The document discusses tools that can be used to assess beta-cell health and function in research and clinical settings. It notes that simply measuring insulin levels is not sufficient because insulin levels are determined by both beta-cell function and insulin resistance. The document argues that glucose levels better reflect beta-cell function and compensation for insulin resistance, as normal beta-cell function should maintain normal glucose levels even with varying degrees of insulin sensitivity. Failure of beta-cells to adequately compensate for insulin resistance results in elevated glucose levels over time.