INS and diabetes mellitus: Among these characteristics, 501 men were diagnosed with hypogonadism by total T, 334 men were diagnosed by free T and 122 men were diagnosed by both total and free T. Compared to men without hypogonadism, the men with hypogonadism were older and had significantly lower 25(OH)D levels, higher fasting insulin levels, HOMA-IR, BMI and systolic pressure as well as a higher prevalence of diabetes.