Table 2.
Characteristics of included studies investigating the impact of DM on NPC prognosis
| Author/year | Design | Group | Sample size | Male/female | Diabetes assessment/types | Matching factors | Adjusted factors | Follow-up | NOS |
|---|---|---|---|---|---|---|---|---|---|
| Liu et al,23 2006 | Retrospective | Diabetes Nondiabetes |
37 897 |
30/7 658/239 |
Medical record/type 2 | None | None | 34.6 months* | 7 |
| Chen et al,22 2016 | Retrospective | Diabetes Nondiabetes |
71 530 |
0/71 0/530 |
Medical record/type 2 | None | Age and sex | NA | 5 |
| OuYang et al,21 2014 | Retrospective | Normoglycemic Diabetes Prediabetes |
3,949 345 1,566 |
2,916/1,033 270/75 1,187/379 |
Medical record/type 2 | None | Age, sex, smoking, drinking, hypertension, heart diseases, BMI, levels of CHO, TG, HDL-C and LDL-C, titer of VCA-IgA and EA-IgA, histological type, T stage, N stage, chemotherapy, and radiotherapy with forward selection method | 55.6 months* (range: 3.1–119.2 months) | 7 |
| Peng et al,20 2016 | Retrospective | Diabetes Nondiabetes |
186 372 |
160/2 52/320 |
Medical record/type 2 | Sex, age (within 5 years), T stage, N stage, chemotherapy (with or not), and radiotherapy (two-dimensional radiotherapy or intensity-modulated radiation therapy) | Gender, age, T stage, N stage, overall stage, chemotherapy, and radiotherapy | 66 months* (range: 3–157 months) | 9 |
| Peng et al,19 2016 | Retrospective | Nondiabetes Diabetes Prediabetes |
1,240 81 168 |
914/326 64/17 132/36 |
Medical record/type 2 | None | Age, sex, pathology, T stage, N stage, pre-DNA, smoking, drinking, CHO, TG, LDL-C, HDL-C, hypertension, cardiovascular complications, and chemotherapy | 49.8 months* (range: 1.3–70.7 months) | 7 |
Note:
*
Median follow-up time.
Abbreviations: CHO, total cholesterol; DM, diabetes mellitus; EA-IgA, early antigen immunoglobulin A; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; NA, not available; NOS, Newcastle–Ottawa Scale; NPC, nasopharyngeal carcinoma; TG, triglycerides; VCA-IgA, viral capsid antigen immunoglobulin A.