Using the Finometer to examine sex differences in hemodynamic responses to orthostasis in older people.

Objectives: In young and middle age, women have higher orthostatic intolerance (OI) than men, and hemodynamic differences have been found supporting this finding. In older people, these sex differences are less studied. Our aim was to contribute evidence.

Methods: Two hundred and twenty-four community-dwelling older participants were studied (154 females and 70 males, mean age 72.6, standard deviation 7.3) who were without dementia or risk factors for autonomic neuropathy. Men and women were well matched for baseline characteristics. Finometer Pro was used to noninvasively monitor participants during an active stand test. Derived hemodynamic parameters were extracted with BeatScope (5-s averages method) at different phases (baseline, nadir, and recovery at 2 minutes), and compared between men and women. OI symptoms were recorded. Subgroup analyses were conducted focusing on the presence or absence of antihypertensives.

Results: Men and women did not differ in OI. Men tended to drop to a lower nadir (117 vs. 128 mmHg, P=0.001) and reach lower recovery systolic blood pressure than women (161 vs. 171 mmHg, P=0.006); Women had greater total peripheral resistance (P<0.001) and a trend towards lower stroke volumes (P<0.01). However, these differences disappeared in the nonmedicated subgroup. Consistently, women had greater aortic impedance and lower arterial compliance (P<0.001), suggesting greater arterial stiffness.

Conclusion: The Finometer is a useful tool to monitor orthostatic hemodynamics in older people, and in this study it allowed establishment of interesting sex differences. For further understanding, validation of Modelflow-derived parameters against other clinical standards is desirable.