What is the recommended treatment for abnormal glucose metabolism?

Treatment of Abnormal Glucose Metabolism

For adults aged 40-70 years who are overweight or obese with abnormal glucose metabolism (impaired fasting glucose, impaired glucose tolerance, or prediabetes), intensive behavioral counseling interventions focused on diet and physical activity are the primary recommended treatment, as lifestyle interventions have greater effects on reducing progression to diabetes than metformin or other medications. 1

Screening and Diagnosis

• Screen for abnormal blood glucose using hemoglobin A1C, fasting plasma glucose, or oral glucose tolerance test in adults aged 40-70 years who are overweight or obese 1
• Confirm diagnosis with repeated testing (same test on a different day is preferred) 1
• Rescreening every 3 years is a reasonable approach for those with initial normal glucose tests 1
• Risk factors include overweight/obesity, abdominal fat, physical inactivity, smoking, family history of diabetes, history of gestational diabetes, and certain racial/ethnic groups 1

Primary Treatment: Intensive Behavioral Interventions

Lifestyle interventions consistently show moderate benefit in reducing progression to diabetes and are superior to pharmacologic therapy. 1

Dietary Modifications

• Reduce total energy intake with fat comprising ≤30% of total energy 1
• Limit saturated fatty acids to ≤7% of energy intake 1
• Minimize trans fatty acid intake 1
• Increase intake of fruits, vegetables, whole grains, and nuts 1
• Increase soluble (viscous) fiber intake 1
• Consider adding plant stanols/sterols to enhance lipid lowering 1

Physical Activity Requirements

• Perform at least 150 minutes per week of moderate-intensity aerobic physical activity (50-70% of maximum heart rate) 1
• Spread activity over at least 3 days per week with no more than 2 consecutive days without exercise 1
• Add resistance training at least twice per week 1
• Physical activity improves insulin sensitivity, with effects lasting up to 16 hours post-exercise in both healthy individuals and those with diabetes 2, 3

Common pitfall: The beneficial effect of exercise on insulin sensitivity decreases within 3 days and is no longer apparent after 1 week, requiring continued regular activity 4

Weight Management

• Target 5-7% weight loss from starting weight through structured programs 1
• Modest weight loss improves insulin resistance in overweight and obese insulin-resistant individuals 1
• Weight loss beneficially affects blood pressure 1

Program Structure

• Effective behavioral interventions combine counseling on healthful diet and physical activity 1
• Require multiple contacts over extended periods 1
• Should be provided by registered dietitians familiar with diabetes medical nutrition therapy when possible 1
• Counseling should be sensitive to personal needs, willingness to change, and ability to make changes 1

Pharmacologic Therapy Considerations

There is insufficient evidence that medications have the same benefits as behavioral interventions for preventing progression to diabetes. 1

• Lifestyle interventions have greater effects than metformin or other medications 1
• Harms of drug therapy for diabetes prevention are small to moderate, depending on the drug and dosage 1
• Medications should not replace lifestyle interventions as first-line therapy 1

Management of Associated Cardiovascular Risk Factors

Hypertension Management

• Reduce sodium intake to ≤2,300 mg/day (or ≤2,000 mg/day for symptomatic heart failure) 1
• Regular aerobic physical activity has antihypertensive effects 1
• Light to moderate alcohol intake may be acceptable, though chronic excessive intake increases hypertension risk 1

Dyslipidemia Management

• Limit saturated fat to ≤7% of energy intake 1
• Minimize trans fatty acid intake 1
• Replace saturated fat with either carbohydrates or monounsaturated fats 1
• Increase plant stanols/sterols and soluble fiber 1

Monitoring and Follow-up

• Provide regular participant contact to maintain long-term weight loss and lifestyle changes 1
• Monitor for progression to diabetes 1
• Address multiple cardiovascular risk factors simultaneously (overweight/obesity, physical inactivity, abnormal lipids, high blood pressure, smoking) 1

Benefits and Harms

• Benefits include reductions in blood pressure, glucose and lipid levels, obesity, and increases in physical activity 1
• Moderate benefit in reducing progression to diabetes (approximately 50% risk reduction in intervention studies) 1
• Harms of lifestyle interventions are small to none 1
• Measuring blood glucose is associated with short-term anxiety but not long-term psychological harms 1

Critical caveat: Approximately 86 million Americans aged 20 years or older have impaired fasting glucose or impaired glucose tolerance, representing a substantial population at risk for cardiovascular disease and diabetes progression 1