Clinical characteristics of Japanese Americans with normal glucose tolerance with 1-h hyperglycemia: A cross-sectional study.

AIMS/

INTRODUCTION

High 1-h plasma glucose levels have an increased risk of type 2 diabetes. To determine the pathophysiological features in participants with normal glucose tolerance (NGT) with 1-h hyperglycemia (HG), we investigated the variability in the glucagon and insulin secretions after oral glucose loading and nutrient survey.

MATERIALS AND

METHODS

A 75-g oral glucose tolerance test (OGTT) was performed in Japanese Americans (aged 40-75 years), enrolled in medical surveys conducted in 2015. We recruited only participants with NGT defined as fasting glucose values <110 mg/dL and 2-h glucose levels <140 mg/dL. We evaluated homeostatic model assessment for insulin resistance (HOMA-IR), insulin sensitivity index (MATSUDA-Index), insulin, and glucagon (GCG) secretions during the 75-g OGTT and compared them between 1-h serum glucose values: <155 mg/dL (1-h non-hyperglycemia: NHG, n = 76) and 1-h serum glucose values: ≥155 mg/dL (HG, n = 41). We also conducted a dietary intake survey to determine the association between 1-h serum glucose and nutritional intake in the usual diet.

RESULTS

The HG group demonstrated significant insulin resistance compared to the NHG group. Two-h GCG levels were significantly lower in the HG group. Additionally, low vegetable fat intake was significantly associated with 1-h HG after adjusting for sex, age, and body mass index.

CONCLUSIONS

Insulin resistance is already present in the HG group. Vegetable fat intake may be associated with glucose metabolism regardless of clinical background.