Isolated Postchallenge Hyperglycemia Research Articles

Ten-year atherosclerotic cardiovascular disease risk prediction for postmenopausal women: Impacts of isolated postchallenge hyperglycemia.

Isolated postchallenge hyperglycemia (IPH) is a type of diabetes mellitus defined as 2-h glucose ≥200 mg/dL but fasting glucose <126 mg/dL. The purpose of the study was to assess impacts of IPH on 10-year atherosclerotic cardiovascular disease (ASCVD) risk scores in postmenopausal women. This study analyzed data from 428 postmenopausal women who underwent oral glucose tolerance test at a medical center. Ten-year ASCVD risk was evaluated by using Pooled Cohort Equations. Logistic regression analysis was performed to estimate odds ratios for having high 10-year ASCVD risk scores (≥5%) among these women. The subjects with IPH had higher systolic blood pressure and worse lipid profile than those without IPH. Ten-year ASCVD risk scores for postmenopausal women with IPH were calculated under 2 scenarios: the IPH women were considered non-diabetic, they were designated as patients with DM. The median ASCVD risk score of the participants with IPH increased significantly from 3.7% under scenario 1 to 7.1% under scenario 2. Approximately 20% women with IPH were re-categorized from risk category of <5% to ≥7.5% once they were identified as patients with DM (scenario 2). The results of logistic regression analyses showed that IPH was independently positively associated with 10-year ASCVD risk scores ≥5% under both scenarios. Postmenopausal women with IPH were characterized by unfavorable cardiovascular risk profile and high predicted 10-year ASCVD risk. Knowing the women's hidden DM status would significantly alter their risk categorization.

Association between serum somatostatin levels and glucose-lipid metabolism in the Jino ethnic minority and Han Chinese population.

We aim to investigate the relationship between serum somatostatin (SST) levels and glucose-lipid metabolism at various stages of glucose tolerance in the Jino ethnic minority (n=111) and Han population (n=113) of Yunnan Province, southwest China. Anthropometric parameters and biochemical traits were measured. Serum SST and plasma glucagon levels were tested. Participants were divided into three subgroups: isolated fasting hyperglycemia (IFH), isolated post challenge hyperglycemia (IPH) and normal glucose tolerance (NGT). SST levels were found lower while glucagon levels were significantly higher in the Jino ethnic with IPH (P=0.0026 and P=0.0069, respectively). Fasting glucose and high density lipoprotein-cholesterol (HDL-C) levels were higher (P=0.0055 and P=0.0021, respectively) and fasting insulin levels and homeostasis model assessments β-cell function were lower (P=0.0479 and P=0.0007, respectively) in the Jino population. After adjusting for confounding factors, the serum SST level was associated with glucagon (P<0.0001) in both populations. The SST level was correlated with fasting Cpeptide (P=0.0267) in Jino and HDL-C levels in Han (P=0.0079). Our findings suggest that serum SST levels and plasma glucagon levels may vary in subjects with IPH between two ethnics.

Longer time to peak glucose during the oral glucose tolerance test increases cardiovascular risk score and diabetes prevalence.

IntroductionThe pattern of glucose levels during an oral glucose tolerance test (OGTT) may be useful for predicting diabetes or cardiovascular disease (CVD). Our aim was to determine whether the time to peak glucose during the OGTT is associated with CVD risk scores and diabetes.MethodsIndividuals with impaired fasting glucose (IFG) were enrolled in this observational study. Participants were grouped by the measured time to peak glucose (30, 60, 90 and 120 min) during the 75g OGTT. The primary outcome was 10-year CVD risk scores (using the Framingham risk score calculator). Secondary outcomes evaluated effect of time to peak glucose on prevalence of diabetes and indicators of glucose homeostasis.ResultsA total of 125 patients with IFG underwent OGTTs. Framingham 10-year risk score for the 90-min group was 1.7 times higher than for the 60-min group (6.98±6.56% vs. 4.05±4.60%, P = 0.023). Based on multivariate linear regression, time to peak glucose at 90 min was associated with a higher Framingham risk score than 60-min group (β coefficient: 2.043, 95% confidence interval: 0.067–6.008, P = 0.045). The percentages of patients with HbA1c ≥6.5%, isolated post-challenge hyperglycemia (IPH) and diabetes (combined IPH and HbA1c ≥6.5%) were significantly increased with longer times to peak glucose. Prevalence of diabetes was higher in the 90-min group than in the 60-min group (31.5% vs. 5.7%, P = 0.001).ConclusionsIn subjects with IFG, those with a longer time to peak glucose had a higher Framingham 10-year risk score and were associated with a greater likelihood of IPH and diabetes.

