Adult males with higher daily sodium intake had a lower risk of constipation, with an odds ratio (OR) of 0.78 per incremental increase in intake, according to a recent study.
A study examined the association between daily sodium intake and constipation in U.S. adult males, using data from the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2010. This cross-sectional analysis included 7,116 male participants aged 20 years or older, representing a weighted U.S. population of approximately 95.5 million individuals. Researchers utilized multivariable logistic regression models and restricted cubic spline (RCS) methods to evaluate linear and nonlinear trends while adjusting for demographic, health, and dietary confounders.
Sodium intake was assessed via two-day dietary recalls, averaging sodium consumption from food and beverages. Constipation was defined based on stool consistency, using the Bristol Stool Form Scale (types 1 and 2 classified as constipation), and defecation frequency (less than three times per week). Covariates included demographic factors, physical activity, and nutritional variables, such as dietary fiber and potassium intake.
Published in BMC Gastroenterology, the results indicated a statistically significant inverse association between daily sodium intake and constipation across all models. In Model 1, without adjustments, the odds ratio (OR) was 0.78 (95% confidence interval [CI]: 0.71–0.85; P < 0.001). Model 2, adjusted for demographic and health factors, showed an OR of 0.79 (95% CI: 0.73–0.87; P < 0.001). In Model 3, further adjusting for dietary factors, the association persisted (OR: 0.82; 95% CI: 0.69–0.97; P = 0.023). Trend analysis confirmed a significant decline in constipation risk with increasing sodium intake across all models (P for trend < 0.05). However, the RCS analysis did not reveal a nonlinear relationship (P = 0.528).
Subgroup analyses demonstrated consistent findings across demographic and clinical subgroups, with no significant interactions observed. The researchers proposed potential mechanisms, including sodium's role in hydration regulation, which increases stool moisture, and its influence on intestinal motility via smooth muscle contractions.
Prior studies, such as one by Rollet et al. in Luxembourg, found a positive association between sodium intake and constipation. The authors suggested that regional differences in dietary habits and sodium sources may explain this discrepancy. Further research may help clarify these associations across populations.
While the study provides significant findings, its reliance on self-reported data and its cross-sectional design, which precludes causal inference, are notable limitations. Longitudinal studies could help further clarify sodium's role in managing constipation and its implications for dietary guidelines.
Full disclosures can be found in the published study.
