Lower dietary variety is associated with worse sleep quality in community-dwelling elderly Japanese women.

Background And Objectives: Sleep disturbance is a common health problem in the elderly population. We examined the association between dietary variety and subjective sleep quality in community-dwelling elderly Japanese women.

Methods And Study Design: This cross-sectional study recruited 160 community-dwelling elderly women aged ≥65 years. Subjective sleep quality and dietary variety were assessed by Pittsburgh Sleep Quality Index (PSQI) and dietary variety score (DVS), respectively. DVS was calculated from the eating frequency of 10 food groups. Sleep disturbance was defined as PSQI score of ≥6.

Results: The DVS in subjects with sleep disturbance was significantly lower than that of those without the disturbance (4.1±2.1 vs 5.3±2.1, p<0.01). In the multivariable regression model, the PSQI score was negatively correlated with the DVS score in age-adjusted model (standardized coefficient; -0.234, p<0.01). In the further adjusted model that included depression levels, the negative association between PSQI score and DVS score was retained (standardized coefficient; -0.211, p<0.05). Among 10 food groups comprising DVS, the eating frequency of soybean and soybean products was the determinant of sleep disturbance in the stepwise liner regression analysis. In the further model that contained DVS, DVS was the independent determinant of sleep disturbance, while the eating frequency of soybean and soybean products was excluded.

Conclusions: A worse sleep quality was associated with lower DVS in elderly Japanese women. Diet comprising various food groups was better for sleep quality than consuming only a particular food in the elderly.