Table 1

Prevalence of microvascular complications in different HbA1c categories and long-term weighted mean HbA1c in an unselected population of patients with type 1 diabetes after 20–24 years of diabetes duration

Prevalence in various HbA1c categories NGSP values % (IFCC value mmol/mol)Long-term weighted mean HbA1c
≤6.7 (≤50)6.8–7.6 (51–60)7.7–8.6 (61–70)8.6–9.5 (71–80)>9.5 (>80)AllNGSP value % mean (95% CI)IFCC value mmol/mol mean (95% CI)
nnnnnn%
Retinopathy
 None201813305412.57.2 (6.9–7.4)55 (52–58)
 Mild simplex16564623414533.67.8 (7.7–8.0)62 (60–64)
 Moderate simplex13969461917440.48.4 (8.3–8.6)68 (67–70)
 Proliferative/laser therapy011419245813.59.4 (9.1–9.7)79 (76–83)
 All3711414291474318.2 (8.1–8.3)66 (65–67)
Nephropathy
 Normoalbuminuria30102119642534081.08.0 (7.9–8.2)64 (63–66)
 Microalbuminuria391920126315.08.6 (8.3–8.9)71 (68–74)
 Macroalbuminuria00241117*4.010.1 (9.5–10.6)86 (80–93)
 All3311114088484208.2 (8.1–8.3)66 (65–67)
  • P < 0.001 for HbA1c and grade of retinopathy and nephropathy. Data were analyzed using one-way ANOVA and Bonferroni post hoc test. All differences were significant in pairwise comparisons, apart from normoalbuminuria compared with microalbuminuria.

  • * Three patients had end-stage renal disease: two patients had kidney transplantation; one patient had long-term dialysis.