PRL and type 2 diabetes mellitus: The incidences of type 2 diabetes at phase-2 examination in men with phase-1 PRL levels of 5-34.9 ng/ml (considered the normal range), 3-4.9 ng/ml, and 0.3–2.9 ng/ml were 6.3%, 9.3% and 22.7%, respectively (Fig. 3).