2.1 Screening for prediabetes and diabetes

• Testing for prediabetes/ diabetes should be considered in all asymptomatic adults ≥ 30 years of age (even if without risk factors).¹
• Testing for prediabetes/ diabetes should be considered in all asymptomatic adults <30 years of age who are over-weight/obese (BMI ≥23 kg/m2).^1-3
• Testing for prediabetes/ diabetes should be considered in all asymptomatic adults <30 years of age with a BMI <23 kg/m² and who have one or more of the following risk factors:¹
  • First-degree relative with diabetes
  • History of GDM
  • History of CVD with Hypertension (140/90 mmHg or on therapy for hypertension)
  • HDL cholesterol level <35 mg/dL and/or a triglyceride level >250 mg/dL
  • Women with polycystic ovary syndrome
  • Physical inactivity
• Immediate testing is required in symptomatic cases.¹
• Testing is advised in all patients with HIV.¹

If results are normal, testing should be repeated at 1 year interval, with consideration of more frequent testing depending on initial results, deteriorating risk status and appearance of symptoms. People with prediabetes (HbA1c >5.7-6.4%, IGT or IFG) and women who were diagnosed with GDM should be tested yearly.

• Testing for prediabetes/diabetes should be considered after the onset of puberty or after 10 years of age, whichever occurs earlier, in all asymptomatic children and adolescents who are over-weight (BMI ≥85^th percentile) or obese (BMI ≥95^th percentile).¹
• Testing for prediabetes/diabetes should be considered before 10 years of age in asymptomatic children and adolescents who are over-weight (BMI ≥85^th percentile) or obese (BMI ≥95^th percentile) and who have additional risk factors for diabetes:¹
  • History of diabetes or GDM during the child’s gestation
  • Both parents with diabetes
  • Family history of type 2 diabetes in first- or second-degree relative
  • Signs of insulin resistance or conditions associated with insulin resistance (acanthosis nigricans, hypertension, dyslipidemia, polycystic ovary syndrome, or small-for-gestational-age birth weight)
• Immediate testing is required in symptomatic cases.¹

If results are normal, testing should be repeated at 2-year intervals, with consideration of more frequent testing depending on initial results, deteriorating risk status or appearance of symptoms. Children with prediabetes should be tested yearly.

• Testing for prediabetes/ diabetes should be considered in all women planning pregnancy.¹
• If preconception test is negative, test all women at the first antenatal visit with 3 sample 75 gm OGTT.¹
• If early screening is negative, screening should be done at 24-28 weeks of gestation with 3 sample 75 gm OGTT.¹
• Women with GDM should be tested with 2 sample 75 gm OGTT and non-pregnant diagnostic criteria at 4-12 weeks postpartum, preferably at 6th week considering vaccination schedule of children in Bangladesh.¹

• Plasma glucose rather than HbA1c should be used to diagnose the acute onset of T1DM in individuals with symptoms of hyperglycemia.¹
• Screening for T1DM risk with a panel of autoantibodies (autoantibodies to islet cell, insulin, GAD, Zinc transporter) can be done in first-degree family members of a proband with T1DM where facility is available.¹

• In those with hemoglobinopathies, annual screening with standard OGTT should begin at 10 years of age. There is limited role of HbA1c in this setting.⁴
• After organ transplantation, testing with OGTT should be performed once the patient is stable on immunosuppressive therapy and there is no infection.¹