GDF15 and diabetes mellitus: Moreover, regarding categorical variables, GDF-15 levels were significantly related to the hypertension (1600.8 ± 830.9 ng/l vs. 1097.6 ± 590.3 ng/l, p = 0.037, Fig. 2A) and diabetes (1668 ± 269.1 ng/l vs. 1379 ± 123.5 ng/l, P = 0.006, Fig. 2B).