Comparison of the fasting and the 2-h glucose criteria for diabetes in different Asian cohorts

Sex differences in the control of glucose homeostasis

PURPOSE OF REVIEW

A markedly higher prevalence of impaired glucose tolerance has been reported in women than in men, whereas the opposite was seen for impaired fasting glucose. The present review focuses on the underlying mechanisms.

RECENT FINDINGS

An increased meal glucose appearance and disturbances in postprandial glucose disposal may contribute to higher glucose concentrations in women. An increased, similar or reduced insulin sensitivity has been reported in women than in men, which makes it unclear to what extent a disturbed insulin-mediated glucose disposal may contribute to increased postprandial glucose concentrations in women. This discrepancy may be explained by differences in the phase of menstrual cycle during the study, the use of oral contraceptives and different degrees of physical fitness. Nevertheless, there are consistent data indicating that women are protected against fatty acid-induced insulin resistance. Furthermore, both disturbances in endogenous glucose output and metabolic clearance of glucose may contribute to the reduced fasting glucose concentrations in women.

SUMMARY

There is an urgent need for studies that test whether sex-related disturbances in glucose metabolism may be involved in the pathogenesis of type 2 diabetes and the metabolic syndrome, taking age, menstrual cycle, the use of oral contraceptives and physical activity into account.

Glucose tolerance in a rural population of Bangladesh

CONTEXT

The prevalence of type 2 diabetes is increasing in the Bangladeshi population. However, there is little information available on the prevalence of glucose intolerance, ie, type 2 diabetes, impaired glucose tolerance, and impaired fasting glucose.

AIMS

The main aim of this study is to determine the prevalence of different categories of glucose intolerance and their relationship with different anthropometric and demographic characteristics.

SETTINGS AND DESIGN

This cross-sectional study was performed in a rural area of Bangladesh.

MATERIALS AND METHODS

A random sample of 5000 persons aged >/= 20 years was included in this study. Fasting blood glucose was measured in 3981 individuals and 2-h post-glucose blood glucose was measured in 3954 subjects after the known cases of diabetes (n = 27) were excluded. Height, weight, waist and hip circumference, and blood pressure were measured.

STATISTICAL ANALYSIS

Pearson Chi-squared test and correlation test were used for analysis as appropriate.

RESULTS

The prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and diabetes (DM) were 1.3, 2.0, and 7.0%, respectively. IFG, IGT, and IFG + IGT were more prevalent in females. Age showed a significant positive relationship with increasing levels of glucose intolerance. Body mass index, waist circumference, and waist-to-hip ratio were higher in the glucose-intolerant group than in the normal glucose tolerance (NGT) group. There was a positive correlation between FBG and 2-h BG in NGT and DM subjects.

CONCLUSION

The FBG value identified more people with glucose intolerance than the 2-h BG. These findings will help developing diabetes preventive strategy in rural populations.

Differences in height explain gender differences in the response to the oral glucose tolerance test- the AusDiab study

AIM

To determine the extent of gender-related differences in the prevalence of glucose intolerance for the Australian population and whether body size may explain such differences.

METHODS

Cross-sectional data were collected from a national cohort of 11 247 Australians aged > or = 25 years. Glucose tolerance status was assessed according to both fasting plasma glucose (FPG) and 2-h plasma glucose (2hPG) levels following a 75-g oral glucose tolerance test (OGTT). Anthropometric and glycated haemoglobin measurements were also made.

RESULTS

Undiagnosed diabetes and non-diabetic glucose abnormalities were more prevalent among men than women when based only on the FPG results (diabetes: men 2.2%, women 1.6%, P = 0.02; impaired fasting glycaemia: men 12.3%, women 6.6%, P < 0.001). In contrast 16.0% of women and 13.0% of men had a 2hPG abnormality (either diabetes or impaired glucose tolerance, P = 0.14). Women had a mean FPG 0.3 mmol/l lower than men (P < 0.001), but 2hPG 0.3 mmol/l higher (P = 0.002) and FPG-2hPG increment 0.5 mmol/l greater (P < 0.001). The gender difference in mean 2hPG and FPG-2hPG increment disappeared following adjustment for height. For both genders, those in the shortest height quartile had 2hPG levels 0.5 mmol/l higher than the tallest quartile, but height showed almost no relationship with the FPG.

CONCLUSIONS

Men and women had different glycaemic profiles; women had higher mean 2hPG levels, despite lower fasting levels. It appeared that the higher 2hPG levels for women related to lesser height and may be a consequence of using a fixed glucose load in the OGTT, irrespective of body size.

Age at diagnosis of diabetes in a secondary care population: 1992—2005

To assess the change in age at diagnosis of diabetes over time in a secondary care diabetes clinic, clinical characteristics of patients attending were compared in 1992 and 2005. Those of European and South Asian origins were analysed separately.