β-Cell function in postmenopausal women with isolated post-challenge hyperglycemia.

Isolated post-challenge hyperglycemia (IPH) is an early stage of type 2 diabetes mellitus (T2DM), with fasting glucose <126 mg/dL and 2-h glucose ≥200 mg/dL. Observations of insulin secretion profile in subjects with IPH may provide an insight into the pathogenesis of T2DM in older women. We recruited 555 naturally postmenopausal women without a history of T2DM to the present study. All participants received a 75-g oral glucose tolerance test to determine whether they had IPH. General linear models were used to compare differences in glucose metabolism among subjects. Early phase insulin responses to oral glucose were significantly decreased in women with IPH versus those with impaired glucose tolerance (IGT) and normal glucose tolerance (geometric mean [95% confidence interval] insulinogenic index 61 [54-79] vs 90 [83-97] and 105 [96-116], respectively; P < 0.0001). In addition, there were significant decreases in late-phase insulin release as metabolic status shifted from normal glucose tolerance to IGT to IPH. In the present cohort, the relative contribution of early insulin secretion to 2-h glucose was no longer significant ( P = 0.15) after multiple factors, including indicators of insulin resistance and late-phase insulin release, were entered into the regression model simultaneously. The results demonstrate that postmenopausal women with IPH are characterized by impaired β-cell function. There were significant decreases in early and late-phase insulin release as glucose intolerance escalated. Disturbance in β-cell function seems to be an important factor associated with early T2DM in postmenopausal women.

High Levels of C-Reactive Protein Are Positively Associated with Isolated Postchallenge Hyperglycemia in Postmenopausal Women.

Isolated postchallenge hyperglycemia (IPH) is an early form of type 2 diabetes with fasting glucose <126 mg/dL and 2-hr postchallenge glucose ≥200 mg/dL. The purpose of this study was to explore the relationships of high-sensitivity C-reactive protein (hsCRP) with IPH. We recruited 476 naturally postmenopausal women without a history of diabetes mellitus for the study. Fasting blood samples were collected for the measurements of hsCRP and biochemistry. All participants received a 75 g oral glucose tolerance test to examine if they had IPH. The relative contributions of body mass index (BMI) and homeostasis model assessment of insulin resistance (HOMA-IR) to the association of hsCRP with IPH were evaluated by logistic regression. There was an increasing trend in prevalence of IPH with increasing quartiles of hsCRP (2.9%, 3.6%, 5.9%, and 7.6% in quartile 1-4, respectively) (P = 0.001). BMI and HOMA-IR were the most important determinants of hsCRP in this cohort. We observed a significant and positive association between high hsCRP levels and IPH in our subjects. Compared with subjects in the lowest quartile group, individuals with high levels of hsCRP (the 3rd and the 4th quartiles) were 2-2.5 times more likely associated with IPH, before and after adjustments for BMI and HOMA-IR values (all P < 0.05). Our results demonstrated that chronic inflammation, measured by elevated serum hsCRP levels, was positively associated with IPH in postmenopausal women. This finding was independent of obesity and insulin resistance.

