The mediating effect of sleep duration on metabolic syndrome severity in adults: a structural equation modeling approach.

BACKGROUND: Metabolic syndrome (MetS) is associated to sleep duration. It is crucial to identify factors that disrupt sleep regulation. The study aimed to assess the indirect effect of risk factors related to MetS severity through sleep duration by utilizing a structural equation model (SEM). METHODS: The study involving 3,935 adults from the baseline data of the Ravansar Non-Communicable Disease (RaNCD) cohort study. MetS severity scores were the outcome variables. SEM was employed to explore the relationships, utilizing IBM SPSS and AMOS version 23. RESULTS: The mean MetS severity score was higher in women compared to men (0.25 vs. 0.16, P = 0.003). In men, socioeconomic status (SES) has a positive direct effect (ß = 0.048) and a negative indirect effect (ß=-0.006) on MetS severity. Increased physical activity is directly (ß=-0.036) and indirectly (ß=-0.093) associated with reducing MetS severity. Nap duration is directly linked to an increase (ß = 0.072) but has an indirect effect (ß=-0.008) in decreasing MetS severity. In women, SES has a direct (ß=-0.020) and indirect (ß=-0.001) inverse relationship with MetS severity. Increased physical activity is directly (ß=-0.048) and indirectly (ß=-0.036) associated with decreasing MetS severity in women. Nap duration is directly associated with an increase in MetS severity (ß=-0.018) but indirectly contributes to its reduction (ß=-0.002). Sleep duration not only directly affects MetS severity but is also influenced by age, SES, physical activity, obesity and nap duration. CONCLUSION: Physical activity, SES, and nap duration directly and indirectly effect the MetS severity. Sleep duration was recognized as a mediating variable that supports the indirect effects.

Global prevalence of hepatitis C in general population: A systematic review and meta-analysis.

BACKGROUND: According to published reports from the World Health Organization, it is estimated that more than 3% of the world's population is infected with HCV. Given the impact of various factors on the prevalence of HCV in the world's population and the lack of general statistics around the world, this study aims to review the studies conducted in this field and statistical analysis of the results of general statistical studies on the prevalence of HCV in the world population. METHODS: In this study, systematic review and meta-analysis of information of the studies related to the prevalence of HCV in the world using keywords including: Prevalence, HCV, Hepatitis C, Healthy Population, Healthy subjects, and General Population in SID, MagIran, IranMedex, IranDoc, ScienceDirect, Embase, Scopus, PubMed, Web of Science (WoS) databases and Google Scholar search engine were extracted without time limit until April 2020. In order to perform the analysis of qualified studies, the model of random effects was used, and the inconsistency of studies with I2 index was investigated. Data analysis was performed with Comprehensive Meta-Analysis (Version 2). RESULTS: In a study of 98 studies with a total sample size of 236,964 people in the world, the overall prevalence of HCV was 1.8% (95% CI: 1.4%-2.3%). Also, according to the subgroup analysis in different continents; the highest prevalence of HCV in the African continent was 7.1% (95% CI: 4.4-11.5%). CONCLUSION: The results of this study show that the prevalence of hepatitis C in the world's population, especially in Africa, is almost high. Therefore, the officials of the World Health Organization should design measures to prevent the spread of this infection.

Validation of the Persian version of the Pittsburgh Sleep Quality Index in elderly population.

OBJECTIVE: The purpose of this study is to determine the validity and reliability of the Persian version of the Pittsburgh Sleep Quality Index in the elderly population. MATERIAL AND METHODS: A methodological study was conducted as a confirmatory factor analysis. Totally, 598 elderly people were selected through cluster sampling. In addition to analyzing the three-factor structure of PSQI, internal consistency reliability, structural validity, and its concurrent validity were examined. The structural credibility of PSQI was examined using other similar tools such as Sleep Health, Epworth Sleepiness, Insomnia Severity, Global Sleep Assessment, and Berlin indices. Finally, the concurrent criterion validity of PSQI was evaluated through multivariable regression analysis and all statistical analyzes were performed using SPSS and AMOS software. RESULTS: The reliability of the test according to Cronbach's alpha was 0.81. Confirmatory factor analysis indicators supported goodness of fit of the structural equation model. The confirmatory factor analysis showed that the ratio of χ2/ DF was 2.66 for the three-factor structure of PSQI and the goodness of fit indices of model were acceptable for this structural model (RMSEA=0.053, CFI=0.98, TLI=0.96, NFI=0.97, GFI=0.99). In addition, the internal consistency of the PSQI was 0.81 and the scales correlation score ranged from 0.48 to 0.71. CONCLUSION: The results indicated that Persian version of Pittsburgh Sleep Quality Index had the required validity and reliability for the elderly population of Iran and it can be used as a useful tool by other studies.