@article{Wyse2018,
title = {Population-Level Seasonality in Cardiovascular Mortality, Blood Pressure, BMI and Inflammatory Cells in UK Biobank},
author = {Cathy A. Wyse and Carlos A. Celis Morales and Joey Ward and Donald Lyall and Daniel J. Smith and Daniel Mackay and Annie M. Curtis and Mark E.S. Bailey and Stephany Biello and Jason M.R. Gill and J.P. Pell},
url = {https://www.tandfonline.com/doi/abs/10.1080/07853890.2018.1472389},
year = {2018},
date = {2018-05-03},
journal = {Annals of Medicine},
abstract = {Introduction The risk of mortality from cardiovascular disease (CVD) is higher in wintertime throughout the world, but it is not known if this reflects annual changes in diet or lifestyle, or an endogenous photoperiodic mechanism that is sensitive to changes in daylength.

Methods Phenotypic data on cardiometabolic and lifestyle factors were collected throughout a 4 year time period from 502,642 middle-aged participants in UK Biobank. To assess the impact of seasonal environmental changes on cardiovascular risk factors, we linked these data to the outdoor temperature and day length at the time of assessment. Self-reported information on physical activity, diet and disease status were used to adjust for confounding factors related to health and lifestyle.

Results Mortality related to CVD was higher in winter, as were risk factors for this condition including blood pressure, markers of inflammation and BMI. These seasonal rhythms were significantly related to day length after adjustment for other factors that might affect seasonality including physical activity, diet and outdoor temperature.

Conclusions The risk of CVD may be modulated by day length at temperate latitudes, and the implications of seasonality should be considered in all studies of human cardiometabolic health.},
keywords = {blood pressure, cardiovascular, featured, seasonality},
pubstate = {published},
tppubtype = {article}
}

@article{Lyall2018,
title = {Seasonality of depressive symptoms in women but not in men: a cross-sectional study in the UK Biobank cohort},
author = { Laura M. Lyall and Cathy A. Wyse and Carlos A. Celis Morales and Donald M. Lyall and Breda Cullen and Daniel Mackay and Joey Ward and and Nicholas Graham and Rona J. Strawbridge and Jason M.R. Gill and Amy Ferguson and Mark E.S. Bailey and Jill P. Pell and Annie M. Curtis and Daniel J. Smith},
url = {http://www.jad-journal.com/article/S0165-0327(17)31856-6/fulltext},
year = {2018},
date = {2018-03-01},
journal = {Journal of affective disorders},
abstract = {Background

We examined whether seasonal variations in depressive symptoms occurred independently of demographic and lifestyle factors, and were related to change in day length and/or outdoor temperature.

Methods

In a cross-sectional analysis of >150,000 participants of the UK Biobank cohort, we used the cosinor method to assess evidence of seasonality of a total depressive symptoms score and of low mood, anhedonia, tenseness and tiredness scores in women and men. Associations of depressive symptoms with day length and mean outdoor temperature were then examined.

Results

Seasonality of total depressive symptom scores, anhedonia and tiredness scores was observed in women but not men, with peaks in winter. In women, increased day length was associated with reduced low mood and anhedonia scores, independent of demographic and lifestyle factors. For women, longer day length was associated with increased tiredness. Associations with day length were not independent of the average outdoor temperature preceding assessment.

Limitations

This was a cross-sectional investigation – longitudinal studies of within-subject seasonal variation in mood are necessary. Outcome measures relied on self-report and measured only a subset of depressive symptoms.

Conclusion

This large, population-based study provides evidence of seasonal variation in depressive symptoms in women. Shorter days were associated with increased feelings of low mood and anhedonia in women. Clinicians should be aware of these population-level sex differences in seasonal mood variations in order to aid recognition and treatment of depression and subclinical depressive symptoms.},
keywords = {6553, depression, men, seasonality, Women},
pubstate = {published},
tppubtype = {article}
}