TABLE 2.
The association between each oral hypoglycemic drug class and memory performance over time
| Normal cognition | Amnestic MCI | AD dementia | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Beta [95% CI] | t | df | P‐value | Beta [95% CI] | t | df | P‐value | RR [95% CI] | z | P‐value | |
| Immediate memory | |||||||||||
| Met × time | 0.069 [0.011, 0.128] | 2.33 | 751.92 | .0202 | 0.002 [−0.101, 0.106] | 0.04 | 229.72 | .9646 | 0.964 [0.900, 1.032] | −1.05 a | .2920 |
| SU × time | 0.02 [−0.024, 0.063] | 0.89 | 637.22 | .3748 | 0.069 [−0.01, 0.148] | 1.72 | 135.43 | .0871 | 1.059 [0.998, 1.125] | 1.89 a | .0584 |
| TZD × time | 0.015 [−0.021, 0.052] | 0.82 | 463.86 | .4115 | −0.065 [−0.136, 0.006] | −1.81 | 256.65 | .0720 | 0.889 [0.815, 0.970] | −2.66 a | .0078 |
| Gliptin × time | −0.008 [−0.051, 0.035] | −0.36 | 955.98 | .7197 | 0.033 [−0.025, 0.092] | 1.11 | 197.91 | .2678 | 1.067 [0.983, 1.159] | 1.55 a | .1220 |
| Delayed memory | |||||||||||
| Met × time | 0.089 [0.032, 0.146] | 3.04 | 915.19 | .0024 | 0.028 [−0.063, 0.119] | 0.60 | 252.71 | .5480 | 0.925 [0.823, 1.040] | −1.31 a | .1904 |
| SU × time | 0.019 [−0.024, 0.062] | 0.85 | 729.56 | .3934 | −0.006 [−0.081, 0.068] | −0.17 | 270.24 | .8679 | 1.042 [0.941, 1.154] | 0.79 a | .4269 |
| TZD × time | 0.024 [−0.013, 0.061] | 1.26 | 735.56 | .2090 | 0.004 [−0.062, 0.069] | 0.11 | 311.41 | .9113 | 0.874 [0.740, 1.031] | −1.60 a | .1106 |
| Gliptin × time | 0.005 [−0.037, 0.047] | 0.23 | 1309.16 | .8172 | 0.002 [−0.053, 0.057] | 0.08 | 397.84 | .9386 | 1.220 [1.060, 1.403] | 2.78 a | .0055 |
Notes: Inverse probability treatment weighting was used to adjust for confounding by indication, including comorbid cardiovascular disease, stroke history, body mass index, and vitamin B12 deficiency. The effects of each oral drug class were determined by separate regression models with inverse probability treatment weights toward the tested drug.
All estimates were controlled for age, sex, education, APOE ε4 carrier status, baseline MMSE score, comorbid depression, hypercholesterolemia, and hypertension, concurrent use of other hypoglycemic drug classes, and concurrent use of medications for AD.
Abbreviations: AD, Alzheimer's disease; Beta, standardized coefficient; CI, confidence interval; Gliptin, dipeptidyl peptidase‐4 inhibitors; MCI, mild cognitive impairment; Met, metformin; RR, rate ratio; SU, sulfonylurea; TZD, thiazolidinedione.
Mixed‐effects zero‐inflated quasi‐Poisson regression (random‐intercepts) was used.