No significant association between dipeptidyl peptidase-4 inhibitors and adverse outcomes of COVID-19

Table 1 Characteristics of patients with type 2 diabetes in dipeptidyl peptidase-4 inhibitor and non-dipeptidyl peptidase-4 inhibitor groups before and after propensity score matching

	Unmatched			Matched (1:3)3
Parameter	DPP4i4 (n = 142)	Non-DPP4i5 (n = 1115)	SD	DPP4i4 (n = 111)	Non-DPP4i5 (n = 333)	SD
Clinical characteristics on admission
Age, median (IQR)	63 (55-67)	64 (56.5-69)	-0.107	63 (55.5-67)	64 (56-69)	-0.068
Male gender, n (%)	66 (46.48)	588 (52.74)	-0.125	57 (51.35)	159 (47.75)	0.072
Female gender, n (%)	76 (53.52)	527 (47.26)	0.125	54 (48.65)	174 (52.25)	-0.072
Heart rate, median (IQR)	82 (75-91)	85 (78-98)	-0.192	82.5 (75-97.25)	82 (76-96)	0.032
Respiratory rate, median (IQR)	20 (19-21)	20 (19-21)	0.030	20 (19-20)	20 (19-21)	0.014
DBP, median (IQR)	80 (73.25-90)	80 (72-89)	0.116	80 (72-91)	80 (74-89)	0.018
SBP, median (IQR)	133 (123-146)	133 (121-145)	0.070	133 (123-146)	135 (122-148)	-0.021
SpO2, median (IQR)	97 (95-98)	97 (95-98)	0.018	97 (95-98)	97 (95-98)	0.049
Comorbidities on admission
Heart failure, n (%)	0 (0.00)	3 (0.27)	-0.073	0 (0.00)	0 (0.00)	0
Coronary heart disease, n (%)	16 (11.27)	150 (13.45)	-0.066	13 (11.71)	44 (13.21)	-0.045
Cerebrovascular diseases, n (%)	5 (3.52)	41 (3.68)	-0.008	4 (3.60)	16 (4.80)	-0.060
Chronic liver disease, n (%)	0 (0.00)	25 (2.24)	-0.214	0 (0.00)	0 (0.00)	0
Chronic renal diseases, n (%)	2 (1.41)	23 (2.06)	-0.050	2 (1.80)	3 (0.90)	0.078
Chronic obstructive pulmonary disease, n (%)	1 (0.70)	9 (0.81)	-0.012	1 (0.90)	3 (0.90)	0
Background anti-diabetic drugs1
1 type, n (%)	24 (16.90)	526 (47.17)	-0.686	24 (21.62)	82 (24.62)	-0.071
2 types, n (%)	47 (33.10)	439 (39.37)	-0.131	47 (42.34)	133 (39.94)	0.049
3 types, n (%)	52 (36.62)	135 (12.11)	0.596	39 (35.14)	113 (33.93)	0.025
≥ 4 types, n (%)	19 (13.38)	12 (1.08)	0.489	1 (0.90)	5 (1.50)	-0.055
Insulin, n (%)	81 (57.04)	607 (54.44)	0.052	59 (53.15)	184 (55.26)	-0.042
Chest CT on admission
Bilateral lesions, n (%)	119 (92.25)	957 (90.71)	0.055	91 (91.92)	289 (92.33)	-0.015
Laboratory examination on admission
Leukocyte count > 9.5 × 109/L, n (%)	16 (11.35)	101 (9.41)	0.063	13 (11.71)	29 (8.95)	0.091
Neutrophil count > 6.3 × 109/L, n (%)	22 (15.60)	166 (15.47)	0.004	18 (16.22)	53 (16.36)	-0.004
Lymphocyte count < 1.1, 109/L, n (%)	55 (39.01)	437 (40.73)	-0.035	42 (37.84)	130 (40.12)	-0.047
Red blood count < 3.5 (for female), 4.0 (for male) × 1012/L, n (%)	61 (43.26)	480 (44.73)	-0.030	48 (43.24)	156 (48.15)	-0.099
C-reactive protein increase > ULN2, n (%)	36 (49.32)	298 (50.85)	-0.031	26 (44.07)	98 (56.32)	-0.247
Procalcitonin level increase > ULN2, n (%)	54 (46.96)	399 (44.19)	0.056	39 (43.82)	132 (48.18)	-0.087
ALT increase > 40 U/L, n (%)	22 (15.83)	234 (21.89)	-0.155	16 (14.68)	53 (16.46)	-0.049
eGFR, median (IQR)	104.20 (90.60-119.76)	101.18 (84.33-119.66)	0.088	103.78 (90.77-116.18)	101.33 (83.55-117.81)	0.028
D-dimer > ULN2, n (%)	62 (49.60)	526 (53.08)	-0.070	51 (52.04)	148 (50.00)	0.041
LDL-c > 3.4 mmol/L, n (%)	25 (22.73)	135 (15.96)	0.172	16 (19.51)	51 (19.54)	-0.001

¹Background anti-diabetic drugs were defined as the number of types of combined oral hypoglycemic agents and the proportion of patients using insulin.

²Upper limit of normal was defined according to criteria in each hospital and normal ranges of tests in each hospital.

³In the propensity score matched model, age, gender, heart rate, blood pressure, SpO₂ < 95%, computed tomography-diagnosed bilateral lung lesions, incidence of increased neutrophil count, leukocyte count, C-reactive protein, procalcitonin, alanine transaminase, D-dimer, low density lipoprotein cholesterol and decreased lymphocyte count, estimated glomerular filtration rate, comorbidities (chronic obstructive pulmonary disease, cerebrovascular diseases, chronic liver disease, and chronic renal diseases), the numbers of oral hypoglycemic agents, and the proportion of insulin usage were matched.

⁴Patients with type 2 diabetes who received dipeptidyl peptidase-4 inhibitors (DPP4i) throughout the whole 28-d follow-up period were enrolled in the DPP4i cohort.

⁵Patients with type 2 diabetes who never received DPP4i but took other anti-diabetic drugs throughout the observation time during hospitalization were classified as the non-DPP4i group. Data are n (%) or medians (IQR).

DPP4i: Dipeptidyl peptidase-4 inhibitors; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; SpO₂: Pulse oxygen saturation; ALT: Alanine transaminase; eGFR: Estimated glomerular filtration rate; LDL-c: Low density lipoprotein cholesterol; IQR: Interquartile range; SD: Standardized difference; ULN: Upper limit of normal; CT: Computed tomography.