Diabetes: Type 1 and Type 2

 Neerja L. Bisht, MD


Diabetes or diabetes mellitus (Type I or Type II) is a long-term condition leading to increased blood sugar levels, also called hyperglycemia. The need to control these levels is very important as uncontrolled increase in blood sugar levels can lead to serious damage to many vital organs in the body. Therefore prevention of diabetes significantly reduces the risk for diabetic complications and can even delay the onset of diabetes. Diabetes Type 1 and Type 2 are mainly recognized although Type 2 diabetes is the most common type to affect people worldwide. It has now been established that obesity is linked to development of diabetes. Since the incidence of obesity is on the rise, globally, diabetes has also reached epidemic proportions leading experts to coin the term “diabesity”. Once diagnosed, treatment must be initiated as early as possible. Oral antidiabetic agents and insulin are commonly used. Find out the cutting edge report on treatments, prevention, and self-management of Diabetes. Empower yourself with knowledge on Diabetes and take charge of your health today.

What is Diabetes?

Diabetes (Type I or Type II) is a disease or condition, that leads to increased concentration of blood glucose level (hyperglycemia, increase in blood sugar ). This happens when pancreas, an organ in the digestive system, (just behind the stomach) does not produce enough insulin, or when the body cannot effectively use the insulin it produces. Insulin allows the body to convert sugar from food to energy required by the body [1]. Diabetes is also called Diabetes Mellitus which is the Latin name for diabetes. It was known as a condition that produced sweet urine, in ancient times. Due to low levels of produced insulin, there is too much sugar in blood that is then passed out with urine thus making urine sweet.

Diabetes is classified as following types:

Type 1 diabetes: It is dependent on Insulin production, which means there is a lack of insulin production. Although this can occur at any age, it is commonly seen in children or young adults. It is also called Juvenille Diabetes.

Type 2 diabetes:  is caused by the body’s ineffective use of insulin. This type of diabetes is more common and can occur at any age. It often results from excess body weight (obesity) and physical inactivity.

Gestational diabetes: this condition/diabetes only occurs during pregnancy. This type of diabetes usually disappears after pregnancy but carries the risk for the mother and the child to develop type 2 diabetes later on in life.


It is important to know that some people may not meet diagnostic clinical criteria for diabetes but will still demonstrate high blood glucose levels [2] This condition is called Prediabetes. Such persons are recognized to have impaired fasting glucose (IFG). These values have been defined at (FPG levels 100–125mg/dL [5.6–6.9 mmol/L]), or impaired glucose tolerance (IGT) (2-h PG OGTT values of 140–199 mg/dL [7.8–11.0 mmol/L], or A1C 5.7–6.4%). People with prediabetes carry a high risk of developing type 2 diabetes and cardiovascular disease, which can lead to heart attack or stroke. These values have been known to be associated with obesity. Therefore testing for diabetes is recommended in adults and children with a body mass index (BMI) of greater or equal to 25 kg/m2, especially if one or more of the known risk factors for diabetes are present. Repeat testing every 3 years is recommended.


The latest figures (2014) reveal an alarming progression in the worldwide prevalence of diabetes. In 2014 the global prevalence of diabetes was estimated to be 9% among adults aged 18+ years (fasting blood glucose >= 7 mmol/l or on medication for raised blood glucose or with a history of diagnosis of diabetes) [3].  According to National Diabetes Statistics Report (2017), an estimated 30.3 million people in the U.S. have diabetes (9.4 percent of the U.S. population); out of which an estimated 7.2 million adults, ages 18 years or older are undiagnosed (23.8 percent of people with diabetes). The International Diabetes Federation has indicated that 387 million people have diabetes and will increase to 592 million by 2035 [4].

Risk factors for developing diabetes

There are two kinds of risk factors that increase an individual’s risk for developing prediabetes and diabetes type 2:

I. Non-Modifiable Risk Factors: These are the factors that the person has no control over:

(i) Family history: If someone in the family (a blood relative) has diabetes, the risk increases

(ii) Race/ethnic background: Some races e.g. African-American, Asian-American, Latino/Hispanic-American, Native American or Pacific Islander descent, have a greater likelihood of developing diabetes

(iii) Age: The risk of developing diabetes or prediabetes increases with advancing age, especially after 45 years of age

(iv) Gestational Diabetes: Women who developed diabetes during pregnancy, are at increased risk of developing diabetes

II. Modifiable Risk Factors: By making healthy choices, people can reduce their risk of developing diabetes and even prevent it, thus improving their overall quality of life

(i) Overweight or Obesity: Being overweight increases the risk of developing diabetes. Making healthy choices and losing weight cuts down the risk of developing diabetes.

(iii) Reduced physical activity: Even moderate physical activity for 75mins per week like brisk walk would play a significant role in delaying the onset of diabetes. 

(iv) High Blood Pressure (Hypertension): Untreated high blood pressure can lead to development of diabetes along with damaging cardiovascular health

(v) High Cholesterol (lipid) levels: Low levels of HDL (good cholesterol) and/or high levels of LDL increase the risk of both heart disease and diabetes.

