Poor Sleep Quality as a Risk Factor for Constipation Among Community-Dwelling Older Adults in Japan

Background Older adults commonly experience both sleep disturbances and constipation. Pathophysiological mechanisms such as inhibition of colonic peristalsis due to sympathetic activation associated with sleep disturbances have been postulated. Here, we aimed to assess the temporal association between the degree of sleep quality and the incidence of constipation. Methods We conducted a prospective cohort study of independent community-dwelling older adults aged ≥75 years (the Sukagawa Study). Using a self-administered questionnaire inquiring about awareness of own constipation or the use of laxatives in 2019 and 2020, we determined the onset of constipation. The Japanese version of the Pittsburgh Sleep Quality Index (PSQI) was used to measure sleep quality in 2019. The global PSQI score was divided into quartiles. We analyzed the association between the degree of sleep quality and the incidence of constipation using logistic regression models. Results Overall, 1,696 participants without constipation at baseline were analyzed after 1 year, of whom 823 (48.5%) were male. The mean age of participants was 79.9 years. In total, 191 participants (11.3%) developed constipation. The median (interquartile range; IQR) global PSQI score was 4 (2, 6). According to the quartiles of the global PSQI scores (0-2, 3-4, 5-6, and ≥7), 35 (7.8%), 55 (11.3%), 48 (12.8%), and 53 (13.8%), respectively, developed constipation. Compared to those with global PSQI scores of 0-2, the odds ratios, adjusted by age, sex, smoking status, alcohol status, educational level, working status, exercise, and medical history were 1.57, 1.78, and 2.02 for participants with global PSQI scores of 3-4, 5-6, and ≥7, respectively (p = 0.003 for trend). Conclusions We identified poor sleep quality as a new risk factor for developing constipation in independent, community-dwelling, older adults aged ≥75 years.