Results In 1992, 28.4% of patients of European and 7.5% of patients of South Asian origins had type 1 diabetes. These proportions were similar in 2005. Mean age at diagnosis of type 1 diabetes remained unchanged from 1992 to 2005: Europeans: 20.6 versus 20.2 years (p=0.63) and in South Asians: 23.7 versus 21.3 years (p=0.21). By contrast the age at diagnosis of type 2 diabetes was younger in both groups in 2005 compared with 1992: Europeans: 54.0 versus 57.1 years (p<0.001). South Asians: 47.5 versus 49.0 years (p=0.003).

Conclusions These data suggest an earlier age at diagnosis of type 2 diabetes in those of both, European and South Asian origin over 13 years of study.

Factors responsible for age-related elevation in fasting plasma glucose: a cross-sectional study in Japanese men

To evaluate the factors associated with age-related increase in fasting plasma glucose (FPG) in Japanese men with normal fasting glucose, we measured FPG, fasting immunoreactive insulin, glycated hemoglobin, total cholesterol, triglyceride, and high-density lipoprotein cholesterol levels in health check examinees. Subjects with FPG less than 6.1 mmol/L together with glycated hemoglobin less than 5.6% were enrolled in the study. The homeostasis model assessment of insulin resistance (HOMA-IR) and HOMA-beta were used as the indices of insulin sensitivity and insulin secretion, respectively. Fasting plasma glucose increased significantly with age (r = 0.30, P < .0001), and HOMA-beta decreased significantly with age (r = 0.24, P < .0001). The HOMA-IR had no significant relation with age (r = 0.06, not significant), whereas body mass index and serum triglyceride were associated with HOMA-IR (r = 0.49, P < .0001 and r = 0.33, P < .0001, respectively). Thus, in Japanese male subjects with normal fasting glucose, it is suggested that the FPG increment with age is associated with decreased beta-cell function rather than with insulin resistance. Further analyses were performed by comparing 3 groups: low FPG (FPG <5.0 mmol/L), high FPG (5.0 < or = FPG < 5.6 mmol/L), and mild impairment of fasting glycemia (mild IFG) (5.6 < or = FPG < 6.1 mmol/L). The insulin levels in mild IFG and high FPG were significantly higher than in low FPG (P < .001), but those in mild IFG were similar to those in high FPG. Analysis of the 3 subgroups revealed that, whereas insulin sensitivity was impaired more in high FPG, there was little compensatory increase in insulin in mild IFG, suggesting that beta-cell function is already deteriorated when the FPG level is greater than 5.6 mmol/L.

Best practice in primary care pathology: review 10

This tenth best practice review examines four series of common primary care questions in laboratory medicine: (i) antenatal testing in pregnant women; (ii) estimated glomerular filtration rate calculation; (iii) safety testing for methotrexate; and (iv) blood glucose measurement in diabetes. The review is presented in question-answer format, referenced for each question series. The recommendations represent a precis of guidance found using a standardised literature search of national and international guidance notes, consensus statements, health policy documents and evidence-based medicine reviews, supplemented by Medline Embase searches to identify relevant primary research documents. They are not standards but form a guide to be set in the clinical context. Most are consensus rather than evidence-based. They will be updated periodically to take account of new information.

Diabetes and the risk of tuberculosis: a neglected threat to public health?

OBJECTIVES

Tuberculosis (TB) remains a major global public health problem. In the past, a relationship between TB and diabetes mellitus (DM) was recognized, and its importance was acknowledged through joint treatment clinics. However, this is rarely highlighted in current research or control priorities. This paper aims to evaluate the evidence for an association between these two diseases.

METHODS

A Medline literature search was undertaken, supplemented by checking references and contacting experts. We critically appraised studies that quantified the association between TB and DM, and were published after 1995. We assessed study quality according to criteria such as sample size, method of selection of cases and controls, losses to follow-up, quality and method of control of confounding, and summarized the results narratively and in tabular form.

RESULTS

All studies identified statistically significant and clinically important associations, with the increase in risk or odds of TB varying between 1.5- and 7.8-fold for those with DM. Risk was highest at younger ages. Most studies had not measured and controlled adequately for potential major confounders.

DISCUSSION

There is strong evidence for an association between TB and DM, which has potential public health implications. Further well-designed studies are needed to assess the magnitude precisely.

Prevalence of undiagnosed diabetes and postchallenge hyperglycaemia in Chinese patients with non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease is prevalent in affluent countries and is strongly associated with metabolic syndrome.

AIM

To study the prevalence of undiagnosed diabetes and postchallenge hyperglycaemia in Chinese patients with non-alcoholic fatty liver disease.

METHODS

73 consecutive patients with biopsy-proven non-alcoholic fatty liver disease and no history of diabetes underwent comprehensive metabolic screening. Diagnosis of diabetes and impaired glucose regulation was based on the 2006 American Diabetes Association criteria.

