Figure 2.

Comparisons of indices for insulin secretion and sensitivity between short and long nap groups. Parameters for insulin secretion [insulinogenic index, corrected insulin response (CIR), disposition index] and insulin sensitivity (QUICKI, BIGTT- S_I, Matsuda index) were calculated based on plasma glucose and insulin levels determined at 0, 30, 60, 90, 120 minutes with a 75-g oral glucose tolerance test. These parameters were natural logarithm transformed to achieve a normal distribution. Each column shows the mean ± standard error. P values were determined using Student’s t-test.