Clinical Focus
6 OCTOBER 2023 ausdoc . com . au
AUSDOC ’ S TOP FIVE CLINICAL ARTICLES
Case Report
Unusual case
of diabetes
| THE | DIABETES ISSUE
1 . Spot diagnosis : Which condition rings true ?
Page views : 3500
2 . Popular decongestant no better than placebo
Page views : 2500
3 . Baby rashes
Page views : 2100
4 . A GP guide to the Japanese encephalitis vaccination update
Page views : 1900
5 . Watch for arrhythmia risk with common SSRIs : study
Page views : 1300
Source : AusDoc website ; 4-26 Sep
An elevated HbA1c in an older female patient with a complicated medical history leads a GP to make an unexpected diagnosis .
Dr Liz Frazer GP in Canberra , ACT .
WHEN her usual GP is on leave , 67-year-old Jen presents to a GP she has not seen previously with early cellulitis affecting her forearm , after a day of heavy pruning and mulching in the garden .
A retired nurse , Jen has a complex medical history , including breast cancer treatment in 2008 . Post-chemotherapy , she developed chronic neutropenia and cardiomyopathy , and in 2017 she needed percutaneous coronary intervention .
She also has a history of glaucoma and a branch retinal vein occlusion .
Her medications include clopidogrel , perindopril , metoprolol , ezetimibe , esomeprazole , atorvastatin and latanoprost eye drops .
On examination , Jen is systemically well with normal vital signs and localised cellulitis of the left forearm with no associated lymphangitis or lymphadenopathy . She weighs 60kg , with a BMI of 22.5kg / m 2 .
Progress
The GP recommends a course of flucloxacillin and arranges follow-up review in a week . Perusing Jen ’ s file , the GP notes that the most recent HbA1c was 6.4 %, so asks Jen to do repeat pathology before this review . This HbA1c returns at 6.6 %.
At follow-up , the cellulitis has completely resolved . With regard to the new diabetes diagnosis , Jen says she is very reluctant to take more medication , so the GP suggests she trial the low-carb ( LC ) dietary approach . During telephone follow-up two weeks later , Jen reports that after buying a low-carb cookbook , she has readily adapted her diet and feels much better . Within four months , her HbA1c has reduced to 5.6 %, and at eight months is 5.2 %. At follow-up , Jen remains well while her other health conditions are stable .
Around this time , the GP reads an article about latent autoimmune diabetes of adulthood ( LADA ) 1 and thinks of Jen , particularly as Jen is not overweight . The GP arranges autoantibody testing for glutamic acid decarboxylase ( GAD ), islet antigen 2 ( IA2 ) and zinc transporter 8 protein ( ZnT8 ) antibodies . All are positive , and at 1679U / mL , the GAD antibodies are especially high ( normal < 10 ). Screening for thyroid autoimmunity and coeliac disease is negative . C peptide is 1.1nmol / L ( normal 0.4-1.5 ).
The GP explains that Jen has LADA , a slowly progressive form of autoimmune type 1 diabetes , but because of her excellent
LC diet , she currently does not need medication . However , it is important to monitor the diabetes regularly and in future she may require insulin .
Discussion
LADA is a slowly progressive form of autoimmune diabetes that has the hallmark serum immune markers of type 1 diabetes ( T1D ) but not requiring insulin at diagnosis . 2 While people with LADA still have beta cell function at diagnosis , it is expected that beta cell function will continue to decline over time .
LADA may account for up to 12 % of adult onset diabetes . 2 Table 1 lists the clinical clues to this condition . 1 While clinical guidelines for LADA are lacking , expert consensus recommends screening for diabetes