제 2형 당뇨병에서 목표 당화혈색소, Target HbA1c(A1C) in type 2 diabetes mellitus

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제2형 당뇨병에서 목표 당화혈색소는 저혈당 위험과 미세혈관합병증과의 균혈을 고려하여 개별화되어야 하며 고령이고 기대 여명이 길지 않은 경우는 7.5 ~ 8 %까지는 적절합니다.

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1. ACCORD trial suggest that lowering A1C to near normal may be unsafe in patients with a long history of diabetes who were at high risk for cardiovascular disease (CVD). After a mean follow-up of approximately 4.5 years, all-cause mortality was highest in those with the lowest (less than 6.7 percent) and highest (9.9 percent) A1C values. An A1C level of 7.5 percent was associated with the lowest all-cause mortality. There was a U-shaped relationship between A1C and mortality, with risk of mortality increasing with A1C values below 6.5 or above 8 percent.

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2. All of the guidelines also recommended tailoring A1C goals for individual patients. Less stringent treatment goals (eg, <8 percent or higher) may be appropriate for patients with a history of severe hypoglycemia, patients with limited life expectancy, very young children or older adults, and individuals with comorbid conditions.

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Target A1C levels in patients with type 2 diabetes should be tailored to the individual, balancing the improvement in microvascular complications with the risk of hypoglycemia.

● A reasonable goal of therapy might be an A1C value of ≤7.0 percent for most patients (using a Diabetes Control and Complications Trial [DCCT]/United Kingdom Prospective Diabetes Study [UKPDS]-aligned assay in which the upper limit of normal is 6.0 percent). In order to achieve the A1C goal, a fasting glucose of 80 to 130 mg/dL (4.4 to 7.2 mmol/L) and a postprandial glucose (90 to 120 minutes after a meal) less than 180 mg/dL (10 mmol/L) are usually necessary, but slightly higher levels may suffice.

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● The A1C goal should be set somewhat higher (eg, <8 percent) for older patients and those with a limited life expectancy. The American Geriatrics Society suggests an A1C target of 8 percent for frail older adults and individuals with life expectancy of less than five years. These recommendations are supported by a decision analysis integrating multiple prediction models. In this analysis, comorbid conditions and functional impairment were better predictors of both life expectancy and less benefit from intensive glucose control than age alone.

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Only limited clinical trial data (the long-term follow-up of the UKPDS) have demonstrated a macrovascular benefit with intensive therapy in patients with newly diagnosed type 2 diabetes, and data from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial suggest that lowering A1C to near normal may be unsafe in patients with a long history of diabetes who were at high risk for cardiovascular disease (CVD). The results of the ACCORD trial suggest that a target A1C of 7.0 to 7.9 percent (achieving a median of 7.5 percent) may be safer for patients with longstanding type 2 diabetes who are at high risk for CVD than a target A1C of 6.0 percent (achieving a median of 6.4 percent). This target is supported by the results of a retrospective cohort study of approximately 48,000 patients with type 2 diabetes, aged 50 years and older, whose treatment had been intensified. After a mean follow-up of approximately 4.5 years, all-cause mortality was highest in those with the lowest (less than 6.7 percent) and highest (9.9 percent) A1C values. An A1C level of 7.5 percent was associated with the lowest all-cause mortality. Similar findings were reported in a population-based cohort study of patients with diabetes and chronic kidney disease (estimated glomerular filtration rate [eGFR] 15 to 59.9 mL/min/1.73 m2). There was a U-shaped relationship between A1C and mortality, with risk of mortality increasing with A1C values below 6.5 or above 8 percent.

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The American Diabetes Association (ADA) and European Association for the Study of Diabetes (EASD) consensus algorithm recommend an A1C of less than 7 percent for most nonpregnant adults, due to the benefits of reducing microvascular complications. The American College of Physicians recommends an A1C between 7 and 8 percent. However, all of the guidelines also recommended tailoring A1C goals for individual patients. Less stringent treatment goals (eg, <8 percent or higher) may be appropriate for patients with a history of severe hypoglycemia, patients with limited life expectancy, very young children or older adults, and individuals with comorbid conditions.

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REF. UpToDate 2020.01.18