Mediation effect of JAK2 methylation on the association between sitting time and abdominal obesity in rural adults.

BACKGROUND: Sitting time may affect health by altering the methylation of certain genes. This research aimed to estimate the association of sitting time with abdominal obesity and the role of Janus kinase 2 (JAK2) methylation in the association among rural adults. METHODS: A total of 1062 rural adults from the Henan Rural Cohort Study were included. Whole blood was used to extract genomic DNA. JAK2 DNA methylation level was assessed by MethylTargetTM. The logistic regression model was utilized to assess the association of sitting time with abdominal obesity, and the possible effect of JAK2 DNA methylation on the association were conducted by using mediation analyses. RESULTS: Average time of sitting of participants was 7.28 ± 3.37 h/d. For per 1 h increment in sitting time, the odd ratio (OR) and 95% confidence interval (CI) of abdominal obesity was 1.153 (1.095, 1.214) after controlling potential risk factors. Simultaneously, the methylation levels of Chr9: 4985407 site and Chr9: 4985238-4985455 region were negatively correlated with abdominal obesity (OR: 0.549, 95% CI: 0.394, 0.765; OR: 0.189, 95% CI: 0.056, 0.640, respectively). Moreover, Chr9: 4985407 site and Chr9: 4985238-4985455 region methylation levels mediated the association of sitting time with abdominal obesity, and the indirect effects account for 6.78% and 4.24%, respectively. CONCLUSIONS: Longer sitting time was positively correlated with abdominal obesity in the rural population, and methylation level of JAK2 may be an underlying mediation of the effect.

The Effect of Kitchen Ventilation Modification on Independent and Combined Associations of Cooking Fuel Type and Cooking Duration with Suicidal Ideation: A Cross-Sectional Study.

Although household air pollution (HAP) is associated with an increased risk of mental disorders, evidence remains scarce for the relationship between HAP and suicidal ideation. A total of 21,381 qualified participants were enrolled on the Henan Rural Cohort Study. HAP information including cooking fuel type, cooking duration and kitchen ventilation was collected by questionnaires. Suicidal ideation was evaluated by item nine of the Patient Health Questionnaire-9 (PHQ-9). Independent and combined associations of cooking fuel type and cooking duration with suicidal ideation were explored by logistic regression models. Analyses were conducted in different kitchen ventilation groups to detect the potential effect modification. The adjusted odds ratio (OR) and 95% confidence interval (95% CI) of solid fuel users versus clean fuel users for suicidal ideation was 1.37 (1.16, 1.62), and the risk of suicidal ideation increased by 15% (95% CI: 5%, 26%) for each additional hour of the cooking duration. Participants cooking with solid fuel for long durations were related to the highest risk of suicidal ideation (OR (95% CI): 1.51 (1.22, 1.87)). However, all these associations were not observed in those cooking with mechanical ventilation. Mechanical ventilation ameliorated relationships between solid fuel use and long-duration cooking with suicidal ideation.

Physical activity attenuates the association between household air pollution and health-related quality of life in Chinese rural population: the Henan Rural Cohort Study.

BACKGROUND AND PURPOSE: Limited research focused on the association between household air pollution (HAP) and health-related quality of life (HRQoL). This study aimed to investigate the association of HAP with HRQoL and the effect modification of physical activity. METHOD: A total of 16,761 eligible participants were derived from the Henan Rural Cohort Study. Based on structured questionnaires, HAP was assessed by fuel type, cooking duration and kitchen ventilation; HRQoL was measured with utility index and VAS score from the European Quality of Life Five Dimension Five Level Scale (EQ-5D-5L); physical activity was assessed by the International Physical Activity Questionnaire. Generalized linear models and tobit regression models were utilized to explore the relationship of HAP with HRQoL. Further sensitivity analyses were conducted using structural equation models. RESULTS: Compared with those who cooked with clean fuels, short-duration, or good kitchen ventilation, participants who cooked with solid fuels, long-duration, and poor ventilation had lower utility index and VAS score (All P < 0.001). The decrease in utility index for solid fuel users vs. clean fuel users were 0.06 [95%confidence interval (CI) 003, 0.08], 0.03 (95%CI 0.01, 0.04) and 0.02 (95%CI 0.01, 0.04) in low, moderate and high physical activity group, respectively, which decreased with physical activity levels (Pfor interaction < 0.05). Similar results were observed in associations of kitchen ventilation with utility index and VAS score. CONCLUSION: HAP negatively associated with HRQoL in rural population, and potential intervention aimed at maintaining adequate physical activity. TRAIL REGISTRATION: The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 06 July, 2015. http://www.chictr.org.cn/showproj.aspx?proj=11375 .