DIABETES MELLITUS
1. What is diabetes?
Diabetes Mellitus, commonly termed diabetes, is a chronic (a long-term) condition where the body has trouble moving glucose from the blood to the cells. As a result, the body experiences constant high blood sugar levels. Over time, having an excess of glucose in your blood can cause health problems as it affects various body organs such as eyes, kidneys, blood vessels, nerves and heart.
2. How common is diabetes?
As of 2019, nearly 463 million adults aged 20-79 years live with diabetes worldwide, which is predicted to rise to 700 million by 2045. About 374 million adults are at increased risk of developing diabetes.
India ranks second worldwide, with 77 million adults living with diabetes and 25 million adults with prediabetes. One in twelve adults in India suffers from diabetes.2
3. Is diabetes a condition to worry about?
The mechanism of diabetes is such that once diabetes occurs, it stays in the body throughout the person’s life. Almost 90% of the persons with diabetes have type 2 diabetes, which was previously referred to as ‘mild condition’ because it is often asymptomatic (a person does not suffer from any symptoms). According to IDF's latest report (International diabetesfederation), 43 million Indians have undiagnosed diabetes. A person can live several years without knowing that he or she may have diabetes. However, high blood glucose continues to damage various organs of the body. It ultimately can lead to the development of complications as well. People with diabetes may have complications at the time of diagnosis, and they should be screened for the same.
Diabetes also affects the nerves of the body and can result in loss of pain sensation. Loss of protective sensation within the peripherial regions such as feet can cause the affected foot to be vulnerable to repeated injuries, ulceration, infection and even amputation of the feet. Moreover, due to lak of sensation, if a person with uncontrolled diabetes gets a heart attack, he may not feel any chest pain and not even realize that he or she has had a silent heart attack. Thus, diabetes is believed to be a silent killer because it gradually and silently damages various organs of the body.1
4. What are the symptoms of diabetes?
5. How to diagnose diabetes?
If the person shows classic symptoms of hyperglycemia or if a person is at risk of diabetes, the following tests should be done to confirm the diagnosis3
Figure 2: Diagnostic criteria for diabetes mellitus
Blood collection:
The blood can be collected either by pricking the finger (capillary blood) or drawing from a large vein (venous blood).Although capillary blood glucose is easy to test, it is advisable to go for a venous blood test to confirm the diagnosis. The capillary blood glucose depicts the arterial blood and is slightly higher than the venous blood glucose. However, capillary blood glucose is a good measure for self- monitoring the blood glucose levels in diabetes management.
Oral Glucose Tolerance Test (OGTT)
The OGTT is a two-hour test that checks your blood sugar levels before and two hours after having 75 g glucose drink. In a normal individual, the glucose graph over time is lower than those with pre-diabetes or diabetes.HbA1c
The A1C test is a blood test that provides average levels of blood glucose over the past 3 months.It measures the glucose attached to the red blood cells of the blood.
Therefore, A1c test is not accurate with the people who have anemia or any other problem in the blood.
Although ADA considers HbA1c as diagnostic criteria, it is not recommended by WHO or IDF. In a country like India, where there is no standardization of laboratories, one should not rely on HbA1c as diagnostic criteria but use it more as a guidance.
Fasting blood sugar (FBS)
It measures the blood glucose at a single point in time. It is best to measure in the morning after fasting for at least 8 hours for better reliability of the results.Postprandial blood glucose levels (PPBS) (2 hours from start of the meal)
It measures the post meal blood glucose levels after 2 hours of the start of the meal.
Random blood sugar (RBS) RBS is done when the patient shows symptoms of high blood glucose (hyperglycemia). It can be done at any time of the day and does not require fasting.
6. What are different types of diabetes?
Diabetes is classified into 4 major types.
1. Type 1
2. Type 2
3. Gestational diabetes
4. Other specific types of diabetes
1. Type 1 Diabetes
It is a chronic condition caused due to autoimmunity i.e., our own body’s immune system attacks insulin-producing cells (called beta cells) of the pancreas, resulting in little or no insulin production.
Figure 3: Type 1 diabetes
People with T1DM need daily insulin injections to maintain their blood glucose level and hence known as insulin-dependent diabetes. This condition occurs more frequently in children at a very young age, so earlier, it used to be called as juvenile diabetes.
