Association between glucose levels of children with type 1 diabetes and parental economic status in mobile health application

Table 1 Baseline characteristics of participants with type 1 diabetes

Characteristics	All, n = 1406	Low-income, n = 320	Middle-income, n = 724	High-income, n = 362	P value
Age (yr)	8.11 (4.64, 11.61)	10.06 (5.23, 13.18)	7.84 (4.61, 11.29)	7.15 (3.83, 10.76)	< 0.001
Duration of T1D (yr)	0.06 (0.02, 0.44)	0.12 (0.03, 0.92)	0.06 (0.02, 0.40)	0.04 (0.01, 0.22)	< 0.001
HbA1c at onset (%)	12.10 (10.50, 14.00)	12.80 (10.80, 14.40)	12.00 (10.00, 14.00)	12.30 (11.00, 13.70)	0.072
Sex					0.004
Male	627 (44.59)	123 (38.44)	319 (44.06)	185 (51.10)
Female	779 (55.41)	197 (61.56)	405 (55.94)	177 (48.90)
Parents' education level (n = 1383)1					< 0.001
Low level	493 (35.65)	211 (67.63)	244 (34.32)	38 (10.56)
High level	890 (64.35)	101 (32.37)	467 (65.68)	322 (89.44)
Insulin treatment					< 0.001
CSII	631 (44.88)	129 (40.31)	300 (41.44)	202 (55.80)
MDI	719 (51.14)	180 (56.25)	391 (54.01)	148 (40.88)
Others	56 (3.98)	11 (3.44)	33 (4.56)	12 (3.31)
Typical symptoms at onset2 (n = 1292)					0.552
No	69 (5.34)	14 (4.91)	40 (5.98)	15 (4.44)
Yes	1223 (94.66)	271 (95.09)	629 (94.02)	323 (95.56)
DKA at onset (n = 1288)					0.002
No	373 (28.96)	70 (24.56)	180 (27.15)	123 (36.18)
Yes	915 (71.04)	215 (75.44)	483 (72.85)	217 (63.82)
Diabetes family history (n = 1366)					0.138
No	1053 (77.09)	240 (76.92)	552 (78.97)	261 (73.52)
Yes	313 (22.91)	72 (23.08)	147 (21.03)	94 (26.48)

¹Based on the education level of the parents, the study population was divided into a low education group (secondary school and below) and a high education group (college and above).

²Typical symptoms at onset including, polydipsia, polyphagia, polyuria and weight loss.

Data are presented as median (interquartile range), or number (%). T1D: Type 1 diabetes; HbA1c: Hemoglobin A1c; CSII: Continuous subcutaneous insulin infusion; MDI: Multiple daily insulin injections; DKA: Diabetic ketoacidosis.

Table 2 Comparison of glycemic changes at 36 months after registration

Glucose level at different time periods (mmol/L)	Low-income		P value	Middle-income		P value	High-income		P value
	3th month	36th month		3th month	36th month		3th month	36th month
Pre-breakfast	6.60 (5.70, 7.90)	7.65 (6.80, 8.72)	0.008	6.30 (5.40, 7.60)	7.15 (6.00, 8.03)	0.023	6.25 (5.50, 7.40)	6.60 (5.83, 7.20)	0.584
Post-breakfast	8.40 (7.10, 9.65)	8.75 (7.40, 9.70)	0.436	8.30 (7.05, 10.10)	7.80 (6.80, 10.00)	0.550	7.90 (7.00, 9.47)	6.90 (6.40, 7.82)	0.058
Pre-lunch	7.10 (6.10, 8.60)	8.85 (6.53, 11.05)	0.013	7.20 (6.07, 8.80)	7.50 (6.00, 10.10)	0.589	7.00 (5.90, 8.40)	7.40 (5.80, 7.80)	0.866
Post-lunch	7.40 (6.50, 8.90)	9.80 (7.75, 11.85)	< 0.001	7.70 (6.70, 9.10)	8.05 (6.98, 10.45)	0.194	7.40 (6.50, 8.40)	7.50 (6.70, 10.60)	0.533
Pre-dinner	8.10 (6.60, 10.20)	9.20 (7.95, 11.75)	0.005	8.15 (6.70, 10.20)	7.80 (6.90, 11.60)	0.882	7.60 (6.30, 9.75)	6.80 (5.60, 8.00)	0.095
Post-dinner	7.60 (6.60, 8.90)	9.40 (7.25, 11.90)	0.002	7.80 (6.60, 9.20)	7.70 (6.28, 10.15)	0.900	7.60 (6.70, 8.70)	7.55 (6.35, 9.40)	0.870
Bedtime	8.20 (7.05, 9.65)	9.60 (8.20, 11.45)	0.018	8.30 (7.10, 9.80)	8.40 (6.80, 9.90)	0.754	7.90 (7.00, 9.60)	8.00 (7.65, 10.50)	0.328

Data are presented as median (interquartile range).

