The importance of cardiorespiratory fitness and sleep duration in early CVD prevention. BMI, resting heart rate and questions about sleep patterns are suggested in risk assessment of young adults, 18-25 years.

Abstract

Background: Physical activity (PA) and sleep habits are lifestyle factors with potential to prevent cardiovascular disease (CVD). CVD is the leading cause of death worldwide, it is therefore important to establish a healthy lifestyle at young age. In the Lifestyle, biomarkers and atherosclerosis (LBA) study we have examined 834 healthy non-smoking adults, 18-25 years. The general aim of the LBA study was to evaluate the effect of lifestyle on biomarkers known to influence CVD risk in young adults. The specific aim of the present study was to evaluate sleep habits, study the effect of sleep habits on CVD risk, and compare the influence of sleep habits with other lifestyle factors, regarding CVD risk. Additional aim, in the preventive work against CVD, was to find easy and reliable biomarkers to detect young adults with increased risk to develop CVD.Methods: The participants have previously been examined for traditional CVD risk biomarkers and lifestyle factors. The participants filled in a validated computerized questionnaire about their general physical and mental health. The questionnaire included questions on sleep duration and experienced quality of sleep.Results: In total 27.1% of the young adult study participants (18-25 years) answered that they had difficulties to fall asleep or experiences anxious sleep with several awakenings per night. The experienced anxious sleep was not related to higher CVD risk score, but sleep quality and sleep duration was correlated. Shorter sleep duration was significantly associated to higher body mass index (BMI), body fat (%), homeostasis model assessment of insulin resistance (HOMA-IR) and CVD risk. The modifiable lifestyle factor with the highest odds ratio (OR) for CVD risk was cardiorespiratory fitness (CRF). Sleep duration was the second most influential lifestyle factor, more important than PA and food habits. Correlations between CRF and heart rate (HR) (P<0.01) and between HOMA-IR and BMI (P<0.01) was observed, indicating that BMI and resting HR in combination with questions about sleep patterns are easy and reliable biomarkers to detect young adults with increased risk to develop CVD. Conclusion: Decreased sleep duration in combination with decreased CRF, in young adults, is a serious health issue.