Table 1.
Characteristics of the included studies.
| Studies | Hari et al. (NCT01235819) | Griffin et al. (NCT01155284) | Garg et al. (NCT01227460) | Zhao et al. (NCT01159847) | Farngren et al. (NCT01147276) |
|---|---|---|---|---|---|
| Experimental treatment | Sitagliptin (100 mg, qd) + insulina (premix insulin) | Sitagliptin (100/50 mg, qd) + lansoprazole (60/30 mg, qd) + insulin (unspecified) | Sitagliptin (100 mg, qd) + insulinb (premixed insulin excluded) | Sitagliptin (100 mg, qd) + insulin (unspecified) | Vildagliptin (50 mg, bid) + insulinc (long-acting and short-acting insulin) |
| Control treatmentd | Insulin (bid-tid) | Placebo + insulin | Placebo + insulin | Insulin | Placebo + insulin |
| Treatment period (weeks) | 52 | 52 | 16 | 52 | 8 |
| Experimental samples | 6 | 40 | 63 | 15 | 14 |
| Control samples | 6 | 18 | 62 | 15 | 14 |
| Average age (years) | 27.15 ± 4.20 | 16.18 ± 5.78 | 37.99 ± 14.01 | 47.45 ± 3.27 | U |
| Mean duration of T1DM | 33.25 ± 9.37 d | 103.41 ± 51.74 d | 21.01 ± 11.00 y | 1.4 ± 0.20 y | 11.0 ± 4.30 y |
| Average BMI (kg/m2) | 21.50 ± 3.39 | 21.51 ± 3.95 | 27.45 ± 4.54 | 23.35 ± 0.85 | 24.8 ± 3.30 |
| Design | RCT | RCT | RCT | RCT | RCT |
| Number of centers | 1 | 3 | 3 | 1 | 1 |
| HbA1c at baseline (%) | 9.75 ± 0.83 | 7.18 ± 1.09 | 8.55 ± 0.70 | 6.45 ± 0.20 | 7.49 ± 0.55 |
| Cholesterol at baseline (mmol/L) | U | U | U | 4.65 ± 0.16 | U |
| C-peptide at baseline (pmol/L) | 0.395 ± 0.15e | 685.44 ± 412.36 | ≥16 pmol/Lf | 401.75 ± 52.27g | U |
| LDL-C at baseline (mmol/L) | U | U | U | 2.75 ± 0.13 | U |
| Triglyceride at baseline (mmol/L) | U | U | U | 1.2 ± 0.1 | U |
| Inclusion criteria | Recent T1DM < 3 m, GAD+or stimulated CP < 0.5 ng/mL, age < 30 y | Aged 11–36 y, <6 m | Aged 18–80 y, after diagnosed for 1 y, BMI < 35 kg/m2 | Aged 25–70 y, FCP ≥ 200/2 hCP ≥ 400 pmol/L, duration < 3 y, LADA | Age > 18 y, duration of 2–20 y, HbA1c of 6.5–8.5% |
| Exclusion criteria | C-peptide < 0.1 ng/mL, age > 30 y, pancreatic disease | Risk of pancreatitis, pregnant | BMI ≥ 35 kg/m2 | Other autoimmune diseases, insulin > 0.8 U/kg/d, renal disease | Pregnant or lactating, acute infection, liver disease, blood donor, using GH or oral steroid |
d: days; m: months; y: years. Data are presented as the mean ± SD or as numbers (percentages). U: unknown; NG: not given; GH: growth hormone; BMI: body mass index; RCT: randomized controlled trial. aPatients initially were started on a twice daily premixed insulin regime (25% insulin Lispro and 75% insulin Lispro protamine) and later shifted to a three-times-daily premixed regime depending on their glycemic profiles. bPatients may be using insulin via a continuous subcutaneous insulin infusion (CSII) or multiple daily injections (MDI) containing bolus and basal insulin. cTwenty-six patients were treated with daily basal-bolus injections; their mean insulin dose was 30 U/d (long-acting insulin; 0.37 ± 0.07 U/kg) and 31 U/d (short-acting insulin; 0.37 ± 0.09 U/kg). Two patients were treated with a continuous sc insulin infusion [daily dose 60 and 36 U (0.67 and 0.52 U/kg), resp.]. dThe insulin dosages used were consistent with the experimental group. eng/mL; fonly 20 patients were reported to be C-peptide-positive; gfasting C-peptide level.