RESULTS

The prevalence of undiagnosed diabetes and impaired glucose tolerance in non-alcoholic fatty liver disease patients was 33% and 29%, respectively. Among patients with 2-h plasma glucose above 7.8 mm, 47% had normal fasting glucose (below 5.6 mm). Impaired glucose tolerance was more common in patients with non-alcoholic steatohepatitis than those with simple hepatic steatosis (P = 0.036), and 2-h plasma glucose correlated with fibrosis stage (Spearman coefficient: 0.25, P = 0.046). In a binary logistic regression analysis, high fasting glucose and low high-density lipoprotein cholesterol were independent factors associated with diabetes. Nevertheless, if oral glucose tolerance test was only performed in non-alcoholic fatty liver disease patients with impaired fasting glucose, 20.8% of diabetes cases would be missed.

CONCLUSIONS

Isolated postchallenge hyperglycaemia is common among Chinese non-alcoholic fatty liver disease patients without history of diabetes. It is associated with histological severe disease, and cannot be accurately predicted by any fasting glucose cut-off.

Prevalence of type 2 diabetes mellitus of Chinese populations in Mainland China, Hong Kong, and Taiwan

This article reviews and describes trends and differences in prevalence of type 2 diabetes mellitus of Chinese populations in Mainland China, Hong Kong and Taiwan based on literatures published in the MEDLINE Advanced database (January 1966-October 2005) in both Chinese and English languages. Chinese populations in Hong Kong and Taiwan have significant higher prevalence rates of diabetes than their Mainland counterparts, with odds ratios 1.5 (95% confidence intervals: 1.4, 1.7) and 2.0 (95% confidence intervals: 1.8, 2.2), respectively in 1995-2003 adjusted for age and diagnostic criteria. Using stratified diagnostic criteria; the odds ratios in Hong Kong and Taiwan were consistently higher than Mainland China for the periods of 1985-1994 and 1995-2003. A large proportion, i.e. 68.6% (95% confidence intervals: 67.4%, 69.7%) of diabetic patients remains undiagnosed in Mainland China as compared to 52.6% (95% confidence intervals: 49.8%, 55.5%) undiagnosed in Hong Kong and Taiwan. The prevalence rates of diabetes and impaired glucose tolerance of the Chinese populations rise in older age groups. In tandem with economic development and change toward lifestyle that is lack of physical activity and rich in high-fat diet, prevalence of diabetes of the Chinese populations are on the rise. If the undiagnosed individuals left uncontrolled, they are subject to higher risks of developing diabetes and its complications. These will increase the burdens of diabetes medically and financially.

Contributions of beta-cell dysfunction and insulin resistance to the pathogenesis of impaired glucose tolerance and impaired fasting glucose

Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) are intermediate states in glucose metabolism that exist between normal glucose tolerance and overt diabetes. Epidemiological studies demonstrate that the two categories describe distinct populations with only partial overlap, suggesting that different metabolic abnormalities characterize IGT and IFG. Insulin resistance and impaired beta-cell function, the primary defects observed in type 2 diabetes, both can be detected in subjects with IGT and IFG. However, clinical studies suggest that the site of insulin resistance varies between the two disorders. While subjects with IGT have marked muscle insulin resistance with only mild hepatic insulin resistance, subjects with IFG have severe hepatic insulin resistance with normal or near-normal muscle insulin sensitivity. Both IFG and IGT are characterized by a reduction in early-phase insulin secretion, while subjects with IGT also have impaired late-phase insulin secretion. The distinct metabolic features present in subjects with IFG and IGT may require different therapeutic interventions to prevent their progression to type 2 diabetes.

Test agreement for classifying diabetes in indigenous Australians

OBJECTIVE

To evaluate for Indigenous Australians the agreement between a fasting plasma glucose (FPG) criterion of 7.0 mmol/L and diabetes test results using a two-hour oral glucose tolerance test (OGTT), comparing relationships between test agreement and prevalence to similar studies.

METHODS

Screening was undertaken in 25 remote settlements. Agreement between FPG and OGTT results was evaluated using the kappa coefficient (chance-corrected agreement).

RESULTS

Participants (n=3,249) ranged from 15-94 years. Kappa ranged from 0.70-0.77 for diabetes prevalence of 5-30%, with overall agreement of 0.76. In comparison studies, the relationship between kappa and diabetes prevalence was similar, but with kappa 0.21-0.48.

CONCLUSIONS AND IMPLICATIONS

A FPG test with a 7.0 mmol/L cut-off is a reliable screening method, relative to the OGTT, for remote Indigenous settlements. The level of agreement between the FPG test and the OGTT for the Indigenous population surveyed is superior by far to agreement reported for non-Indigenous samples.

Postprandial glucose regulation: new data and new implications

BACKGROUND

Type 2 diabetes is characterized by a gradual decline in insulin secretion in response to nutrient loads; hence, it is primarily a disorder of postprandial glucose (PPG) regulation. However, physicians continue to rely on fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c) to guide management.

OBJECTIVES

The objectives of this article are to review current data on postprandial hyperglycemia and to assess whether, and how, management of type 2 diabetes should change to reflect new clinical findings.

