Serum pepsinogen levels and their infl uencing factors: A population-based study in 6990 Chinese from North China

AIM:To explore the essential characteristics of serum pepsinogen (PG) levels in Chinese people, by analyzing the population-based data on the serum levels of PG Ⅰ and Ⅱ and the PGⅠ/Ⅱ ratio, and their influencing factors in Chinese from North China. METHODS:A total of 6990 subjects, who underwent a gastric cancer screening in North China from 1997 to 2002, were collected in this study.Serum pepsinogen levels were measured by enzyme-linked immunosorbent assay (ELISA).H pylori status was determined by histological examination and H pylori -IgG ELISA.The cut-off point was calculated by using receiving operator characteristics (ROC) curves.Factors linked to serum PG Ⅰ/Ⅱ ratio were identified using a multivariate logistic regression. RESULTS:The serum PGⅠ and PGⅡ levels were significantly higher in males than in females (95.2 μg/L vs 79.7 μg/L, P < 0.01; 12.1 μg/L vs 9.4 μg/L, P < 0.01), PGⅠ/Ⅱ ratio was significantly lower in males than in females (7.9 vs 8.3, P < 0.01).The PG Ⅰ/Ⅱ ratio decreased significantly in the aged groups following the progression of gastric mucosa from normal to non-atrophic and atrophic lesions (10.4,8.8, and 6.6, respectively).The serum PGⅠand Ⅱ levels were significantly higher in patients with H pylori infection than in those without H pylori infection (88.7 μg/L vs 81.4 μg/L, P < 0.01; 11.4 μg/L vs 8.4 μg/L, P < 0.01), while the PGⅠ/Ⅱ ratio was significantly lower in patients with H pylori infection than in those without H pylori infection (7.7 vs 9.6, P < 0.01).For patients with atrophic lesions, the area under the PGⅠ/Ⅱ ROC curve was 0.622.The best cut-off point for PGⅠ/Ⅱ was 6.9, with a sensitivity of 53.2%, and a specificity of 67.5%.Factors linked to PG Ⅰ/Ⅱ were sensitive to identified PG using a multinomial logistic regression relying on the following inputs: males (OR: 1.151, 95% CI: 1.042-1.272,P = 0.006), age ≥ 61 years (OR: 1.358, 95% CI: 1.188-1.553,P = 0.000), atrophic lesion (OR: 2.075, 95% CI: 1.870-2.302,P = 0.000), and H pylori infection (OR: 1.546, 95% CI: 1.368-1.748,P = 0.000). CONCLUSION:The essential characteristics of serum PG levels in Chinese are significantly skewed from the normal distribution, and influenced by age, sex, gastric mucosa lesions and H pylori infection.PGⅠ/Ⅱ ratio is more suitable for identifying subgroups with different influence factors compared with PGⅠor PGⅡ alone.