Symptoms
Along with the symptoms mentioned in Q 4, people with type 1 diabetes also suffer from ketoacidosis (if one’s own body can’t get enough glucose for energy production, it utilizes fat cells thus releasing ketone bodies in the cells).
Causes:
Insulin is a hormone that helps in the movement of sugar (glucose) into the cells for energy production.
Insulin is produced by beta cells of pancreas. Damage to these beta cells leads to destructive process resulting in high blood sugar level and no energy to the cells.
1. Type 1
2. Type 2
3. Gestational diabetes
4. Other specific types of diabetes
1. Type 1 Diabetes
It is a chronic condition caused due to autoimmunity i.e., our own body’s immune system attacks insulin-producing cells (called beta cells) of the pancreas, resulting in little or no insulin production.
Figure 3: Type 1 diabetes
People with T1DM need daily insulin injections to maintain their blood glucose level and hence known as insulin-dependent diabetes. This condition occurs more frequently in children at a very young age, so earlier, it used to be called as juvenile diabetes.
Symptoms
Along with the symptoms mentioned in Q 4, people with type 1 diabetes also suffer from ketoacidosis (if one’s own body can’t get enough glucose for energy production, it utilizes fat cells thus releasing ketone bodies in the cells).
Causes:
Insulin is a hormone that helps in the movement of sugar (glucose) into the cells for energy production.
Insulin is produced by beta cells of pancreas. Damage to these beta cells leads to destructive process resulting in high blood sugar level and no energy to the cells.
Figure 4: Role of Insulin for glucose uptake in the cells
2. Type 2 diabetes mellitus
It is a long-term metabolic disorder that manifests with high blood glucose (also called hyperglycemia). Type 2 diabetes occurs as a consequence of impaired insulin secretion from beta cells or progression in insulin resistance (inability of cells and tissues to respond to insulin) or usually a combination of both. Type 2 diabetes is the most common type of diabetes observed among 90% of the people with diabetes. 5
Causes:
The major cause of type 2 diabetes – 1) Low or no production of insulin by the beta cells 2) inability of cells and tissues to respond to insulin (also known as insulin resistance).
It is a long-term metabolic disorder that manifests with high blood glucose (also called hyperglycemia). Type 2 diabetes occurs as a consequence of impaired insulin secretion from beta cells or progression in insulin resistance (inability of cells and tissues to respond to insulin) or usually a combination of both. Type 2 diabetes is the most common type of diabetes observed among 90% of the people with diabetes. 5
Causes:
The major cause of type 2 diabetes – 1) Low or no production of insulin by the beta cells 2) inability of cells and tissues to respond to insulin (also known as insulin resistance).
Figure 5: Mechanisms in Type 1 and Type 2 diabetes vs healthy individual
Difference between type 1 and type 2 diabetes
3. Gestational Diabetes
Diabetes diagnosed for the first-time during pregnancy is called gestational diabetes. Most women are diagnosed in the 26-28 weeks of pregnancy. Women with gestational diabetes are at the higher risk of developing type 2 diabetes during their lifetime. At present, universal screening for diabetes in pregnancy is advised for all pregnant women at the first antenatal visit or with 12 weeks of pregnancy to diagnose preexisting diabetes at the earliest. If the initial screen is negative, repeat testing should be done universally between 24-28 weeks of gestation as the insulin resistance because of placental hormones tends to peak at this point of time.
4. Other specific types of diabetes
Recently, researchers have also identified diabetes caused due to certain other causes such as genetic defects of pancreatic cell function, genetic defects in insulin action, disease of exocrine pancreas, drug or chemical induced diabetes, infections, and forms of immune mediated diabetes. 2
7. What is pre-diabetes? Is it reversible?
Pre-diabetes, also termed impaired glucose tolerance and impaired fasting glucose is the condition where blood sugar levels are higher than normal range but not that high to be diagnosed as diabetes. The person with pre-diabetes has a high risk of developing future diabetes and heart-related disease (cardio-vascular disease). People with pre-diabetes can delay their progress or prevent diabetes with healthy lifestyle changes. If taken proper care in lifestyle management, the person may not develop diabetes.
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