Different glucose tolerance status and incident cardiovascular disease and all-cause mortality among elderly Iranians.

To determine the effect of different glucose categories on incident cardiovascular disease (CVD) and all-cause mortality in a population-based cohort. A total of 834 individuals aged 65 years and older without a history of CVD at baseline were stratified according to 2-h post-load glucose fasting glucose test into six categories including: (i) normal fasting glucose/normal glucose tolerance; (ii) prediabetes, (iii) isolated fasting hyperglycemia (IFH); (iv) isolated post-challenge hyperglycemia (IPH); (v) IPH and IFH; and (vi) known diabetes mellitus. The prognostic significance of these groups on CVD and total mortality were examined by Cox proportional hazard ratios in a multivariate adjusted model. Over 9 years of follow up, 186 incidents of CVD and 218 deaths occurred (72 CVD mortality).Of the population, 45.2%, 30.7%, 1.2%, 6.1% 4.7%, and 11.9% were normal fasting glucose/normal glucose tolerance, prediabetes IFH, IPH, IFH and IPH, and known diabetes mellitus, respectively. Multivariate adjusted hazard ratios for CVD were 1.13 (95% CI 0.78-1.64), 1.03 (95% CI 0.25-4.22), 1.17 (95% CI 0.65-2.11), 2.52 (95% CI 1.43-4.42) and 2.39 (95% CI 1.55-3.69), and for CVD mortality were 0.59 (95% CI 0.27-1.30), 2.02 (95% CI 0.27-15.15), 1.26 (95% CI 0.51-3.16), 3.57 (95% CI 1.64-7.75), and 4.70 (95% CI 2.54-8.69) for prediabetes, IFH, IPH, IFH and IPH, and known diabetes mellitus phenotypes, respectively. Corresponding hazard ratios for all-cause mortality in multivariate model adjusted for prevalent CVD were 1.07 (95% CI 0.73-1.57), 0.59 (95% CI 0.08-4.30), 0.92 (95% CI 0.5-1.70), 2.31 (95% CI 1.33-4.01) and 3.88 (95% CI 2.70-5.55), respectively. Among the elderly population with newly diagnosed diabetes, only the combined IFH and IPH phenotype, but not IFH or IPH alone, was a significant predictor of CVD and mortality events. Prediabetes was not associated with any risk. Geriatr Gerontol Int 2016; 16: 1263-1271.

The Metabolic Change of Serum Dehydroepiandrosterone Sulfate, Free Fatty Acids and Desaturase Activity in Isolated Post-Challenge Hyperglycemia

The aim of this study is to investigate the association between endogenous dehydroepiandrosterone sulfate (DHEA-S) and fatty acid, desaturase in isolated post-challenge hyperglycemia (IPH) subjects. 241 IPH subjects aged 35 to 70 years participated. Serum DHEA-S concentration was measured using the enzyme-linked immunosorbent assays. Fatty acid profiles were detected by gas chromatography-mass spectrometry, and desaturase activities were expressed by fatty acid product-to-precursor ratios. Relationships were assessed using multiple regression. The results suggested that DHEA-S concentration was negatively associated with palmitic acid (P < 0.001), and positively with γ-linolenic acid and eicosatetraenoic acid in men (P = 0.002 and P = 0.001, respectively), and negatively with palmitic acid (P = 0.037) and positively with docosapentaenoic acid, docosahexaenoic acid (P = 0.018 and P < 0.001, respectively) in women. In addition, a positive association was observed between DHEA-S and delta-9-desaturase (D9D-18, P = 0.031) in men, and also delta-6-desaturase (D6D, P = 0.034) in women. In Conclusions, there is different DHEA-S, fatty acid profile and the desaturase activities in both genders with the IPH subjects.

