What is type 2 diabetes?
Diabetes is a chronic condition marked by abnormally high blood sugar (glucose) which can damage nerves and blood vessels. There are two types of diabetes: type 1 and type 2. This information focuses on type 2 diabetes. Type 2 diabetes (T2D) affects around 425 million people worldwide [1], and one in 20 Australians [2].
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Main types of diabetes, [3,4]
Type 1 (T1D)
Onset: Childhood/ young adulthood
Autoimmune (body attacks pancreas) therefore insufficient insulin produced
Type 2 (T2D)
Onset: People aged over 45 but increasingly being seen in younger people
Body responds poorly to insulin (insulin resistance), or stops making enough
Gestational diabetes
Onset: Pregnancy
Hormonal changes and weight gain cause insulin resistance
Normal sugar metabolism:
The rise of blood sugar from a digested meal triggers the pancreas to release insulin, enabling glucose to be used for energy, or stored. When blood sugars drop, insulin levels fall, leading to release of energy from reserves.
Abnormally high blood sugar occurs when:
The body produces insufficient insulin due to the body making antibodies that attack the pancreas (type 1 diabetes)
There is insulin resistance which is a condition where the body’s liver, muscle and fat cells do not respond adequately to insulin, which is worsened by the development of insulin resistance (type 2 diabetes)
In a normal pregnancy, the placenta produces several hormones which leads to a necessary insulin resistance to provide enough carbohydrates to the growing foetus. However, most women with gestational diabetes are unable to produce enough insulin, although a minority are women who already have pre-existing diabetes
Data suggest there is an interplay between genes and environment. Some common risk factors or associations are:
- Genetics – 40% (four in ten) risk of type 2 diabetes if one parent has the condition; 70% (seven in ten) risk if both; increased risk in twins [5]
- Increasing age [6]
- Higher body mass index (BMI)—increases risk up to 10-fold [7]
- Higher intake of processed meat and sugar-sweetened drinks, or lower wholegrain intake [7]
- Physical inactivity [7]
- History of gestational diabetes [7]
Diagnosis of type 2 diabetes can be delayed due to lack of symptoms [8].
Common symptoms include [9]
Increased thirst and urination
Fatigue
Bacterial and fungal infections
Sensory changes in hands or feet
Weight loss
Circulation complications can cause
Stroke
Heart attack
Leg pain with walking
Chronic wounds
Foot/leg ulcers
Kidney failure
Blurred vision
For many years, type 2 diabetes has been diagnosed by either a fasting glucose test (a blood test after not eating for eight hours), or a “random” glucose test (where the test does not require fasting, but the criteria for an abnormal result is different).
A more time-consuming test is the glucose tolerance test. After eight hours of no food, a fasting blood test is taken, the person has a glucose drink, and after two hours a further fasting test. This can be used to diagnose both diabetes and pre-diabetes (the condition where there are no symptoms but the person has a higher risk than average of developing true diabetes).
In recent years, another test is now also available called glycated haemoglobin (HbA1c). This name arises because glucose becomes attached to haemoglobin, the red oxygen-carrying pigment in blood. As red blood cells live for about four months, HbA1c indicates glucose control for the preceding three months or so. In some situations, this test might be used in addition to fasting tests.
Management of type 2 diabetes is lifelong, with education, lifestyle changes and regular physical checks.
