Moreover, some potential confounding variables (e.g., dietary habits [25], systolic blood pressure [69], diuretics, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers, insulin) were not collected in our study, and future studies should assess more potential variables that may affect the relationship between serum UA and cognitive function in CHF patients. Here, ACE is linked to congestive heart failure.