Farming habit, light exposure, physical activity, and depressive symptoms. A cross-sectional study of the HEIJO-KYO cohort.

Background: Bright light therapy and exercise interventions are effective methods for treating seasonal and non-seasonal affective disorders. Synchronization of internal circadian rhythms with the external environment by light therapy and physical activity may partly explain its efficacy. In the present study, we objectively measured daytime light exposure and physical activity in real life situations with elderly participants, and investigated the association between farming habits and the prevalence of depressive symptoms.

Objective sleep quality and night-time blood pressure in the general elderly population: a cross-sectional study of the HEIJO-KYO cohort.

Objectives: Night-time blood pressure (BP) - prognostically more important than circadian BP variability - has not been evaluated for quantitative associations with objective sleep quality in large populations.

Methods: The cross-sectional study measured actigraphic sleep parameters and night-time BP for two nights in 1101 elderly participants.

Results: Mean age of the participants was 71.