Work

Low Dietary Bromide Intake and Sex-Specific Mortality in Kidney Transplant Recipients

Year: 2026

Type: article

Abstract: Background Low bromide intake may be a modifiable risk factor of the reduced survival among kidney transplant recipients (KTR). Objective We investigated dietary determinants of 24-hour urinary bromide excretion and examined the association between 24-hour urinary bromide excretion and mortality. Given potential sex differences, additional sex-stratified analyses were performed. Methods Adult KTR from the TransplantLines Food & Nutrition Biobank and Cohort Study were included. Dietary determinants of urinary bromide excretion were assessed with multivariable linear regression. Associations of 24-hour urinary bromide excretion were evaluated using multivariable sex-stratified Cox regression analyses. Results The study included 693 KTR (43% female, 53 ± 13 years). Urinary bromide excretion was lower in females as compared to males (2958 [2343-3713] vs 3640 [2853-4585] μg/24h; P<0.001). Energy intake (β=0.12, P=0.002), animal protein intake (β=0.16, P=0.001), and water intake (β=0.13, P=0.005) were positively associated with urinary bromide excretion. In sex-stratified analyses, animal protein intake was a significant determinant of bromide excretion in females (β=0.22, P=0.002), whereas water (β=0.15, P=0.02) and energy intake (β=0.13, P=0.01) were associated with bromide excretion in males. During a median follow-up of 5.3 [4.8–6.1] years, 150 KTR (21.6%) died. Higher urinary bromide excretion was consistently associated with a lower risk of mortality, also after adjustment for potential confounders (HR: 0.67 [95%CI: 0.50;0.90]; P=0.008). The association of urinary bromide excretion with mortality was significantly modified by sex (P interaction =0.02). Among females, there was a significant independent association of higher urinary bromide excretion with lower mortality (HR: 0.45 [95%CI: 0.29;0.72], P=0.001), whereas no such association was observed in males. Conclusion Energy, animal protein, and water intake were positively associated with urinary bromide excretion, with sex-specific differences. Lower urinary bromide excretion was independently associated with increased all-cause mortality in female, but not in male KTR. These findings support further investigation whether improving bromide status could reduce mortality, particularly among female KTR. Clinical Trial Registry Number TransplantLines Food & Nutrition Biobank and Cohort Study (ClinicalTrials.gov: NCT02811835

Source: Current Developments in Nutrition

DOI: 10.1016/j.cdnut.2026.109543