Table 2.

The linear association between BUN and the probability of DR in different models.

Variable	Crude model	Minimally adjusted model	Fully adjusted model
BUN	1.18 (1.10, 1.26) < 0.001	1.18 (1.09, 1.27) < 0.001	1.11 (1.03, 1.21) 0.011
BUN (Quartile)
Q1	Reference	Reference	Reference
Q2	1.67 (0.93, 3.00) 0.087	1.70 (0.91, 3.15) 0.094	1.82 (0.95, 3.48) 0.070
Q3	1.56 (0.88, 2.79) 0.131	1.58 (0.85, 2.94) 0.150	1.64 (0.84, 3.18) 0.144
Q4	3.27 (1.85, 5.77) < 0.001	3.35 (1.75, 6.42) 0.001	2.14 (1.06, 4.31) 0.033
P for trend	0.001	0.001	0.053

The models were presented as OR (95%CI) P-value.

Crude model: we did not adjust other covariants.

Minimally adjusted model: we adjusted age, sex and DM duration.

Fully adjusted model: we adjusted age, sex, DM duration, D-dimer, LDL, HbA1c, serum albumin, HBP, SBP.