Characteristics of studies for tAs in urine included in the meta-analysis
| Author (reference) | Country (year) | Study design | Mean age (case/control) Percentage of male (case/control) | Sample size (cases) | Definition of cases | Cut-points for arsenic exposure | Adjustment for covariates |
|---|---|---|---|---|---|---|---|
| Coronado-Gonzalez et al12 | Mexico (2007) | Case-control | – 31.5/38.0 | 400 (200) | Fasting glucose test, taking insulin or oral hypoglycaemic drugs | Urine arsenic concentration (µg/g creatinine) <35 (referent), 35–100, >100 (2.45 (1.27 to 4.73)) | Sex, age, triglycerides, BMI, hypertension, and family history of diabetes |
| Chen et al14 | Bangladesh (2010) | Cross-sectional | –– | 11 319 (241) | A self-reported physician diagnosis, taking insulin or oral hypoglycaemic drugs | Urine arsenic concentration (µg/L) 1–36 (referent), 37–66, 67–114, 115–204, ≥205 (1.22 (0.73 to 2.03)) | Age, sex, BMI, smoking status, educational attainment, and urinary creatinine |
| Gribble et al16 | American Indians (2012) | Cross-sectional | 56.9/55.6 37.2/44.3 | 3925 (1939) | Fasting glucose test, 75-g oral glucose tolerance test, taking insulin or oral hypoglycaemic drugs | Urine arsenic concentration (µg/L) <7.9 (referent), 7.9–14.1, 14.1–24.2, ≥24.2 (1.28 (1.14 to 1.44)) | Urine creatinine, age group, sex, educational level, alcohol consumption, smoking, BMI, and region |
| Kim et al17 | American Indians (2013) | Case-control | 33.0/31.6– | 300 (150) | 75-g oral glucose tolerance test | Urine arsenic concentration (µg/L) 0–10.0 (referent) | Urinary creatinine concentration, age, sex, and BMI |
| Rhee et al18 | Korea (2013) | Case-control | –– | 3602 (310) | Fasting glucose test, 75-g oral glucose tolerance test, a self-reported physician diagnosis, taking insulin or oral hypoglycaemic drugs | Urine arsenic concentration (µg/g creatinine) <70.7 (referent), 70.7–117.7, 117.7–193.4, ≥193.4 (1.56 (1.03 to 2.36)) | Sex, age, residence area, smoking, alcohol, occupation, and serum mercury level |
| Navas-Acien et al13 | USA (2009) | Cross-sectional | –– | 1279 (160) | Fasting glucose test, a self-reported physician diagnosis, | Urine arsenic concentration (µg/L) 20th centile of arsenic exposure (referent), 80th vs 20th centile (0.90 (0.37 to 2.20)) | Age, sex, race/ethnicity, and urine creatinine, education, BMI, serum cotinine, and hypertension medication |
| Del Razo et al15 | Mexico (2011) | Cross-sectional | 50.4/32.3 24.0/33.5 | 258 (25) | Fasting glucose test, 75-g oral glucose tolerance test, a self-reported physician diagnosis, taking insulin or oral hypoglycaemic drugs | Urine arsenic concentration (ng/mL)– | Age, sex, obesity, and hypertension |
–, Not available; ; BMI, body mass index; T2DM, Type 2 diabetes mellitus.