What is Diabetes Mellitus and what are its primary causes?

Diabetes mellitus (type II diabetes) is a syndrome characterized by chronic hyperglycemia with disturbances of carbohydrates, fat, and protein metabolism resulting from defects in insulin secretion, insulin action, or both. Diabetes occurs when the pancreas produces very little or no insulin, or when the body's response to insulin is not as expected/normal.

Type 2 diabetes is a lifelong disease that keeps your body from using insulin the way it should be used. People with type 2 diabetes are said to have insulin resistance. If you have type 2 diabetes, your pancreas secretes less insulin than your body requires because your body is resistant to its effect. People who are middle-aged or older are most likely to get this kind of diabetes. This disease is often associated with long-term complications involving organs like the eyes, kidneys, nerves, and heart.

• The pancreas makes a hormone called insulin, which helps the cells turn glucose (sugar) from the food we eat into energy. People with type-2 diabetes make insulin but cells in muscle, fat, and the liver become resistant to insulin. Because these cells don’t interact in a normal way with insulin, they don’t take in enough sugar and the unutilized sugar increases blood sugar levels.
• When the pancreas is unable to produce enough insulin altogether to manage blood sugar levels (this also increases blood sugar levels).

• Being overweight or obese can cause insulin resistance, especially if you carry your extra kilos around your belly area. Obesity increases the levels of fatty acids and inflammation, leading to insulin resistance, which can lead to type 2 diabetes. You will typically experience frequent urination, increased thirst, and increased hunger. Dehydration may also cause excess fatigue. Untreated or poorly controlled diabetes can cause other health concerns like vision problems, nerve damage, infections, heart problems, high blood pressure, mental health issues, ketoacidosis, and stroke.
• You’re more likely to develop the condition if a parent or sibling has it. Several gene mutations have been linked to the development of type 2 diabetes. These gene mutations can interact with the environment and each other to further increase your risk.
• Other metabolic disorders such as high blood pressure, high cholesterol & triglycerides can also cause resistance to insulin.
• After you eat a meal, your blood sugar shoots up, and your liver function will usually slow down and store its glucose for later. But some people’s livers don’t. They keep cranking out sugar which increases the glucose levels in the blood. If broken beta cells make and send out high amounts of insulin at the wrong time, your blood sugar usually shoots up.

Type II Diabetes is characterized by insufficient secretion of insulin from the β-cells of the pancreatic islets, coupled with impaired insulin action in target tissues such as muscle, liver, and fat (a condition termed insulin resistance). Hyperglycemia results when insulin secretion is unable to compensate for insulin resistance.

Progressive loss of β-cell mass during disease progression places an ever-greater secretory burden on the β-cells that remain functional. Obesity is believed to be a promoter of type 2 diabetes and poorly managed diabetes can lead to serious consequences causing damage to a wide range of your body’s organs and tissues — including your heart, kidneys, eyes, and nerves.

1. https://www.webmd.com/diabetes/default.htm
2. https://www.mayoclinic.org/diseases-conditions/diabetes/symptoms-causes/syc-20371444
3. https://main.icmr.nic.in/sites/default/files/guidelines/ICMR_GuidelinesType2diabetes2018_0.pdf