Background and aims: Social jetlag is the discrepancy between our internal circadian clock and social clock and is a measure of circadian misalignment. Previous studies have shown that up to two thirds of the general population, aged 18-35y, suffer from social jetlag and its negative effects on metabolic parameters. As data from the general population over 40+y is missing, the aim of this study is to examine the prevalence of social jetlag and the association between social jetlag, the metabolic syndrome and type 2 diabetes in a 40+yearold, population-based cohort. Materials and methods: We used cross-sectional data from the New Hoorn study cohort, n=1734, 48% male, aged 45-73y. Social jetlag was measured using a questionnaire, calculated as the difference in mid-point sleep on week and weekend days and defined as 0-1h, 1-2h or >2h social jetlag.Metabolic syndrome was defined according to the Adult Treatment Panel III, including waist circumference, hypertension and levels of fasting plasma glucose, HDL-C and triglycerides. Pre-diabetes and Type 2 diabetes were defined according to the WHO guidelines; glucose levels > 6.1 mmol/l, HbA1c > 6% or use of diabetes medication. Results: In our 40+year-old population-based cohort, we observed that only 15% of the unemployed/retired participants had social jetlag of >1h and 65% of the employed participants. In the unemployed/retired group no significant associations were observed between social jetlag status, (parameters of) metabolic syndrome and (pre-)diabetes. However, in the employed group, logistic regression adjusted for age, sex and sleep duration showed a positive association between social jetlag, metabolic syndrome and (pre-)diabetes, with respectively OR 1.1 (95%CI 0.7-1.7) and OR 1.7 (95%CI 1.2-2.4) for participants with 1-2h social jetlag, as well as OR 2.1 (95%CI 1.2-3.6) and OR 2.3 (95%CI 1.5-3.8) for >2h of social jetlag, when compared to participants with 0-1h social jetlag. Conclusion: Social jetlag is associated with metabolic syndrome and (pre-)diabetes in working, 40+year-old participants.
Rutters, F., Koopman, A. D., Rauh, S. P., Van't Riet, E., Groeneveld, L., Van Der Linden, A., ... Nijpels, G. (2016). The association between social jetlag, the metabolic syndrome and type 2 diabetes in a 40+year old population: the New Hoorn study. Diabetologia, 59 (1 Supp, S183. https://doi.org/10.1007/s00125-016-4046-9