Endocrine Abstracts

Oral glucose tolerance test (OGTT) is the main tool in population based screening for type 2 diabetes mellitus. Sometimes OGTT results are showing asymptomatic lowering of post-load blood glucose. Post-load plasma glucose (2hPG) level 3.9 mmol/l (70 mg/dl) and lower shows biochemical hypoglycaemia. Biochemical hypoglycaemia might be observed among individuals with abnormal glucose tolerance and in healthy population. The objective of the investigation was to assess a prevalence of biochemical hypoglycaemia during OGTT in routine outpatient practice.

Material and methods: We conducted an audit of 75 g standardized OGTT performed at Vilnius Antakalnio outpatient clinic from 3 January 2011 to 15 December 2014 and analysed data of 5575 adult patients. We applied 2006 WHO criteria for impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and diabetes. Patients with biochemical hypoglycaemia during OGTT, and with normal glucose tolerance (NGT) or IFG were compared using Student t-test.

Results: Mean patients’ age was 53.64±15.59 years (36.4% male and 63.6% female). Mean FPG was 5.87±0.65 mmol/l, mean 2hPG was 6.20±2.25 mmol/l. OGTT detected IFG in 1518 (27.2%), IGT in 778 (14.0%), diabetes in 286 (5.1%) patients. NGT was found in 2993 patients. Total 760 patients (13.6%) had biochemical hypoglycaemia: 547 (18.3%) patients with NGT and 213 (14.0%) patients with IFG. Within NGT group patients having biochemical hypoglycaemia were younger by 5.02 years (P<0.0001) and had lower level of FPG by 0.07 mmol/l (P=0.001) than those who did not present biochemical hypoglycaemia. Males experienced biochemical hypoglycaemia more frequently than women (24.4% vs 15.5%, P<0.0001). Within IFG group patients with biochemical hypoglycaemia were younger by 3.61 years (P<0.0001) and had lower level of FPG by 0.09 mmol/l (P<0.0001) than those who did not present biochemical hypoglycaemia.

Conclusion: Prevalence of biochemical hypoglycaemia is about 14%. Biochemical hypoglycaemia is associated with younger age, male gender and lower fasting plasma glucose level.