Table 2. The main characteristics of included studies on plasma 25(OH)D levels and pancreatic cancer risk.
| Article | Country | Study design | Sample (M/F) | Age (years) | Follow up (years) | Baseline 25(OH)D (ng/mL) | BMI | Adjusted variables | Study quality |
|---|---|---|---|---|---|---|---|---|---|
| Piper 2015 | USA | Nested CCS | 882(549/333) | Median: 65; IDR:57-71 | Follow-up to 15.1 | Case:24.36(IDR11.28-37.32);conrol:25.28 (14.16-36.28) | BMI<25:306;BMI:25-30:395;BMI≥30:181 | Age, race-ethnicity, sex, and date of blood draw, smoking status and diabetes | 7 |
| Ananthakris-hnan 2014 | USA | Cohorts | 2809 (1097/1712) | Median:46; IQR:32-60 | Median:11(IQR5-18) | Median:26;IQR:17-35 | NR | Age, sex, race, measurement season, follow-up duration, immunosuppression use and IBD type | 6 |
| Afzal 2013 | Denmark | Cohorts | 9791 (4358/5431) | <5ng/ml:59(IQR50-65); 5-9.9:58(IQR49-65);10-19.9:58 (IQR48-64);≥20:57(IQR47-64) | Median:21;range:0.01-28 | Median:16.4 | <5ng/ml:25 (22-29);5-9.9:26 (23-29);10-19.9:25 (23-28);≥20:24 (22-27) | Age, sex, pack-years, BMI, alcohol consumption, leisure time, physical activity and education duration | 7 |
| Wolpin 2012 | USA | Nested CCS | 1618 (518/1100) | Mean:62.5;SD:8.5 | Median:14.3 | Mean:25.8; SD:9.28 | Mean:25.9; SD:4.5 | Age, cohort, BMI, smoking status, history of diabetes mellitus, multivitamin use and month of blood draw. | 7 |
| Stolzenberg-Solomon 2010 | USA | Nested CCS | 2285 (1521/764) | Median:case:62(IQR56-68);control:62(IQR57-67) | Median:6.5;range:0-30.6 | Range:case:0.8-62.4;control:1.04-50.88 | BMI<25:876;BMI:25-30:935;BMI≥30:356 | Age, race/ethnicity, sex, cohort, date of blood draw, BMI, smoking and diabetes status. | 7 |
25(OH)D: 25-hydroxyvitamin D; BMI: body mass index; CCS: case-control study; IDR: interdecile range; IQR: interquartile range; M/F: male/female; NR: not reported; SD: standard deviation; USA: the United States of America.