Likelihood of having isolated postchallenge hyperglycemia in an Iranian urban population

To identify subjects who would most likely benefit from oral glucose tolerance test (OGTT) for diagnosis of diabetes mellitus (DM), namely isolated postchallenge hyperglycemia (IPH) (i.e. FPG < 126 mg/dl and 2 h-PG ≥ 200 mg/dl), we evaluated data and results of OGTT of 9745 participants of Tehran Lipid and Glucose Study (TLGS), aged >20 years and without previously diagnosed DM. The overall prevalence of IPH was 3.1% (95% CI: 2.8–3.4%, n = 302). In the multivariate logistic regression analysis, the odds ratios (OR) for IPH were statistically significant for FPG ≥ 100 mg/dl (OR 9.5; 95% CI: 7.1–12.5), age ≥40 years (OR 2.6; 95% CI: 1.8–3.7), triglycerides ≥200 mg/dl (OR 2.1; 95% CI: 1.6–2.7), hypertension (OR 2.0; 95% CI: 1.5–2.6) and abnormal waist circumference (OR 1.9; 95% CI: 1.3–2.8). In subjects with FPG < 126 mg/dl, findings that best distinguished between IPH and non-diabetic subjects were FPG ≥ 100 mg/dl [positive likelihood ratio (LR(+)) = 5.2], FPG ≥ 100 mg/dl together with triglycerides ≥200 mg/dl [LR(+) = 9.7] and a combination of all the five factors [LR(+) = 12.9]. This analysis showed that in Iranian urban subjects with FPG < 126 mg/dl, factors such as FPG ≥ 100 mg/dl, older age, hypertriglyceridemia, hypertension and abnormal waist circumference were the best predictors of presence of IPH; OGTT would hence be recommended for opportunistic screening of IPH in subjects with above mentioned characteristics.

Contribution of nonesterified fatty acids to insulin resistance in the elderly with normal fasting but diabetic 2-hour postchallenge plasma glucose levels: the Baltimore Longitudinal Study of Aging

Isolated postchallenge hyperglycemia (IPH) with normal fasting plasma glucose <100 mg/dL and plasma glucose with diabetic 2-hour plasma glucose ≥200 mg/dL after an oral glucose tolerance test (OGTT) is a common occurrence in the elderly. We sought to understand what unique characteristics this population might have that puts it at risk for this particular metabolic finding. We therefore conducted a longitudinal study of volunteers in the Baltimore Longitudinal Study of Aging (BLSA). All volunteers had an OGTT performed (75 g) on 2 or more occasions. We measured plasma levels of glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), ghrelin, leptin, adiponectin, resistin, C-reactive protein, cytokines, and their soluble receptors, as well as nonesterified free fatty acids (NEFAs). We determined that 22 subjects in BLSA had IPH, accounting for 2.1% of the BLSA population. All 22 were older than 65 years. They were then matched by age, sex, and body mass index to 12 subjects who had isolated impaired glucose tolerance (IGT) and 15 subjects with normal glucose tolerance (NGT). All subjects had normal fasting glucose levels <100 mg/dL in accordance with the American Diabetes Association Expert Committee on the Classification and Diagnosis of Diabetes Mellitus criteria (2003). We found that subjects with IPH had similar plasma insulin levels to the other 2 groups, except at the 2-hour time when their insulin levels were higher than NGT ( P < .05). Although there was a clear trend for differences in the insulinogenic index, the areas under the curves for insulin, systolic blood pressure, adiponectin, and C-reactive protein across the glucose tolerance categories revealed no statistical significance. Cytokines and their soluble receptors, gut hormones, and adipokines were similar in all 3 groups. The NEFA levels were significantly elevated in the fasting state ( P < .05) in the IPH compared with NGT, with IGT intermediate between the other 2 groups. The rate of clearance of NEFAs after the OGTT decreased progressively from the NGT to the IPH group (in micromoles per liter per minute: NGT, 11.9 vs IGT, 7.6 vs IPH, 3.0). We conclude that the rate of suppression of lipolysis in the elderly determines the sensitivity of glucose uptake to insulin after OGTT.

Factors Responsible for Glucose Intolerance in Japanese Subjects with Impaired Fasting Glucose

Impaired fasting glucose (IFG) represents risk of development of diabetes (DM) and its complications. We investigated insulin secretion and insulin sensitivity in 403 IFG subjects divided into three levels of 2-hour postchallenge glucose (2-h PG) to clarify the factors responsible in the development of glucose intolerance in Japanese IFG. Nearly 60% of the subjects at annual medical check-up with FPG of 6.1-7.0 mmol/l at the first screening were diagnosed by 75 g oral glucose tolerance test (OGTT) to have impaired glucose tolerance (IGT; FPG <7.0 mmol/l and 7.8 mmol/l <2-h PG <11.1 mmol/l) or DM (isolated postchallenge hyperglycemia (IPH); FPG <7.0 mmol/l and 11.1 mmol/l <2-h PG level). The primary factor in the decreased glucose tolerance was a decrease in early-phase insulin, with some contribution of increasing insulin resistance. In addition, IFG/IGT and IFG/IPH subjects showed a compensatory increase in basal insulin secretion sufficient to keep FPG levels within the non-diabetic range. IFG is composed of three different categories in basal, early-phase insulin secretion, and insulin sensitivity.

Reproducibility of diabetes mellitus diagnosis (WHO 1999 criteria) in women.

Reproducibility of diabetes mellitus (DM) diagnosis has been recognized as non-optimal and a few studies have analyzed its reproducibility using new diagnostic criteria. Our aim was to evaluate the reproducibility of WHO 1999 criteria for DM diagnosis in women. A total of 696 caucasian women with previous gestational diabetes mellitus (GDM) underwent an OGTT at a median of 6.2 years (interquartile range, 0.5-7.3) after delivery. When OGTT was diagnostic of DM, a second test was scheduled and performed after a median of 3 months (interquartile range, 1.6-10.6). At the second test, 35 women were diagnosed with DM (12 by fasting plasma glucose (FPG) alone, 10 by isolated post-challenge hyperglycemia (IPH), 10 by fasting and 2-h plasma glucose, 3 by symptoms of hyperglycemia plus measurement of plasma glucose). DM was confirmed in 56.3% of women diagnosed without symptoms. In this subgroup, reproducibility according to the abnormality at the first test was: 33.3% in those diagnosed by FPG alone, 40% in those diagnosed by IPH, and 100% in those diagnosed by both fasting and 2-h plasma glucose ( p<0.05 vs. the two previous groups). In women with former GDM, the reproducibility of DM diagnosis by FPG alone or IPH is similar and lower than the diagnosis made by abnormality in both values.

Factors responsible for development from normal glucose tolerance to isolated postchallenge hyperglycemia.

Isolated postchallenge hyperglycemia (IPH), defined as fasting plasma glucose (FPG) level <7.0 mmol/l and 2-h plasma glucose (PG) level >/=11.1 mmol/l, is a subtype of early-stage diabetes. This study evaluates the metabolic profiles of insulin secretion and insulin sensitivity in IPH to clarify the factors responsible for development of this form of type 2 diabetes. We conducted cross-sectional analysis of 231 Japanese men aged 20-70 years. The subjects were classified into the following three groups, based on the results of a 75-g oral glucose tolerance test (OGTT): 1) normal glucose tolerance (NGT), defined as FPG level <6.1 mmol/l and 2-h PG level <7.8 mmol/l (n = 89); 2) impaired glucose tolerance (IGT), defined as FPG level <7.0 mmol/l and 2-h PG level of 7.8-11.1 mmol/l (n = 94); and 3) IPH (n = 48). We compared the three groups for insulin secretion (insulinogenic index) and insulin sensitivity (index of insulin resistance using homeostasis model assessment [HOMA-IR]). The insulinogenic index in IPH was the lowest of the three groups (P < 0.001 versus NGT). The HOMA-IR in the IGT and IPH groups were significantly higher than in the NGT group (P < 0.001), but both were similar. By linear regression analysis, the insulinogenic index rather than fasting insulin or HOMA-IR was the more significant factor in the 2-h PG level in IGT and IPH. Subjects with IPH exhibited distinctly impaired early-phase insulin secretion and only mild insulin resistance, indicating that reduced insulin secretion is the primary determinant of deterioration from NGT to IGT and IPH in development of type 2 diabetes in these subjects.

Effects of Isolated Post-challenge Hyperglycemia on Mortality in American Indians

To assess the effects of isolated post-challenge hyperglycemia (IPH) on risk of cardiovascular disease (CVD), cancer, and all-cause mortality in American Indians using longitudinal data from the Strong Heart Study.Of 4549 American Indian women and men aged 45 to 74 years participating in the Strong Heart Study, 4304 had fasting blood measurements or oral glucose tolerance test (OGTT) data to ascertain diabetes status. At baseline and follow-up, a personal interview was conducted, and physical examinations and laboratory tests were performed. Fasting blood samples were drawn for measurement of glucose, fibrinogen, insulin, lipids, lipoproteins, creatinine, and hemoglobin A1c (HbA1c). A 75-g OGTT was performed. Five diabetes categories were defined: (i) known diabetes, (ii) newly diagnosed diabetes (fasting glucose > or =126 mg/dL and no history of diabetes or diabetes medication; ADA-new diabetes), (iii) IPH, (iv) impaired fasting glucose (> or =110 - <126 mg/dL; IFG), and (v) normal fasting glucose (<110 mg/dL; NFG). Surveillance was initiated to determine CVD, cancer, and all-cause mortality over 9 years.IPH had a worse CVD risk factor profile than NFG, but IPH was associated with a better CVD risk factor profile than known diabetes or ADA-new diabetes. At follow-up, individuals with IFG had no increased risk for CVD or all-cause mortality, whereas those with ADA-new or known diabetes had significantly increased risk (RR = 1.70 and 1.40 for ADA-new diabetes, and RR = 2.87 and 2.19 for known diabetes, respectively). Those with IPH had nonsignificant elevations in risk for CVD (RR = 1.54) and all-cause (RR = 1.27) mortality. Cancer mortality was not increased in those with IFG, IPH, ADA-new diabetes, or known diabetes compared to those with NFG.Among American Indians 45 to 74 years of age, IPH is associated with nonsignificant elevations in total and CVD mortality. The magnitude of mortality risk associated with IPH is intermediate between diabetes and IFG. Because those with IPH are at high risk for diabetes, American Indians with IPH should be targeted for diabetes prevention.

From Policemen to Policies: What Is the Future for 2-h Glucose?

To describe the characteristics and vital prognosis of men with diabetes diagnosed by one fasting plasma glucose (FPG) concentration > or =7.0 mmol/l, with diabetes diagnosed by one isolated postchallenge hyperglycemia (IPH) (FPG <7.0 mmol/l and a 2-h plasma glucose concentration > or =11.1 mmol/l), or with impaired glucose tolerance (IGT). This study involved a cohort of 6,881 Caucasian nondiabetic men from the Paris Prospective Study, aged 44-55 years, who were followed for cause of death for 20 years. Diabetes was diagnosed in 4.3% of the men (1.0% diabetes diagnosed by IPH), and IGT was diagnosed in 9% of the men. At baseline, the men with diabetes diagnosed by IPH had a lower cardiovascular risk profile than those with diabetes diagnosed by FPG, as did the men with IGT and a normal fasting glucose level (<6.1 mmol/l, IGT and normal fasting glucose), compared with men with impaired fasting glucose (6.1-6.9 mmol/l, IGT and impaired fasting glucose [IFG]). At 20 years of follow-up, all-cause and cancer death rates were higher in men with diabetes diagnosed by IPH than in men with diabetes diagnosed by FPG (55 vs. 44%, P < 0.1 and 31 vs. 17%, P < 0.01, respectively) but were not significantly different for coronary causes (6 vs. 11%). Men with IGT and normal fasting glucose also had significantly higher cancer death rates than men with IGT and IFG. The most likely explanation for the high cancer and low coronary death rates is that men with diabetes diagnosed by IPH consumed alcohol; the men in this study drank 49 g of pure alcohol on average per day, equivalent to 0.6 l of wine. If these results are confirmed by other prospective studies, screening subjects for isolated postchallenge hyperglycemia may not be worthwhile.

