Insulin resistance is the most common cause of type 2 diabetes, but it is possible to have type 2 and not be insulin resistant. You can have a form of type 2 where you body simply doesn’t produce enough insulin; that’s not as common. Researchers aren’t sure what exactly keeps some people from producing enough insulin, but that’s another thing they’re working hard to figure out.
A proper diet and exercise are the foundations of diabetic care,[23] with a greater amount of exercise yielding better results.[80] Exercise improves blood sugar control, decreases body fat content and decreases blood lipid levels, and these effects are evident even without weight loss.[81] Aerobic exercise leads to a decrease in HbA1c and improved insulin sensitivity.[82] Resistance training is also useful and the combination of both types of exercise may be most effective.[82]
Many studies have shown that awareness about the diabetes and its complications is poor among the general population specially in the rural areas6,7. There is an urgent need to create awareness among the population regarding diabetes and about the serious consequences of this chronic disorder. Epidemiological data from India have shown the presence of a number of risk factors which can be easily identified by simple non-invasive risk scores8,9. The major risk factors are listed in Box 1.
A healthy meal plan for people with diabetes is generally the same as healthy eating for anyone – low in saturated fat, moderate in salt and sugar, with meals based on lean protein, non-starchy vegetables, whole grains, healthy fats, and fruit. Foods that say they are healthier for people with diabetes generally offer no special benefit. Most of them still raise blood glucose levels, are more expensive, and can also have a laxative effect if they contain sugar alcohols.
Other potentially important mechanisms associated with type 2 diabetes and insulin resistance include: increased breakdown of lipids within fat cells, resistance to and lack of incretin, high glucagon levels in the blood, increased retention of salt and water by the kidneys, and inappropriate regulation of metabolism by the central nervous system.[10] However, not all people with insulin resistance develop diabetes, since an impairment of insulin secretion by pancreatic beta cells is also required.[13]
Patients need to ensure that their blood glucose levels are kept as normal as possible so that delicate tissues in the body (especially blood vessels in the eyes, kidneys and peripheral nerves) are not damaged by high glucose levels over a long period of time. To achieve this, patients need to measure their glucose regularly and learn how to adjust their insulin doses in order to optimise their glucose levels (diabetes control). Good diabetes control helps to minimise the risk of long-term diabetes complications, as well as short-term symptoms (such as thirst).
Diabetes can also result from other hormonal disturbances, such as excessive growth hormone production (acromegaly) and Cushing's syndrome. In acromegaly, a pituitary gland tumor at the base of the brain causes excessive production of growth hormone, leading to hyperglycemia. In Cushing's syndrome, the adrenal glands produce an excess of cortisol, which promotes blood sugar elevation.
Type 2 diabetes is due to insufficient insulin production from beta cells in the setting of insulin resistance.[13] Insulin resistance, which is the inability of cells to respond adequately to normal levels of insulin, occurs primarily within the muscles, liver, and fat tissue.[44] In the liver, insulin normally suppresses glucose release. However, in the setting of insulin resistance, the liver inappropriately releases glucose into the blood.[10] The proportion of insulin resistance versus beta cell dysfunction differs among individuals, with some having primarily insulin resistance and only a minor defect in insulin secretion and others with slight insulin resistance and primarily a lack of insulin secretion.[13]
Jump up ^ Qaseem, Amir; Wilt, Timothy J.; Kansagara, Devan; Horwitch, Carrie; Barry, Michael J.; Forciea, Mary Ann (6 March 2018). "Hemoglobin A Targets for Glycemic Control With Pharmacologic Therapy for Nonpregnant Adults With Type 2 Diabetes Mellitus: A Guidance Statement Update From the American College of Physicians". Annals of Internal Medicine. doi:10.7326/M17-0939.

If you are at increased risk of diabetes, have symptoms of diabetes, or have pre-diabetes (a major warning sign for diabetes), your doctor will check to see if you have diabetes. Your doctor may also check to see if you have diabetes if you are over the age of 45, have a family history of the disease, are overweight, or if you are at increased risk for another reason. The tests used to check for diabetes are the same tests used to check for pre-diabetes.
