Since the accuracy of HOMA mostly relies on the ability of fasting insulin to mirror insulin resistance, in the extreme insulin sensitivity ranges (high or low, e.g. athletes and T2DM subjects) the overall approximately hyperbolic relationship of HOMA and insulin sensitivity appears as a (respectively horizontal and vertical) asymptote, and correlation between insulin sensitivity and HOMA in both extreme ranges is lost. Here, INS is linked to type 2 diabetes mellitus.