Insulin secretion and sensitivity during oral glucose tolerance test in Korean lean elderly women.

Impaired glucose tolerance (IGT) and type 2 diabetes including undiagnosed isolated postchallenge hyperglycemia (IPH) are common in the elderly. The aim of this study was to investigate the insulin secretion and sensitivity in Korean elderly lean diabetic women. Forty-one lean women aged 65-88 years took 2 hr oral glucose tolerance test (OGTT) and were stratified according to the WHO criteria (normal glucose tolerance [NGT], n=20; IGT, n=6; and type 2 diabetics, n=15 including seven IPH). HbA1c and fructosamine progressively increased from the NGT to the diabetic subjects (p=0.006 and p=0.001, respectively). Compared with subjects with NGT, the insulinogenic index, a marker of early insulin secretion and the AUC(ins), a marker of total insulin secretion, decreased significantly in diabetic group [0.53 (-0.44 -1.45) vs. 0.18 (0.00 -1.11), p=0.03 and 306+/-165 vs. 199+/-78 pmol/L, p=0.02 respectively]. A significant difference was found in the AUC(c-peptide) among each group (221+/-59 vs. 206+/-34 vs. 149+/-51 pmol/L, p=0.001 for each). The homeostasis model assessment of insulin resistance (HOMA-IR), a marker of insulin resistance, was not different among the groups. We conclude that compared with NGT subjects, elderly lean women with diabetes have impaired oral glucose-induced insulin secretion but have relatively preserved insulin sensitivity. This suggests that insulin resistance is not necessarily an essential component of Korean elderly lean diabetic women.

American Diabetes Association diabetes diagnostic criteria, advancing age, and cardiovascular disease risk profiles: results from the Third National Health and Nutrition Examination Survey.

To evaluate age-specific effects on diabetes prevalence estimates resulting from the American Diabetes Association (ADA) recommendation against use of the oral glucose tolerance test (OGTT), we contrasted the prevalence of two mutually exclusive groups: undiagnosed diabetes according to ADA criteria (no report of diabetes and fasting glucose [FG] > or =126 mg/dl) and isolated postchallenge hyperglycemia (IPH) (FG <126 mg/dl and OGTT > or =200 mg/dl), a group designated to have diabetes by World Health Organization (WHO) criteria but not ADA criteria. The weighted age-specific ratios of undiagnosed diabetes:IPH were calculated for 2,844 subjects aged 40-74 years without reported diabetes who had both FG and OGTT. A ratio > 1.0 indicated that the proportion of undiagnosed diabetes was greater than that of IPH. Mean levels of HbA1c and cardiovascular disease (CVD) risk factors were contrasted among people with undiagnosed diabetes and IPH and those without either abnormality ("nondiabetic"). Both undiagnosed diabetes and IPH increased with age, but age-specific undiagnosed diabetes:IPH ratios decreased from 5.49 in the 40-44 age-group to 0.77 in the 70-74 age-group. Regression analysis showed a significant (P = 0.006) negative association between age and these ratios. Mean HbA1c was 7.1% in the undiagnosed diabetes group and differed significantly from that of the IPH and nondiabetic groups (5.6 and 5.3%, respectively). Individuals with undiagnosed diabetes had less favorable triglycerides, BMI, and HDL cholesterol compared with people with IPH. Compared with WHO criteria, the ADA criteria underestimate glucose abnormalities more with increasing age. However, compared to those with undiagnosed diabetes, individuals with IPH had a mean HbA1c level that is considered in the nondiabetic range, and this group had significantly more favorable levels of several key CVD risk factors. These findings suggest that the ADA criteria, although underestimating the abnormalities of postchallenge hyperglycemia that occur frequently with increasing age, appear to be effective at identifying a group of individuals with both unfavorable CVD risk factor profiles and evidence of long-term exposure to hyperglycemia.

