The risk of transient postprandial oxyhypoglycemia in nonalcoholic fatty liver disease.

Background: Nonalcoholic fatty liver disease (NAFLD) is frequently associated with insulin resistance (IR) and abnormalities in glucose metabolism. Prevalent postprandial hyperinsulinemia along with insulin resistance in NAFLD may lead to hypoglycemia. This study investigated the prevalence of postprandial oxyhypoglycemia in patients with NAFLD.

Methods: The oral glucose tolerance test (OGTT) with 75 g glucose was performed in 375 biopsy-proven NAFLD patients with prior unknown type 2 diabetes mellitus (DM). Serum glucose and insulin levels were measured for 3 h after glucose loading and the clinical parameters were compared.

Results: Normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and DM were observed in 36, 36, and 28 %, respectively. Hypoglycemia (≤70 mg/dL) after 3 h was observed in 14.4 % of all patients. The rate of hypoglycemia was significantly higher in NGT (63 % of NGT) than in IGT (30 % of IGT) and DM (7 % of DM) (P < 0.05). In patients with hypoglycemia, the levels of insulin were significantly higher at 30 and 60 min than those without hypoglycemia (P < 0.05). By multivariate analysis, high-LDL cholesterolemia (P < 0.05), low-HDL cholesterolemia (P < 0.05), and fibrosis (P < 0.05) were significant factors that contributed to hypoglycemia after 3 h on 75 g OGTT.

Conclusions: A relatively higher proportion of NAFLD cases exhibited transient postprandial hypoglycemia after 3 h on OGTT, especially in NAFLD patients with early-stage fibrosis. By performing 75 g OGTT for 3 h, hypoglycemia would be diagnosed earlier and the treatment intervention would decrease the progression of NAFLD and deterioration of glucose metabolism.