DHEA and polycystic ovarian syndrome: Meta-analysis of case-control studies.

BACKGROUND: Polycystic ovarian syndrome is a heterogenous endocrine disorder characterized by irregular menstrual cycles, hirsuitism and polycystic ovaries. It is further complicated by metabolic syndrome, infertility and psychological stress. Although the etiopathogenesis is unclear, many studies have pointed out the role of stress in this syndrome. DHEA, being a stress marker is being used by scientists to compare the stress levels between polycystic ovarian cases and healthy controls. However, the results obtained from previous studies are equivocal. OBJECTIVE: To perform meta-analysis and find the association between stress and the syndrome. DATA SOURCES: Relevant data till January 2021 were retrieved from PubMed, Scopus, Embase and Web of Science using MeSH terms. STUDY SELECTION: Case-control studies having PCOS subjects as cases and healthy women as controls were selected provided; their basal DHEA levels were mentioned in the published articles. DATA EXTRACTION: Two authors independently extracted the articles and qualified the final studies. DATA SYNTHESI: Pooled meta-analysis was done using random effect model and showed level of DHEA statistically significant in PCOS compared to healthy controls (SMD = 1.15, 95% CI = 0.59-1.71).Heterogeneity was statistically significant as well (I2 = 95%). CONCLUSION: Thismeta-analysis on DHEA and PCOS has helped in generating evidence regarding the involvement of stress in the pathogenesis of PCOS.

How does cognitive function measured by the reaction time and critical flicker fusion frequency correlate with the academic performance of students?

BACKGROUND: The reaction time (RT) is "the time taken for the appearance of rapid voluntary reaction by an individual following a stimulus, either auditory or visual" and the Critical Flickering Fusion Frequency (CFFF) is "the rate at which successively presented light stimuli appear to be steady and continuous". RT and CFFF are commonly used for the assessment of cognitive functions that are known to influence academic performance. However, data about the exact correlation between these are scarce, particularly in India. This research aimed to study the association between visual RT (VRT), auditory RT (ART) and CFFF and their impact on the academic performance of undergraduate students. METHODS: This cross-sectional study was conducted on 700 students of Faculty of Medicine and Dentistry at a private medical university in South India, during the period from 2015 to 2017. The VRT, ART and CFFF were evaluated, and the best out of three subsequent attempts was recorded. The mean score (in percentage) of the three best marks out of the five internal assessments for the course during each academic year was considered for analysis. The association between the different cognitive tests and the average academic performance was analysed. RESULTS: Female students had faster VRT (n = 345, mean = 243.97, SD = 83.87) than male students (n = 273, mean = 274.86, SD = 96.97) (p = 0.001). VRT and ART had a moderate negative correlation with academic performance (for ART, r = - 0.42, p < 0.001; for VRT; r = - 0.40, p < 0.001). CFFF had a very weak positive correlation with academic performance (r = 0.19, p = 0.01). The only independent predictors of academic performance were RT and gender (Adjusted R2 = 0.11). CONCLUSION: Although there is a correlation between CFFF and cognitive function, our study showed only a weak correlation between CFFF and academic performance. Female students had faster RTs, and gender was an independent predictor of academic performance. Rather, students with faster RTs appear to have an advantage in academic performance.