Type 2 (formerly called 'adult-onset' or 'non insulin-dependent') diabetes results when the body doesn’t produce enough insulin and/or is unable to use insulin properly (this is also referred to as ‘insulin resistance’). This form of diabetes usually occurs in people who are over 40 years of age, overweight, and have a family history of diabetes, although today it is increasingly found in younger people.
A study by Chan et al indicated that in pediatric patients with type 1 diabetes, the presence of hypoglycemia is a sign of decreased insulin sensitivity, while hyperglycemia in these patients, especially overnight, signals improved sensitivity to insulin. In contrast, the investigators found evidence that in pediatric patients with type 2 diabetes, markers of metabolic syndrome and hyperglycemia are associated with reduced insulin sensitivity. Patients in the study were between ages 12 and 19 years. [23]
Type 1 DM is caused by autoimmune destruction of the insulin-secreting beta cells of the pancreas. The loss of these cells results in nearly complete insulin deficiency; without exogenous insulin, type 1 DM is rapidly fatal. Type 2 DM results partly from a decreased sensitivity of muscle cells to insulin-mediated glucose uptake and partly from a relative decrease in pancreatic insulin secretion.
The blood vessels and blood are the highways that transport sugar from where it is either taken in (the stomach) or manufactured (in the liver) to the cells where it is used (muscles) or where it is stored (fat). Sugar cannot go into the cells by itself. The pancreas releases insulin into the blood, which serves as the helper, or the "key," that lets sugar into the cells for use as energy.
Different environmental effects on type 1 diabetes mellitus development complicate the influence of race, but racial differences are evident. Whites have the highest reported incidence, whereas Chinese individuals have the lowest. Type 1 diabetes mellitus is 1.5 times more likely to develop in American whites than in American blacks or Hispanics. Current evidence suggests that when immigrants from an area with low incidence move to an area with higher incidence, their rates of type 1 diabetes mellitus tend to increase toward the higher level.
Blurred vision can result from elevated blood sugar. Similarly, fluid that is pulled from the cells into the bloodstream to dilute the sugar can also be pulled from the lenses of your eyes. When the lens of the eye becomes dry, the eye is unable to focus, resulting in blurry vision. It's important that all people diagnosed with type 2 diabetes have a dilated eye exam shortly after diagnosis. Damage to the eye can even occur before a diagnosis of diabetes exists.
The term "diabetes" or "to pass through" was first used in 230 BCE by the Greek Apollonius of Memphis.[108] The disease was considered rare during the time of the Roman empire, with Galen commenting he had only seen two cases during his career.[108] This is possibly due to the diet and lifestyle of the ancients, or because the clinical symptoms were observed during the advanced stage of the disease. Galen named the disease "diarrhea of the urine" (diarrhea urinosa).[110]
Fasting glucose test This test involves giving a blood sample after you have fasted for eight hours. (18) If you have a fasting blood sugar level of less than 100 milligrams per deciliter (mg/dl), your blood sugar levels are normal. But if you have one from 100 to 125 mg/dl, you have prediabetes, and if you have 126 mg/dl on two separate occasions, you have diabetes. (17)
Apart from these medications, treating diabetes effectively means taking a well-rounded approach: You’ll need to eat well, exercise, and manage stress, because all these factors can affect your blood sugar levels. Staying healthy with diabetes also requires caring for yourself — like protecting your feet, practicing oral hygiene, and tending to your mental health.
With type 1, a disease that often seems to strike suddenly and unexpectedly, the effects of environment and lifestyle are far less clear. But several theories attempt to explain why cases of type 1 have increased so dramatically in recent decades, by around 5 percent per year since 1980. The three main suspects now are too little sun, too good hygiene, and too much cow's milk.
Gestational diabetes mellitus (GDM) resembles type 2 DM in several respects, involving a combination of relatively inadequate insulin secretion and responsiveness. It occurs in about 2–10% of all pregnancies and may improve or disappear after delivery.[50] However, after pregnancy approximately 5–10% of women with GDM are found to have DM, most commonly type 2.[50] GDM is fully treatable, but requires careful medical supervision throughout the pregnancy. Management may include dietary changes, blood glucose monitoring, and in some cases, insulin may be required.
To diagnose diabetes, doctors will  take a medical history (ask you about symptoms) and ask for blood and urine samples. Finding protein and sugar in the urine are signs of type 2 diabetes. Increased glucose and triglyceride (a type of lipid or fat) levels in the blood are also common findings. In most cases, blood glucose levels are checked after a person has been fasting for 8 hours.
"Secondary" diabetes refers to elevated blood sugar levels from another medical condition. Secondary diabetes may develop when the pancreatic tissue responsible for the production of insulin is destroyed by disease, such as chronic pancreatitis (inflammation of the pancreas by toxins like excessive alcohol), trauma, or surgical removal of the pancreas.
Type 2 diabetes is typically a chronic disease associated with a ten-year-shorter life expectancy.[10] This is partly due to a number of complications with which it is associated, including: two to four times the risk of cardiovascular disease, including ischemic heart disease and stroke; a 20-fold increase in lower limb amputations, and increased rates of hospitalizations.[10] In the developed world, and increasingly elsewhere, type 2 diabetes is the largest cause of nontraumatic blindness and kidney failure.[24] It has also been associated with an increased risk of cognitive dysfunction and dementia through disease processes such as Alzheimer's disease and vascular dementia.[25] Other complications include acanthosis nigricans, sexual dysfunction, and frequent infections.[23]

