Initial management of blood glucose in adults with type 2 diabetes mellitus
- David K McCulloch, MD
David K McCulloch, MD
- Clinical Professor of Medicine
- University of Washington
Treatment of patients with type 2 diabetes mellitus includes education, evaluation for microvascular and macrovascular complications, attempts to achieve near-normal glycemia, minimization of cardiovascular and other long-term risk factors, and avoidance of drugs that can aggravate abnormalities of insulin or lipid metabolism. All of these treatments need to be tempered based on individual factors, such as age, life expectancy, and comorbidities. Although several studies have noted remissions of type 2 diabetes mellitus that may last several years, most patients require continuous treatment in order to maintain normal or near-normal glycemia. Treatments to achieve normoglycemia focus on increasing insulin availability (either through direct insulin administration or through agents that promote insulin secretion), improving sensitivity to insulin, delaying the delivery and absorption of carbohydrate from the gastrointestinal tract, or increasing urinary glucose excretion.
Methods used to control blood glucose in patients with newly-diagnosed type 2 diabetes are reviewed here. Further management of persistent hyperglycemia and other therapeutic issues, such as the frequency of monitoring and evaluation for microvascular and macrovascular complications, are discussed separately. (See "Management of persistent hyperglycemia in type 2 diabetes mellitus" and "Overview of medical care in adults with diabetes mellitus".)
Degree of glycemic control — Improved glycemic control improves the risk of microvascular complications in patients with type 2 diabetes (figure 1) . Every 1 percent drop in glycated hemoglobin (A1C) is associated with improved outcomes with no threshold effect. To date, only one randomized clinical trial has demonstrated a beneficial effect of intensive therapy on macrovascular outcomes in type 2 diabetes , with several trials not supporting a beneficial effect [3,4] and one trial suggesting harm . A reasonable goal of therapy might be an A1C value of ≤7.0 percent (53.0 mmol/mol) (calculator 1) for most patients. However, target A1C goals in patients with type 2 diabetes should be tailored to the individual, balancing the improvement in microvascular complications with the risk of hypoglycemia. Glycemic targets are generally set somewhat higher for older adult patients and those with comorbidities or a limited life expectancy and little likelihood of benefit from intensive therapy. Glycemic goals are discussed in more detail separately. (See "Glycemic control and vascular complications in type 2 diabetes mellitus", section on 'Glycemic targets' and "Overview of medical care in adults with diabetes mellitus", section on 'Glycemic control' and "Treatment of type 2 diabetes mellitus in the older patient", section on 'Glycemic targets'.)
Cardiovascular risk factor management — In addition to glycemic control, vigorous cardiac risk reduction (smoking cessation, aspirin, blood pressure control, reduction in serum lipids, diet, and exercise) should be a top priority for all patients with type 2 diabetes. However, in spite of evidence that aggressive risk factor reduction lowers the risk of both micro- and macrovascular complications in patients with diabetes, many patients do not achieve recommended goals for A1C, blood pressure control, and management of dyslipidemia. (See "Overview of medical care in adults with diabetes mellitus" and "Treatment of hypertension in patients with diabetes mellitus" and "Treatment of lipids (including hypercholesterolemia) in primary prevention" and "Treatment of lipids (including hypercholesterolemia) in secondary prevention".)
Patients with newly diagnosed diabetes should participate in a comprehensive diabetes self-management education program, which includes instruction on nutrition, physical activity, optimizing metabolic control, and preventing complications. In clinical trials comparing diabetes education with usual care, there was a small but statistically significant reduction in glycated hemoglobin (A1C) in patients receiving the diabetes education intervention . There was no difference in quality of life. In two meta-analyses, use of mobile phone interventions for diabetes education was successful in significantly reducing A1C (-0.5 percentage points) [7,8].
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- TREATMENT GOALS
- Degree of glycemic control
- Cardiovascular risk factor management
- DIABETES EDUCATION
- Weight reduction
- - Diet
- - Pharmacologic therapy
- - Surgical therapy
- Intensive lifestyle modification
- Psychological interventions
- INITIAL PHARMACOLOGIC THERAPY
- When to start
- Choice of initial therapy
- - Asymptomatic
- A1C at (<7.6 percent) or close to (>0.5 to 1.5 percent above, eg, 7.6 to 8.5 percent) treatment goal
- A1C relatively far from goal (eg, 8.5 to 9.5 percent)
- Contraindications to metformin
- - Symptomatic or severe hyperglycemia
- - Difficult to distinguish type 1 from type 2
- Glycemic efficacy
- Cardiovascular outcomes
- PERSISTENT HYPERGLYCEMIA
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS