Endocrine Abstracts

We report a 77 year old male who presented to the respiratory clinic with episodes of periodic sweating. These episodes were associated nausea. They came on with exercise and always occurred before meals. The resolving factor noted by the patient was food intake and no features suggestive of reactive hypoglycaemia were noted. His past medical history was significant for hypertension, mild bronchiectasis, mild to moderate obstructive sleep apnea requiring CPAP therapy and ischemic heart disease. He was previously taking Ramipril for his blood pressure control but was switched to Losartan two months back due to cough. He was not known to have diabetes. The patient was reviewed in the cardiology clinic as well and the possibility of a cardiac arrhythmia was ruled out. Blood insulin and C-peptide levels were sent off which came back raised. On the basis of this the patient was referred to the Endocrinology clinic to rule out the possibility of an Insulinoma and for further workup. The patient was provided with a glucometer and was checking his blood glucose levels when he was symptomatic and three times a day. Blood glucose readings as low as 2.5 mmol coinciding with symptoms of sweating and nausea were recorded. Physical examination was unremarkable with the exception of some mild respiratory crackles at the right base which were stable from previous examination. He had a BMI of 32. A 72 hour fasting test and short Synacthen test was done, both of which were normal, and the possibility of insulinoma was ruled out. The patient’s Losartan was stopped and the hypoglycaemic episodes were resolved. ACE inhibitors and ARBs are the first line treatment for hypertension as recommended by NICE. Several studies have reported ACE inhibitors and ARBs improve insulin sensitivity and is favoured in patients with impaired glucose tolerance. Due to this, ACE inhibitors can lead to approximately three to four fold increase in hypoglycaemic episodes in in diabetics and rarely in non-diabetics. However no cases of hypoglycaemia in non-diabetics have been reported with ARBs so far.