Use of proton pump inhibitor and risk of iron deficiency: a population-based case-control study

BACKGROUND: Hypochlorhydric states are an important cause of iron deficiency (ID). Nevertheless, the association between therapy with proton pump inhibitors (PPIs) and ID has long been a subject of debate. This case-control study aimed to investigate the risk of ID associated with the use of PPIs using the UK Clinical Practice Research Datalink (CRPD) database.

METHODS: Cases were patients aged 19 years or older with first-time diagnosis of ID between 2005 and 2015 (n = 26,806). The dates of first diagnosis of ID in cases defined the index dates. For each case, one control was matched by age, sex and general practice. A PPI "full" user (PFU) was defined as a subject who had received PPIs for a continuous duration of at least one year prior to the index date. A PPI "limited" users (PLU) was a subject who intermittently received PPI therapy. A PPI non-user (PNU) was a subject who received no PPIs prescriptions prior to the index date. The odds ratio of ID in PFU and PLU compared to PNU was estimated using conditional logistic regression.

RESULTS: Among cases, 2,960 were PFU, 6,607 PLU and 17,239 PNU. Among controls, 1,091 were PFU, 5,058 PLU and 20,657 PNU. Adjusted odds ratio of ID in PFU and PLU compared to PNU was 3.60 (95%CI, [3.32 - 3.91]) and 1.51 (95% CI, [1.44 - 1.58]). Positive dose-response and time-response relationships were observed.

CONCLUSIONS: Chronic PPI use increases the risk of ID. Physicians should consider this when balancing the risks and benefits of chronic PPI prescription. This article is protected by copyright. All rights reserved.