Late-Onset Menopause Attenuates Aortic Stiffness in the Postmenopausal Period

BACKGROUND: A later age at menopause (≥55 years) is associated with lower cardiovascular disease risk compared with a normal age at menopause (45–54 years) in postmenopausal women (PMW). Aortic stiffening increases cardiovascular disease risk, but the impact of late-onset menopause on aortic stiffness is unknown. METHODS: Total aortic stiffness (carotid-femoral pulse wave velocity [PWV CF ]) was measured in 40 late-onset and 86 normal-onset PMW. Structural- and load/blood pressure-dependent PWV CF were calculated with exponential models; the percent of total PWV CF attributable to each was determined. Elastic modulus was assessed in aortic rings from female C57BL/6 N mice (3–6 months) exposed to 5% PMW serum. Lipidomics and triglyceride-related metabolite exposure of aortas with/without the mitochondrial antioxidant MitoQ identified lipid drivers of mitochondrial reactive oxygen species-related stiffness. RESULTS: PWV CF was 128 cm/s lower in late-onset (835±24 cm/s) versus normal-onset (963±24 cm/s) PMW. The difference in PWV CF remained >100 cm/s in multivariable models adjusted for age and education, cardiovascular disease risk factors, and medication use. Systolic and diastolic blood pressure were 10 and 6 mmHg lower in late-onset PMW. Some (