Chronotype and lipid metabolism in Arctic Sojourn Workers

ABSTRACT

This study relates answers to the Munich Chronotype Questionnaire (MCTQ) and Pittsburgh Sleep Quality Index (PSQI) from Arctic Sojourn Workers (ASW) of Yamburg Settlement, 68° Latitude North, 75° Longitude East (n = 180; mean age ± SD; range: 49.2 ± 7.8; 25–66 y; 45% women) to Arctic Sojourn Work Experience (ASWE), age and health status. Chronotype, Mid Sleep on Free Days sleep corrected (MSFsc) and sleep characteristics of ASW were compared to those of age-matched Tyumen Residents (TR, n = 270; mean age ± SD; range: 48.4 ± 8.4; 25–69 y; 48% women), 57° Latitude North, 65° Longitude East. ASW have earlier MSFsc than TR (70 min in men, p < 0.0001, and 45 min in women, p < 0.0001). Unlike TR, their MSFsc was not associated with age (r = 0.037; p = 0.627) and was linked to a larger Social Jet Lag (+21 min in men; p = 0.003, and +18 min in women; p = 0.003). These differences were not due to outdoor light exposure (OLE): OLE on work (OLEw) or free (OLEf) days was not significantly different between ASW and TR in men and was significantly less in ASW than in TR women (OLEw: −31 min; p < 0.001; OLEf: −24 min; p = 0.036). ASWE, but not age, was associated with compromised lipid metabolism in men. After accounting for multiple testing, when corrected for age and sex, higher triglycerides to high-density lipoprotein ratio, TG/HDL correlated with ASWE (r = 0.271, p < 0.05). In men, greater SJL was associated with lower HDL (r = -0.204; p = 0.043). Worse proxies of metabolic health were related to unfavorable components of the Pittsburgh Sleep Quality Index in ASW. Higher OLE on free days was associated with lower systolic (b = -0.210; p < 0.05) and diastolic (b = -0.240; p < 0.05) blood pressure.

KEYWORDS:

• Chronotype
• sleep
• MCTQ
• Arctic
• high latitudes
• Arctic Sojourn experience
• outdoor light
• health

Author contributions

Conceptualization, D.G., A.V. and D.W.; methodology, D.G., A.V., N.S., L.G., M.B., G.C., and D.W.; software, D.G., A.V., and G.C.; validation, A.V., N.S., and A.G.; formal analysis, A.V., N.S., D.G., D.W., and G.C.; investigation, D.G., A.V., N.S., L.G., B.S., and D.W.; resources, D.G., A.V., N.S., and L.G.; data curation, A.V., N.S., L.G. and D.G.; writing – original draft preparation, D.G.; writing – review and editing, A.V., L.G., D.W., G.C. and M.B.; visualization, D.G., A.V., D.W., and G.C.; supervision, L.G., N.S., A.V. and D.M.; project administration, V.N., T.M. and D.G.; funding acquisition, L.G., A.V., N.S., and D.G. All authors have read and agreed to the published version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data presented in this study are available on request from the corresponding author. The data are not publicly available due to privacy.

Informed consent statement

Written informed consent was obtained from all participants.

Institutional Review board statement

This cross-sectional study adhered to the tenets of the Declaration of Helsinki and was approved by the Ethics Committee of Tyumen Cardiology Research Center, Tomsk National Research Medical Center, Russian Academy of Science (Protocol No. 149, June 3, 2019). Written informed consent was obtained from all participants.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/07420528.2023.2256839.

Additional information

Funding

The study was supported by West-Siberian Science and Education Center, Government of Tyumen District, Decree of 20.11.2020, No. 928-rp. The funding organization had no role in the design or conduct of this research. The author(s) have no proprietary or commercial interest in any materials discussed in this article.