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Diabetes mellitus type 2

Diabetes mellitus is a chronic, multifactor pathology characterized by the existence of hyperglycemia (high blood sugar) when fasting or after eating in the context of insulin resistance and relative lack of insulin. This is in contrast to diabetes mellitus type 1, in which there is an absolute lack of insulin due to breakdown of islet cells in the pancreas. Insulin is needed to move blood sugar (glucose) into cells where it is stored and later used for energy. Over time, the illness can cause organ damage, dysfunction and insufficiency.

Diabetes is not only one illness, but rather encompasses a heterogeneous group of alterations of carbohydrate metabolism with distinct genetic patterns as well as different etiologies and pathophysiological mechanisms.

There are two main types of diabetes:

  • Type 1 diabetes (T1B) usually develops in childhood and adolescence. It is an autoimmune illness which generates a deficiency in insulin production causing patients to require lifelong insulin injections for survival.
  • Type 2 diabetes (T2B) usually develops in adulthood and is related to obesity, lack of physical activity, and unhealthy diets. This is the more common type of diabetes (representing 90% of diabetic cases worldwide) and treatment may involve lifestyle changes and weight loss alone, or oral medications or even insulin injections.

Diabetes screening is recommended for:

  • Overweight children who have other risk factors for diabetes, starting at age 10 and repeated every 2 years
  • Overweight adults (BMI of 25 or higher) who have other risk factors
  • Adults starting at age 45 every 3 years, or at a younger age if the person has risk factors such as
    • A history of gestational diabetes, glucose intolerance or impaired basal glucose
    • Women with a history of giving birth to babies weighing over 4.5 kg
    • Persons who are overweight (have a BMI Body Mass Index greater than or equal to 27 kg/m2 or greater than or equal to 120% ideal weight)
    • High blood pressure
    • a HDL cholesterol level less than or equal to 35 mg/dl and/or a triglyceride level greater than 250 mg/dl)
    • a family history of type 1 diabetes

Recommended testing

Fasting plasma venous glucose test.

Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2D), once known as adult-onset or noninsulin-dependent diabetes, is a chronic condition that affects the way your body metabolizes sugar (glucose), your body’s important source of fuel. This form is more frequent in adults over 40 although the incidence of T2D in preadolescents and adolescents in increasing due to obesity.

In this type of diabetes, the capacity for producing insulin does not disappear, but the body resists the effects of it. In the early phases of the illness, the amount of insulin produced by the pancreas is normal or high. Over time, insulin production in the pancreas tends to diminish.

The etiology of diabetes is multifactorial, but most important among them are:

  • Genetic or hereditary factor: The hereditary risk for Type 2 diabetes is greater than for type 1. In almost all cases, a parent or grandparent has the illness. In the case of identical twins, if one has the illness, the other has an 80% chance of developing it also.
  • Lifestyle: 80% of the persons who develop type 2 diabetes are obese and do not lead an active life. The remaining 20% often have a hereditary defect which causes resistance to insulin.


  • TCF7L2
  • KCNJ11
  • SLC30A8
  • FTO
  • TCF7L2
  • MTNR1B
  • TCF7L2
  • CDKAL1
  • PDE4B
  • RBMS1
  • ZNF239
  • HIGD1C
  • CCDC33
  • ZFAND6
  • SREBF1
  • TRIB3
  • 9p21.3
  • 7p13
  • 11p12
  • 3p14.3
  • 4q27
  • 12q21.1