Table 3 Glycemic changes in subgroups of different insulin treatment regimens

Glucose level	Low-income		P value	Middle-income		P value	High-income		P value
at different time periods (mmol/L)	3th month	36th month		3th month	36th month		3th month	36th month
CSII subgroup
Pre-breakfast	6.30 (5.57, 7.70)	7.81 (1.83)	0.01	6.30 (5.40, 7.32)	7.13 (2.22)	0.289	6.05 (5.50, 7.03)	6.46 (1.58)	0.521
Post-breakfast	8.60 (7.10, 9.85)	8.75 (7.90, 9.70)	0.644	8.80 (7.30, 10.40)	7.70 (7.00, 9.70)	0.347	7.90 (7.00, 9.50)	7.00 (6.55, 7.75)	0.148
Pre-lunch	7.10 (6.10, 8.60)	9.60 (6.30, 11.60)	0.042	7.15 (6.00, 8.40)	6.60 (5.97, 8.18)	0.747	6.80 (5.90, 8.22)	7.50 (5.80, 7.80)	0.892
Post-lunch	7.40 (6.68, 8.90)	10.70 (7.55, 12.50)	0.003	8.00 (6.80, 9.30)	9.20 (7.90, 10.60)	0.097	7.40 (6.55, 8.45)	7.50 (7.20, 10.60)	0.468
Pre-dinner	7.70 (6.50, 9.70)	9.40 (8.60, 11.90)	0.001	7.90 (6.55, 10.00)	7.80 (6.10, 10.90)	0.636	7.20 (6.10, 9.00)	6.10 (5.55, 7.45)	0.263
Post-dinner	7.75 (6.73, 8.90)	10.00 (8.25, 12.35)	0.001	7.80 (6.60, 9.20)	7.70 (6.95, 9.10)	0.785	7.40 (6.60, 8.65)	7.60 (5.25, 10.00)	0.708
Bedtime	8.25 (6.90, 10.15)	10.13 (2.74)	0.027	8.20 (7.20, 9.65)	7.42 (2.24)	0.114	7.80 (7.00, 9.00)	8.21 (2.28)	0.646
MDI subgroup
Pre-breakfast	6.70 (5.80, 7.97)	7.50 (7.20, 8.40)	0.127	6.30 (5.40, 7.70)	7.15 (6.07, 8.03)	0.057	6.40 (5.60, 7.50)	6.10 (6.00, 7.10)	0.849
Post-breakfast	8.20 (7.15, 9.40)	8.55 (7.32, 9.15)	0.752	8.00 (6.90, 9.65)	8.15 (6.80, 10.00)	0.982	7.90 (6.97, 9.72)	6.60 (6.40, 7.80)	0.258
Pre-lunch	7.15 (6.35, 8.53)	8.40 (7.50, 9.60)	0.112	7.30 (6.20, 9.15)	8.00 (6.00, 10.40)	0.41	7.20 (5.85, 8.60)	7.00 (6.20, 7.90)	0.894
Post-lunch	7.40 (6.40, 8.90)	8.85 (7.83, 10.05)	0.023	7.50 (6.60, 8.90)	7.70 (6.40, 10.00)	0.616	7.40 (6.30, 8.10)	6.95 (6.30, 8.65)	0.921
Pre-dinner	8.35 (6.82, 10.40)	8.60 (7.43, 10.15)	0.459	8.40 (7.10, 10.28)	8.05 (7.18, 11.60)	0.826	8.70 (6.90, 10.70)	7.30 (6.00, 7.85)	0.117
Post-dinner	7.60 (6.40, 9.15)	8.30 (6.83, 10.05)	0.319	7.60 (6.50, 9.17)	7.70 (5.95, 10.60)	0.924	7.70 (6.80, 8.80)	7.50 (7.20, 8.70)	0.873
Bedtime	8.10 (7.20, 9.45)	8.80 (7.70, 10.65)	0.298	8.35 (7.18, 9.80)	8.60 (7.40, 11.00)	0.579	8.45 (6.95, 10.20)	11.00 (7.90, 12.10)	0.176

Data are presented as median (interquartile range) or mean (SD). T1D: Type 1 diabetes; CSII: Continuous subcutaneous insulin infusion; MDI: Multiple daily insulin injections.

Table 4 The relationship between household income and glycemic control by using binary logistic regression analysis

	Model 1	Model 2
Pre-breakfast
Low	Ref.	Ref.
Middle	1.25 (0.50 to 3.23)	1.40 (0.49 to 4.16)
High	3.18 (0.94 to 11.67)	2.15 (0.52 to 9.52)
Post-breakfast
Low	Ref.	Ref.
Middle	1.24 (0.39 to 3.91)	0.84 (0.22 to 3.08)
High	0.58 (0.14 to 2.70)	0.41 (0.07 to 2.37)
Pre-lunch
Low	Ref.	Ref.
Middle	1.91 (0.74 to 5.12)	2.11 (0.74 to 6.31)
High	1.38 (0.34 to 5.26)	1.42 (0.30 to 6.51)
Post-lunch
Low	Ref.	Ref.
Middle	2.42 (0.91 to 6.59)	4.17 (1.26 to 15.52)
High	1.20 (0.30 to 5.00)	0.59 (0.11 to 3.28)
Pre-dinner
Low	Ref.	Ref.
Middle	6.00 (1.47 to 40.79)	9.06 (1.79 to 73.61)
High	16.92 (3.21to 135.11)	13.02 (1.99 to 126.05)
Post-dinner
Low	Ref.	Ref.
Middle	1.85 (0.72 to 4.87)	1.68 (0.58 to 5.01)
High	0.91 (0.25 to 3.40)	0.79 (0.18 to 3.49)
Bedtime
Low	Ref.	Ref.
Middle	1.15 (0.26 to 6.01)	1.07 (0.17 to 7.50)
High	1.50 (0.18 to 10.22)	0.36 (0.03 to 3.56)

Model 1: Unadjusted; Model 2: Including, household income, sex, age, duration of type 1 diabetes, insulin treatment, and parents' education level.