METHODS

Articles were selected from MEDLINE searches (key words: postprandial glucose, postprandial hyperglycemia, and cardiovascular disease) and from our personal reference files, with emphasis on the contribution of postprandial hyperglycemia to overall glycemic load or cardiovascular (CV) risk.

RESULTS

About 33% of people diagnosed as having type 2 diabetes based on postprandial hyperglycemia have normal FPG. PPG contributes > or =70% to the total glycemic load in patients who are fairly well controlled (HbA1c <7.3%). Furthermore, there is a linear relationship between the risk of CV death and the 2-hour oral glucose tolerance test (OGTT). Increased mortality is evident at OGTT levels of approximately 90 mg/dL (5 mmol/L), which is well below current definitions of type 2 diabetes. Biphasic insulin aspart was shown to be more effective at reducing HbA1c below currently recommended levels than basal insulin glargine (66% vs 40%; P < 0.001), and it reduced endothelial dysfunction more effectively than regular insulin (P < 0.01). Repaglinide achieved regression of carotid atherosclerosis (intima-media thickness) in 52% of patients versus 18% for glyburide (P < 0.01) over 1 year, although levels of HbA1c and CV risk factors were similar for both treatment groups. Finally, acarbose reduced the relative risk of CV events by 49% over 3.3 years versus placebo in patients with impaired glucose tolerance (2.2% vs 4.7%; P = 0.03) and by 35% over > or =1 year in patients with type 2 diabetes (9.4% vs 6.1%; P = 0.006).

CONCLUSIONS

All components of the glucose triad (ie, FPG, HbA1c, and PPG) should be considered in the management of type 2 diabetes. Therapy targeted at PPG has been shown to improve glucose control and to reduce the progression of atherosclerosis and CV events; therefore, physicians should consider monitoring and targeting PPG, as well as HbA1c and FPG, in patients with type 2 diabetes.

Diabetes and associated disorders in Cambodia: two epidemiological surveys

BACKGROUND

The Asia-Pacific region is thought to be severely affected by diabetes. However, reliable, standardised data on prevalence and characteristics of glucose intolerance in Asian populations remain sparse. We describe the results of two field surveys undertaken in Cambodia in 2004.

METHODS

2246 randomly selected adults aged 25 years and older were examined in two communities, one rural (Siemreap) and one semi-urban (Kampong Cham). The diagnosis of diabetes and impaired glucose tolerance was based on 2-h blood glucose estimation using criteria recommended by the latest report of a WHO Expert Group. Blood pressure, anthropometry, habitual diet, and other relevant characteristics were also recorded.

FINDINGS

Prevalence of diabetes was 5% in Siemreap and 11% in Kampong Cham. Prevalence of impaired glucose tolerance was 10% in Siemreap and 15% in Kampong Cham. About two-thirds of all cases of diabetes were undiagnosed before the survey. Prevalence of hypertension was 12% at Siemreap and 25% at Kampong Cham. People in Kampong Cham had higher estimates of central obesity than those in Siemreap.

INTERPRETATION

Diabetes and hypertension are not uncommon in Cambodia. A quarter of all adults in the chosen suburban community had some degree of glucose intolerance. Since Cambodian society is relatively poor, and lifestyle is fairly traditional by international standards, these findings are unexpected.

Insulin secretion and insulin sensitivity in Japanese subjects with impaired fasting glucose and isolated fasting hyperglycemia

Impaired fasting glucose (IFG) is a subgroup of impaired glucose regulation exhibiting an elevated fasting glucose levels without elevated 2-h glucose levels on oral glucose tolerance test (OGTT). Diabetes mellitus with isolated fasting hyperglycemia (DM/IFH) is a similar subgroup of diabetes having higher fasting glucose levels with 2-h glucose levels within the non-diabetic range. The aim of this study is to profile the characteristics of these subgroups to estimate the factors involved in the development from normal glucose tolerance (NGT) via IFG to DM/IFH. Five hundred and sixty seven Japanese males were classified on the basis of 75 g OGTT into four groups, NGT, IFG, DM/IFH, and isolated impaired glucose tolerance (isolated IGT). Insulin secretion was evaluated by insulinogenic index, insulin sensitivity was evaluated by ISI composite, and insulin secretory patterns were compared additionally. IFG and DM/IFH subjects exhibited both lower insulin secretion and lower insulin sensitivity than NGT subjects. There was an insulin peak in NGT, IFG, and DM/IFH at 60 min, which did not occur in isolated IGT. Impaired early-phase and basal insulin secretion and decreased insulin sensitivity both are estimated as factors in progression from NGT via IFG to DM/IFH in these subjects. IFG and DM/IFH subjects have definite fasting hyperglycemia in contrast to isolated IGT subjects, 2-h glucose levels being maintained within the non-diabetic range partly by the insulin peak at 60 min.

Prevalence of Type 2 diabetes in urban and rural Chinese populations in Qingdao, China

AIMS

To determine the prevalence of diabetes in the Chinese adult population in rural and urban areas of Qingdao city.

METHODS

A population-based cross-sectional study of diabetes was performed in 12 436 (5346 men) Chinese adults (20-74 years old) from 2001 to 2002. Fasting capillary whole blood glucose test (FCG) was performed in all participants and a 2-h 75-g oral glucose tolerance test in those with FCG > or = 6.1 mmol/l following initial screening. The 1999 World Health Organization diagnostic criteria for diabetes were used.

RESULTS

The age-standardized prevalence of diabetes was 6.1% (4.1% for undiagnosed and 2.1% for previously known diabetes) in adults aged 20-74 years. Diabetes prevalence increased with age up to the oldest age group (70-74); in subjects over 50 years of age, the prevalence reached 10%. Men tended to have a higher prevalence of known diabetes than women, whereas the prevalence of undiagnosed diabetes was lower in men than in women (4.6% vs. 3.3%, d.f. = 1, P = 0.001). Diabetes was more prevalent in the urban than in the rural population (6.9% vs. 5.6%, d.f. = 1, P < 0.001). However, the proportion of undiagnosed diabetes was higher in the rural than in the urban areas (70.5% vs. 58.0%, d.f. = 1, P < 0.001).

CONCLUSIONS

The prevalence of Type 2 diabetes in Qingdao city is moderately high, but much higher than reported in 1996. The large proportion of undiagnosed cases of diabetes indicates the lack of public awareness of diabetes and shortage of medical facilities. In view of the huge population in China, the results of this study emphasize the need to improve the early detection and prevention of diabetes in China to prevent the emerging diabetes epidemic.

High incidence of glucose intolerance in Asian-Indian subjects with acute coronary syndrome

OBJECTIVE

The risk of diabetes and coronary heart disease is high in Asian Indians. In this study, we aim to assess 1) the prevalence of hyperglycemia in incident acute coronary syndrome (ACS), 2) the effect of glycemia on the outcome, and 3) the association of plasma levels of insulin and proinsulin with ACS.

RESEARCH DESIGN AND METHODS

A total of 146 nondiabetic subjects (121 men, 25 women) with ACS admitted to two hospitals in 1 year were enrolled. Random blood glucose at admission and a standard oral glucose tolerance test within 3 days were done. Glucose tolerance was categorized as normal glucose tolerance, impaired glucose tolerance (IGT) or impaired fasting glucose, and diabetes. Diabetes was arbitrarily classified further as undiagnosed (HbA1c [A1C] >6.0%) or possibly stress diabetes (A1C <6.0%). Subjects not on antidiabetic treatment were reassessed with a glucose tolerance test between 1 and 2 months. Fasting plasma specific insulin, proinsulin, their molar ratios, and insulin resistance (homeostasis model assessment) were estimated at baseline.

RESULTS

Mean age of the cohort was 55 +/- 10.6 (SD) years. At baseline, 24 (16.4%) had normal glucose tolerance, 67 (45.9%) had IGT or impaired fasting glucose, and 55 (37%) had diabetes (35 [24%] were undiagnosed and 20 [13.7%] had stress diabetes). At follow-up, 53 of 92 responders (57.6%) continued to have IGT or diabetes. Mean baseline plasma insulin, proinsulin and its ratios, and insulin resistance were higher than normal in all subgroups.

CONCLUSIONS

Nondiabetic Asian Indians showed a high prevalence of hyperglycemia following ACS. ACS was associated with insulin resistance and increased levels of specific insulin, proinsulin, and high proinsulin-to-insulin ratios.

Post-challenge hyperinsulinaemia rather than hyperglycaemia is associated with the severity of coronary artery disease in patients without a previous diagnosis of diabetes mellitus

OBJECTIVE

To ascertain the prevalence of abnormal glucose metabolism in patients with coronary artery disease (CAD) but no previous diagnosis of diabetes mellitus (DM) and to examine the relation between the severity of CAD and responses of glucose and insulin to the glucose tolerance test.

METHODS AND RESULTS

Abnormalities of glucose metabolism and insulin response were analysed in 144 patients with CAD without a previous diagnosis of DM who underwent both coronary arteriography and 75 g oral glucose tolerance test. The proportions of impaired and diabetic glucose tolerance were very high (39% for impaired and 21% for diabetic glucose tolerance); only 40% had normal glucose tolerance. The parameters of glucose metabolism were not associated with the number of diseased coronary arteries or the presence of previous myocardial infarction (MI). However, the insulin concentration at 60 minutes or 120 minutes after glucose challenge, insulin area, and the ratio of insulin to glucose area were significantly higher in patients with significant coronary stenosis and with previous MI. Fasting glucose concentration and most conventional risk factors did not predict post-challenge hyperinsulinaemia.

CONCLUSION

Patients with CAD without a previous diagnosis of DM had a high prevalence of abnormal glucose tolerance. Post-challenge hyperinsulinaemia was associated with the number of diseased coronary arteries and the presence of previous MI. The insulin response to the glucose challenge test requires further investigation as a potential risk factor for CAD and a potential target for intervention.

