Salt Intake and Risk of Gastric Intestinal Metaplasia: Systematic Review and Meta-Analysis

Abstract

The understanding of the association between salt intake and precancerous lesions may contribute to clarify the causal relation with gastric cancer. We systematically reviewed 17 articles addressing the association between dietary salt exposure and gastric intestinal metaplasia and conducted meta-analyses for quantitative synthesis (random effects model). Salt exposure was estimated assessing salted/salty food consumption, preference for salted/salty foods, use of table salt, or sodium urinary excretion. Heterogeneity was also large regarding food items evaluated, consumption categories, and data analysis. The combined odds ratio (OR) was 1.68 (95% confidence interval (CI) = 0.98–2.90; I² = 55.4%) for the association between salted/salty meat and intestinal metaplasia (4 studies) and the OR was 1.53 (95% CI = 0.72–3.24; I² = 76.8%) for salt preference. There was a positive, nonstatistically significant association between intestinal metaplasia and urinary sodium excretion. The heterogeneity of methodological options and results preclude quantitative synthesis or its proper interpretation, even if the available evidence may suggest a positive association between salt and intestinal metaplasia.

ACKNOWLEDGMENTS

A grant from the Agência Portuguesa de Segurança Alimentar is gratefully acknowledged. Marina Dias-Neto and Mariana Pintalhão contributed equally to the study.

Notes

^a Abbreviations are as follows: NS, not specified. IM, intestinal metaplasia. In all the studies the diagnosis of IM was made by endoscopy and subsequent histological analysis of biopsies except in Stemmermann et al. ⁽¹¹⁾ in which confirmation of IM was performed by macroscopic and microscopic analysis of the surgical specimens.

^b More biopsies were done when lesions were found.

^a Abbreviations are as follows: GC, gastric cancer; OR, odds ratio; CI, confidence interval; HP, Helicobacter pylori; IM, intestinal metaplasia. In all the studies the diagnosis of IM was made by endoscopy and subsequent histological analysis of biopsies.

^b Excluding cases of ulcer or gastric cancer.

^c Type II IM incomplete with sialomucines; type III IM incomplete with sulfomucines.

^d OR and 95% CI computed by the authors of this review.

^a Abbreviations are as follows: IM: intestinal metaplasia; GC, gastric cancer; OR, odds ratio; CI, confidence interval; HP, Helicobacter pylori; NS, Not specified.

^b For quantitative synthesis, the lower bound of the CI was assumed to be 2, and the upper bound was computed by the authors of this review assuming that the difference between the log of the upper limit of the CI and the log of the point estimate was equal to the difference between the log of the lower limit of the CI and the log of the point estimate.

^a Abbreviations are as follows: IM, intestinal metaplasia; GC, gastric cancer; OR, odds ratio; CI, confidence interval.

^a Abbreviations are as follows: IM, intestinal metaplasia; GC, gastric cancer; EC, endoscoped control; NC, not endoscoped control.