Associations Between Sleep Satisfaction and Physical Activity Rates Among Secondary Medical Areas in Japan: An Ecological Study.

Objective Insomnia is a common problem in Japan and other countries, indicating the need for effective strategies to improve sleep quality. Although the associations between specific exercises, physical activity, and sleep satisfaction have been clarified, few reports have examined the associations with normal lifestyle habits. This study aims to clarify the associations between sleep satisfaction and physical activity (i.e., regular exercise, daily living activities, and fast walking speed) at secondary medical area levels in Japan. Methodology This ecological study utilizes the 2021 National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) open data managed by the Japanese Ministry of Health, Labour, and Welfare across 335 Japanese secondary medical areas. The data were analyzed using the multiple regression analysis forced entry method, in which the percentages of sleep satisfaction and physical activity were the objective and explanatory variables, respectively. Results Data from 335 medical areas and a total of 30.39 million individuals, comprising 16.49 million males and 13.90 million females, were analyzed. Among the 335 medical areas, the mean sleep satisfaction percentages were 70.8% for males and 67.0% for females. The mean percentages for three physical activities were (1) regular exercise for 31.8% of males and 25.3% of females, (2) daily living activities for 43.2% of males and 43.7% of females, and (3) fast walking speed for 46.8% of males and 43.4% for females. The sleep satisfaction percentage was negatively associated with regular exercise in males aged 70-74 (B = -0.10, p = 0.029). Significant positive associations were found for daily living activities in males aged 40-49 (B = 0.24, p < 0.001), 50-59 (B = 0.14, p = 0.023), and 60-69 (B = 0.09, p = 0.024) and in females aged 40-49 (B = 0.12, p = 0.001) and 50-59 (B = 0.08, p = 0.036). Positive associations were also found for fast waking speed in males aged 60-69 years (B = 0.12, p = 0.029) and 70-74 (B = 0.24, p < 0.001) and in females aged 70-74 (B = 0.16, p = 0.001). Conclusions This study revealed that the factors positively associated with sleep satisfaction include daily living activities and walking speed, which vary by gender and age group. Tailored daily lifestyle health guidance is needed to improve sleep quality across various demographics.