Preparation and Processing of a Large-Scale Heart Rate Variability and Lifestyle Assessment Results Data

Abstract

In this thesis, a database is constructed from Lifestyle Assessment results conducted by Firstbeat Technologies Ltd in years 2000‒2013 for about 20 000 Finns. The Lifestyle Assessment is a three-day heart rate variability (HRV) measurement which is used for estimating the physiological state of the body. HRV decreases during stress and HRV increases during recovery. Moreover, physical activity affects heart rate and HRV. Thus, the Lifestyle Assessment Results are estimates about the physiological states of the body, such as stress, recovery and physical activity, and their amounts. The database includes background parameters, for example subject’s gender, age and level of physical activity assessed by activity class (AC), the events of measurement days, for example the working hours, and the Lifestyle Assessment Results presented as selected time dependent variables whose typical resolution is 10 minutes. The time dependent variables are presented by measurement days describing the circadian rhythm of the subject. The time dependent variables enable assessing the results separately for work or sleep, for instance. Moreover, the circadian rhythm of the physiological states can be assessed with this database’s results. The graphical user interface, implemented as a part of this thesis work, can be used for simple analysis of the database’s results. In this thesis, the results of the database are analyzed using statistical methods. The results are studied between the genders, the age groups, the body-mass-index (BMI) groups and the AC groups. Some results are studied also between working days and days off. The statistically significant results show that HRV, quality of sleep and the amounts of stress and energy expenditure decrease with age. In both genders the high AC and low BMI are related to good quality of sleep, low amount of stress and high EE. In men the high AC and low BMI are also related to increase in HRV. In men the amount of stress is greater than in women but the quality of sleep is better in men than in women. Moreover, men have greater energy expenditure and more health promoting physical activity than women. The physical activity was found out to be greater during work days than days off in both men and women. The advantages of this database are its big size and the variety of information the database includes about the subjects’ physiological states and parameters. In future, variety of research questions can be studied using this database