Here are some interesting data about people with type 2 diabetes:
- Almost 75% require medication [10]
- The average person takes 4-10 drugs daily [11]
- 25% are taking insulin [10]
- Only 20% regularly take their medications [12]
Treatment for type 2 diabetes [1,8,13]
Lifestyle changes – for prevention and/or treatment
Reduce weight if overweight/obese using calorie restriction
Healthy diet including:
- Fibre: >40 g/day
- Carbohydrates: 45-60% total energy
- Protein: 10-20% total energy
- Fat :< 35% total energy; saturated/trans fats < 10% total daily energy
- Regular fruit/vegetable intake
Alcohol ≤2 standard drinks/day
Regular aerobic and/or resistance training for >150 minutes/week
Avoid/stop smoking
Medications
Oral glucose-lowering medicine
Addition of injectable medications such as insulin
Weight loss surgery
In obese people, can reduce risk of type 2 diabetes; variable rates of “remission”
1.Hallberg SJ, Gershuni VM, Athinarayanan SJ. Reversing Type 2 Diabetes: A Narrative Review of the Evidence. Nutrients [Internet]. 2019 Apr 1 [cited 2022 Feb 10];11(4):766. Available from: /labs/pmc/articles/PMC6520897/
2. AIHW. Diabetes Overview. (CC BY) [Internet]. 2022 [cited 2022 Feb 9]. Available from: https://www.aihw.gov.au/reports-data/health-conditions-disability-deaths/diabetes/overview
3. NDSS. All types of diabetes. 2021;(December):1. Available from: https://www.ndss.com.au/wp-content/uploads/ndss-data-snapshot-202112-all-types-of-diabetes.pdf
4. NIDDK. Symptoms & Causes of Gestational Diabetes | NIDDK [Internet]. 2017 [cited 2022 Feb 12]. Available from: https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/gestational/symptoms-causes
5. Murea M, Ma L, Freedman BI. Genetic and environmental factors associated with type 2 diabetes and diabetic vascular complications. Rev Diabet Stud [Internet]. 2012 [cited 2022 Feb 11];9(1):6–22. Available from: /labs/pmc/articles/PMC3448170/
6. AIHW. Diabetes Web report. (CC BY) [Internet]. 2020 [cited 2022 Feb 9]. Available from: https://www.aihw.gov.au/reports/diabetes/diabetes
7. Bellou V, Belbasis L, Tzoulaki I, Evangelou E. Risk factors for type 2 diabetes mellitus: An exposure-wide umbrella review of meta-analyses. (CC BY 4.0). PLoS One [Internet]. 2018 Mar 1 [cited 2022 Feb 11];13(3):e0194127. Available from: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0194127
8. Ryden L, Grant P, Anker S, et al. ESC GUIDELINES ESC Guidelines on diabetes, pre-diabetes, and cardiovascular diseases developed in collaboration with the EASD. Eur Heart J [Internet]. 2013;34:3035–87. Available from: www.escardio.org/guidelines
9. Goyal R, Jialal I. Diabetes Mellitus Type 2. (CC BY 4.0) [Internet]. StatPearls [Internet]. 2021 [cited 2022 Feb 9]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513253/
10. Australian Bureau of Statistics. Diabetes mellitus. (CC BY 4.0) [Internet]. c=AU; o=Commonwealth of Australia; ou=Australian Bureau of Statistics; 2017 [cited 2022 Feb 12]. p. 02017. Available from: https://www.abs.gov.au/ausstats/[email protected]/Lookup/by Subject/4364.0.55.002~2014-15~Main Features~Diabetes mellitus~10005
11. Black JA, Simmons RK, Boothby CE, Davies MJ, Webb D, Khunti K, et al. Medication burden in the first 5 years following diagnosis of type 2 diabetes: findings from the ADDITION-UK trial cohort. BMJ Open Diabetes Res Care [Internet]. 2015 Oct 1 [cited 2022 Feb 12];3:e000075. Available from: https://drc.bmj.com/content/3/1/e000075
12. Krass I, Schieback P, Dhippayom T. Adherence to diabetes medication: a systematic review. Diabet Med [Internet]. 2015 Jun 1 [cited 2022 Feb 12];32(6):725–37. Available from: https://onlinelibrary.wiley.com/doi/full/10.1111/dme.12651
13. NDSS. Alcohol fact sheet [Internet]. 2020 [cited 2022 Feb 12]. p. 1–3. Available from: https://www.ndss.com.au/wp-content/uploads/fact-sheets/fact-sheet-alcohol.pdf
Medical disclaimer
This article contains general information relating to a medical condition. Such information is provided for informational purposes only and does not replace medical advice given by your healthcare professional.
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