The HOMA2-%S calculation reflects the sensitivity of cells and tissues to insulin. If cells are very sensitive they will allow insulin and its glucose cargo into the cell. If the cells are resistant and shut out insulin, then both insulin and glucose will remain elevated in the blood.
A higher HOMA2-%S indicates that the cells are sensitive and receptive to insulin. A lower HOMA2-%S value means the cells are less sensitive to insulin, another stop on the road to type 2 diabetes. Detection of decreased sensitivity at this stage should be addressed with nutrition and lifestyle changes in order to reverse course and head for optimal health instead.