A Retrospective Study Evaluating the Association of Gastric Intestinal Metaplasia and Serum Vitamin D Levels in an Urban Medical Center

Abstract

Introduction: Recent studies suggest that there is an association between gastric adenocarcinoma and low serum vitamin D levels. However, to date, there are no studies in the literature that have investigated the relationship between the premalignant stages of gastric adenocarcinoma such as intestinal metaplasia and low serum vitamin D levels. Methods: A retrospective, randomized and matched case-control study was conducted with cases defined as subjects who had intestinal metaplasia identified by gastric biopsy and the controls classified as subjects who did not have intestinal metaplasia detected by biopsy and were therefore healthy. All subjects who were included were older than 18 years old, had underwent EGD and had a documented serum 25-hydroxyvitamin D level prior to EGD without repletion. Subjects that were excluded included those who were younger than 18 years old, did not undergo EGD, subjects who did not have a documented Vitamin D level prior to EGD, or if the patient had prior gastrectomy, gastric ulcers, adenomatous polyps, intestinal metaplasia of the esophagus or malignancy including gastric cancer. The cases and control subjects were matched according to age, gender, ethnicity, Body Mass Index (BMI), and H. Pylori infection. A normal serum 25-hydroxyvitamin D level was defined as 30-100 ng/dL. Hypovitamonosis D was divided into two groups based on severity: Vitamin D insufficiency (VDi) and Vitamin D deficiency (VDd). A serum 25-hydroxyvitamin D level that was 20 ng/dL or greater but less than 30 ng/dL was considered VDi in contrast with VDd that was defined as a level less than 20 ng/dL. The mean and standard deviation of the matched patients' age, 25-hydroxyvitamin D level, BMI were calculated. The odds ratio was calculated to assess the association between 25-hydroxyvitamin D levels and Gastric Intestinal Metaplasia with statistical significance defined as a p-value < 0.05. Results: 906 subjects were recruited for this study and 324 subjects met the inclusion criteria. After matching, 168 subjects were included in the final analysis; 84 cases and controls each. The case and control subjects were similar in regards to age, gender, ethnicity, and BMI; most subjects were female (63.1%), Hispanic (77.4%), overweight, and did not have H. Pylori infection (75%). The average serum 25-hydroxyvitamin D level was lower in the Intestinal Metaplasia group (21.88 ng/dL) in comparison with patients who did not have evidence of Intestinal Metaplasia 32.26 ng/dL). Hypovitaminosis D was more common in patients with Intestinal Metaplasia (OR 12.6). Most patients with Intestinal Metaplasia who were found to have hypovitamosis D were more likely to have VDi (OR 78.76) than VDd (OR 34.61). All results had a p-value < 0.01. Conclusion: Although the development of intestinal metaplasia is multifactorial, hypovitaminosis D may contribute as a treatable risk factor.Table: Table. Demographic Information