Patient education: Diabetes mellitus type 2: Treatment (Beyond the Basics)
- David K McCulloch, MD
David K McCulloch, MD
- Washington Permanente Medical Group
TYPE 2 DIABETES OVERVIEW
Type 2 diabetes mellitus occurs when the pancreas (an organ in the abdomen) produces insufficient amounts of the hormone insulin and/or the body becomes resistant to normal or even high levels of insulin. This causes high blood sugar (glucose) levels, which can lead to a number of complications if untreated.
People with type 2 diabetes require regular monitoring and ongoing treatment to maintain normal or near-normal blood sugar levels. Treatment includes lifestyle adjustments, self-care measures, and medicines, which can minimize the risk of diabetes and cardiovascular (heart-related) complications.
This topic review will discuss the treatment of type 2 diabetes. Topics that discuss other aspects of type 2 diabetes are also available:
TYPE 2 DIABETES TREATMENT GOALS
Blood sugar control — The goal of treatment in type 2 diabetes is to keep blood sugar levels at normal or near-normal levels. Careful control of blood sugars can help prevent the long-term effects of poorly controlled blood sugar (diabetic complications of the eye, kidney, nervous system, and cardiovascular system).
Home blood sugar testing — In people with type 2 diabetes, home blood sugar testing might be recommended, especially in those who take certain oral diabetes medicines or insulin. Home blood sugar testing is not usually necessary for people who are diet controlled. (See "Patient education: Self-monitoring of blood glucose in diabetes mellitus (Beyond the Basics)".)
A normal fasting blood sugar is less than 100 mg/dL (5.6 mmol/L), although some people will have a different goal. Your doctor or nurse can help set your blood sugar goal.
A1C testing — Blood sugar control can also be estimated with a blood test called glycated hemoglobin, or A1C. The A1C blood test measures your average blood sugar level during the past two to three months. The goal A1C for most people with type 2 diabetes is 7 percent or less, which corresponds to an average blood sugar of 150 mg/dL (8.3 mmol/L) (table 1). Reducing A1C levels reduces risk for kidney, eye, and nerve disease (so-called microvascular complications). For some people, a higher A1C goal may be chosen for safety reasons. A health care provider can help determine your A1C goal.
Your average blood sugar (150 mg/dL or 8.3 mmol/L) is higher than your fasting blood sugar goal (100 mg/dL or 5.6 mmol/L) for several reasons:
●Blood sugar goes up after eating
●How much and how fast your blood sugar goes up depends on the type and amount of food you eat at a particular meal
●The amount your blood sugar goes up also depends on what diabetes treatment(s) you use and your activity level
Cardiovascular risk control — The most common, serious, long-term complication of type 2 diabetes is cardiovascular disease, which can lead to heart attack, chest pain, stroke, amputations, and even death. People with type 2 diabetes have on average twice the risk of cardiovascular disease as those without diabetes.
However, you can substantially lower your risk of cardiovascular disease by:
●Managing high blood pressure and high cholesterol with diet, exercise, and medicines
●Taking a low-dose aspirin (81 mg) every day, if indicated
Some studies have shown that lowering A1C levels with specific diabetes drugs may also reduce your risk for cardiovascular disease.
A detailed discussion of ways to prevent complications is available separately. (See "Patient education: Preventing complications in diabetes mellitus (Beyond the Basics)".)
DIET AND EXERCISE IN TYPE 2 DIABETES
Changes in diet can improve many aspects of type 2 diabetes, including your weight, blood pressure, and your body's ability to produce and respond to insulin. Detailed information about type 2 diabetes and diet is available separately. (See "Patient education: Type 2 diabetes mellitus and diet (Beyond the Basics)".)
Regular exercise can help control type 2 diabetes, even if you do not lose weight. Exercise improves blood sugar control because it improves how your body responds to insulin. (See "Patient education: Diabetes mellitus type 2: Alcohol, exercise, and medical care (Beyond the Basics)".)
TYPE 2 DIABETES MEDICINES
A number of oral medicines (pills) are available to treat type 2 diabetes.
Metformin — Most people who are newly diagnosed with type 2 diabetes will immediately begin a medicine called metformin (sample brand names: Glucophage, Glumetza, Riomet, Fortamet). Metformin improves how your body responds to insulin to reduce high blood sugar levels.
Metformin is a pill that is usually started with the evening meal; a second dose is added one to two weeks later (with breakfast). The dose may be increased every one to two weeks thereafter.
Side effects — Common side effects of metformin include nausea, diarrhea, and gas. These are usually not severe, especially if you take metformin along with food.
Patients with certain types of kidney, liver, and heart disease and those who drink alcohol excessively should not take metformin. You should stop taking metformin 48 hours before any test that uses iodine-based contrast dye (like a computed tomography [CT] scan with contrast), and you should stop it before any type of surgery.
When to add a second medicine — Your doctor or nurse might recommend a second medicine within the first two to three months if your blood sugar levels and glycated hemoglobin (A1C) are still higher than your goal. (See "Patient education: Diabetes mellitus type 2: Insulin treatment (Beyond the Basics)".)
Which second medicine is best? — If your blood sugar levels are still high after two to three months but your A1C is close to the goal (between 7 and 8.5 percent), a second oral medicine might be added. Insulin shots might be recommended as the second medicine if your A1C is higher than 8.5 percent. The "best" second medicine depends upon individual factors, including the person's weight, other medical problems, and preferences regarding use of injections. The following are general recommendations:
●The most commonly recommended second medicine is a short-acting sulfonylurea, such as glipizide. (See 'Sulfonylureas' below.)
●A thiazolidinedione, such as pioglitazone, is an alternative to sulfonylureas but only for people who are not at increased risk of heart failure or bone fracture. (See 'Thiazolidinediones' below.)
●A glucagon-like peptide (GLP) agonist, which requires injections, is an option for patients who are overweight and who want to avoid developing low blood sugar. (See 'GLP agonists' below.)
●A meglitinide, such as repaglinide, is another option for people who cannot take a sulfonylurea because of kidney failure. (See 'Meglitinides' below.)
Sulfonylureas — Sulfonylureas have been used to treat type 2 diabetes for many years. They work by increasing the amount of insulin your body makes and can lower blood sugar levels by approximately 20 percent. However, they stop working over time.
Sulfonylureas are generally used if metformin does not adequately control blood sugar levels when taken alone. You should not take a sulfonylurea in the setting of kidney failure. Most clinicians use sulfonylureas in patients with allergies to sulfonamide antibiotics (sulfa drugs), which share some characteristics with sulfonylureas, without any problems.
A number of sulfonylureas are available (sample brand names: Glucotrol, DiaBeta, Micronase, Glynase, Amaryl), and the choice between them depends mainly upon cost and availability. Although they work similarly, we usually recommend the shorter-duration medications, such as glipizide (brand name: Glucotrol) and glimepiride (brand name: Amaryl), as they are safer with regard to hypoglycemia.
If you take a sulfonylurea, you can develop low blood sugar, known as hypoglycemia. Low blood sugar symptoms can include:
Low blood sugar must be treated quickly by eating 10 to 15 grams of fast-acting carbohydrate (eg, fruit juice, hard candy, glucose tablets). It is possible to pass out if you do not treat low blood sugar fast enough. A full discussion of low blood sugar is available separately. (See "Patient education: Hypoglycemia (low blood sugar) in diabetes mellitus (Beyond the Basics)".)
Insulin — In the past, insulin treatment was reserved for patients with type 2 diabetes whose blood sugars were not controlled with oral medicines and lifestyle changes. However, there is increasing evidence that using insulin at earlier stages may improve overall diabetes control and help to preserve the pancreas' ability to make insulin.
Insulin injections may be used as a first-line treatment in some people with type 2 diabetes, or it can be added to or substituted for oral medicines. Insulin must be injected by the patient or a family member/friend. In 2015, an inhaled form of insulin became available for clinical use. Inhaled insulins have not been shown to be effective in reducing A1C levels to the goal of less than 7 percent that is often recommended. (See "Patient education: Diabetes mellitus type 2: Insulin treatment (Beyond the Basics)".)
Thiazolidinediones — This class of medicines includes pioglitazone (brand name: Actos) and rosiglitazone (brand name: Avandia), which work to lower blood sugar levels by increasing the body's sensitivity to insulin. They are taken in pill form and usually in combination with other medicines such as metformin, a sulfonylurea, or insulin.
Common side effects of thiazolidinediones include:
●Weight gain and swelling of the feet and ankles.
