What are the Causes of Type 2 Diabetes Mellitus?

Dr. Yogesh Yadav
MBBS, MD, DM, SCE from RCP, UK

Type 2 diabetes mellitus (T2DM) is a chronic illness characterized by high blood glucose (sugar).

It commonly results from:

  • Less insulin production by the pancreas (an organ near the stomach)
  • Decreased efficacy of insulin (i.e., insulin is produced in normal or higher in quantity but is unable to provide the desired effect, also termed as insulin resistance)
  • Usually a combination of the above two

Multiple factors can lead to decreased insulin production and insulin resistance.

type 1 diabetes causes

Common factors include:

  1. Genetic factors: Presence of type 2 diabetes mellitus in a first-degree relative (father/ mother/brother/sister) is the most critical risk factor for the development of T2DM in later life. The risk further increases if both the parents are affected, or multiple family members are affected, suggesting significant genetic risk.
  2. Obesity: Multiple studies have observed that obesity puts a person on the path to the future development of T2DM, hypertension & cardiovascular diseases. Obesity commonly leads to insulin resistance early on, paving the way for future diabetes mellitus.
  3. Lack of exercise: another very common risk factor for T2DM. Lack of exercise leads to obesity as well as insulin resistance.
  4. Diet: A diet rich in calories(french fries, burgers, fried food items, etc.) or simple sugars(soft drinks, juices, sweets), and a sedentary lifestyle leads to obesity and, in turn, obesity, T2DM. Also, the pancreas needs to do extra work to overcome the excess sugars provided by such a diet, leading to pancreatic dysfunction.
  5. Ethnicity: Indians are at increased risk of developing T2DM.
  6. Age: The risk of T2DM increases with increasing age, especially after the age of 45 years.
  7. History of diabetes during pregnancy (gestational diabetes): puts a woman on the increased risk of future development of T2DM
  8. PCOS (Polycystic ovarian syndrome): women with PCOS are at high risk of developing T2DM, mainly due to common factors between both namely obesity & insulin resistance.
  9. Lower sleep duration: has also been found to be associated with T2DM.
  10. Stress: is a common risk factor in multiple chronic diseases like T2DM, hypertension, cardiovascular diseases.
  11. Hypertension (high blood pressure), high cholesterol or triglycerides are also a risk factor for T2DM
  12. Smoking: also increases the risk of T2DM.
  13. Low birth weight: has also been associated with future T2DM.

Some of the risk factors are modifiable (which we can change) like

  • Dietary habits
  • Lack of exercise or daily physical activities
  • Increased body weight
  • Stress
  • Smoking addiction
  • Altered sleep duration etc.

While others are not under our control (non-modifiable risk factors) like

  • Genetics,
  • Age
  • Low birth weight etc.

So, one should try to modify the factors under our control to avoid or delay T2DM onset.