Cardiometabolic Risk in Impaired Fasting Glucose and Impaired Glucose Tolerance

Abstract

OBJECTIVE -We compared and contrasted cardiovascular disease (CVD) risk factors, subclinical manifestations of CVD, incident coronary heart disease (CHD), and all-cause mortality by categories of impaired glucose regulation in nondiabetic individuals.RESEARCH DESIGN AND METHODS -The study included 6,888 participants aged 52-75 years who had no history of diabetes or CVD. All-cause mortality and incident CHD were ascertained over a median of 6.3 years of follow-up.RESULTS -Agreement between fasting and postchallenge glucose impairment was poor: 3,048 subjects (44%) had neither impaired fasting glucose (IFG) nor impaired glucose tolerance (IGT), 1,690 (25%) had isolated IFG, 1,000 (14%) had isolated IGT, and 1,149 (17%) had both IFG and IGT. After adjustment for age, sex, race, and center, subjects with isolated IFG were more likely to smoke, consume alcohol, and had higher mean BMI, waist circumference, LDL cholesterol, and fasting insulin and lower HDL cholesterol than those with isolated IGT, while subjects with isolated IGT had higher mean triglycerides, systolic blood pressure, and white cell counts. Measures of subclinical CVD and rates of all-cause mortality and incident CHD were similar in isolated IFG and isolated IGT.CONCLUSIONS -Neither isolated IFG nor isolated IGT was associated with a more adverse CVD risk profile. Diabetes Care 30:325-331, 2007T ype 2 diabetes imposes an increased burden of atherosclerotic cardiovascular disease (CVD), particularly of the coronary arteries, peripheral arteries, and cerebrovascular system (1). However, evidence of CVD risk can also be traced to glucose regulation abnormalities antecedent to diabetes status (2,3). The American Diabetes Association (ADA) and the World Health Organization both recognize "impaired" glucose categories, metabolic stages of glucose homeostasis intermediary between normal and diabetes (4,5). Impaired glucose tolerance (IGT) is defined by both organizations as a 2-h postchallenge glucose level Ն7.8 mmol/l (140 mg/dl) but Ͻ11.1 mmol/l (200 mg/dl). Although both organizations originally defined impaired fasting glucose (IFG) as a fasting glucose level between 6.1 mmol/l (110 mg/dl) and 6.9 mmol/l (125 mg/dl) (4,5), the ADA recommended in 2003 that the lower cut point for IFG be reduced to 5.6 mmol/l (100 mg/dl) (6). Studies (7,8) in diverse populations worldwide have reported substantial disagreement between fasting and postchallenge glucose impairment categories, although few studies (9 -13) have investigated the impact of the lower cut point of 5.6 mmol/l for IFG.Possible differences in CVD morbidity and mortality between IFG and IGT remain unclear, although the current evidence indicates that IGT entails greater risk of CVD (2,14). The DECODE (Diabetes Epidemiology: Collaborative Analysis of Diagnostic Criteria in Europe) investigators pooled data from a large number of prospective studies conducted in Europe and found that 2-h glucose was a better predictor than fasting glucose for all-cause and CVD mortality (15,16). Individual prospectiv...

Dysglycaemia in non-diabetic hypertensive patients: comparison of the impact of two different classifications of impaired fasting glucose on the cardiovascular risk profile

“…See Table 3 for further statistics. 20 as FPG levels in the 100-110 mg 100 ml À1 range are weak, and statistically not significant predictors of cardiovascular risk, 18,[21][22][23] while increasing substantially the proportion of individuals labelled as prediabetic. 24 Moreover, although the 2007 ESH/ESC hypertension guidelines 7 equated MetS to target organ damage and diabetes as risk modifier, the value of a formal diagnosis of MetS in clinical practice is contentious 25 and may not overcome the contribution of its individual components for both diabetes prediction and determination of vascular risk.…”

Plasma glucose levels as predictors of diabetes: the Mexico City diabetes study

“…Criteria for lesser degrees of dysglycaemia are less well established. Impaired glucose tolerance (IGT), defined by the 2 h glucose concentration, carries heightened risk of diabetes [3][4][5] and, possibly, cardiovascular disease [6][7]. The pathophysiology of IGT is a combination of insulin resistance, hepatic as well as peripheral, and beta cell dysfunction [8] that is similar to that of diabetes, only of a milder degree.…”

Topics in Type 2 Diabetes and Insulin Resistance

“…There is evidence of increased cardiovascular risk with IGT, and some (13), though not all (14), studies show increased risk with IFG. Taking into account CVD risk factors may reduce the excess risk associated with pre-diabetes (15,16). Part of the difficulty in associating pre-diabetes with risk may be that only a subset of these individuals progress to diabetes, with evidence that adverse effects are restricted to those individuals who progress to development of diabetes shown in studies in the Netherlands (17) and among Pimas (18).…”