Does intentional weight loss improve daytime sleepiness? A systematic review and meta-analysis.

Obesity is associated with excessive daytime sleepiness, but its causality remains unclear. We aimed to assess the extent to which intentional weight loss affects daytime sleepiness. Electronic databases were searched through 24 October 2016. Studies involving overweight or obese adults, a weight loss intervention and repeated valid measures of daytime sleepiness were included in the review. Two independent reviewers extracted data on study characteristics, main outcome (change in daytime sleepiness score standardized by standard deviation of baseline sleepiness scores), potential mediators (e.g. amount of weight loss and change in apnoea-hypopnoea index) and other co-factors (e.g. baseline demographics). Forty-two studies were included in the review. Fifteen before-and-after studies on surgical weight loss interventions showed large improvements in daytime sleepiness, with a standardized effect size of -0.97 (95% confidence interval [CI] -1.21 to -0.72). Twenty-seven studies on non-surgical weight loss interventions showed small-to-moderate improvement in daytime sleepiness, with a standardized effect size of -0.40 (95%CI -0.52 to -0.27), with no difference between controlled and before-and-after studies. We found a nonlinear association between amount of weight loss and change in daytime sleepiness. This review suggests that weight loss interventions improve daytime sleepiness, with a clear dose-response relationship. This supports the previously hypothesized causal effect of obesity on daytime sleepiness. It is important to assess and manage daytime sleepiness in obese patients.

A systematic review of the effectiveness of whole-of-community interventions by socioeconomic position.

Whole-of-community (WOC) interventions have led to modest reductions in population weight gain. Whether they exhibit differential effectiveness by socioeconomic position (SEP) remains unknown. We aimed to summarize evidence of differential effectiveness of WOC interventions by SEP. Electronic databases and grey literature were searched to identify studies that evaluated the effectiveness of a WOC intervention on behavioural change measures, energy balance behaviours and/or anthropometric outcomes according to any measure of SEP. Interventions were assessed for the following characteristics: structural changes to the environment, number of settings the intervention acted in, presence of community engagement and whether equity was considered in its design. Ten studies were included. Nine reported a greater or equal effect among low SEP groups compared with high SEP groups. These studies commonly featured interventions that incorporated structural changes to the environment, acted across more than three settings and/or employed community engagement. Conclusions did not change when excluding low-quality studies (n = 4). WOC interventions represent an effective and equitable approach for the reduction of population weight. Structural components, a larger number of settings and community engagement were common in equitable WOC interventions and should be considered in the design of future WOC interventions.