Cigarette Smoking Increases Risk for Gastric Intestinal Metaplasia

Cigarette smoking is a risk factor for gastric intestinal metaplasia, and the risk for former smokers remains significantly elevated until 15 years postcessation, according to the results of a study published in the Journal of Clinical Gastroenterology.

Investigators analyzed data from 385 patients with gastric intestinal metaplasia and 1577 controls without gastric intestinal metaplasia from a cross-sectional study at a Veterans Affairs (VA) medical center. All participants underwent endoscopy with gastric mapping biopsies and completed standardized questionnaires. The gastric intestinal metaplasia cohort included patients who had intestinal metaplasia identified on any noncardia gastric biopsy specimen.

Overall, approximately 92% of participants were men, and patients with gastric intestinal metaplasia were significantly more likely to be men than were controls (97.1% vs 90.8%, respectively). Patients with gastric intestinal metaplasia were also older on average, and the group had a lower proportion of White patients compared with controls (41.3% vs 61.6%, respectively).

Among the gastric intestinal metaplasia cohort, 50.9% of participants were aged 60 to 69 years, and 16.4% were 70 years of age and older. In the control group, 46.7% of participants were aged 60 to 69 years, and 11% were 70 years and older. Body mass index and waist-to-hip ratios were similar for the gastric intestinal metaplasia and control groups.

The study authors found that current smokers had a 2-fold increased risk for gastric intestinal metaplasia compared with never smokers (adjusted odds ratio, 2.05; 95% CI, 1.47-2.85). Longer smoking duration and total dose were significantly associated with an increased risk for gastric intestinal metaplasia among ever smokers (P trend, .004 and .01, respectively). Among former smokers, the risk for gastric intestinal metaplasia decreased over time and was no different than the risk for never smokers at 15 years following smoking cessation.

Patients with gastric intestinal metaplasia were more likely to have Helicobacter pylori infection compared with control participants (53.2% vs 21.7%, respectively), although the smoking effect on gastric intestinal metaplasia was not different according to H pylori infection status.

The risk for gastric intestinal metaplasia associated with current smoking was stronger in Black patients (adjusted odds ratio, 3.99; 95% CI, 2.30-6.94) compared with other races and ethnicities (P interaction, .01).

“In this large cross-sectional study, we confirmed that smoking is a significant risk factor for gastric intestinal metaplasia,” stated the researchers. “The risk of gastric intestinal metaplasia increased with increasing duration of smoking and pack-years of smoking exposure. We also found tentative evidence that the relationship between cigarette smoking and gastric intestinal metaplasia may be stronger in [Black individuals].”

The fact that most participants were White men was among several study limitations. Additionally, since the characteristics of VA vs non-VA populations may differ, the findings may not be generalizable to women or non-White men from the general non-VA population. Also, residual confounding by poorly measured or unmeasured factors could have influenced the results, and the study was limited by its cross-sectional design.

“We found that duration of smoking was a strong determinant of risk, but risk of gastric intestinal metaplasia among smokers was not influenced by intensity of use or H. pylori infection,” the investigators commented. “Importantly, time since quitting was an independent risk factor, with evidence that risk among formers smokers was no different [than in] never smokers after 15 years smoking cessation.”

Reference

Thrift AP, Jove AG, Liu Y, Tan MC, El-Serag HB. Associations of duration, intensity, and quantity of smoking with risk of gastric intestinal metaplasia. Published online December 16, 2020. J Clin Gastroenterol. doi:10.1097/MCG.0000000000001479