Table 2.
Relationship of measures of insulin sensitivity and β-cell function with short-term and long-term change in HbA1c (%)
| Overall† | Glimepiride* | Liraglutide* | Sitagliptin* | Heterogeneity P* | Overall P† | Pairwise P‡ | |
|---|---|---|---|---|---|---|---|
| Difference in short-term HbA1c change per 1-unit increase in OGTT measure (95% CI) | |||||||
| Log HOMA2-%S | −0.178 (−0.266, −0.090) | −0.224 (−0.310, −0.139) | −0.358 (−0.440, −0.275) | 0.009 | N/A | G-L 0.739, G-S 0.010, L-S 0.071 | |
| CPI | −0.010 (−0.070, 0.050) | −0.060 (−0.108, −0.011) | −0.123 (−0.175, −0.071) | 0.018 | N/A | G-L 0.421, G-S 0.014, L-S 0.185 | |
| Total CP response | −0.080 (−0.134, −0.025) | −0.045 (−0.076, −0.014) | −0.139 (−0.178, −0.099) | 0.001 | N/A | G-L 0.526, G-S 0.192, L-S 0.001 | |
| Difference in long-term HbA1c change (slope) per 1-unit increase in OGTT measure (95% CI) | |||||||
| Log HOMA2-%S | 0.011 (−0.004, 0.026) | 0.175 | 0.143 | N/A | |||
| CPI | −0.061 (−0.082, −0.039) | −0.042 (−0.060, −0.025) | −0.016 (−0.034, 0.002) | 0.006 | N/A | G-L 0.388, G-S 0.005, L-S 0.101 | |
| Total CP response | −0.064 (−0.083, −0.046) | −0.045 (−0.057, −0.034) | −0.013 (−0.026, 0.000) | <0.001 | N/A | G-L 0.199, G-S <0.001, L-S 0.001 |
For short-term change in HbA1c, data are presented as mean change in HbA1c from baseline to 3 months, and for long-term change in HbA1c, data are presented as the average rate of change per year after 3 months postrandomization through the end of follow-up. Results in this table are based on linear repeated-measures regression models including all available HbA1c measurements with the time-varying metabolic measure as a predictor in the model. All models include adjustment for baseline HbA1c as a covariate. All models for β-cell function (CPI, total CP response) also include adjustment for insulin sensitivity (HOMA2-%S) as a covariate. G, glimepiride; L, liraglutide; N/A, not applicable; S, sitagliptin.
*The heterogeneity P value is from the test of treatment group differences in the association of insulin sensitivity or β-cell function with HbA1c change. If there are significant treatment group differences, the treatment-specific columns present the difference in short-term or long-term change in HbA1c (95% CI) per unit increase in the insulin sensitivity or β-cell function index within that treatment group.
†If there are not significant treatment group differences, the overall P value is presented from the test of an overall association (i.e., across all treatment groups) of insulin sensitivity or β-cell function with HbA1c change, and differences in HbA1c change per unit increase in the metabolic variable are presented in the “overall” column. If there were significant treatment group differences, the test of an overall association was not conducted and “N/A” is presented for the overall P value.
‡If there are significant treatment group differences, then pairwise comparisons of the treatment groups were tested. “G-L” indicates the P value testing the comparison of glimepiride vs. liraglutide. “G-S” indicates the P value testing the comparison of glimepiride vs. sitagliptin. “L-S” indicates the P value testing the comparison of liraglutide vs. sitagliptin. If the test of heterogeneity across treatment groups is not significant, then tests of pairwise comparisons were not conducted, and “N/A” is presented in the pairwise P values column.