Table 3

 Factors associated with occurrence of retinopathy in adolescents with type 1 diabetes mellitus who were retinopathy-free at baseline: longitudinal analysis using generalised estimating equations (n=1093)

CovariatesOdds ratio (95% CI)P value
Model 1*
Systolic blood pressure (mm Hg)1.01 (1.003 to 1.02)0.008
Diastolic blood pressure (mm Hg)1.01 (1.002 to 1.03)0.02
Age (years)1.13 (1.08 to 1.17)<0.001
Duration (years)1.16 (1.13 to 1.19)<0.001
Haemoglobin A1c1.08 ( 1.02 to 1.15)0.01
Log albumin excretion rate1.27 (1.13 to 1.42)<0.001
Height (cm)0.98 ( 0.97 to 0.99)<0.001
Model 2†
Diastolic blood pressure (mm Hg)1.02 (1.01 to 1.04)0.004
Age (years)1.12 (1.06 to 1.18)<0.001
Duration (years)1.14 (1.09 to 1.18)<0.001
Haemoglobin A1c1.14 (1.03 to 1.26)0.009

*Included systolic and diastolic blood pressure measurements from patients who were retinopathy-free at baseline (n=1093) along with other covariates.

†Included systolic and diastolic blood pressure measurements from patients who were retinopathy-free at baseline and had albumin excretion rate consistently below 7.5 μg/min throughout follow-up (n=594).