Type 1 diabetes occurs when the immune system attacks and destroys the insulin-producing cells in the pancreas (the beta cells). As a result, the body is left without enough insulin to function normally (i.e. it becomes insulin deficient). This is called an autoimmune reaction, because the body attacks itself and produces antibodies to its own insulin-producing cells, thereby destroying them.
It’s no surprise that most people could stand to drink more water. In fact, the majority of Americans are drinking less than half of the recommended eight glasses of water each day. However, if you’re finding yourself excessively thirsty, that could be a sign that you’re dealing with dangerously high blood sugar. Patients with diabetes often find themselves extremely thirsty as their bodies try to flush out excess sugar in their blood when their own insulin production just won’t cut it. If you’re parched, instead of turning to a sugary drink, quench that thirst with one of the 50 Best Detox Waters for Fat Burning and Weight Loss!
Which came first: the diabetes or the PCOS? For many women, a diagnosis of polycystic ovary syndrome means a diabetes diagnosis isn’t far behind. PCOS and diabetes are both associated with insulin resistance, meaning there are similar hormonal issues at play in both diseases. Fortunately, managing your PCOS and losing weight may help reduce your risk of becoming diabetic over time.
Diabetes mellitus (DM) is best defined as a syndrome characterized by inappropriate fasting or postprandial hyperglycemia, caused by absolute or relative insulin deficiency and its metabolic consequences, which include disturbed metabolism of protein and fat. This syndrome results from a combination of deficiency of insulin secretion and its action. Diabetes mellitus occurs when the normal constant of the product of insulin secretion times insulin sensitivity, a parabolic function termed the “disposition index” (Figure 19-1), is inadequate to prevent hyperglycemia and its clinical consequences of polyuria, polydipsia, and weight loss. At high degrees of insulin sensitivity, small declines in the ability to secrete insulin cause only mild, clinically imperceptible defects in glucose metabolism. However, irrespective of insulin sensitivity, a minimum amount of insulin is necessary for normal metabolism. Thus, near absolute deficiency of insulin must result in severe metabolic disturbance as occurs in type 1 diabetes mellitus (T1DM). By contrast, with decreasing sensitivity to its action, higher amounts of insulin secretion are required for a normal disposition index. At a critical point in the disposition index curve (see Figure 19-1), a further small decrement in insulin sensitivity requires a large increase in insulin secretion; those who can mount these higher rates of insulin secretion retain normal glucose metabolism, whereas those who cannot increase their insulin secretion because of genetic or acquired defects now manifest clinical diabetes as occurs in type 2 diabetes (T2DM).
Onset of type 2 diabetes can be delayed or prevented through proper nutrition and regular exercise.[60][61] Intensive lifestyle measures may reduce the risk by over half.[24][62] The benefit of exercise occurs regardless of the person's initial weight or subsequent weight loss.[63] High levels of physical activity reduce the risk of diabetes by about 28%.[64] Evidence for the benefit of dietary changes alone, however, is limited,[65] with some evidence for a diet high in green leafy vegetables[66] and some for limiting the intake of sugary drinks.[32] In those with impaired glucose tolerance, diet and exercise either alone or in combination with metformin or acarbose may decrease the risk of developing diabetes.[24][67] Lifestyle interventions are more effective than metformin.[24] A 2017 review found that, long term, lifestyle changes decreased the risk by 28%, while medication does not reduce risk after withdrawal.[68] While low vitamin D levels are associated with an increased risk of diabetes, correcting the levels by supplementing vitamin D3 does not improve that risk.[69]
Research continues on diabetes prevention and improved detection of those at risk for developing diabetes. While the onset of Type I diabetes is unpredictable, the risk of developing Type II diabetes can be reduced by maintaining ideal weight and exercising regularly. The physical and emotional stress of surgery, illness, pregnancy, and alcoholism can increase the risks of diabetes, so maintaining a healthy lifestyle is critical to preventing the onset of Type II diabetes and preventing further complications of the disease.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
While there are competing explanations of the link between obesity and type 2 diabetes, Gerald Shulman, MD, PhD, a professor of internal medicine and physiology at Yale University, believes the key is figuring out insulin resistance. He has studied the causes of insulin resistance for 25 years and thinks he may have the answer to the weight-diabetes link.