Complications and health risks associated with diabetes

Diabetes can affect most major organs and systems of the body, namely the nerves, eyes, kidneys, heart, and blood vessels [5].

(i) Nerves: this is called diabetic neuropathy causing tingling, numbness and a burning sensation in the toes or tips of fingers. This can move upwards causing extreme discomfort. In men, erectile dysfunction can occur. Severe foot damage due to nerve damage in the feet can lead to serious infections and may lead to toe, foot or leg amputation.

(ii) Eyes: this is called diabetic retinopathy caused by bleeding of the eye blood vessels. Diabetes can also cause early cataracts and glaucoma.

(iii) Kidney: this is called diabetic nephropathy resulting in kidney failure.

(iv) Heart and blood vessels: when affected by uncontrolled increased blood glucose levels can cause heart attack, angina (chest pain), coronary artery disease, stroke, and high blood pressure.

(v) Skin: fungal and other bacterial infections can occur.

(vi) Ear: Can cause hearing defects.

Diagnostic tests

The American Diabetes Association has set the following criteria to diagnose diabetes:

(i) Usually, a fasting blood glucose (FPG) is assessed. The normal value is an FPG of less than or equal to 126 mg/dL (7.0 mmol/L). Fasting is defined as no caloric intake for at least 8 hours before the test.

(ii) A 2-hour plasma glucose (2-h PG) test may also be ordered. This is done after an ingestion of 75-g oral glucose; this test is called the oral glucose tolerance test (OGTT).

(iii) Recently, HbA1C has been recommended as this test has certain advantages over FPG and OGTT. Fasting is not required for this test. A value of greater or equal to 6.5% will confirm diabetes status of an individual.

(iv) If a person exhibits signs and symptoms of hyperglycemia, a random blood test can also detect blood glucose level. Random plasma glucose in excess of 200 mg/dL (11.1 mmol/L) is significantly high.

Other than the random glucose blood test, other tests may have to be repeated for concurrence and to rule out laboratory error before confirming the diagnosis of diabetes and initiating treatment.

Prevention and management of type 2 diabetes

The goal of treatment is to reduce the risk of acute complications and prevent long-term complications [6].

  • Weight Loss: Patients with IGT, IFG or an A1C between 5.7–6.4% should target weight loss, at least up to 7% of body weight. Physical activity should be at about 30-35 minutes/day, seven times a week of moderate activity such as brisk walking. Additionally, a healthy eating pattern further promotes weight loss. Prediabetes is associated with other cardiovascular risk factors, such as obesity, hypertension, and dyslipidemia, and such individuals are at an increased risk for cardiovascular disease events.
  • For individuals with diabetes, low glycemic index (GI) foods and increasing fiber intake can control blood glucose levels. It is also advised to consume foods that do not contain trans fats and increasing consumption of foods rich in long-chain n-3 fatty acids (EPA and DHA) such as fish and n-3 linolenic acid (ALA).

Pharmacotherapy [7]

Treatment for type 1 diabetes consists mainly of multiple-dose insulin (MDI) injections (three to four injections per day of basal and prandial insulin) or continuous subcutaneous insulin infusion (CSII). Insulin analogs are recommended to reduce the risk for hypoglycemic events. In some obese persons, or when blood glucose targets need to be me, oral antidiabetic medications are also added.

In type 2 diabetes, metformin, unless contraindicated, is the preferred first drug of choice. Other oral anti-diabetic medications or insulin may also be required as combination therapy in case blood glucose levels are not controlled.

Bariatric surgery is an option in adults with type 2 diabetes and whose BMI is greater than 35 kg/m2


In conclusion, diabetes causes serious health problems. In persons with increased risk for diabetes, simple blood tests could be done at regular intervals. Maintaining a healthy lifestyle can delay or prevent diabetes. Hence, lifestyle measures such as increasing physical activity, consuming a healthy balanced diet, and maintaining optimal weight has been recommended. 


1. Available at: http://www.idf.org/about-diabetes. Accessed 23-02-15.

2. Standards of medical care in diabetes 2014. Diabetes Care Volume 37, Supplement 1, January 2014. Available at: http://care.diabetesjournals.org/content/37/Supplement_1/S14.full.pdf+html. Accessed 27-02-15.
3. Diabetes. Fact sheet N°312 Updated January 2015. Available at http://www.who.int/mediacentre/factsheets/fs312/en/. Accessed 23-02-15.
4. IDF Diabetes Atlas Sixth Edition Update, International Diabetes Federation 2014.

5. Available at http://www.diabetes.org/living-with-diabetes/complications/. Accesed 06-03-2015.

6. American Diabetes Association. Prevention or delay in type 2 diabetes. Diabetes Care 2015;38(Suppl. 1):S31–S32 | DOI: 10.2337/dc15-S008.

7. American Diabetes Association. Approaches to glycemic treatment. Sec. 7. In Standards of Medical Care in Diabetes.2015. Diabetes Care 2015;38(Suppl. 1):S41–S48.