Standardized definitions for outcome measures beyond A1c for patients with type 1 diabetes

Standardized definitions for outcome measures beyond A1c for patients with type 1 diabetes

A new joint consensus statement from the American Association of Clinical Endocrinologists (AACE), American Association of Diabetes Educators (AADE), American Diabetes Association (ADA), Endocrine Society, JDRF International, Leona M and Harry B Helmsley Charitable Trust, Pediatric Endocrine Society and T1D Exchange standardizes definitions for clinically meaningful outcome measures beyond HbA1c for patients with type 1 diabetes.

Glycosylated hemoglobin or HbA1c is a commonly used parameter to evaluate glycemic control as it provides a measurement of the mean blood glucose levels over the past three months. A1c is also a surrogate measure for a person’s risk of developing diabetes-related complications. According to the statement, there are limitations to what the HbA1C can tell patients and physicians about their diabetes such as it does not detect short-term variations in blood glucose, exposure to hypoglycemia and hyperglycemia, or the impact of blood glucose variations on the quality of life of the patient.

Recent advances technologies such as continuous glucose monitoring (CGM) have made it feasible to assess the efficacy of therapies and technologies using a set of outcomes beyond HbA1c in type 1 diabetes. The statement says that while hypoglycemia has been defined in clinical care, these definitions are not standardized.

Published online November 21, 2017 in the journal Diabetes Care, the consensus statement has developed definitions for outcomes beyond HbA1c including hypoglycemia, hyperglycemia, time in range, and diabetic ketoacidosis (DKA) in type 1 diabetes. 

Three levels of hypoglycemia have been defined:

·         Level 1 hypoglycemia: Measurable glucose concentration <70 mg/dL (3.9 mmol/L) but ≥54 mg/dL (3.0 mmol/L) that can alert a person to take action.

·         Level 2 hypoglycemia: Measurable glucose concentration <54 mg/dL (3.0 mmol/L) that needs immediate action. 

·         Level 3 hypoglycemia: Severe event characterized by altered mental and/or physical status requiring assistance.

Two levels of hyperglycemia have been defined:

·         Level 1: Eevated glucose: glucose >180 mg/dL (10 mmol/L) and glucose ≤250 mg/dL (13.9 mmol/L)

·         Level 2: Very elevated glucose: glucose >250 mg/dL (13.9 mmol/L)

Time in range has been defined as percentage of readings ranging from 70–180 mg/dL (3.9–10.0 mmol/L) per unit of time. CGM is used to obtain data from which time in range can be derived.

Diabetic ketoacidosis

·         Elevated serum or urine ketones (greater than the upper limit of the normal range), and

·         Serum bicarbonate <15 mmol/L or blood pH <7.3

(Source: ADA Press Release, Diabetes Care. 2017 Dec;40(12):1622-1630)