Research Article

Effects of Metformin Added to Insulin in Adolescents with Type 1 Diabetes: An Exploratory Crossover Randomized Trial

Table 1

Baseline characteristics of the randomized participants.

CharacteristicOverallSequence A†Sequence B† value

Number of subjects ()1798
Female, (%)7 (41.18)3(33.33)4 (50)0.64
Age (years)0.09
Duration of diabetes (years)4.50 (3.58, 6.92)4.67 (4, 10.5)3.96 (3.04, 5.88)0.34
Tanner stage‡4 (2-5)4 (2-5)3 (2-4)0.24
BMI (kg/m2)0.85
Systolic BP (mmHg)0.29
Diastolic BP (mmHg)0.39
Insulin dose (units/kg/day)0.94 (0.89, 1.02)0.96 (0.91, 1.02)0.92 (0.85, 1.06)0.85
Lipid profiles
 TC (mmol/L)0.97
 LDL-C (mmol/L)2.53 (2.13, 3.25)2.24 (2.13, 3.26)2.58 (2.13, 2.99)0.92
 HDL-C (mmol/L)0.34
 TG (mmol/L)0.61 (0.51, 0.76)0.52 (0.47, 0.61)0.73 (0.61, 0.82)0.03
Fasting glucose (mmol/L)0.54
HbA1c (%)9.0 (8.5, 9.4)8.7 (8.4, 9.1)9.3 (8.7, 9.6)0.18
Insulin sensitivity index (lnIS)§0.32
CGM parameters
1697
 MBG (mmol/L)0.56
 %CV0.62
 MAGE (mmol/L)0.37
 MODD (mmol/L)0.20
Holter parameters
1587
 SDNN (ms)0.37
 SDANN (ms)0.41
 RMSSD (ms)0.50
 PNN50 (%)0.92
 LogLF (ms2)0.55
 LogHF (ms2)0.56
 LF/HF0.66

Data are (SD), median (interquartile range (IQR)), or counts (percentage) unless otherwise noted. †Sequence A, metformin nonmetformin; sequence B, nonmetformin metformin. ‡Tanner stage was presented as median (range). § (mg/dL, to convert TG values from mmol/L to mg/dL, divide by 0.0113). BMI: body mass index; BP: blood pressure; TC: total cholesterol; LDL-C: low-density lipoprotein cholesterol; HDL-C: high-density lipoprotein cholesterol; TG: triglyceride; CGM: continuous glucose monitoring; MBG: mean blood glucose; %CV: coefficient of variability of glycemia; MAGE: mean amplitude of glycemic excursions; MODD: means of daily differences; HRV: heart rate variability; SDNN: standard deviation of all RR intervals; SDANN: standard deviation of all the 5-minute RR intervals; RMSSD: square root of the mean of the sum of squares of differences between adjacent RR intervals; PNN50: the percentage of the interval differences of successive RR intervals greater than 50 ms; LF: low frequency; HF: high frequency; LF/HF: low frequency/high frequency.