One-hour postload hyperglycemia confers higher risk of hepatic steatosis to HbA1c-defined prediabetic subjects

CONTEXT: Individuals with glycated hemoglobin (HbA1c)-defined prediabetes (HbA1c value of 5.7-6.4%) and 1-hour plasma glucose ≥155 mg/dL during an oral glucose tolerance test have an increased risk of developing type 2 diabetes. OBJECTIVE: To evaluate the degree to which HbA1c-defined prediabetes and 1-hour postload glucose ≥155 mg/dL individually and jointly associate with hepatic steatosis and related biomarkers. DESIGN AND PATIENTS: A cross-sectional analysis was performed on 1108 White individuals. SETTING: Ambulatory care. MAIN OUTCOME MEASURES: Anthropometric and metabolic characteristics including hepatic steatosis assessed by ultrasonography. RESULTS: Compared with the normal group (HbA1c <5.7%), HbA1c-defined prediabetic and diabetic individuals exhibit higher values of fasting, 1-hour, and 2-hour postload glucose; fasting and 2-hour postload insulin; triglycerides; uric acid; homeostasis model of assessment for insulin resistance; liver insulin resistance index; liver enzymes; and inflammatory biomarkers; and lower levels of high-density lipoprotein cholesterol and IGF-1. Prediabetic and diabetic subjects have increased risk of hepatic steatosis (1.5- and 2.46-fold, respectively). Stratifying participants according to HbA1c and 1-hour postload glucose, we found that individuals with HbA1c-defined prediabetes and 1-hour postload glucose ≥155 mg/dL have significantly higher risk of hepatic steatosis as compared with individuals with HbA1c-defined prediabetes but 1-hour postload glucose <155 mg/dL. Individuals with HbA1c-defined prediabetes and 1-hour postload glucose ≥155 mg/dL exhibit higher values of liver enzymes; fasting, 1-hour, and 2-hour postload glucose; insulin; triglycerides; uric acid; and inflammatory biomarkers; and lower levels of high-density lipoprotein and IGF-1. CONCLUSIONS: These data suggest that a value of 1-hour postload glucose ≥155 mg/dL may be helpful to identify a subset of individuals within HbA1c-defined glycemic categories at higher risk of hepatic steatosis.