Adrenomedullin and galanin responses to orthostasis in older persons

The Importance of Orthostatic Increase in Pulse Wave Velocity in the Diagnosis of Early Vascular Aging

Background/Objectives: Vascular aging can be assessed by arterial stiffness measured through pulse wave velocity (PWV). Increased PWV predicts arterial hypertension, cardiovascular events and all-cause mortality. Detection of early signs of vascular aging remains an unmet problem. To search for the most sensitive markers for the early increase in vascular stiffness in a healthy population. Methods: One-hundred and twenty healthy subjects were divided in three equal age groups: <30 years, 30-45 years and >45 years. Head-up tilt test (HUTT) protocol was applied, providing a standardized hydrostatic column height. PWV at the brachial-ankle artery site (baPWV) was measured using a multichannel sphygmomanometer ABI System 100 PWV in three positions: in the baseline horizontal (supine) position-baPWVb; during the head tilt-up with an individual angle of inclination-baPWVt; and when returning to supine. Results: The most sensitive marker of early stiffness increase in a healthy population is the relative orthostatic increase in baPWV, ΔbaPWV/baPWVb, where ΔbaPWV = baPWVt - baPWVb. The significance of differences in this parameter between the young and elderly groups reached p = 0.000075 and p = 0.000006, respectively. Conclusions: The proposed index ΔbaPWV/baPWVb can be considered as a promising sensitive early biomarker of vascular aging and as a potential effective indicator in cardiovascular prevention. A longitudinal cohort study is needed to confirm this assumption.

Postural hemodynamic parameters in older persons have a seasonal dependency : A pilot study

Aims

It is known that blood pressure regulation differs seasonally. It is unknown, however, how the cardiovascular system in patients with a stroke reacts to postural changes in different seasons. The aim was therefore to investigate how different temperatures in cold and warm seasons influence the reactions of haemodynamic mechanisms as well as heart rate variability during a sit-to-stand test in patients with stroke and a control group.

Methods

Hemodynamic responses were assessed in both groups during a sit-to-stand test (5 min sitting followed by 5 min standing) beat to beat within two different seasons. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), heart rate (HR), stroke index (SI), cardiac index (CI) and heart rate variability (HRV) were continuously monitored.

Results

During the sitting baseline period delta values of DBP (+15.1 [Standard error (SE) 3.75] mmHg, p < 0.05) and MBP (+14.35 [SE 4.18] mmHg, p < 0.05) were significantly higher in colder months compared to warmer months whereas SI (−3.86 [SE 1.43] ml/beat/m², p < 0.05) and CI (−0.4 [SE 0.11] l/min/m², p < 0.05) were lower in colder months compared to warmer months in non-stroke participants. In patients with stroke during sitting, baseline period delta values of DBP (+19.92 [SE 8.03] mmHg, p < 0.05) and MBP (+19.29 [SE 8.6] mmHg, p < 0.05) were significantly higher in colder months compared to warmer months but SI (−5.43 [SE 1.96] ml/beat/m², p < 0.05) was significantly lower in colder months compared to warmer months. After standing, there was a significant decrease in SBP in warmer months (−16.84 [SE 4.38] mmHg, p < 0.05) and a decrease in DBP in warmer months (−7.8 [SE 2.3] mmHg, p < 0.05) and colder months (−6.73 [SE 1.5] mmHg, p < 0.05) in non-stroke participants and a decrease in MBP in warmer months (−12.5 [SE 2.8] mmHg, p < 0.05) and colder months (−8.93 [SE 1.8] mmHg, p < 0.05) in non-stroke participants and in warmer months (−14.54 [SE 4.1] mmHg, p < 0.05) in patients with stroke.

Conclusion

Elderly with and without stroke respond to orthostatic stress with a greater drop in blood pressure in the warmer seasons.

Orthostatic Intolerance in Older Persons: Etiology and Countermeasures

Orthostatic challenge produced by upright posture may lead to syncope if the cardiovascular system is unable to maintain adequate brain perfusion. This review outlines orthostatic intolerance related to the aging process, long-term bedrest confinement, drugs, and disease. Aging-associated illness or injury due to falls often leads to hospitalization. Older patients spend up to 83% of hospital admission lying in bed and thus the consequences of bedrest confinement such as physiological deconditioning, functional decline, and orthostatic intolerance represent a central challenge in the care of the vulnerable older population. This review examines current scientific knowledge regarding orthostatic intolerance and how it comes about and provides a framework for understanding of (patho-) physiological concepts of cardiovascular (in-) stability in ambulatory and bedrest confined senior citizens as well as in individuals with disease conditions [e.g., orthostatic intolerance in patients with diabetes mellitus, multiple sclerosis, Parkinson's, spinal cord injury (SCI)] or those on multiple medications (polypharmacy). Understanding these aspects, along with cardio-postural interactions, is particularly important as blood pressure destabilization leading to orthostatic intolerance affects 3-4% of the general population, and in 4 out of 10 cases the exact cause remains elusive. Reviewed also are countermeasures to orthostatic intolerance such as exercise, water drinking, mental arithmetic, cognitive training, and respiration training in SCI patients. We speculate that optimally applied countermeasures such as mental challenge maintain sympathetic activity, and improve venous return, stroke volume, and consequently, blood pressure during upright standing. Finally, this paper emphasizes the importance of an active life style in old age and why early re-mobilization following bedrest confinement or bedrest is crucial in preventing orthostatic intolerance, falls and falls-related injuries in older persons.