Easily obtainable clinical features increase the diagnostic accuracy for latent autoimmune diabetes in adults: An evidence-based report

Abstract 

Background

Latent autoimmune diabetes in adults (LADA) represents a subgroup of diabetes mellitus. LADA is characterised by adult-onset diabetes and circulating autoimmune antibodies. LADA patients may need a different therapeutic approach than the usual type 2 diabetes mellitus. When LADA is inadequately diagnosed as type 2 diabetes mellitus, LADA patients will mistakenly be exposed to a high dose of oral glucose lowering drugs and their possible side effects.

Aim

To assess which clinical features predict the presence or absence of LADA in patients older than 25 years presenting with hyperglycemia.

Methods

A structured Medline and Embase search was conducted. Titles and abstracts were screened using predetermined selection criteria. Critical appraisal was based on standardized validity criteria for diagnostic research.

Results

One-hundred and eighty-four papers were retrieved of which after assessment of relevance and validity 2 studies remained for further analysis. One study reported a probability of LADA of 0.99 with one or two out of the following five clinical features: age at onset <50 years; acute symptoms; BMI<25kg/m²; a history of autoimmune disease; a family history positive for diabetes mellitus. The other study reported a probability of LADA of zero with none of the following clinical features and of 0.32 with one out of three: fasting blood glucose≥15mmol/l and/or HbA_1c≥10%; 10% reduction in body weight in the previous 3 months; BMI<25kg/m².

Conclusion

Further testing for LADA by measurement of autoimmune antibodies appears to be unnecessary in the absence of a specific set of clinical features. Before initiating therapy applying the above criteria may help to separate LADA from usual type 2 diabetes.

Abbreviations: GP, general practitioner, LADA, latent autoimmune diabetes in adults, GADA, glutamic acid decarboxylase antibodies, UKPDS, United Kingdom Prospective Diabetes Study, BMI, body mass index, PPV, positive predictive value, NPV, negative predictive value, NICE, National Institute for Health and Clinical Excellence, ADA, American Diabetes Association, ICA, Islet cell antibodies

Keywords: Latent autoimmune diabetes in adults, Diagnosis, Screening, Evidence-based medicine