Glycated hemoglobin is not enough: The role of glycemia risk index for glycemic control assessment in type 1 diabetes

Table 1 Clinical characteristics of the total population and according to glycemia risk index zones, mean ± SD/n (%)

Characteristic	Total (n = 6811)	GRI zone					P value
		Zone A (0-20), (n = 731)	Zone B (21-40), (n = 1851)	Zone C (41-60), (n = 1881)	Zone D (61-80), (n = 1331)	Zone E (81-100), (n = 1021)
Age, years (IQR)	13 (9-21)	15 (11-23)	13 (8-21)	12 (8-25)	13 (9-17)	12 (9-16)	0.150
Age subgroup, children and adolescents	471 (69.5)	42 (57.5)	126 (68.5)	125 (66.8)	100 (75.8)	78 (76.5)	0.034
Sex, female	378 (55.5)	35 (47.9)	111 (60.0)	104 (55.3)	73 (54.9)	55 (53.9)	0.504
Duration, months (IQR)	28 (13-49)	13 (8-34)	23 (11-42)	29 (14-47)	35 (18-54)	35 (20-59)	< 0.001
SBP, mmHg (IQR)	106 (99-117)	107 (101-118)	105 (98-113)	106 (97-118)	107 (100-115)	109 (100-120)	0.087
DBP, mmHg (IQR)	64 (58-71)	67 (60-73)	64 (57-70)	63 (58-71)	65 (57-70)	66 (60-71)	0.136
BMI for children and adolescents, kg/m2 (IQR)	0.14 (-0.56 to 0.84)	0.03 (-0.55 to 0.77)	0.06 (-0.63 to 0.60)	0.15 (-0.56 to 0.87)	0.39 (-0.52 to 1.03)	0.27 (-0.38 to 0.85)	0.2942
BMI for adult, kg/m2 (IQR)	21.33 (19.55-23.19)	21.48 (19.26-22.15)	21.63 (19.97-22.75)	20.43 (19.49-23.52)	21.60 (20.17-23.45)	21.03 (19.77-23.45)	0.489
Treatment method							0.366
CSII	225 (33.0)	19 (26.0)	67 (36.2)	66 (35.1)	45 (33.8)	28 (27.5)
MDI	456 (67.0)	54 (74.0)	118 (63.8)	122 (64.9)	88 (66.2)	74 (72.5)
FCP, pmol/L (IQR)	33 (17-121)	153 (56-209)	58 (17-137)	24 (17-76)	20 (17-77)	17 (17-77)	< 0.001
2hCP, pmol/L (IQR)	53 (17-203)	340 (178-582)	109 (17-266)	35 (17-162)	22 (17-134)	19 (17-115)	< 0.001
HbA1c, % (IQR)	7.20 (6.60-8.00)	6.45 (6.05-6.70)	6.90 (6.56-7.40)	7.30 (6.81-7.90)	7.80 (7.00-8.29)	8.36 (7.23-9.00)	< 0.001
HbA1c < 7%	273 (40.1)	65 (89.0)	98 (53.0)	61 (32.4)	31 (23.3)	18 (17.6)	< 0.001
MG, mmol/L (IQR)	8.10 (7.01-9.41)	7.01 (6.47-7.30)	7.65 (6.84-8.31)	8.39 (7.35-9.37)	9.18 (7.36-10.37)	10.98 (7.95-12.54)	< 0.001
GMI (%)	6.93 ± 0.87	6.33 (6.10-6.45)	6.61 (6.26-6.89)	6.92 (6.48-7.35)	7.26 (6.48-7.77)	8.04 (6.73-8.71)	< 0.001
GMI < 7%	417 (61.2)	73 (100)	158 (85.4)	105 (55.9)	51 (38.3)	30 (29.4)	< 0.001
CV, % (IQR)	39 (34-44)	29 (27-31)	35 (33-38)	40 (38-42)	44 (40-48)	47 (40-52)	< 0.001
