Arterial stiffness and the response to carotid sinus massage in older adults

Carotid sinus hypersensitivity (CSH) is a common cause of fainting and falls in the older adult population and is diagnosed by carotid sinus massage (CSM). Previous work has suggested that age-related stiffening of blood vessels reduces afferent input from the carotid sinus leading to central upregulation of the overall arterial baroreflex response. We examined the differences in arterial stiffness and baroreflex function in older adults at high cardiovascular risk (advanced age, Type 2 diabetes, hypertension and hyperlipidemia) with and without CSH.

Forty-three older adults (mean age 71.4+/-0.7) with Type 2 diabetes, hyperlipidemia and hypertension were recruited. After resting supine for 45 minutes prior to the start of data collection, each subject had arterial stiffness measured by pulse wave velocity (PWV, Complior SD), followed by spontaneous baroreflex measures (Baroreflex sensitivity, BRS) and CSM.

Of the 43 subjects tested, 10 subjects met the criteria for CSH (8 pure vasodepressor and 2 mixed CSH). CSH subjects had higher measures of arterial stiffness when compared to normal subjects for both radial PWV (11.5+/-0.6 vs 9.6+/-0.4 m/s, p=0.043) and femoral PWV (13.4+/-0.9 vs 11.0+/-0.5 m/s, p=0.036). The CSH group demonstrated significantly lower BRS as compared to the normal group (BRS, 6.73+/-0.58 vs 10.41+/-0.85 ms/mmHg, p=0.038). These results were unchanged when the analysis was repeated with only the VD subjects.

Older adults with CSH have higher arterial stiffness and reduced arterial baroreflex sensitivity. There was no evidence to support upregulation of the arterial baroreflex in patients with CSH.