Dietary patterns associated with the incidence of hypertension among adult Japanese males: application of machine learning to a cohort study.

PURPOSE: The previous studies that examined the effectiveness of unsupervised machine learning methods versus traditional methods in assessing dietary patterns and their association with incident hypertension showed contradictory results. Consequently, our aim is to explore the correlation between the incidence of hypertension and overall dietary patterns that were extracted using unsupervised machine learning techniques. METHODS: Data were obtained from Japanese male participants enrolled in a prospective cohort study between August 2008 and August 2010. A final dataset of 447 male participants was used for analysis. Dimension reduction using uniform manifold approximation and projection (UMAP) and subsequent K-means clustering was used to derive dietary patterns. In addition, multivariable logistic regression was used to evaluate the association between dietary patterns and the incidence of hypertension. RESULTS: We identified four dietary patterns: 'Low-protein/fiber High-sugar,' 'Dairy/vegetable-based,' 'Meat-based,' and 'Seafood and Alcohol.' Compared with 'Seafood and Alcohol' as a reference, the protective dietary patterns for hypertension were 'Dairy/vegetable-based' (OR 0.39, 95% CI 0.19-0.80, P = 0.013) and the 'Meat-based' (OR 0.37, 95% CI 0.16-0.86, P = 0.022) after adjusting for potential confounding factors, including age, body mass index, smoking, education, physical activity, dyslipidemia, and diabetes. An age-matched sensitivity analysis confirmed this finding. CONCLUSION: This study finds that relative to the 'Seafood and Alcohol' pattern, the 'Dairy/vegetable-based' and 'Meat-based' dietary patterns are associated with a lower risk of hypertension among men.

Impact of carbon dioxide exposures on sleep latency among healthy volunteers: A randomized order, paired crossover study, evidence from the multiple sleep latency test.

BACKGROUND: Daytime sleepiness affects work efficiency, occupational safety, and public health. Although previous studies have reported an association between environmental carbon dioxide (eCO2) and daytime sleepiness, it has been challenging to draw a firm conclusion due to the lack of standardized sampling and profiling protocols. OBJECTIVE: We examined the effect of pure CO2 exposure at 5000 (ppm, parts per million) on daytime sleepiness. METHODS: Eleven healthy participants (males of 24 ± 3 years, mean ± SD) completed a four-nap multiple sleep latency test (MSLT) protocol in the environmentally controlled chamber under two conditions: the CO2 condition (4851 ± 229 ppm) and the Control condition (1102 ± 204 ppm). The subjective sleepiness level and cognitive performances were also evaluated using the Stanford Sleepiness Scale (SSS) questionnaire, Psychomotor Vigilance Test (PVT), and Stroop test after each nap session. RESULTS: A significant reduction in sleep latency was observed in the CO2 exposure condition (Control vs. CO2 = 13.1 ± 3.3 min vs. 9.7 ± 3.2 min). The subjective sleepiness scores were also significantly higher in the CO2 exposure condition than in the Control condition (Control vs. CO2 = 2.7 ± 0.5 vs. 4.7 ± 0.8). Cognitive responses after naps showed no significant difference across conditions. CONCLUSION: This study revealed that exposure to environmental CO2 at a concentration as high as the upper safety limit at work sites significantly shortened the sleep latency and enhanced subjective sleepiness during naps in the MSLT without affecting cognitive responses after each exposure. Our results demonstrated that exposure to high environmental CO2 induces daytime sleepiness that potentially compromises work efficiency and safety.

Association between maternal physical activity from pre-pregnancy to child-rearing and their children's physical activity in early childhood among Japanese.