Consequences of the new diagnostic criteria for diabetes in older men and women. DECODE Study (Diabetes Epidemiology: Collaborative Analysis of Diagnostic Criteria in Europe).

To evaluate the prevalence of diabetes and the risk of death in older European men and women aged between 60 and 79 years at baseline using the new American Diabetes Association diagnostic criteria for diabetes. The analysis involved existing population-based European studies from the DECODE Study Group (Diabetes Epidemiology: Collaborative Analysis of Diagnostic Criteria in Europe) and involved baseline measures of fasting and 2-h glucose concentrations after a 75-g oral glucose tolerance test (OGTT) and follow-up to determine deaths. This analysis included 4,032 men and 2,207 women who were not previously known to have diabetes and 383 men and 319 women who had established diabetes. More than half of the diabetic subjects had already been diagnosed, one sixth had a fasting hyperglycemia > or = 7.8 mmol/l (140 mg/dl), one-sixth had a fasting glucose level of 7.0-7.8 mmol/l (126-140 mg/dl), and one-sixth had an isolated postchallenge hyperglycemia (fasting glucose < 7.0 mmol/l and 2-h glucose > or = 11.1 mmol/l [200 g/dl]). Compared with non-diabetic subjects, the hazard ratios for death in diabetic subjects were close to 2 and did not differ significantly according to the method of diagnosis of diabetes, age-group, or sex. One-third of the older diabetic subjects who were undiagnosed at baseline had isolated postchallenge hyperglycemia. OGTT screening of the subjects with impaired fasting glucose (6.1-6.9 mmol/l) would reduce this fraction by half. The group with isolated postchallenge hyperglycemia had an elevated risk of mortality similar to that of other diabetic subjects.

Isolated postchallenge hyperglycemia and the risk of fatal cardiovascular disease in older women and men. The Rancho Bernardo Study.

To determine whether diabetes defined by isolated postchallenge hyperglycemia (IPH) (2-h postchallenge plasma glucose > or = 11.1 mmol/l with fasting plasma glucose [FPG] < 7.0 mmol/l) increases the risk of fatal cardiovascular disease (CVD) in older women and men. In a prospective study, we followed 769 men and 1,089 women, aged 50-89 years, who had no history of diabetes or myocardial infarction and demonstrated no fasting hyperglycemia (i.e., FPG < 7.0 mmol/l) when they underwent oral glucose tolerance testing at baseline in 1984-1987. At baseline, 70% of 125 women and 48% of 133 men with previously undiagnosed diabetes had IPH. Over the next 7 years, women with IPH had a significantly increased risk of fatal CVD and heart disease compared with nondiabetic women. This increased risk was not observed in men with IPH. This association was independent of age, hypertension, central obesity, cigarette smoking, HDL cholesterol, and triglycerides (multiply adjusted hazard ratio and 95% CI: 2.6 and 1.4-4.7 for CVD; 2.9 and 1.3-6.4 for heart disease). Diabetes defined by IPH alone is common in older adults and more than doubles the risk of fatal CVD and heart disease in older women. Because the prevalence of IPH increases with age, the use of fasting glucose alone for diabetes screening or diagnosis may fail to identify most older adults at high risk for CVD and should be reevaluated.