FIGURE 19-1 ■. This figure shows the hyperbolic relationship of insulin resistance and beta cell function. On the y-axis is beta cell function as reflected in the first-phase insulin response during intravenous (IV) glucose infusion; on the x-axis is insulin sensitivity and its mirror image resistance. In a subject with normal glucose tolerance (NGT) and beta-cell reserve, an increase in insulin resistance results in increased insulin release and normal glucose tolerance. In an individual for whom the capacity to increase insulin release is compromised, increasing insulin resistance with partial or no beta-cell compensation results in progression from normal glucose tolerance, to impaired glucose tolerance (IGT), and finally to diabetes (T2D). Differences between these categories are small at high insulin sensitivity, which may be maintained by weight reduction, exercise, and certain drugs. At a critical degree of insulin resistance, due to obesity or other listed factors, only a further small increment in resistance requires a large increase in insulin output. Those that can increase insulin secretion to this extent retain normal glucose tolerance; those who cannot achieve this degree of insulin secretion (e.g., due to a mild defect in genes regulating insulin synthesis, insulin secretion, insulin action, or an ongoing immune destruction of beta cells) now unmask varying degrees of carbohydrate intolerance. The product of insulin sensitivity (the reciprocal of insulin resistance) and acute insulin response (a measurement beta-cell function) has been called the “disposition index.” This index remains constant in an individual with normal beta cell compensation in response to changes in insulin resistance. IGT, impaired glucose tolerance; NGT, normal glucose tolerance; T2D, type 2 diabetes.
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.

Monogenic diabetes is caused by mutations, or changes, in a single gene. These changes are usually passed through families, but sometimes the gene mutation happens on its own. Most of these gene mutations cause diabetes by making the pancreas less able to make insulin. The most common types of monogenic diabetes are neonatal diabetes and maturity-onset diabetes of the young (MODY). Neonatal diabetes occurs in the first 6 months of life. Doctors usually diagnose MODY during adolescence or early adulthood, but sometimes the disease is not diagnosed until later in life.
Endocrinology is the specialty of medicine that deals with hormone disturbances, and both endocrinologists and pediatric endocrinologists manage patients with diabetes. People with diabetes may also be treated by family medicine or internal medicine specialists. When complications arise, people with diabetes may be treated by other specialists, including neurologists, gastroenterologists, ophthalmologists, surgeons, cardiologists, or others.
Patients with type 1 diabetes require life-long treatment with exogenous (artificial) insulin to regulate their blood sugar levels. This insulin may be given through the use of a hypodermic needle (seen right), or other methods such as the use of an insulin pump. Over time, many patients suffer chronic complications: vascular, neurological and organ-specific (such as kidney and eye disease). The frequency and severity of these complications is related to duration that the patient has suffered the disease for, and by how well their blood sugar levels have been controlled. If blood sugar levels, blood pressure and lipids are tightly controlled, many complications of diabetes may be prevented. Some patients may develop the major emergency complication of diabetes, known as ketoacidosis (extremely high blood glucose levels accompanied with extremely low insulin levels), which has a mortality rate of 5-10%.
Endocrinology A chronic condition which affects ±10% of the general population, characterized by ↑ serum glucose and a relative or absolute ↓ in pancreatic insulin production, or ↓ tissue responsiveness to insulin; if not properly controlled, the excess glucose damages blood vessels of the eyes, kidneys, nerves, heart Types Insulin dependent–type I and non-insulin dependent–type II diabetes Symptoms type 1 DM is associated with ↑ urine output, thirst, fatigue, and weight loss (despite an ↑ appetite), N&V; type 2 DM is associated with, in addition, non-healing ulcers, oral and bladder infections, blurred vision, paresthesias in the hands and feet, and itching Cardiovascular MI, stoke Eyes Retinal damage, blindness Legs/feet Nonhealing ulcers, cuts leading to gangrene and amputation Kidneys HTN, renal failure Neurology Paresthesias, neuropathy Diagnosis Serum glucose above cut-off points after meals or when fasting; once therapy is begun, serum levels of glycosylated Hb are measured periodically to assess adequacy of glucose control Management Therapy reflects type of DM; metformin and triglitazone have equal and additive effects on glycemic control Prognosis A function of stringency of glucose control and presence of complications. See ABCD Trial, Brittle diabetes, Bronze diabetes, Chemical diabetes, Gestational diabetes, Insulin-dependent diabetes, Metformin, MODY diabetes, Nephrogenic diabetes insipidus, Non-insulin-dependent diabetes mellitus, Pseudodiabetes, Secondary diabetes, Starvation diabetes, Troglitazone.
