Early detection and treatment of diabetes mellitus is important in preventing the chronic and acute complications of this disease. Individuals with symptoms suggestive of hyperglycemia, such as polyuria, polyphagia, polydipsia, unexplained weight loss, blurred vision, excessive fatigue, or infections or wounds that heal poorly, should be promptly tested.
The American Diabetes Association recommends routinely screening all adults for type 2 diabetes beginning at age 45 especially if they are overweight or obese (BMI > 25kg/m2), with repeat screening every three years (1). Fasting plasma glucose is the preferred screening test (see below Sections 1 and 2), but the optimal screening methods, cutoff points, and screening intervals remain controversial (2).
For people with one or more risk factor for the development of type 2 diabetes mellitus, the American Diabetes Association recommends testing earlier and more frequently, with no age cutoff specified (1). The American Association of Clinical Endocrinologists recommends screening individuals at risk beginning at age 30 (3).
Family history of diabetes (first or second degree relative)
Overweight (BMI >25 kg/m2)
Sedentary lifestyle
Age > 45 years
High risk ethnicity (African American, Latino/Hispanic, Native American, Asian American, Pacific Islanders)
History of gestational diabetes or delivery of a baby that weighed >9 lbs.
History of impaired glucose tolerance or impaired fasting glucose
Hypertension
Dyslipidemia: triglyceride level > 250mg/dl (2.82 mmol/l) and/or HDL-cholesterol level < 35 mg/dl (0.90 mmol/l)
Polycystic ovarian disease, acanthosis nigricans or another insulin-resistant condition
History of vascular disease
Type 2 diabetes is becoming a growing problem in children and adolescents in high-risk populations. To address this issue, the American Diabetes Association recommends screening children every 2 years, beginning at age 10 or the onset of puberty, if they have 2 or more risk factors listed below and are overweight (1).
Overweight (BMI >85th percentile for age and gender, weight for height >85th percentile or weight > 120% of ideal for height)
Family history of type 2 diabetes (first and second degree relatives)
High risk ethnicity (Native Americans, African-Americans, Hispanic Americans, Asians/South Pacific Islanders)
Signs of insulin resistance (acanthosis nigricans, hypertension, dyslipidemia, polycystic ovary syndrome)
Maternal history of diabetes
The diagnosis of diabetes can be made using the fasting plasma glucose, casual plasma glucose, or the oral glucose tolerance test (4). Testing should be performed on 2 separate days using one or more of the above tests, unless evidence for acute metabolic decompensation is present. The use of the hemoglobin A1c assay for the diagnosis of diabetes is not recommended (3).