How to decrease Hemoglobin A1c (HbA1c) levels?

Strategies to Decrease Hemoglobin A1c Levels

To effectively decrease A1c levels, implement a combination of structured exercise training, carbohydrate-restricted eating patterns, and appropriate medication management, as these interventions have shown the strongest evidence for improving glycemic control. 1

Exercise Interventions

Structured Exercise Training

• Structured exercise training consisting of aerobic exercise, resistance training, or both combined significantly reduces A1c levels by an average of 0.67% compared to control groups 2
• High-intensity interval training (HIIT) appears to be the most effective exercise modality for reducing A1c (0.61% reduction), followed by combined training and aerobic training (both 0.58% reduction) 3
• Exercise duration matters - structured exercise of more than 150 minutes per week is associated with greater A1c reductions (0.89%) compared to 150 minutes or less per week (0.36%) 2
• Daily exercise, or at least not allowing more than 2 days to elapse between exercise sessions, is recommended to decrease insulin resistance 1

Exercise Recommendations

• Adults with type 2 diabetes should perform at least 150 minutes of moderate-to-vigorous aerobic activity per week, spread over at least 3 days with no more than 2 consecutive days without activity 1
• Include at least 2 weekly sessions of resistance exercise involving large muscle groups 1
• Higher exercise adherence leads to greater A1c reductions - each 20% increase in adherence (approximately two additional sessions per month) is associated with a 0.15% decrease in A1c 4
• The dose-response relationship between exercise and A1c reduction is particularly strong for aerobic and combined training, and less evident for resistance training alone 4

Dietary Interventions

Carbohydrate Management

• Reducing overall carbohydrate intake has demonstrated strong evidence for improving glycemia in individuals with diabetes 1
• Low-carbohydrate and very-low-carbohydrate eating patterns are particularly effective for reducing A1c and the need for glucose-lowering medications in people with type 2 diabetes 1
• Very-low-carbohydrate eating patterns (<26% total energy from carbohydrates) can reduce A1c by 0.5% in the short term (<6 months) 1
• Focus on high-quality, minimally processed, nutrient-dense carbohydrate sources high in fiber 1

Practical Dietary Recommendations

• Emphasize non-starchy vegetables, minimize added sugars and refined grains, and choose whole foods over highly processed foods 1
• Consume a minimum of 14g of fiber per 1,000 kcal, with at least half of grain consumption being whole, intact grains 1
• For individuals using mealtime insulin, education on insulin-to-carbohydrate ratios is essential for effective glycemic management 1
• Consider a Mediterranean-style eating pattern rich in polyunsaturated and monounsaturated fats, which can improve both glycemic control and blood lipids 1

Medication Management

Pharmacological Options

• For patients with type 2 diabetes not meeting A1c targets with lifestyle modifications alone, medication therapy should be initiated or intensified 1
• SGLT2 inhibitors like empagliflozin can provide significant A1c reductions (0.6-0.7%) when added to metformin therapy 5
• DPP-4 inhibitors like sitagliptin can reduce A1c by 0.7-0.8% in patients with diabetes 6
• When using medications that lower blood glucose, particularly insulin, careful monitoring is essential to avoid hypoglycemia 7

Setting Appropriate A1c Targets

• The general A1c target for most non-pregnant adults with diabetes is <7.0% 1
• For selected individuals, a more stringent A1c goal (such as <6.5%) may be appropriate if it can be achieved without significant hypoglycemia 1
• Less stringent A1c goals may be appropriate for patients with a history of severe hypoglycemia, limited life expectancy, or extensive comorbid conditions 1

Common Pitfalls and Considerations

• Very-low-carbohydrate eating plans should be used with caution in individuals taking SGLT2 inhibitors due to potential risk of ketoacidosis 1
• Very-low-carbohydrate eating plans are not currently recommended for pregnant or lactating individuals, children, people with kidney disease, or those at risk for disordered eating 1
• The benefits of carbohydrate restriction may diminish over time (>12 months), highlighting the importance of long-term adherence and monitoring 1
• When implementing exercise programs, be aware that individuals with type 1 diabetes have variable glycemic responses to exercise and require careful monitoring to prevent hypoglycemia 1, 8

By implementing these evidence-based strategies, significant reductions in A1c levels can be achieved, leading to improved health outcomes and reduced risk of diabetes-related complications.