Management of type 2 diabetes focuses on lifestyle interventions, lowering other cardiovascular risk factors, and maintaining blood glucose levels in the normal range.[24] Self-monitoring of blood glucose for people with newly diagnosed type 2 diabetes may be used in combination with education,[70] however the benefit of self monitoring in those not using multi-dose insulin is questionable.[24][71] In those who do not want to measure blood levels, measuring urine levels may be done.[70] Managing other cardiovascular risk factors, such as hypertension, high cholesterol, and microalbuminuria, improves a person's life expectancy.[24] Decreasing the systolic blood pressure to less than 140 mmHg is associated with a lower risk of death and better outcomes.[72] Intensive blood pressure management (less than 130/80 mmHg) as opposed to standard blood pressure management (less than 140-160 mmHg systolic to 85–100 mmHg diastolic) results in a slight decrease in stroke risk but no effect on overall risk of death.[73]
Jump up ^ Boussageon, R; Supper, I; Bejan-Angoulvant, T; Kellou, N; Cucherat, M; Boissel, JP; Kassai, B; Moreau, A; Gueyffier, F; Cornu, C (2012). Groop, Leif, ed. "Reappraisal of metformin efficacy in the treatment of type 2 diabetes: a meta-analysis of randomised controlled trials". PLOS Medicine. 9 (4): e1001204. doi:10.1371/journal.pmed.1001204. PMC 3323508. PMID 22509138.

Onset of type 2 diabetes can be delayed or prevented through proper nutrition and regular exercise.[60][61] Intensive lifestyle measures may reduce the risk by over half.[24][62] The benefit of exercise occurs regardless of the person's initial weight or subsequent weight loss.[63] High levels of physical activity reduce the risk of diabetes by about 28%.[64] Evidence for the benefit of dietary changes alone, however, is limited,[65] with some evidence for a diet high in green leafy vegetables[66] and some for limiting the intake of sugary drinks.[32] In those with impaired glucose tolerance, diet and exercise either alone or in combination with metformin or acarbose may decrease the risk of developing diabetes.[24][67] Lifestyle interventions are more effective than metformin.[24] A 2017 review found that, long term, lifestyle changes decreased the risk by 28%, while medication does not reduce risk after withdrawal.[68] While low vitamin D levels are associated with an increased risk of diabetes, correcting the levels by supplementing vitamin D3 does not improve that risk.[69]
Type 1 diabetes mellitus is predominantly a disease of the young, usually developing before 20 years of age. Overall, type I DM makes up approximately 15% of all cases of diabetes. It develops in approximately 1 in 600 children and is one of the most common chronic diseases in children. The incidence is relatively low for children under the age of 5, increases between 5 and 15, and then tapers off.

In type 2 diabetes, there also is a steady decline of beta cells that adds to the process of elevated blood sugars. Essentially, if someone is resistant to insulin, the body can, to some degree, increase production of insulin and overcome the level of resistance. After time, if production decreases and insulin cannot be released as vigorously, hyperglycemia develops.
Abnormal cholesterol and triglyceride levels. If you have low levels of high-density lipoprotein (HDL), or "good," cholesterol, your risk of type 2 diabetes is higher. Triglycerides are another type of fat carried in the blood. People with high levels of triglycerides have an increased risk of type 2 diabetes. Your doctor can let you know what your cholesterol and triglyceride levels are.
×