onset menopause (n = 19) and late-onset menopause (n = 16; A). Mean and standard errors are shown. MCAv reactivity between early-onset menopause and late-onset menopause (B). Mean (line) and individual data shown. An analysis of covariance (ANCOVA) with mean arterial pressure (MAP) as a covariate demonstrated attenuated MCAv reactivity in the Early group compared with the Late group (P = 0.02). Relationship between ETCO₂ and cerebrovascular conductance index (CVCi) by early-onset menopause (n = 19) and late-onset menopause (n = 16; C). Mean and standard errors are shown. CVCi reactivity between early-onset menopause and late-onset menopause (D). Mean (line) and individual data shown. An ANCOVA with MAP as a covariate demonstrated no difference in CVCi reactivity between groups (P = 0.15). *P < 0.05 between groups.