Elevated 1-h post-challenge plasma glucose levels in subjects with normal glucose tolerance or impaired glucose tolerance are associated with whole blood viscosity

Abstract

Aim It has been suggested that glucose levels C155 mg/dl at 1-h during an oral glucose tolerance test (OGTT) may predict development of type 2 diabetes and cardiovascular events among adults with normal glucose tolerance (NGT 1 h-high). Studies showed a link between increased blood viscosity and type 2 diabetes. However, whether blood viscosity is associated with dysglycemic conditions such as NGT 1 h-high, impaired glucose tolerance (IGT) or impaired fasting glucose (IFG) is unsettled. Methods 1723 non-diabetic adults underwent biochemical evaluation and OGTT. A validated formula based on hematocrit and total plasma proteins was employed to estimate whole blood viscosity. Subjects were categorized into NGT with 1 h glucose \155 mg/dL (NGT-1 h-low), NGT-1 h-high, IFG and/or IGT. Results Hematocrit and blood viscosity values appeared significantly higher in individuals with NGT 1 h-high, IFG and/or IGT as compared to NGT 1 h-low subjects. Blood viscosity was significantly correlated with age, waist circumference, blood pressure, HbA1c, fasting, 1-and 2-h post-challenge insulin levels, total cholesterol and lowdensity lipoprotein, triglycerides, fibrinogen, white blood cell, and inversely correlated with high-density lipoprotein and insulin sensitivity. Of the four glycemic parameters, 1-h post-challenge glucose showed the strongest correlation with blood viscosity (b = 0.158, P \ 0.0001) in a multivariate regression analysis model including several atherosclerosis risk factors. Conclusions Our results demonstrate a positive relationship between blood viscosity and 1-h post-challenge plasma glucose. They also suggest that a subgroup of NGT individuals with 1-h post-challenge plasma [155 mg/dl have increased blood viscosity comparable to that observed in subjects with IFG and/or IGT.

Lessons learned from the 1‐hour post‐load glucose level during OGTT: Current screening recommendations for dysglycaemia should be revised

“…• Abnormal lipids 44,73,[76][77][78] • Increased WBC 73,78 • Increased fibrinogen 70,78 • Subclinical target organ damage:…”

“…They were also found to be at high risk for the development of chronic kidney disease, ultrasonographic diagnosis of non‐alcoholic fatty liver disease, increased vascular stiffness, and early carotid atherosclerosis than those with IFG or NGT and 1‐hour PG < 155 mg/dl (8.6 mmol/L). Sub‐analyses demonstrated an association between NGT individuals and a 1‐hour PG ≥155 mg/dl (8.6 mmol/L) with elevated liver enzymes, adverse atherogenic profile, reduced vitamin D concentrations, decreased insulin clearance, insulin sensitivity and reduced β‐cell function, unfavourable inflammatory profile, and whole blood viscosity …”

1-Hour Post-OGTT Glucose Improves the Early Prediction of Type 2 Diabetes by Clinical and Metabolic Markers

“…Furthermore, the CATAMERI study found that people with normal glucose tolerance having an elevated 1-hour PG level ≥8.6 mmol/L were at higher risk for developing chronic kidney disease (8), nonalcoholic fatty liver disease (9), increased vascular stiffness (10), and early carotid atherosclerosis (11). An elevated 1-hour PG level was also associated with decreased insulin (INS) clearance (12), INS sensitivity, and reduced β -cell function (13), an unfavorable inflammatory profile (14), and whole blood viscosity (15).…”

1 h Postload Glycemia Is Associated with Low Endogenous Secretory Receptor for Advanced Glycation End Product Levels and Early Markers of Cardiovascular Disease

“…In this study, we measured sRAGE, esRAGE, and other markers of inflammation in subjects with high 1 h postload glycemia and examined their association with early markers of cardiovascular damage. Data from other studies have underlined a broad range of metabolic abnormalities in subjects with high 1 h postload glycemia, such as an increased whole blood viscosity, liver enzymes and uric acid, and reduced vitamin D plasma levels [25,26,27,28]. However, none of these studies explored the AGE/RAGE axis in this population.…”