One-hour Plasma Glucose More Than 155 mg/dL May Be Marker for Cardiovascular Risk
By Laurie Barclay, MD
Medscape Medical News
November 29, 2009 — Elevated 1-hour plasma glucose level in persons without overt diabetes may be a marker for cardiovascular risk, according to the results of a study reported ahead of print in the November 16 issue of Diabetes Care.
"Pre-diabetes (pre-DM) identifies subjects with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) at high risk for type 2 diabetes (DM2); moreover, it is associated to insulin resistance (IR), subclinical inflammation and cardiovascular diseases (CVD)," write Gianluca Bardini, MD, PhD, from the University of Florence in Florence, Italy, and colleagues. "Recently, 1-hour hyperglycaemia (1hPG) during glucose tolerance test (OGTT) with a cut point of 155 mg/dl has been indicated as a further risk factor for DM2 and showed early carotid atherosclerosis."
The goal of the study was to evaluate metabolic characteristics and markers of inflammation in 1062 subjects with normal glucose tolerance and prediabetes. Fibrinogen and leukocyte count for subclinical inflammation, lipid ratios, and insulin sensitivity measured with the Matsuda Index were compared in subjects with vs without a 1-hour plasma glucose level of more than 155 mg/dL after oral glucose loading.
Compared with subjects with a 1-hour plasma glucose level of 155 mg/dL or less, those with 1-hour plasma glucose levels of more than 155 mg/dL had significantly increased inflammatory markers and lipid ratios (P < .05 for all comparisons). An analysis adjusted for age, sex, and body mass index showed that 1-hour plasma glucose level was associated with significantly increased white blood cell count and fibrinogen (P < .05). Compared with subjects with 1-hour plasma glucose levels of 155 mg/dL or less, those with 1-hour plasma glucose levels of more than 155 mg/dL had significantly lower insulin sensitivity (P < .01).
"Elevated 1hPG in NGT [normal glucose tolerance] and pre-DM subjects is associated to subclinical inflammation, high lipid ratios and insulin resistance," the study authors write. "Therefore, 1hPG >155 mg/dl could be considered a new 'marker' for cardiovascular risk."
The study authors have disclosed no relevant financial relationships.
Diabetes Care. Published online November 16, 2009.
