Effect of smoking on Brain-Derived Neurotrophic Factor (BDNF) blood levels: A systematic review and meta-analysis.

BACKGROUND: Brain-Derived Neurotrophic Factor (BDNF) is a neurotrophin that plays a crucial role in neuronal survival and plasticity. Previous studies have suggested that smoking may influence BDNF levels, but the findings have been inconsistent. METHODS: A comprehensive search of electronic databases was conducted to identify relevant studies. Inclusion criteria were applied to select studies that investigated the relationship between smoking and blood levels of BDNF. A random-effects model was used to estimate the overall effect size. RESULTS: A total of 23 studies were included. The meta-analysis revealed a significant association between smoking and increased blood levels of BDNF (standardized mean difference [SMD] = -0.38, 95 % confidence interval [CI] 0.15 to 0.62, p = 0.002). Subgroup analyses based on BDNF source showed a significant increase in plasma-derived BDNF levels (SMD = 1.02, 95 % CI 0.50 to 1.53, p = 0.0001), while no significant difference was observed in serum-derived BDNF levels (SMD = 0.02, 95 % CI -0.19 to 0.22, p = 0.87). The pooled analysis revealed a non-significant difference in blood levels of BDNF between former smokers and non-smokers (random-effects model, SMD = 0.21, 95 % CI -0.04 to 0.46, p = 0.1). CONCLUSION: Smokers exhibited significantly higher plasma levels of BDNF compared to non-smokers. Further research is needed to elucidate the underlying mechanisms and explore the potential therapeutic implications of targeting BDNF in smoking.

Investigating oral health among US adults with sleep disorder: a cross-sectional study.

BACKGROUND: This study aims to investigate the relationship between sleep disorders and oral health outcomes among a representative sample of the United States population. METHODS: The study sample comprised 6,161 participants who participated in the NHANES 2017-2018, representing a population of 255,939,599. Oral health outcomes were assessed using the Oral Health Questionnaire (OHQ), covering dental pain, periodontal disease, bone loss, emotional perceptions of oral health, and impact on daily life. Sleep disorders were evaluated using questions related to sleep trouble and daytime sleepiness. RESULTS: Analysis of the NHANES 2017-2018 dataset, revealed notable associations between sleep disorders and oral health outcomes. Individuals with sleep disorders were more likely to report dental pain (19.79% vs. 11.8%), periodontal issues (19.5% vs. 12.25%), and feeling bad or embarrassed about their oral health (21% vs. 12%), compared to those without sleep disorders. Difficulty due to oral health issues was also more prevalent among participants with sleep disorders (32.6% vs. 12.9%). Adjusted models demonstrated that individuals with sleep disorders had a significantly higher likelihood of experiencing oral aches [adjusted odds ratio (aOR) = 1.58 (1.22-2.22)], reporting negative emotions about oral health [aOR = 1.59 (1.06-2.37)], and encountering challenges in school or job performance [aOR = 2.27 (1.47-3.51)], compared to individuals without sleep disorders (refer to Table 3). Other significant covariates affecting oral health outcomes included smoking, income, and education level. CONCLUSIONS: This study reveals a compelling association between sleep disorders and adverse oral health outcomes in the U.S.