Abstract 12182: The Link between Adherence to a Sodium-restricted Diet and Functional Capacity is Mediated by Tumor Necrosis Factor-alpha in Patients with Heart Failure
Background: Non-adherence to a sodium-restricted diet (SRD) and increased tumor necrosis factor alpha (TNFα) have been independently associated with poor functional capacity in patients with heart failure (HF). We hypothesized that non-adherence to SRD increases inflammation which in turn decreases functional capacity.
Purpose: To determine whether proinflammatory cytokine activity mediated the link between non-adherence to SRD and functional capacity.
Method: A total of 168 patients with chronic HF secondary to ischemic heart disease (age 62 ± 12 years, 33% female, ejection fraction [EF] 35 ± 14%) collected a 24-hour urine sodium (UNa) to estimate daily sodium intake. Adherence to a SRD was defined as a UNa of ≤ 3g. Patients completed the Duke Activity Status Index (DASI) to assess functional capacity and were divided into 2 groups using median split of total DASI score to reflect worse vs. better functional capacity. Patients provided blood to measure serum level of TNFα and values were split at median value of 7.40 pg/mL. Covariate data on age, gender, body mass index, EF, total comorbidity score, and prescribed medications were obtained through patient interview and medical record review. Mediation analysis with hierarchical logistic regression was used to determine the relationships among adherence to a SRD, TNFα, and functional capacity.
Results: Greater than 3g UNa (odds ratio [OR] = 2.22, 95% CI = 1.04-4.73) and higher level of TNFα (OR = 2.48, 95% CI = 1.23-4.98) independently predicted worse functional capacity after controlling for covariates. Greater than 3g UNa was associated with higher level of TNFα (OR = 3.01, 95% CI = 1.40-6.47) in hierarchical logistic regression. Mediation analysis indicated TNFα mediated the link between adherence to a SRD and functional capacity.
Conclusion: This study demonstrates that increased pro-inflammatory cytokine activity plays a role in the link between non-adherence to a SRD and functional capacity in patients with HF.
- © 2012 by American Heart Association, Inc.