Bowel Health, Laxative Use, and Cognitive Function in Older Puerto Rican Adults

Objectives: Bowel dysfunction and habitual laxative use are indicators of poor gastrointestinal (GI) health and are inversely associated with cognitive function. These associations are understudied in Latino and Hispanic populations. Therefore, we examined the associations between bowel frequency, stool type, laxative use, and cognitive function in the Boston Puerto Rican Health Study (BPRHS). Methods: The BPRHS is a prospective cohort that enrolled 1502 Puerto Rican adults residing in the Boston Area, aged 45-75 years at baseline, with four waves of collection across 13 years. Cognitive function was measured using a composite global cognitive score (GCS) with low scores indicating worse cognitive function. Bowel health at Wave 4 was assessed by self-reported bowel frequency (times/day) and stool type. Self-reported laxative use (yes/no) was assessed at baseline and Wave 4. Adjusting for relevant covariates, we examined cross-sectional association between bowel frequency, stool type and GCS at Wave 4, and serial cross-sectional associations between laxative use and GCS at baseline and Wave 4. We used linear mixed models to examine time-varying laxative use and GCS over 13 years of follow-up. Results: At Wave 4, 155 (27.1%), 235 (41.0%), and 183 (31.9%) participants self-reported normal, low, and high bowel frequency, respectively, and 334 (65.9%), 72 (14.2%), and 101(19.9%) self-reported normal, hard, and loose stool type, respectively. At Wave 4, participants with high bowel frequency had low GCS (β = -0.152, p=0.02), but stool type was not associated with GCS. Self-reported laxative use increased from 6.8% (baseline) to 18.4% (Wave 4). Laxative users had low GCS at baseline (β = -0.13, p=0.01) and Wave 4 (β = -0.13, p=0.05). However, laxative use was not associated with a change in GCS over 13 years of follow-up (laxative use∗time β = 0.006, p=0.28). Conclusion: Low or high bowel frequency and laxative use may be inversely associated with cognitive function. Our results suggest a relationship between bowel and cognitive health. Trial Registration: ClinicalTrials.gov identifier: NCT01231958.