Our bodies break down the foods we eat into glucose and other nutrients we need, which are then absorbed into the bloodstream from the gastrointestinal tract. The glucose level in the blood rises after a meal and triggers the pancreas to make the hormone insulin and release it into the bloodstream. But in people with diabetes, the body either can't make or can't respond to insulin properly.
The patient, physician, nurse, and dietician must carefully evaluate the patient's life style, nutritional needs, and ability to comply with the proposed dietary prescription. There are a variety of meal planning systems that can be used by the patient with diabetes; each has benefits and drawbacks that need to be evaluated in order to maximize compliance. Two of the most frequently used ones are the exchange system (see accompanying table) and the carbohydrate counting system.

A positive result, in the absence of unequivocal high blood sugar, should be confirmed by a repeat of any of the above methods on a different day. It is preferable to measure a fasting glucose level because of the ease of measurement and the considerable time commitment of formal glucose tolerance testing, which takes two hours to complete and offers no prognostic advantage over the fasting test.[66] According to the current definition, two fasting glucose measurements above 7.0 mmol/l (126 mg/dl) is considered diagnostic for diabetes mellitus.

The diabetic patient should learn to recognize symptoms of low blood sugar (such as confusion, sweats, and palpitations) and high blood sugar (such as, polyuria and polydipsia). When either condition results in hospitalization, vital signs, weight, fluid intake, urine output, and caloric intake are accurately documented. Serum glucose and urine ketone levels are evaluated. Chronic management of DM is also based on periodic measurement of glycosylated hemoglobin levels (HbA1c). Elevated levels of HbA1c suggest poor long-term glucose control. The effects of diabetes on other body systems (such as cerebrovascular, coronary artery, and peripheral vascular) should be regularly assessed. Patients should be evaluated regularly for retinal disease and visual impairment and peripheral and autonomic nervous system abnormalities, e.g., loss of sensation in the feet. The patient is observed for signs and symptoms of diabetic neuropathy, e.g., numbness or pain in the hands and feet, decreased vibratory sense, footdrop, and neurogenic bladder. The urine is checked for microalbumin or overt protein losses, an early indication of nephropathy. The combination of peripheral neuropathy and peripheral arterial disease results in changes in the skin and microvasculature that lead to ulcer formation on the feet and lower legs with poor healing. Approx. 45,000 lower-extremity diabetic amputations are performed in the U.S. each year. Many amputees have a second amputation within five years. Most of these amputations are preventable with regular foot care and examinations. Diabetic patients and their providers should look for changes in sensation to touch and vibration, the integrity of pulses, capillary refill, and the skin. All injuries, cuts, and blisters should be treated promptly. The patient should avoid constricting hose, slippers, shoes, and bed linens or walking barefoot. The patient with ulcerated or insensitive feet is referred to a podiatrist for continuing foot care and is warned that decreased sensation can mask injuries.
Examples of simple or refined carbohydrates, on the other hand, exist in various forms — from the sucrose in the table sugar you use to bake cookies, to the various kinds of added sugar in packaged snacks, fruit drinks, soda, and cereal. Simple carbohydrates are natural components of many fresh foods, too, such as the lactose in milk and the fructose in fruits, and therefore, a healthy, well-balanced diet will always contain these types of sugars.
Diabetes is one of the first diseases described[21] with an Egyptian manuscript from c. 1500 BCE mentioning "too great emptying of the urine."[110] The first described cases are believed to be of type 1 diabetes.[110] Indian physicians around the same time identified the disease and classified it as madhumeha or honey urine noting that the urine would attract ants.[110] The term "diabetes" or "to pass through" was first used in 230 BCE by the Greek Apollonius Of Memphis.[110] The disease was rare during the time of the Roman empire with Galen commenting that he had only seen two cases during his career.[110]