CV < 36%	241 (35.4)	73 (100.0)	105 (56.8)	33 (17.6)	13 (9.8)	17 (16.7)	< 0.001
VLow, % (IQR)	1.3 (0.2-3.6)	0.1 (0.0-0.3)	0.8 (0.3-1.7)	1.9 (0.5-3.6)	3.5 (1.1-7.2)	4.2 (0.8-11.5)	< 0.001
Low, % (IQR)	4.5 (2.3-7.1)	2.4 (1.2-3.3)	4.3 (2.3-6.3)	5.3 (2.8-7.5)	5.5 (3.1-9.2)	4.7 (2.3-9.8)	< 0.001
TBR, % (IQR)	6 (3-11)	2 (1-4)	5 (3-8)	7 (4-12)	9 (5-16)	9 (4-22)	< 0.001
TBR < 4%	238 (34.9)	58 (79.5)	71 (38.4)	54 (28.7)	29 (21.8)	26 (25.5)	< 0.001
TAR, % (IQR)	26 (13-41)	9 (5-12)	19 (11-26)	30 (19-39)	40 (25-51)	54 (31-67)	< 0.001
TAR < 25%	329 (48.3)	73 (100.0)	132 (71.4)	67 (35.6)	34 (25.6)	23 (22.5)	< 0.001
High, % (IQR)	19 (11-25)	8 (5-11)	16 (10-22)	22 (16-27)	24 (18-31)	23 (15-27)	< 0.001
VHigh, % (IQR)	5 (1-13)	0 (0-1)	2 (1-5)	8 (3-11)	13 (4-21)	30 (12-37)	< 0.001
TIR, % (IQR)	65 (52-77)	89 (86-91)	76 (70-80)	63 (57-69)	50 (45-60)	37 (29-47)	< 0.001
TIR > 70%	257 (37.7)	73 (100.0)	140 (75.7)	42 (22.3)	2 (1.5)	0 (0.0)	< 0.001
GRI (IQR)	47 (33-69)	15 (11-18)	32 (27-36)	49 (45-54)	69 (64-74)	92 (85-100)	< 0.001
GRI-lo (IQR)	5 (2-10)	2 (1-3)	4 (2-6)	6 (3-10)	8 (4-14)	8 (3-20)	< 0.001
GRI-hi (IQR)	15 (7-27)	5 (2-6)	11 (6-15)	19 (11-25)	27 (14-36)	42 (22-51)	< 0.001
Number of hypoglycemia at night (IQR)	3.0 (1.0-5.0)	1.0 (0.0-3.0)	3.0 (1.0, 5.0)	4.0 (2.0-6.0)	4.0 (2.0-6.0)	2.5 (1.0-6.0)	< 0.001
Number of severe hypoglycemia at night (IQR)	1.00 (0.00-2.00)	0.00 (0.00-0.00)	1.00 (0.00-1.00)	1.00 (0.00-2.00)	2.00 (1.00-4.00)	2.00 (0.00-5.00)	< 0.001

GRI: Glycemia risk index; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; BMI: Body mass index; CSII: Continuous subcutaneous insulin infusion; MDI: Multiple daily insulin injection; FCP: Fasting C-peptide; 2hCP: 2-hour C-peptide; MG: Mean glucose; GMI: Glucose management indicator; HbA1c: Glycated hemoglobin; CV: Coefficient of variation; Low: Low-glucose hypoglycemia (glucose level: 3.0 mmol/L to < 3.9 mmol/L); VLow: Very-low-glucose hypoglycemia (glucose level: < 3.0 mmol/L); TBR: Time below range; TAR: Time above range; TIR: Time in range; High: High-glucose hyperglycemia (glucose level: 10.0 mmol/L to 13.9 mmol/L); VHigh: Very-high-glucose hyperglycemia (glucose level: > 13.9 mmol/L); GRI-lo: Hypoglycemia component of glycemia risk index; GRI-hi: The hyperglycemia component of glycemia risk index; IQR: Interquartile range.