[Screening for diabetes in France: data from the 2000-2001 cohort of the national medical insurance system]

BACKGROUND

Type 2 diabetes mellitus may go undiagnosed for several Years while complications are silently developing. In France, from 2 to 3.7% of adults aged 35-65 are unaware they have diabetes. Nevertheless fasting serum glucose is a simple diagnostic test.

METHODS

We described people who underwent opportunist diabetes screening (serum glucose) within 2 Years (2000-2001). We used the administrative EPAS cohort from the employee National Health Insurance System which covers 70% of the total population in France. The data are based on reimbursements of glucose testing and hospitalization among people who did not received reimbursements of treatment for diabetes but used medical services during the 2 Years.

RESULTS

The opportunistic screening rate within 2 Years was 48.6% overall and increased with age. Among those 45 Years old or older, it was 71.2%. The screening rate was higher among women than men.

CONCLUSION

Opportunistic screening for diabetes is commonly practised in France, despite the lack of official guidelines. Several hypotheses may explain the discrepancy between common opportunist screening and high prevalence of undiagnosed diabetes: 1). undiagnosed diabetes is mostly present in people who do not use medical services; 2). opportunistic screening is not performed among the most at-risk population; 3). testing is not performed on fasting samples or results are neglected; 4). results of testing are overlooked by doctors/patients; 5). epidemiological studies based on self-report of diagnosis and only one testing overestimate undiagnosed diabetes.

Blood glucose and risk of cardiovascular disease in the Asia Pacific region

OBJECTIVE

To assess the shape and strength of the association between usual blood glucose and cardiovascular disease (CVD) in Asian and Australasian cohorts and to determine the impact of adjusting for other determinants of CVD risk and excluding people with diabetes.

RESEARCH DESIGN AND METHODS

Relative risk estimates and 95% CIs were calculated from Cox models, stratified by sex and cohort, and adjusted for age at risk on individual participant data from 17 cohort studies. Repeat measurements of blood glucose were used to adjust for regression dilution bias.

RESULTS

Fasting blood glucose data were available for 237,468 participants, and during approximately 1.2 million person-years of follow-up, there were 1,661 stroke and 816 ischemic heart disease (IHD) events. Data were also available on 27,996 participants with nonfasting glucose measurements. Continuous positive associations were demonstrated between usual fasting glucose and the risks of CVD down to at least 4.9 mmol/l. Overall, each 1 mmol/l lower usual fasting glucose was associated with a 21% (95% CI 18-24%) lower risk of total stroke and a 23% (19-27%) lower risk of total IHD. The associations were similar in men and women, across age-groups, and in Asian compared with Australasian (Australia and New Zealand) populations. Adjusting for potential confounders or removing those with diabetes as baseline did not substantially affect the associations. Associations for nonfasting glucose were weaker than those with fasting glucose.

CONCLUSIONS

Fasting blood glucose is an important determinant of CVD burden, with considerable potential benefit of usual blood glucose lowering down to levels of at least 4.9 mmol/l.

Insulin secretion and insulin sensitivity at different stages of glucose tolerance: a cross-sectional study of Japanese type 2 diabetes

To evaluate the factors causing glucose intolerance in type 2 diabetes in Japan, insulin secretion and insulin sensitivity were compared across the range of glucose tolerance. Subjects were divided into 3 groups: normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and type 2 diabetes (DM) according to the criteria of the World Health Organization (WHO). We examined insulin secretion and insulin sensitivity using fasting blood glucose and insulin levels and 75 g oral glucose tolerance test (OGTT). We used homeostasis model assessment (HOMA) beta-cell and insulinogenic index (30 minutes) to estimate insulin secretion and HOMA-insulin resistance (IR) and insulin sensitivity index (ISI) composite for insulin sensitivity. Although insulin resistance plays an important role in the development of diabetes in many ethnic populations, the differences in insulin sensitivity between NGT and IGT and between IGT and DM are small in Japanese patients. On the other hand, as glucose intolerance increases, insulin secretion decreases most remarkably both between NGT and IGT and between IGT and DM in Japanese patients. Decreasing insulin secretion and decreasing insulin sensitivity both occur in developing type 2 diabetes in Japanese patients, but decreased basal and early-phase insulin secretion had more pronounced contribution to glucose tolerance than the indices of insulin sensitivity. Japanese type 2 diabetic patients are characterized by a larger decrease in insulin secretion and show less attribution of insulin resistance.

