Orthostatic reactions in the 85-year olds

Reliability of heart rate variability in healthy older women at rest and during orthostatic testing

BACKGROUND AND AIMS

In the older population, the reliability of heart rate variability (HRV) has only been evaluated in a few studies, in the supine position, and covering a broad sample of age and patients of both sexes. To document the relevance of using HRV analysis in healthy older women, the aim of this study was to evaluate the reliability of HRV indexes during three classical tests.

METHODS

33 healthy women (66.9+/-0.7 years old) performed two test sessions. Each session consisted of an ECG recorded in the supine position, first with free breathing (Test 1), then with controlled breathing (Test 2), and in the upright position (Test 3). Time and frequency HRV indexes were obtained by processing the ECG signals. Reliability was assessed between sessions using Student's paired t-test, intraclass correlation coefficient (ICC) and coefficient of variation (CV).

RESULTS

There were no differences between the sessions. ICC showed good reliability for all HRV indexes. CV was low for absolute HRV indexes, except in Test 3 for parasympathetic indexes with modest CV. The CV of HRV ratio indexes were modest to high in all three tests.

CONCLUSIONS

Time and absolute frequency HRV indexes are reliable when testing healthy older women. Our results support the use of such indexes in gerontology research, to assess the effects of clinical or pharmacological interventions on the autonomic nervous system.

Does the level of chronic physical activity alter heart rate variability in healthy older women?

In the present study, we investigated the effects of three levels of chronic physical activity on HRV (heart rate variability) in healthy older women. ECG recordings were taken in three (low-, moderate- and high-) activity groups in supine position with free and with controlled breathing, and during orthostatic stress. Temporal and spectral HRV indices were obtained from the ECG signal processing. The main results showed that, in supine position with free and controlled breathing, the HF (high-frequency) spectral component (P<0.01) and the rMSSD (square root of the mean squared differences) between two adjacent RR intervals (P<0.05 and P<0.01 respectively) were elevated in the high-activity group compared with the low-activity group. No significant difference was observed between groups during the orthostatic test. Within groups, in the supine position, the change from free to controlled breathing produced a decrease in the LF (low-frequency) spectral component in all three groups (P<0.01). The change from supine to standing position produced a decrease in RR in all three groups (P<0.05 in low- and moderate-activity groups, and P<0.01 in high-activity group); the rMSSD and the HF spectral component decreased only in the high-activity group (P<0.01). In conclusion, this study performed on older women showed that parasympathetic indices of resting HRV were significantly elevated in a high physical activity group compared with in a low physical activity group. Furthermore, parasympathetic indices of HRV decreased during an orthostatic test only in the high-activity group. The influence of chronic moderate physical activity on HRV in older women was small in the present study.

Social status, life changes, housing conditions, health, functional abilities and life-style as risk factors for recurrent falls among the home-dwelling elderly

OBJECTIVE

To define the risk factors for recurrent falls in the home-dwelling elderly.

DESIGN

A prospective population-based study covering two years.

SETTING

Five rural municipalities around the city Oulu, northern Finland.

PARTICIPANTS

All home-dwelling elderly persons (N = 1,016) aged 70 years or older living in the municipalities.

OUTCOME MEASURES

The risk factors of recurrent falling by variables related to social status, life changes, housing conditions, health, functional abilities and life style, using cross-tabulations and multivariate analyses.

RESULTS

The recurrent fallers (at least two falls within 365 days after the examination day) consisted of 17 men (6% of the men) and 71 women (14%). Logistic regression analyses showed female sex, urinary urgency, frequent fear of falling, dizziness, a poor pulse rate rise 30 seconds after standing up and falling during the previous year to be risk factors for recurrent falls. After the variable representing previous falls had been removed from the analysis, urinary incontinence and a change in housing conditions during the past two years emerged and urinary urgency dropped out of the model.

CONCLUSIONS

Women particularly are a target group for the prevention of falls among the elderly. Urinary urgency and urinary incontinence, fear of falling, dizziness and changes in the housing conditions should be inquired about to identify the elderly at risk for falling and to take preventive interventions. In addition to testing blood pressure changes after standing up, the changes in pulse rate should be determined to identify and treat elderly people who have orthostatic conditions.