●A small but serious increased risk of developing or worsening heart failure. An early sign of heart failure is swelling of the feet and ankles. People who take thiazolidinediones should monitor for swelling.
●A small but serious increased risk of developing fluid retention at the back of the eyes (macular edema).
●A small but serious increased risk of developing certain types of cancer (like bladder cancer).
●A small increased risk of bone fractures.
GLP agonists — The glucagon-like peptide (GLP) agonists, exenatide (brand name: Byetta), exenatide extended release (Bydureon), liraglutide (brand name: Victoza), albiglutide (brand name: Tanzeum), dulaglutide (brand name: Trulicity), and lixisenatide (brand name: Adlyxin), are injectable medicines. They are not a first-line treatment but might be considered for people whose blood sugar is not controlled on the highest dose of one or two oral medicines. They may be especially helpful for overweight patients who are gaining weight on oral medicine. Among patients who already have had a heart attack or stroke, liraglutide has been shown to improve cardiovascular disease outcomes. Studies looking to see if there are similar benefits from other GLP agonists are ongoing.
GLP agonists do not usually cause low blood sugar. They promote weight loss but can also cause bothersome side effects, including nausea, vomiting, and diarrhea. Pancreatitis has been reported rarely in patients taking GLP agonists, but it is not known if the drugs caused the pancreatitis. You should stop taking these drugs if you develop severe abdominal pain. Exenatide and lixisenatide should not be used in patients with abnormal kidney function, and liraglutide, dulaglutide, and albiglutide should be used with caution in patients with renal impairment. These drugs are more expensive than insulin. Because they are relatively new drugs, long-term risks and benefits are not known.
DPP-4 inhibitors — This class of medicines includes sitagliptin (brand name: Januvia), saxagliptin (brand name: Onglyza), linagliptin (brand name: Tradjenta), alogliptin (brand name: Nesina), and vildagliptin (brand name: Galvus). Vildagliptin is available in Europe but not in the United States. They lower blood sugar levels by increasing insulin release from the pancreas in response to a meal. They are not a first-line treatment, but they can be given alone in patients who can't tolerate the first-line medicines (metformin, sulfonylureas), or they can be given with other oral medicines if blood sugars are still higher than goal. These medicines do not cause hypoglycemia or changes in body weight. However, they may cause some nausea and diarrhea. There have been rare reports of pancreatitis and skin reactions. Dipeptidyl peptidase-4 (DPP-4) inhibitors are expensive, and the long-term risks and benefits are unknown.
Meglitinides — Meglitinides include repaglinide (brand name: Prandin) and nateglinide (brand name: Starlix). They work to lower blood sugar levels, similar to the sulfonylureas, and might be recommended in people who are allergic to sulfa-based drugs. They are taken in pill form. Meglitinides are not generally used as a first-line treatment, because they are more expensive than sulfonylureas and are short acting, so they must be taken with each meal. Repaglinide can be used safely in patients with kidney failure.
Alpha-glucosidase inhibitors — These medicines, which include acarbose (brand name: Precose) and miglitol (brand name: Glyset), work by interfering with the absorption of carbohydrates in the intestines. This helps to lower blood sugar levels but not as well as metformin or the sulfonylureas. They can be combined with other medicines if the first medicine does not lower blood sugar levels enough.
The main side effects of alpha-glucosidase inhibitors are gas (flatulence), diarrhea, and abdominal pain; starting with a low dose may minimize these side effects. The medicine is usually taken three times per day with the first bite of each meal.
SGLT2 inhibitors — The sodium-glucose co-transporter 2 (SGLT2) inhibitors, dapagliflozin (brand name: Farxiga), canagliflozin (brand name: Invokana), and empagliflozin (brand name: Jardiance), lower blood sugar by increasing the excretion of sugar in the urine. They are relatively weak diabetes drugs, similar in potency to the DPP-4 inhibitors. They are not a first-line treatment. Although they can be combined with other medications, including metformin, sulfonylureas, pioglitazone, sitagliptin, and insulin, in patients with persistently elevated blood sugars, we do not routinely use them, because of the absence of long-term efficacy and safety data. Among patients who already have had a heart attack or stroke, empagliflozin and canagliflozin have been shown to improve cardiovascular disease outcomes. However, there was an increase in the risk of lower limb amputations and fractures with canagliflozin, tempering enthusiasm for this drug.