If the amount of insulin available is insufficient, or if cells respond poorly to the effects of insulin (insulin insensitivity or insulin resistance), or if the insulin itself is defective, then glucose will not be absorbed properly by the body cells that require it, and it will not be stored appropriately in the liver and muscles. The net effect is persistently high levels of blood glucose, poor protein synthesis, and other metabolic derangements, such as acidosis.[60]
The causes of diabetes mellitus are unclear, however, there seem to be both hereditary (genetic factors passed on in families) and environmental factors involved. Research has shown that some people who develop diabetes have common genetic markers. In Type I diabetes, the immune system, the body's defense system against infection, is believed to be triggered by a virus or another microorganism that destroys cells in the pancreas that produce insulin. In Type II diabetes, age, obesity, and family history of diabetes play a role.
Rosiglitazone, a thiazolidinedione, has not been found to improve long-term outcomes even though it improves blood sugar levels.[93] Additionally it is associated with increased rates of heart disease and death.[94] Angiotensin-converting enzyme inhibitors (ACEIs) prevent kidney disease and improve outcomes in those with diabetes.[95][96] The similar medications angiotensin receptor blockers (ARBs) do not.[96] A 2016 review recommended treating to a systolic blood pressure of 140 to 150 mmHg.[97]
In people with type 1 diabetes, the symptoms often begin abruptly and dramatically. A serious condition called diabetic ketoacidosis, a complication in which the body produces excess acid, may quickly develop. In addition to the usual diabetes symptoms of excessive thirst and urination, the initial symptoms of diabetic ketoacidosis also include nausea, vomiting, fatigue, and—particularly in children—abdominal pain. Breathing tends to become deep and rapid as the body attempts to correct the blood’s acidity (see Acidosis), and the breath smells fruity and like nail polish remover. Without treatment, diabetic ketoacidosis can progress to coma and death, sometimes very quickly.
The relationship between type 2 diabetes and the main modifiable risk factors (excess weight, unhealthy diet, physical inactivity and tobacco use) is similar in all regions of the world. There is growing evidence that the underlying determinants of diabetes are a reflection of the major forces driving social, economic and cultural change: globalization, urbanization, population aging, and the general health policy environment.[74]
The blood glucose levels may jump after people eat foods they did not realize were high in carbohydrates. Emotional stress, an infection, and many drugs tend to increase blood glucose levels. Blood glucose levels increase in many people in the early morning hours because of the normal release of hormones (growth hormone and cortisol), a reaction called the dawn phenomenon. Blood glucose may shoot too high if the body releases certain hormones in response to low blood glucose levels (Somogyi effect). Exercise may cause the levels of glucose in the blood to fall low.
There is currently no cure for diabetes. The condition, however, can be managed so that patients can live a relatively normal life. Treatment of diabetes focuses on two goals: keeping blood glucose within normal range and preventing the development of long-term complications. Careful monitoring of diet, exercise, and blood glucose levels are as important as the use of insulin or oral medications in preventing complications of diabetes. In 2003, the American Diabetes Association updated its Standards of Care for the management of diabetes. These standards help manage health care providers in the most recent recommendations for diagnosis and treatment of the disease.
The genes identified so far in people with type 2 include many that affect the insulin-producing beta cells of the pancreas, says Craig Hanis, PhD, a professor at the Human Genetics Center at the University of Texas Health Science Center in Houston. And yet he emphasizes that why people get type 2 isn't at all clear yet: "What it tells us is that diabetes is a complicated disease."
A person of Asian origin aged 35 yr or more with two or more of the above risk factors, should undergo a screening test for diabetes. An oral glucose tolerance test (OGTT) is commonly used as the screening test10. Fasting and 2 h post glucose tests can identify impaired fasting glucose (IFG) (fasting glucose >110 - <125 mg/dl), impaired glucose tolerance (IGT) (2 h glucose >140-<200 mg/dl) and presence of diabetes (fasting > 126 and 2 h glucose >200 mg/dl). If a random blood glucose value is > 150 mg/dl, further confirmation by an OGTT is warranted. Recently, glycosylated haemoglobin (HbA1c) has been recommended as the test for diagnosis of diabetes (>6.5%). Presence of pre-diabetes is indicated by HbA1c values between 5.7 - 6.4 per cent11.