Glucose levels observed in daily clinical practice induce endothelial dysfunction in the rabbit macro- and microcirculation

We investigated whether different concentrations of elevated glucose - corresponding to levels observed in patients with type 2 diabetes under routine care (post-prandial mean and maximum values) and those used for diagnosing diabetes - induce impairment of vascular reactivity of the macro- and microcirculation in non-diabetic rabbits. Aortic rings and isolated perfused kidneys from normal rabbits were acutely exposed (3 h) to normal (5.5 mm) or high (7-25 mM) D-glucose concentrations. Vascular reactivity was evaluated with endothelium-dependent [acetylcholine (ACh) and bradykinin (BK)] and independent [sodium nitroprusside (SNP)] vasodilating agents. Endothelium-dependent relaxation of the thoracic aorta induced by ACh or BK was significantly attenuated after a 3-h exposure to high D-glucose (15-25 mM) but not after corresponding increased osmolarity with mannitol solutions. Relaxation induced by SNP (endothelium-independent) was not affected by high D-glucose concentrations. Moreover, endothelium-dependent but not independent vasodilation of the isolated rabbit kidney was also impaired after 3-h perfusion with high D-glucose (11.1-25 mM). Perfusion with mannitol solutions (15-25 mM) partially blunted endothelium-dependent renal vasodilation. It is concluded that acute hyperglycemia corresponding to post-prandial levels in patients with type 2 diabetes induces endothelial dysfunction of conduit vessels as well as of the renal circulation of non-diabetic rabbits.

Post-challenge hyperglycaemia is an independent risk factor for arterial stiffness in Japanese men

AIMS

Arterial stiffness is an independent predictor of cardiovascular disease, but the impact of post-challenge hyperglycaemia on arterial stiffness is unknown. To investigate the association between arterial stiffness and post-challenge hyperglycaemia, we measured the second derivative of photoplethysmogram as an indicator of arterial stiffness.

METHODS

This study was done in 159 asymptomatic Japanese men aged 50.7 +/- 13.0 years. All subjects underwent a 75-g oral glucose tolerance test and measurement of the second derivative of photoplethysmogram.

RESULTS

According to the World Health Organization criteria (1998), 110 subjects had normal glucose tolerance, 10 had impaired fasting glucose, 30 had impaired glucose tolerance, and nine had diabetes. The b/a ratio (an index of arterial stiffness) showed a significant relationship with age (r = 0.58, P < 0.0001), height (r = -0.33, P < 0.0001), 2-h post-challenge glucose (r = 0.32, P < 0.0001), systolic blood pressure (r = 0.22, P = 0.006), and diastolic blood pressure (r = 0.21, P = 0.009). After adjustment for age and height, there were significant correlations between the b/a ratio and diastolic blood pressure (r = 0.18, P = 0.02), fasting glucose (r = 0.16, P = 0.049), and 2-h post-challenge glucose (r = 0.21, P = 0.009). Stepwise multiple regression analysis showed that only age (beta= 0.006, SE = 0.0007, P < 0.001) and 2-h post-challenge glucose (beta = 0.0005, SE = 0.0002, P < 0.05) contributed significantly to the b/a ratio (adjusted R(2) = 0.38).

CONCLUSIONS

These results indicate that post-challenge hyperglycaemia is an independent risk factor for arterial stiffness.

Prevalence and correlates of diabetes mellitus and impaired glucose tolerance among adults in Luzon, Philippines

Recognizing the problem posed by diabetes mellitus, the National Diabetes Commission was created by Republic Act 8191 in 1996. The Commission identified the need for a Second National Diabetes Survey to have an updated estimate of the magnitude of the disease in the country and to have the needed information for developing a diabetes prevention and control program. This paper reports the prevalence of diabetes mellitus and impaired glucose tolerance (IGT) in adults and the factors associated with the prevalence of these conditions. A cross-sectional population-based study assessed the occurrence of diabetes and impaired glucose tolerance among a random sample of 7044 adults, aged 20-65 years who were residents of urban and rural areas in Luzon. Blood glucose level was measured by OGTT using the current WHO criteria. The crude diabetes prevalence of 5.1% represented a 54% increase over the figure (3.3%) for a similar population in Luzon in 1982. An increase was also noted in the magnitude of IGT which almost doubled from 4.1% in 1982 to 8.1% in the present survey. Only one in three diabetics reported that they had diabetes. The frequency of diabetes and IGT in urban and rural areas were about the same, although a substantial increase from the earlier survey was noted in rural areas. Women registered a higher prevalence for both conditions than men. Aside from age and gender, the other correlates of diabetes mellitus were hypertension, family history of diabetes, WHR, BMI, and physical inactivity. IGT had similar correlates as diabetes except physical inactivity. The present findings which are consistent with those of other studies underscore the role of lifestyle behaviors in diabetes and should be the target of intervention to prevent further increase in disease frequency.

Prevention of Type 2 diabetes mellitus. A review of the evidence and its application in a UK setting

Abstract Type 2 Diabetes mellitus (T2DM) is a complex metabolic, multifactorial disease, which affects the quality, quantity and style of life. People with T2DM have a life expectancy that can be shortened by as much as 15 years, with up to 75% dying of macrovascular complications. To reduce the impact of T2DM in the 21st century, we need an approach that not only optimally treats the person with established diabetes but also prevents diabetes from occurring in the first place. The best evidence for prevention of diabetes is for interventions that target individuals at highest risk. Targeting patients who have impaired glucose tolerance with lifestyle changes including physical activity and dietary factors has been shown to be effective in the Chinese, North American and Finnish populations. In order for such lifestyle interventions to be successful in other populations, they need to be culturally sensitive, individualized and sustained. Some pharmacological agents including metformin and acarbose have also been shown to be effective, although the profile of those who respond is different. There continues to be a need to develop and evaluate interventions that target communities and populations at risk in a UK setting.