SGLT2 inhibitors do not cause low blood sugar. They promote modest weight loss but can also cause bothersome side effects, including vaginal yeast infections and urinary tract infections. Because there have been some reports of kidney problems in people taking SGLT2 inhibitors, kidney function should be tested before starting these medications and then monitored periodically during treatment.
LIVING WITH TYPE 2 DIABETES
People with type 2 diabetes often feel stress related to their disease and the increased responsibilities that come with diabetes, including blood sugar testing, watching the diet, exercise, doctor visits, the need for medicines, and the potential risks of complications. It is not uncommon to become depressed as a result of this stress, and this can make taking care of yourself more difficult.
Committing to new treatments and lifestyle changes can be difficult, and it is not uncommon to feel that the benefits of treatment are not worth the effort. Having an open and honest discussion with a doctor or nurse can help you to understand your diagnosis and the need for treatment.
Involving family and friends can help you to manage your disease by offering reminders to take medicine, test blood sugar levels, and providing a ride to appointments. Family and friends can also give encouragement and support to eat a healthy diet and stick with an exercise plan.
Working with a psychotherapist or social worker can help you cope with new responsibilities and worries. A number of studies have shown that people who have psychotherapy in addition to traditional medical care have reduced stress and improved blood sugar control compared with people who received only traditional care .
WHERE TO GET MORE INFORMATION
Your health care provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our website (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Patient education: Treatment for type 2 diabetes (The Basics)
Patient education: Type 2 diabetes (The Basics)
Patient education: Using insulin (The Basics)
Patient education: Low blood sugar in people with diabetes (The Basics)
Patient education: Nonalcoholic fatty liver disease, including nonalcoholic steatohepatitis (NASH) (The Basics)
Patient education: Exercise (The Basics)
Patient education: Counting carbs if you do not use insulin (The Basics)
Patient education: Preventing type 2 diabetes (The Basics)
Patient education: Diabetic ketoacidosis (The Basics)
Patient education: Hyperosmolar nonketotic coma (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient education: Diabetes mellitus type 2: Overview (Beyond the Basics)
Patient education: Diabetes mellitus type 2: Insulin treatment (Beyond the Basics)
Patient education: Type 2 diabetes mellitus and diet (Beyond the Basics)
Patient education: Self-monitoring of blood glucose in diabetes mellitus (Beyond the Basics)
Patient education: Hypoglycemia (low blood sugar) in diabetes mellitus (Beyond the Basics)
Patient education: Diabetes mellitus type 2: Alcohol, exercise, and medical care (Beyond the Basics)
Patient education: Preventing complications in diabetes mellitus (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Alpha-glucosidase inhibitors and lipase inhibitors for treatment of diabetes mellitus
Estimation of blood glucose control in diabetes mellitus
Glycemic control and vascular complications in type 2 diabetes mellitus
Insulin therapy in type 2 diabetes mellitus
Management of persistent hyperglycemia in type 2 diabetes mellitus
Metformin in the treatment of adults with type 2 diabetes mellitus
Overview of medical care in adults with diabetes mellitus
Sodium-glucose co-transporter 2 inhibitors for the treatment of type 2 diabetes mellitus
Sulfonylureas and meglitinides in the treatment of diabetes mellitus
Thiazolidinediones in the treatment of diabetes mellitus
The following organizations also provide reliable health information.
●National Library of Medicine
●American Diabetes Association (ADA)
●Canadian Diabetes Associates
●US Center for Disease Control and Prevention
- Ismail K, Winkley K, Rabe-Hesketh S. Systematic review and meta-analysis of randomised controlled trials of psychological interventions to improve glycaemic control in patients with type 2 diabetes. Lancet 2004; 363:1589.
- Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33). UK Prospective Diabetes Study (UKPDS) Group. Lancet 1998; 352:837.
- Nathan DM, Buse JB, Davidson MB, et al. Management of hyperglycemia in type 2 diabetes: A consensus algorithm for the initiation and adjustment of therapy: a consensus statement from the American Diabetes Association and the European Association for the Study of Diabetes. Diabetes Care 2006; 29:1963.
- Norris SL, Zhang X, Avenell A, et al. Long-term effectiveness of lifestyle and behavioral weight loss interventions in adults with type 2 diabetes: a meta-analysis. Am J Med 2004; 117:762.
All topics are updated as new information becomes available. Our peer review process typically takes one to six weeks depending on the issue.