Postprandial C-peptide is more relevant to hemoglobin A1c levels and diabetic microvascular complications than fasting C-peptide in type 2 diabetes

Table 1 Characteristics of the participants, n (%)

	n	Median (interquartile range or percent)	Range
Age (years)	453	62 (55, 68)	26-86
Sex (male)	453	273 (60.3)	—
Body mass index (kg/m2)	442	25.2 (23.0, 27.7)	15.8-42.3
Duration of diabetes (years)	453	12 (6, 19)	0.08-40
Hemoglobin A1c (%)	453	8.8 (7.3, 10.4)	5.5-16.7
FPG (mmol/L)	452	7.1 (5.7, 9.0)	3.2-22.7
Postprandial blood glucose (mmol/L)	447	11.8 (9.2, 14.9)	2.8-30.9
Total cholesterol (mmol/L)	451	4.16 (3.50, 4.97)	2.06-7.77
Triglyceride (mmol/L)	451	1.28 (0.97, 1.88)	0.4-18.32
Low-density lipoprotein cholesterol (mmol/L)	451	2.42 (1.81, 3.12)	0.55-5.48
High-density lipoprotein cholesterol (mmol/L)	451	1.06 (0.92, 1.29)	0.54-2.44
Creatinine (μmol/L)	453	63 (54, 76)	31-131
Uric acid (μmol/L)	451	335 (279, 395)	144-661
Alanine transaminase (mmol/L)	453	17 (14, 26)	1-119
FCP (pmol/L)	453	306.3 (190.6, 494.6)	2.9-1582.0
2hCP (pmol/L)	453	858.6 (480.5, 1324.6)	4.7-4652.7
Delta CP	453	484.5 (215.7, 895.7)	-291.1 to 3798.3
CP ratio	453	2.73 (1.75, 3.74)	0.22-437.82
FCP/FPG	452	42.33 (24.82, 65.19)	0.85-268.14
2hCP/postprandial blood glucose	447	66.10 (36.95, 114.83)	0.80-434.83
Delta CP/BG	446	23.03 (6.14, 51.79)	-132.93 to 301.60
CP/BG ratio	446	1.60 (1.18, 2.19)	0.26-265.48
Insulin treatment	453	268 (59.2)	—
OADs treatment	453	447 (98.7)	—
OADs and insulin treatment	453	195 (43.1)	—
Diabetes microvascular complications	453	372 (82.1)	—
Diabetic retinopathy	453	130 (28.7)	—
Diabetic peri-neuropathy	453	325 (71.7)	—
Diabetic kidney disease	453	151 (33.3)	—

Data are shown as median (interquartile ranges) or percentage (%). BG: Blood glucose; CP: C-peptide; FCP: Fasting C-peptide; FPG: Fasting plasma glucose; OADs: Oral anti-diabetic drugs; 2hCP: 2 hours postprandial C-peptide.