Table 1.
Characteristics of 15 studies included in the meta-analysis of the gastric cancer risk of preexisting diabetes
| Study | Study type | Country | DM criteria | Age (yr) | Follow up (yr) | Least interval1 (yr) | Sex | DM prevalence | RR or OR (95%CI) | Adjustment variables/matched variable of selection | NOS | |
| Atchison et al[53] | CS | United States (veterans) | Registration | 18-100 | 27 | 1 | Male | 13.2% | 0.95 (0.89-1.02) | Age, time, latency, race, number of visits, diagnoses of alcohol–related conditions, obesity and COPD | 8 | |
| Carstensen et al[19] | CS | Denmark | Registration | No limit | 15 | Not mentioned | Male | 1.28 (1.15-1.43) | Age, calendar time, date of birth | 8 | ||
| Female | 1.34 (1.14-1.58) | |||||||||||
| Jiang et al[20] | CC | United States | Self reported | 30-74 | 1 | Both | 1.51 (1.10-2.07)2 | Age, sex, race, education, birth place, smoking and BMI | 7 (5)5 | |||
| Lin et al[22] | CS | United States | Self reported | 50-71 | 10 | 2 | Male | 9.9% | 1.52 (1.21-1.92)2 | Age, calories, alcohol consumption, smoking, fruit consumption, vegetable consumption, ethnicity, education, and physical activity | 8 (6)5 | |
| Female | 7.2% | 1.62 (0.98-2.68)2 | ||||||||||
| Wotton et al[16] | ORLS1 | CS | England | Registration | ≥ 30 | 35 | 0 | Both | 5.5% | 1.11 (0.89-1.37) | Sex, age in 5-year bands, time and district of residence | 8 |
| ORLS2 | 9 | 4.0% | 2.05 (1.30-3.10) | |||||||||
| Chodick et al[54] | CS | Israel | Registration | ≥ 21 | 8 | 0 | Male | 1.44 (0.98-2.11) | Age, region, SES level, use of healthcare, BMI, and history of CVD/matched for age, sex | 8 | ||
| Female | 0.99 (0.55-1.80) | |||||||||||
| Ikeda et al[37] | CS | Japan | HbA1c (5.0%-5.9% vs 7.0%) | ≥ 40 | 14 | Not mentioned | Both | 3.9% | 2.69 (1.24-5.85) | Age, sex, H. pylori, history of peptic ulcer, BMI, TC, alcohol intake, smoking, dietary factor4 | 8 | |
| Ogunleye et al[55] | CS | Scotland | Registration (only type 2 DM) | No limit | 11 | 1 | Both | 0.77 (0.36-1.66) | Deprivation deciles of Carstairs/matched for age, sex and doctor practice | 8 | ||
| Kuriki et al[29] | CC | Japan | Self reported | 40-80 | Not mentioned | Male | 1.16 (0.93-1.44) | Age, BMI, drinking, smoking, exercise, bowel movement, FHx of cancer and DM, dietary restriction, vegetable intake, greasy food, snack | 6 | |||
| Female | 1.70 (1.16-2.48) | |||||||||||
| Inoue et al[27] | CS | Japan | Self reported | 40-69 | 13 | 5 | Male | 6.7% | 1.09 (0.79-1.5) | Age, study area, history of CVD and IHD, smoking, BMI, physical activity, alcohol, vegetable, coffee | 9 | |
| Female | 3.0% | 1.92 (1.06-3.47) | ||||||||||
| Jun et al[57] | NCC | Korea | FBS (< 99 mg/dL vs ≥ 126 mg/dL) | ≥ 35 | Case 2.4/control 6.5 h | 2 | Both | 1.77 (0.57-5.45) | H. pylori, smoking, drinking, and education level/matched on age, sex, year and area of enrollment, and follow-up duration | 9 | ||
| Khan et al[28] | CS | Japan | Self reported | 40-79 | 19 | 2 | Male | 7.5% | 0.72 (0.40-1.09) | Age, BMI, smoking, drinking | 8 | |
| Female | 4.6% | 0.26 (0.08-0.82) | ||||||||||
| Rapp et al[15] | CS | Austria | FBS (4.2-5.2 mmol/L vs 7.0 mmol/L) | > 19 | 14 | 1 | Male | 3.9% | 0.84 (0.38-1.87) | Age, smoking, occupation, BMI | 8 | |
| Female | 3.0% | -3 | ||||||||||
| Rousseau et al[56] | CC | Canada | Self reported | 35-70 | 2 | Male | 1.0 (0.5-1.8) | Age, income, education, ethnicity, proxy status, BMI, smoking, beta-carotene, alcohol | 7 | |||
| Jee et al[26] | CS | South Korea | FBS (< 90 mg/dL vs ≥ 126 mg/dL) or DM medication | 30-95 | 10 | 1 | Male | 5.1% | 1.11 (1.04-1.2) | Age, age squared, smoking, alcohol | 8 | |
| Female | 4.5% | 1.15 (0.99-1.34) | ||||||||||
| La Vecchia et al[25] | CC | Italy | Self reported | ≤ 75 | Not mentioned | Male | 0.6 (0.4-1.0) | Age | 6 | |||
| Female | 0.7 (0.4-1.2) | |||||||||||
| O'Mara et al[21] | CC | USA (only white) | Self reported | 30-89 | 1 | Male | 0.91 (0.28-2.27)2 | Age | 4 (3)5 | |||
| Female | 1.57 (0.48-3.94) | |||||||||||
Interval between diabetes mellitus (DM) and gastric cancer to be selected as population;
Calculated from table without adjustment by Fisher’s exact test;
No estimate was reported due to less than 5 cases in DM patients;
Energy, fat, salt, vitamin, dietary fibers;
The first numbers are Newcastle-Ottawa Quality Assessment Scale (NOS) of original studies. The second numbers in brackets are downgraded NOS because we calculated new estimates without adjustment. Subgroup analysis were done according to the second numbers. CS: Cohort study; CC: Case control study; NCC: Nested case-control study; BMI: Body mass index; FBS: Fasting blood glucose; FHx: Family history; TC: Total cholesterol; CVD: Cardiovascular disease; IHD: Ischemic heart disease; ORLS: Oxford Record Linkage Study; H. pylori: Helicobacter pylori; COPD: Chronic obstructive pulmonary disease.