Type 1 diabetes mellitus: long-term complications

2021-03-03 12:00 AM

The risk of developing microvascular or macrovascular complications is related to the duration of diabetes and to the degree of glycaemic control achieved over time. Patients who achieve and maintain good glycaemic control (i.e. HbA1c 7.0% or less) have a lower risk. Genetic factors may also influence the risk of complications. The conditions outlined in Box 12.2 require screening.

Box 12.2 Long-term complications of T1DM

Microvascular complications

  • Renal: microalbuminuria, diabetic nephropathy
  • Eyes: retinopathy
  • Nervous: peripheral neuropathy, autonomic neuropathy


  • Hypertension
  • CHD
  • Macrovascular complications are almost never seen in children and adolescents.
  • Microvascular complications may be seen during the childhood and adolescent years of T1DM. The incidence and frequency are low before puberty. Risk factors for the development of early microvascular disease are the duration of diabetes, glycaemic control (long-term), and the onset of puberty.

Microalbuminuria (MA)

  • Rare before puberty.
  • May be intermittent and transient.
  • May be associated with increased BP.
  • May require treatment with ACE inhibitor if MA persists (+/– hypertension).


Significant changes are rare before the onset of puberty. Background retinopathy (microaneurysms, retinal haemorrhages, soft and hard exudates) may be seen. Pre-proliferative/proliferative retinopathy is rare.

Both the conditions should be screened for annually from age 11yrs (or from 9yrs if the duration of DM >5yrs). MA screening by EMU estimation of urinary albumin: creatinine ratio. Retinopathy screening by digital retinal photography.