Sugar-free chewing gum's effect on patients receiving maintenance hemodialysis: a meta-analysis of RCTs.

OBJECTIVE

Thirst is a prevalent adverse effect in individuals undergoing maintenance hemodialysis (MHD), frequently precipitating complications that impair well-being and quality of life. While no gold-standard therapy is currently available for thirst management in MHD patients, sugar-free chewing gum has been proposed as a low-cost behavioral intervention, though its efficacy requires further validation. This meta-analysis evaluated its impact on thirst, xerostomia, and secondary outcomes (salivary flow rate, interdialysis weight gain [IDWG]).

METHODS

Following PRISMA guidelines (PROSPERO: CRD42024550292), ten databases (PubMed, Embase, Web of Science, Cochrane Library, CINAHL, Ovid, CNKI, Wanfang, VIP, and CBM) were systematically searched from inception to July 7, 2025. Two investigators independently conducted literature screening, data extraction, and quality assessment. Statistical analyses were performed using RevMan 5.3. The primary outcomes were thirst intensity, measured using the Visual Analogue Scale (VAS) and the Dialysis Thirst Inventory (DTI), as well as xerostomia, measured using the Summated Xerostomia Inventory (SXI). Secondary outcomes included the salivary flow rate and IDWG. Subgroup analysis was conducted based on the duration of intervention (< 6 weeks vs.≥6 weeks) and the type of intervention in the control group (non-intervention vs. active control).

RESULTS

Seven studies ( = 395) were included in the analysis. Sugar-free gum significantly reduced VAS-assessed thirst (SMD = -0.7, 95% CI: -1.21 to -0.20;  = 0.006) and xerostomia (MD = -2.21, 95% CI: -2.62 to -1.79;  < 0.01), with ≥ 6-week interventions showing greater thirst reduction (SMD = -0.84) though without significant duration effect ( = 0.62). Control-type subgroup analysis revealed differential DTI effects: a significant reduction compared to non-intervention controls (MD = -2.50) but not active controls (MD = -0.19;  = 0.006 for interaction). No benefits were observed for salivary flow rate (MD = 0.10, 95% CI: -0.14 to 0.33), IDWG (MD = -0.25, 95% CI: -0.68 to 0.18), or overall DTI scores (MD = -1.57, 95% CI: -3.41 to 0.27). Initial heterogeneity (I²= 64–96%) was resolved after sensitivity analyses. Evidence certainty was very low to low (GRADE).

CONCLUSION

Sugar-free chewing gum may reduce xerostomia and the intensity of thirst (measured by VAS), with a more significant effect observed in longer interventions (≥ 6 weeks), but without statistically significant duration effects. It is worth noting that its effectiveness in assessing thirst in DTI seems to depend on the type of control, showing substantial benefits compared to a non-intervention control, but not compared to an active control. Although no benefits were observed in salivary flow rate, overall DTI score, or IDWG, this intervention demonstrates potential as a practical, low-cost adjunct for symptom management. Due to substantial heterogeneity and very low to low-quality evidence (GRADE), these findings should be interpreted with caution. Further high-quality, large-scale randomized controlled trials are warranted to validate these results and optimize thirst management strategies for patients with MHD.

CLINICAL TRIAL NUMBER

Not applicable.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s12882-025-04430-7.