Association between Sleep Duration and Measurable Cardiometabolic Risk Factors in Healthy Korean Women: The Fourth and Fifth Korean National Health and Nutrition Examination Surveys (KNHANES IV and V).

Study Objectives. To examine the association between sleep duration and prevalence of metabolic syndrome (MetS) and its components in healthy Korean women. Design. Cross-sectional study, using the Fourth and Fifth Korean National Health and Nutrition Examination Surveys. Methods. Among 8505 women (25-70 years) from KNHANES IV and V, participants were classified into five sleep groups based on self-reported sleep duration. MetS and its components were defined using the criteria set forth in National Cholesterol Education Program-Adult Treatment Panel III. We used multivariate logistic regression analysis. Results. After adjusting for various confounders, shorter sleep duration (≤6 h) was found to have an association with low risk of reduced high-density lipoprotein cholesterol and increased triglycerides, whereas very long sleep duration was found to have high risk of increased triglycerides. However, abdominal obesity showed an opposite trend: short sleep duration was associated with higher risk of abdominal obesity than long sleep duration. Fasting glucose levels increased as sleep duration increased, but without significance. Moreover, blood pressure was not significantly associated with sleep duration. Consequently, MetS was less prevalent in those with short sleep duration. Conclusions. Sleep duration was positively associated with MetS, especially dyslipidemia and fasting hyperglycemia, but inversely associated with abdominal obesity.

Design and baseline characteristics of participants in the Enhancing Physical Activity and Reducing Obesity through Smartcare and Financial Incentives (EPAROSFI): A pilot randomized controlled trial.

BACKGROUND: An activity tracker combined with a smartphone application (smartcare) may help people track and receive feedback on their own activities. However, activity trackers themselves generally fail to drive long-term sustained engagement for a majority of users. One potential strategy for increasing the effectiveness of smartcare is through the use of incentives. The purpose of this pilot randomized trial is to test the feasibility of our intervention and to assess the extent to which smartcare with or without financial incentives can increase physical activity levels and reduce weight over a 12-week period. METHODS/DESIGN: This study employs a three-arm, open-label randomized controlled trial design: control (standard basic education), smartcare, and smartcare plus financial incentives. Male university students with body mass index ≥ 27 are enrolled. Our primary and secondary endpoints are the amount of weight loss and the level of physical activity respectively. The weight loss goal is 3% of baseline at week 4, 5% at week 8, and 7% at week 12. The daily physical activity goal was individualized according to the participants' weight. Process incentives are accumulated when participants met daily physical activity goals, and outcome incentives are provided when they met weight reduction goals. DISCUSSION: Given the global increase in physical inactivity and obesity, there is a growing need for effective, scalable, and affordable health promotion strategies. Our proof-of-concept study will provide the evidence for the combination of rising health promotion technology of activity trackers and smartphone applications with the modern concept of behavioral economics using financial incentives.