Shared article

Diabetes - Systemic Complications

Pathogenesis of DKA and HONK



The most significant cause of death in patients with diabetes is cardiovascular disease (70%), followed by renal failure (10%) and infection (6%).


The degree and duration of hyperglycaemia play an important role in the likelihood of developing complications. Keeping HbA1c at 7% results in a 60% reduction in complications in patients with Type I diabetes.

Macrovascular complications: Heart disease, stroke and peripheral vascular disease


Diabetes increases the risk of atherosclerosis. The risk increases as you go from the head to toe. Patients with diabetes are:

  • 2 times more likely to suffer a stroke than the general population.
  • 3-5 times more likely to suffer IHD than the general population.
  • 50 times more likely to undergo amputation of a foot due to gangrene.


Intensive treatment of diabetes only has a small effect on cardiovascular risk of patients with diabetes. It is therefore important to take a holistic approach and tackle coexistent cardiovascular risk factors e.g. smoking.


Additional risk factors for macrovascular complications in patients with diabetes include:

  • Duration of diabetes
  • Increasing age
  • Systolic hypertension
  • Hyperinsulinaemia (due to insulin resistence)
  • Hyperlipidaemia
  • Proteinuria


    Treatment with anti-hypertensive drugs, statin, aspirin, and ACE inhibitors/angiotenisin II receptor antagonists should be strongly considered.

        Diabetic eye complications (including diabetic retinopathy)


        1 in 3 young people with diabetes are likely to develop eye complications. Every year 12% of people who are registered blind or partially sighted have diabetic eye disease; it is the leading cause of blindness in young people.


        Early treatment of diabetic retinopathy with laser photocoagulation can reduce vision loss by up to 60%.


        Diabetic nephropathy

        Diabetic neuropathy

        Up to 70% of patients with diabetes have varying degrees of damage to their nervous system.

        The cause of diabetic neuropathy remains unclear. Occlusion of the vasa nervorum (the blood supply to the nerves) is one of the theories that has been proposed.

        Diabetic neuropathy can present in a range of different combinations of sensory, motor and autonomic symptoms. It is important to take a thorough and systematic history and examination.

        The most common presentation of diabetic neuropathy is symmetrical mainly sensory neuropathy


        Diabetic foot complications

        15% of patients with diabetes will develop a foot ulcer. 12-24% of patients with foot ulcers will have to undergo an amputation.

        People with diabetes develop foot ulcers as a result of a combination of diabetic neuropathy, peripheral vascular disease (due to atherosclerosis) and foot deformity.

        The following factors increase the risk of foot ulceration:

        • Peripheral neuropathy
        • Microvascular disease
        • Poor blood glucose control

          Charcot foot

          Charcot foot: Image from Longmore M, Wilkinson I, Davidson E, Foulkes A, Mafi A. 2010 Oxford Handboo

          Charcot foot is a neuropathic osteoarthropathy affecting 2% of patients with diabetes.

          Sensory neuropathy results in repeated, unrecognised trauma to the foot (e.g. due to ill-fitting shoes). Motor neuropathy can also contribute as it can lead to intrinsic muscle weakness and splaying of the foot on weight-bearing. Multiple fractures can result, which go unrecognised until marked bone and joint deformities occur.


          Prevention is key. Patients with diabetes should inspect their feet regularly, avoid trauma, and regularly visit a chiropodist.


          In particular, patients and doctors should be vigilant for:

          • Infection - which can progress to osteomyelitis
          • Ischaemia
          • Abnormal pressure - ulcerated sites should not be weight-bearing. Deep shoes and insoles can help to remove pressure from critical areas.
          • Wound environment - dressings should be used to remove exudates, maintain moisture and prevent infection.




          Clark M, Kumar P. 2009 Kumar & Clark’s Clinical Medicine 7/e Saunders

          Longmore M, Wilkinson I, Davidson E, Foulkes A, Mafi A. 2010 Oxford Handbook of Clinical Medicine 8/e Oxford OUP

          Griffing G 2011 Endocrinology articles, Medscape eMedicine [Online] Available from: Accessed 10/02/11.

          CDC. National Diabetes Fact Sheet, 2007. Centers for Disease Control and Prevention. Available at Accessed on 30/01/11.


          Fastbleep © 2019.