INTRODUCTION: This study aimed to determine the association between cumulative maternal physical activity level and their children's physical activity in early childhood. We also compared the influence of each maternal physical activity on children's physical activity in early childhood. METHODS: We analyzed the data from 1,067 Japanese mother-child pairs. Maternal physical activity was assessed using the International Physical Activity Questionnaire. Cumulative physical activity level in mothers was computed based on the categories (low, moderate, and high) of physical activity from 5 time points (pre-pregnancy, during pregnancy, 1.5, 3.5, and 5.5 years postpartum). Children's physical activity level was measured at age 5.5 years using the WHO Health Behaviour School-aged Children questionnaire and defined as engaging in physical activity for at least 60 minutes per day for more than 5 days. Logistic regression analysis was used to determine the association between maternal and children's physical activity levels. RESULTS: The results showed the positive association between cumulative maternal physical activity and children's physical activity level (P for trend < 0.001). Furthermore, maternal physical activity during pregnancy (P for trend = 0.031) and 5.5 years postpartum (P for trend < 0.001) was positively associated with children's physical activity. CONCLUSION: A positive association was observed between the cumulative maternal physical activity level and the physical activity level of their children at 5.5 years of age. Furthermore, maternal physical activity during pregnancy and at 5.5 years postpartum were positively associated with the level of children's physical activity.

Twenty-four-hour physical activity patterns associated with depressive symptoms: a cross-sectional study using big data-machine learning approach.

BACKGROUND: Depression is a global burden with profound personal and economic consequences. Previous studies have reported that the amount of physical activity is associated with depression. However, the relationship between the temporal patterns of physical activity and depressive symptoms is poorly understood. In this exploratory study, we hypothesize that a particular temporal pattern of daily physical activity could be associated with depressive symptoms and might be a better marker than the total amount of physical activity. METHODS: To address the hypothesis, we investigated the association between depressive symptoms and daily dominant activity behaviors based on 24-h temporal patterns of physical activity. We conducted a cross-sectional study on NHANES 2011-2012 data collected from the noninstitutionalized civilian resident population of the United States. The number of participants that had the whole set of physical activity data collected by the accelerometer is 6613. Among 6613 participants, 4242 participants had complete demography and Patient Health Questionnaire-9 (PHQ-9) questionnaire, a tool to quantify depressive symptoms. The association between activity-count behaviors and depressive symptoms was analyzed using multivariable logistic regression to adjust for confounding factors in sequential models. RESULTS: We identified four physical activity-count behaviors based on five physical activity-counting patterns classified by unsupervised machine learning. Regarding PHQ-9 scores, we found that evening dominant behavior was positively associated with depressive symptoms compared to morning dominant behavior as the control group. CONCLUSIONS: Our results might contribute to monitoring and identifying individuals with latent depressive symptoms, emphasizing the importance of nuanced activity patterns and their probability of assessing depressive symptoms effectively.

Association of physiological factors with grip and leg extension strength: tohoku medical megabank community-based cohort study.

BACKGROUND: Upper and lower extremity muscle strength can be used to predict health outcomes. However, the difference between the relation of upper extremity muscle and of lower extremity muscle with physiological factors is unclear. This study aimed to evaluate the association between physiological data and muscle strength, measured using grip and leg extension strength, among Japanese adults. METHODS: We conducted a cross-sectional study of 2,861 men and 6,717 women aged ≥ 20 years living in Miyagi Prefecture, Japan. Grip strength was measured using a dynamometer. Leg extension strength was measured using a hydraulic isokinetic leg press machine. Anthropometry and physiological data, including blood pressure, calcaneal ultrasound bone status, pulmonary function, carotid echography, and blood information, were assessed. We used a general linear model adjusted for age, body composition, and smoking status to evaluate the association between muscle strength and physiological factors. RESULTS: Grip and leg extension strength were positively associated with bone area ratio, vital capacity, forced vital capacity, forced expiratory volume in one second, and estimated glomerular filtration rate, and negatively associated with waist circumference and percentage body fat mass in both the sexes. Diastolic blood pressure was positively associated with grip strength in both the sexes and leg extension strength in men, but not women. High-density lipoprotein cholesterol and red blood cell counts were positively associated with grip and leg extension strength in women, but not men. In both the sexes, pulse rate, total cholesterol, and uric acid were consistently associated with only leg extension strength, but not grip strength. In women, glycated hemoglobin demonstrated negative and positive associations with grip and leg extension strength, respectively. CONCLUSIONS: Grip and leg extension strength demonstrated similar associations with anthropometry, pulmonary function, and estimated glomerular filtration rate, but the associations with the other factors were not always consistent.