This guideline provides the most up-to-date evidence-based recommendations on diabetes screening, diagnosis, and monitoring.

DOES GLUCOSE NEED TO BE MEASURED IN PLASMA FOR THE DIAGNOSIS OF DIABETES MELLITUS?

Fasting glucose should be measured in venous plasma when used to establish the diagnosis of diabetes, with a value >7.0 mmol/L (> 126 mg/dL) diagnostic of diabetes.

WHEN AND HOW DIABETES MELLITUS SHOULD BE SCREENED IN HIGH-RISK INDIVIDUALS?

Screening by HbA1c, FPG or 2-h OGTT is recommended for individuals who are at high risk of diabetes. If HbA1c is <5.7% (<39 mmol/mol), FPG is <5.6 mmol/L (<100 mg/dL), and/or 2-h plasma glucose is <7.8 mmol/L (<140 mg/dL) testing should be repeated at 3-year intervals. Glucose should be measured in venous plasma when used for screening of high-risk individuals.

DOES PLASMA GLUCOSE NEED TO BE MEASURED FOR THE MONITORING OF DIABETES MELLITUS?

Routine measurement of plasma glucose concentrations is not recommended as the primary means of monitoring or evaluating therapy in individuals with diabetes.

WHAT ARE THE PRE-ANALYTICAL CONSIDERATIONS IN GLUCOSE TESTING?

Blood for fasting plasma glucose analysis should be drawn in the morning after the subject has fasted overnight (at least 8 h).

SHOULD HbA1c BE USED FOR SCREENING AND DIAGNOSIS OF DIABETES MELLITUS?

Laboratory-based HbA1c testing can be used to diagnose a) diabetes, with a value ≥ 6.5% (>48 mmol/mol) diagnostic of diabetes, and) prediabetes (or high risk for diabetes) with aHbA1c level of 5.7% to 6.4% (39-46 mmol/mol)

SHOULD HbA1c BE USED IN MONITORING DIABETES MELLITUS?

HbA1c should be measured routinely (usually every 3 months until acceptable, individualized targets are achieved and then no less than every 6 months) in most individuals with diabetes mellitus to document their degree of glycemic control.

WHAT ARE THE HbA1c TREATMENT GOALS IN DIABETES MELLITUS?

Treatment goals should be based on ADA recommendations which include maintaining HbA1c concentrations <7% (<53 mmol/mol) for many nonpregnant patients with diabetes and more stringent goals in selected individual patients if this can be achieved without significant hypoglycemia or other adverse effects of treatment.

Higher target ranges are recommended for children and adolescents and are appropriate for individuals with limited life expectancy, extensive co-morbid illnesses, a history of severe hypoglycemia and advanced complications.

WHAT ARE THE HbA1c TREATMENT GOALS IN DIABETES MELLITUS DURING PREGNANCY?

During pregnancy and in preparation for pregnancy, women with diabetes should try to achieve HbA1c goals that are more stringent than in the non-pregnant state, aiming ideally for <6.0% (<42 mmol/mol) during pregnancy to protect the fetus from congenital malformations and the baby and mother from perinatal trauma and morbidity owing to large-for-date babies.

SHOULD ISLET AUTOANTIBODIES BE USED FOR THE DIAGNOSIS, SCREENING, MONITORING OF TYPE 1 AND TYPE 2 DIABETES?

Standardized islet autoantibody tests are recommended for the classification of diabetes in adults in whom there is phenotypic overlap between type 1 and type 2 diabetes and uncertainty as to the type of diabetes.

WHEN IS TESTING FOR URINE ALBUMIN INDICATED?

Annual testing for albuminuria should begin in pubertal or post-pubertal individuals 5 years after diagnosis of type 1 diabetes and at the time of diagnosis of type 2 diabetes, regardless of treatment.

Urine albumin should be measured annually in adults with diabetes, using morning spot urine albumin to creatinine ratio (uACR).

If eGFR is <60 ml/min/1.73m2 and/or albuminuria is > 30 mg/g creatinine in a spot urine sample, the uACR should be repeated every 6 months to assess change among people with diabetes and hypertension.

First-morning void urine sample should be used to measure albumin: creatinine ratio.

IS THERE A ROLE FOR THE MEASUREMENT OF INSULIN AND C-PEPTIDE CONCENTRATIONS TO DISTINGUISH TYPE 1 FROM TYPE 2 DIABETES MELLITUS?

In most people with diabetes or risk for diabetes or cardiovascular disease, routine testing for insulin or proinsulin is not recommended. These assays are useful primarily for research purposes.