Endocrine Abstracts

Background: Second generation antipsychotics (SGAs) are increasingly playing a bigger role in the treatment of schizophrenia and other psychiatric conditions due to their lower extra pyramidal side effect profile However, SGAs are known to cause clinically relevant metabolic derangements including hyperglycaemia

Case: A 70-year-old gentleman was admitted with generalised weakness and increased urinary frequency (polyuria) and polydipsia. His blood glucose was noted to be significantly elevated (72.6 mmol/l) and was diagnosed with hyperosmolar hyperglycaemic (HHS) and other blood test revealed acute kidney injury. He was not acidotic on venous blood gas analysis; blood ketones were negative with normal bicarbonate. His background includes pre-diabetes (diet controlled type 2 diabetes), which was diagnosed in May 2021 after about 2 years of olanzapine exposure, Paranoid schizophrenia, Bronchiectesis, Chronic kidney disease and abdominal aortic aneurysm. He was on olanzapine started in 2018. HHS was probably triggered by being on Olanzapine. He was started on IV fluid replacement followed by insulin infusion. His medications include aspirin 75 mg od, furosemide 20 mg od, atorvastatin 40 mg od, omeprazole 20 mg od, olanzapine 7.5 mg od He made improvement clinically and his renal function was better following which his oral metformin as well as Gliclazide. Olanzapine was continued.

Discussion: The prevalence of diabetes in bipolar/schizophrenic patients is 10-15%. This is 2-3 folds that of general population (3.5-5%-Holt et al 2005. Diabetes and other metabolic risk factors contribute to increase rate of CVD. Life expectancy is reduced by 10-15 years in people with schizophrenia (Brown et al 200). Postulated mechanism of olanzapine induced hyperglycaemia include: increased appetite(dopaminergic), induction of weight gain, possible direct beta cell toxicity and pancreatitis, increased insulin resistance and decreased insulin sensitivity, 2-3-fold increased risk of diabetes in mental health patients as well as the role of prolactin in dysregulation of glucose. Ethnicity, family or personal history of diabetes poverty, urbanisation, poor diet, physical inactivity also contribute to hyperglycaemia. The time taken for clinical manifestations of hyperglycaemia varies from a few days to a few years.

Conclsion: Managing diabetes in patients with mental health problems can be challenging. It has to be integrated, MDT team (psychiatry and diabetology teams), use of cognitive behavioural therapy (CBT), use of motivational interview. NICE recommends screening for diabetes at baseline, 3-4 months after initiation of anti-psychotic and then annually.