Type 1 diabetes: laboratory follow-up in adults and children

Laboratory tests

• TSH
• Anti-TPO antibodies (child and adolescent)if neededChild or adolescent: ISPAD recommends TSH, anti-TPO and anti-thyroglobulin antibodies shortly after diagnosis, once the condition is stable ^[2]; the 2007 HAS ALD guide provided for a search for antithyroid antibodies in the initial tests ^[3,4]. Positive antibodies prompt closer TSH monitoring ^[2,5].
• IgA anti-tissue transglutaminase antibodies (tTG-IgA)
• Total IgA (to interpret the serology)
• Lipid profile (child: from age 2)

Laboratory tests

• HbA1c
• Fructosamine (if HbA1c cannot be interpreted)if neededDisturbed red cell turnover or abnormal haemoglobin: fructosamine is one of the alternatives proposed by NICE ^[10]. NABM: only for treatment monitoring, not combinable with HbA1c on the same day ^[13].

Laboratory tests

• HbA1c
• Serum creatinine with eGFR
• Lipid profile
• TSH
• IgA anti-tissue transglutaminase antibodies (tTG-IgA)if needednon-French guidelineUnexplained weight loss, digestive disorders, malabsorption, osteoporosis, vitamin deficiencies or iron-deficiency anaemia: look for coeliac disease ^[6,10].
• Total IgAif needednon-French guidelineUnexplained weight loss, digestive disorders, malabsorption, osteoporosis, vitamin deficiencies or iron-deficiency anaemia: look for coeliac disease ^[6,10].
• Vitamin B12 (if neuropathy or unexplained anaemia)if needednon-French guidelinePeripheral neuropathy or unexplained anaemia: think of pernicious anaemia (Biermer), more frequent in type 1 diabetes ^[6].

Urine tests

• Urine albumin:creatinine ratio (spot sample)

Every 3 months

• HbA1c

Once a year

• TSH
• Urine albumin:creatinine ratio (spot sample) (from age 12)if neededFrom age 12 according to NICE ^[7]; according to ADA, at puberty or from age 11, after 5 years of diabetes ^[5]; according to ISPAD, at puberty or from age 11, after 2 to 5 years of diabetes, then every year ^[9]. The 2007 HAS ALD guide provides for yearly albuminuria ^[4].
• Serum creatinine with eGFR (from puberty or from age 11)if neededISPAD proposes estimating GFR at puberty or from age 11, after 2 to 5 years of diabetes ^[9]; the 2007 HAS ALD guide provides for yearly serum creatinine ^[4].
• IgA anti-tissue transglutaminase antibodies (tTG-IgA)if needednon-French guidelineRepeat coeliac disease screening within 2 years of diagnosis, then 5 years later; more often in case of symptoms or an affected first-degree relative ^[5]; ISPAD: within the year of diagnosis and then every 2 to 5 years ^[2].
• Total IgA (within 2 years of diagnosis, then every 2 to 5 years)if needednon-French guidelineRepeat coeliac disease screening within 2 years of diagnosis, then 5 years later; more often in case of symptoms or an affected first-degree relative ^[5]; ISPAD: within the year of diagnosis and then every 2 to 5 years ^[2].
• Lipid profile (at age 9-11 if the first tests were normal, then every 3 years)if neededIf the initial LDL cholesterol was ≤ 1.00 g/L (2.6 mmol/L): check at age 9-11, then every 3 years ^[5]; ISPAD also repeats every 3 years if the tests are normal ^[9]. The 2007 HAS ALD guide provided for a yearly lipid profile ^[4].