Are sleep time and quality associated with inflammation in children and adolescents? A systematic review.

Sleep restriction in children can trigger the development of problems such as impaired cognition, behavioral problems, cardiovascular problems, and obesity. In addition, the inflammatory profile of children can also be influenced by sleep restriction. The aimed to review and analyze the association between time and sleep quality with inflammatory biomarkers in children and adolescents. Three electronic databases (MEDLINE, Web of Science and Scopus) were searched from August 30, 2022. The search strategy used the following descriptors: children and adolescents; sleep, and inflammatory profile. This review protocol is registered in the PROSPERO database (CRD42020188969). We obtained 2.724 results of articles with potentially relevant titles. Sixteen percent of the articles were excluded because they were duplicates, 84.3% were excluded after reading the title, and 0.9% were studied from systematic reviews or textbooks (0.9%). Accelerometers are the most commonly used method for the objective measurement of sleep time, while the PSQI questionnaire is the most commonly used subjective method to measure sleep quality. The results indicated an inconsistent association between sleep time and CRP in the literature. Sixty percent of studies used the Pittsburgh Sleep Quality Index (PSQI) for subjective assessment of sleep quality and possible sleep disorders. However, only one retrieved study showed significant association between sleep quality and CRP. Thus, sleep time does not present significant association with inflammatory biomarkers; whereas, poor sleep quality shows positive association with CRP with a lower magnitude.

Association Between Sleep Time and Pro- and Anti-Inflammatory Biomarkers Is Mediated by Abdominal Obesity Among Adolescents.

OBJECTIVES: Movement behaviors and abdominal obesity are associated with higher inflammatory biomarkers. However, the role of waist circumference as a mediating factor is still unknown. Thus, our aims were to (1) test the associations between 24-hour movement behavior variables (physical activity, sedentary behavior, and sleep), abdominal obesity, and pro- and anti-inflammatory biomarkers; and (2) investigate whether abdominal obesity had a mediating effect between the investigated associations. METHODS: This multicenter cross-sectional study included 3591 adolescents (aged 12-17 y) from 4 Brazilian cities. Waist circumference (in centimeters; at half the distance between the iliac crest and at the lower costal margin), 24-hour movement behaviors (validated questionnaire), high-sensitive C-reactive protein, and adiponectin (serum plasma) were evaluated. We used multiple mediation regression models (95% confidence interval) to determine if waist circumference mediated the association between 24-hour movement behaviors and pro- and anti-inflammatory biomarkers. RESULTS: The results revealed that screen time and moderate to vigorous physical activity were not associated with pro- or anti-inflammatory biomarkers. However, sleep duration (in hours per day) was negatively associated with pro- (C-reactive protein, ß = -0.08; 95% confidence interval, -0.38 to -0.02) and anti- (adiponectin, ß = -0.31; 95% confidence interval, -2.13 to -0.12) inflammatory biomarkers. Our results also showed that waist circumference mediated the association between sleep duration and high-sensitive C-reactive protein (2.7%), and adiponectin (2.8%). CONCLUSION: Sleep duration was inversely associated with pro- and anti-inflammatory biomarkers, and these relations were mediated by abdominal obesity. Therefore, adolescents having healthy sleep can have implications for reducing waist circumference and inflammatory indicators.