The body obtains glucose from three main sources: the intestinal absorption of food; the breakdown of glycogen (glycogenolysis), the storage form of glucose found in the liver; and gluconeogenesis, the generation of glucose from non-carbohydrate substrates in the body.[60] Insulin plays a critical role in balancing glucose levels in the body. Insulin can inhibit the breakdown of glycogen or the process of gluconeogenesis, it can stimulate the transport of glucose into fat and muscle cells, and it can stimulate the storage of glucose in the form of glycogen.[60]
Type 1 diabetes is considered an autoimmune disease. With an autoimmune disease, your immune system – which helps protect your body from getting sick – is engaged in too little or too much activity. In Type 1 diabetes, beta cells, which are a kind of cell in the pancreas that produces insulin, are destroyed. Our bodies use insulin to take the sugar from carbohydrates we eat and create fuel. With Type 1 diabetes, your body does not produce insulin, and that's why you need to use insulin as part of your treatment.
In addition to the problems with an increase in insulin resistance, the release of insulin by the pancreas may also be defective and suboptimal. In fact, there is a known steady decline in beta cell production of insulin in type 2 diabetes that contributes to worsening glucose control. (This is a major factor for many patients with type 2 diabetes who ultimately require insulin therapy.) Finally, the liver in these patients continues to produce glucose through a process called gluconeogenesis despite elevated glucose levels. The control of gluconeogenesis becomes compromised.
Insulin Therapy. Exogenous insulin is given to patients with diabetes mellitus as a supplement to the insufficient amount of endogenous insulin that they produce. In some cases, this must make up for an absolute lack of insulin from the pancreas. Exogenous insulin is available in various types. It must be given by injection, usually subcutaneously, and because it is a potent drug, the dosage must be measured meticulously. Commonly, regular insulin, which is a fast-acting insulin with a short span of action, is mixed with one of the longer-acting insulins and both types are administered in one injection.

The tuberculosis skin test is based on the fact that infection with M. tuberculosis produces a delayed-type hypersensitivity skin reaction to certain components of the bacterium. The standard recommended tuberculin test is administered by injecting 0.1mL of 5 TU (tuberculin units) PPD into the top layers of skin of the forearm. "Reading" the skin test means detecting a raised, thickened local area of skin reaction, referred to as induration. The area of induration (palpable, raised, hardened area) around the site of injection is the reaction to tuberculin.
Beta cells are vulnerable to more than just bad genes, which may explain the associations between type 2 diabetes and environmental factors that aren't related to how much fat a body has or where it is stored. Beta cells carry vitamin D receptors on their surface, and people with vitamin D deficiency are at increased risk for type 2. Plus, several studies have shown that people with higher levels of toxic substances in their blood—such as from the PCBs found in fish fat—are at increased risk of type 2 diabetes, though a cause-and-effect relationship hasn't been proved. (Toxic substances and vitamin D have also been implicated in type 1 diabetes, but the disease mechanism may be unrelated to what's going on in type 2.)
For people who want to avoid drugs, taking an aggressive approach to healthy eating plan and lifestyle change is an option. It isn't easy, but if someone is very committed and motivated, lifestyle changes can be enough to maintain a healthy blood sugar level and to lose weight. Learning about a healthy diabetes diet (a low glycemic load diet) can be an good place to start.

Awareness about the signs and symptoms and periodic screening especially in the presence of risk factors and warning signs of diabetes, would go a long way in preventing new cases of diabetes by providing an opportunity to intervene at the stage of prediabetes. It is evident that diabetes can be prevented among prediabetic individuals by improvements in physical activity and diet habits. Such strategies will also prevent development of diabetic complications to a great extent. Patient empowerment is vital in diabetes management. This can be done through patient education and sharing information on management and preventive aspects of diabetes.

A healthy lifestyle can prevent almost all cases of type 2 diabetes. A large research study called the Diabetes Prevention Program, found that patients who made intensive changes including diet and exercise, reduced their risk of developing diabetes by 58%. Patients who were over 60 years old seemed to experience extra benefit; they reduced their risk by 71%. In comparison, patients who were given the drug metformin for prevention only reduced their risk by 31%.
Unexplained weight loss can happen for lots of reasons, and diabetes is one of them. Goundan explains that insulin helps your body move sugar from your blood to your cells, so when you have an insulin resistance, you don’t get enough energy into your cells despite all that sugar flowing through your body. “Because you’re unable to get enough energy from sugar, your body burns your own fat and muscle for energy," Kellis says. "Weight loss can be pretty significant, sometimes 10 to 20 pounds."
×