GCG and diabetes mellitus: Each 1 standard deviation (SD) increment of fasting GLP-1 was associated with decreased risk of incident first cancer during the maximum follow-up period of 12.6 years (median 9.9 years, interquartile range 8.0–11.0 years) in Model 2a (adjusted for age, sex, waist circumference, diabetes status, smoking status and physical activity): HR 0.91 (95% CI 0.83–0.99); P = 0.031 (Table 2).