Abstract

The association between ferritin and transferrin saturation (TS), respectively, and all-cause mortality is unclear. Furthermore, the influence of concurrent inflammation has not been sufficiently elucidated. We investigated these associations and the effect of concurrently elevated C-reactive protein (CRP), and accordingly report the levels associated with lowest all-cause mortality for females and males with and without inflammation.

Blood test results from 161,921 individuals were included. Statistical analyses were performed in sex-stratified subpopulations, with ferritin or TS level as continuous exposure variables, and were adjusted for age, co-morbidity and inflammation status using CRP. An interaction was used to investigate whether the effect of ferritin or TS on all-cause mortality was modified by inflammation status (CRP ≥ 10 mg/L or CRP < 10 mg/L). Low and high ferritin and TS levels were respectively associated with increased all-cause mortality in females and in males. These associations persisted with concurrent CRP ≥ 10 mg/L. The ferritin level associated with lowest mortality was 60 µg/L for females and 125 µg/L for males with CRP < 10 mg/L. It was 52 µg/L for females and 118 µg/L for males with CRP ≥ 10 mg/L. The TS level associated with lowest mortality was 33.9% for females and 32.3% for males with CRP < 10 mg/L. It was 28.7% for females and 30.6% for males with CRP ≥ 10 mg/L.

Our findings can nuance clinical interpretation and further aid in defining recommended ranges for ferritin and TS.

摘要

铁蛋白和转铁蛋白饱和度 (TS) 分别与全因死亡率之间的关联尚不清楚。此外，并发炎症的影响尚未得到充分阐明。我们调查了这些关联以及同时升高的 C 反应蛋白 (CRP) 的影响，并相应地报告了与有和没有炎症的女性和男性的最低全因死亡率相关的水平。

包括 161,921 人的血液检测结果。在按性别分层的亚群中进行统计分析，将铁蛋白或 TS 水平作为连续暴露变量，并使用 CRP 针对年龄、合并症和炎症状态进行调整。使用相互作用来研究铁蛋白或 TS 对全因死亡率的影响是否因炎症状态（CRP ≥ 10 mg/L 或 CRP < 10 mg/L）而改变。低和高铁蛋白和 TS 水平分别与女性和男性的全因死亡率增加有关。这些关联在并发 CRP ≥ 10 mg/L 时持续存在。与最低死亡率相关的铁蛋白水平对于女性为 60 µg/L，对于 CRP < 10 mg/L 的男性为 125 µg/L。CRP ≥ 10 mg/L 的女性为 52 µg/L，男性为 118 µg/L。CRP < 10 mg/L 的 TS 水平与最低死亡率相关，女性为 33.9%，男性为 32.3%。CRP ≥ 10 mg/L 的女性为 28.7%，男性为 30.6%。

我们的发现可以细微差别的临床解释，并进一步帮助定义铁蛋白和 TS 的推荐范围。