Sleep Duration and Midday Napping with 5-Year Incidence and Reversion of Metabolic Syndrome in Middle-Aged and Older Chinese

Abstract

Study Objectives: Prospective evidence on the association of sleep duration and midday napping with metabolic syndrome (MetS) is limited. We aimed to examine the associations of sleep duration and midday napping with risk of incidence and reversion of MetS and its components among a middle-aged and older Chinese population. Methods: We included 14,399 subjects from the Dongfeng-Tongji (DFTJ) Cohort Study (2008)(2009)(2010)(2011)(2012)(2013) who were free of coronary heart disease, stroke, and cancer at baseline. Baseline data were obtained by questionnaires and health examinations. Odds ratios (ORs) and 95% confidence interval (CI) were derived from multivariate logistic regression models. Results: After controlling for potential covariates, longer sleep duration ( ≥ 9 h) was associated with a higher risk of MetS incidence (OR, 1.29; 95% CI, 1.08-1.55) and lower reversion of MetS (OR, 0.80; 95% CI, 0.66-0.96) compared with sleep duration of 7 to < 8 h; whereas shorter sleep duration (< 6 h) was not related to incidence or reversion of MetS. For midday napping, subjects with longer napping (≥ 90 min) was also associated with a higher risk of MetS incidence and a lower risk of MetS reversion compared with those with napping of 1 to < 30 min (OR, 1.48; 95% CI, 1.05-2.10 and OR, 0.70; 95% CI, 0.52-0.94, respectively). Significance for incidence or reversion of certain MetS components remained in shorter and longer sleepers but disappeared across napping categories. Conclusions: Both longer sleep duration and longer midday napping were potential risk factors for MetS incidence, and concurrently exert adverse effects on MetS reversion.

Mechanisms of Association of Sleep and Metabolic Syndrome

“…Waking up at 4:30 a.m. will let you experience 5 sleep-cycle and avoid unnecessary REM and its side effects. Also, it is important to limit the daytime napping to 30 minutes, to have enough exposure to natural sunshine and avoid stimulants such as coffee or intense physical activity before going to bed [111,131,132].…”

Changes in Subjective Motivation and Effort During Sleep Restriction Moderate Interindividual Differences in Attentional Performance in Healthy Young Men

“…The scorers adjudicated each recording for inter-rater agreement by verifying number of valid days, cut point, number of sleep intervals, and differences greater than 15 minutes in duration and wake after sleep onset for each sleep interval. Specifically, trained scorers determined sleep intervals using a decrease in activity levels and the aid of light levels for sleep onset and sleep offset, 53 and a nighttime sleep interval was split into two intervals (main sleep and nap) if there was an awakening ≥1 hour during this interval. A sleep actigraphy day was determined invalid and no sleep interval was set if there were ≥4 total hours of off-wrist time, except the first and last day (device should have been worn at least 2 hours before sleep onset on the first day), constant false activity due to battery failure, data unable to be recovered, or an off-wrist period of ≥60 minutes within 10 minutes of the scored beginning or end of the main sleep period for that day.…”

The Relationship Between Workplace Ostracism and Sleep Quality: A Mediated Moderation Model

“…Low sleep quality often gives rise to serious negative outcomes, including workplace accidents and death ( Hublin et al, 2007 ; Uehli et al, 2014 ), coronary heart disease ( Liu and Tanaka, 2002 ), mental disorders ( Breslau et al, 1996 ), absence from work due to illness ( Niedhammer et al, 2009 ), low workplace productivity ( Rosekind et al, 2010 ), and poor job performance ( Kessler et al, 2011 ). Although previous studies have explored sleep quality in the context of work stressors and the development of health impairments, the majority of them have focused on shift-work (e.g., Sallinen and Kecklund, 2010 ; Lin et al, 2014 ), workload ( Åkerstedt et al, 2002 ; Dorrian et al, 2011 ) and work-family conflict/balance ( Berkman et al, 2010 ; Lallukka et al, 2014 ; Buxton et al, 2016 ). Other important stressors, such as stressful interpersonal relationships at work, have been neglected ( Pereira et al, 2013 ).…”