Hyperglycaemia and mortality from all causes and from cardiovascular disease in five populations of Asian origin

AIMS/HYPOTHESIS

The study was done to assess how well fasting and 2-h plasma glucose (FPG, 2-h PG) after a 75-g OGTT predict cardiovascular disease (CVD) and all-cause mortality in Asian subjects.

METHODS

People ( n=6817) of Japanese and Asian Indian origin from five prospective studies in five countries were monitored for 5 to 10 years. Hazard ratios for death from all causes and CVD were estimated using Cox proportional hazard models, adjusting for FPG, 2-h PG and established risk factors.

RESULTS

Multivariate Cox regression analysis showed that an increase in FPG from 7.0 to 8.0 mmol/l (increase of 0.76 SD) increased relative risk (95% CI) by 1.14 (1.05-1.25) for all-cause and 1.24 (1.10-1.39) for CVD mortality. An increase in 2-h PG from 9.0 to 11.9 mmol/l (0.76 SD) increased relative risks by 1.29 (1.18-1.41) and 1.35 (1.19-1.54). Inclusion of 2-h PG in the FPG model improved the predictive value ( p<0.001), whereas FPG did not influence the predictive value of 2-h PG ( p>10). In a model containing FPG and 2-h PG, hazards ratios for 2-h PG in subjects with IGT or diabetes were 1.35 (1.03-1.77) or 3.03 (2.18-4.21) for all-cause and 1.27 (0.86-1.88) or 3.39 (2.14-5.37) for CVD mortality, compared with normal subjects. The respective hazards ratio for FPG in subjects with IFG or diabetes were 0.94 (0.68-1.31) or 0.88 (0.59-1.32) for all-cause and 1.05 (0.67-1.65) or 0.88 (0.51-1.51) for CVD mortality, compared with normal subjects.

CONCLUSIONS/INTERPRETATION

For prediction of premature death, 2-h PG was superior to FPG in several Asian populations.

Type 2 diabetes prevalence in Asian Americans: results of a national health survey

OBJECTIVE

Asians are thought to be at high risk for diabetes, yet there is little population-based information about diabetes in Asian Americans. The purpose of this study was to directly compare the prevalence of type 2 diabetes in Asian Americans with other racial and ethnic groups in the U.S. using data from the 2001 Behavioral Risk Factor Surveillance System (BRFSS).

RESEARCH DESIGN AND METHODS

The BRFSS is a population-based telephone survey of the health status and health behaviors of Americans in all 50 states, Guam, Puerto Rico, and the U.S. Virgin Islands. Subjects included 3,071 Asians, 12,561 blacks, 12,153 Hispanics, 2,299 Native Americans, 626 Pacific Islanders, and 129,116 non-Hispanic whites aged >/=30 years. Subjects who reported a physician-diagnosis of diabetes were considered to have type 2 diabetes unless they were diagnosed before age 30.

RESULTS

Compared with whites, odds ratios (95% CIs) for diabetes, adjusted for age and sex, were 1.0 (0.7-1.4) for Asians, 2.3 (2.1-2.6) for blacks, 2.0 (1.8-2.3) for Hispanics, 2.2 (1.6-2.9) for Native Americans, and 3.1 (1.4-6.8) for Pacific Islanders. Results adjusted for BMI, age, and sex were 1.6 (1.2-2.3) for Asians, 1.9 (1.7-2.2) for blacks, 1.9 (1.6-2.1) for Hispanics, 1.8 (1.3-2.5) for Native Americans, and 3.0 (1.4-6.7) for Pacific Islanders.

CONCLUSIONS

Similar proportions of Asian and non-Hispanic white Americans report having diabetes, but after accounting for the lower BMI of Asians, the adjusted prevalence of diabetes is 60% higher in Asian Americans.

Glicemia pós-prandial

A hiperglicemia pós-prandial (HPP) decorre da diminuição da primeira fase de secreção insulínica e não tanto da resistência à insulina. Embora marcador da glicemia pós-prandial (GPP), a glicemia de 2h (G2h) pós-sobrecarga oral de glicose tem baixa reprodutibilidade. A HPP é importante fator de risco cardiovascular (CV), particularmente no DM, por ser a primeira causa de morte. Em não-diabéticos, tanto a glicemia de jejum (GJ) como a G2h elevam tal risco, que segue um continuum mesmo dentro da faixa normal (disglicemia). Lesões ateroscleróticas são mais acentuadas nos distúrbios do metabolismo glicídico, existindo associação de dano arterial com G2h. Em populações com GJ normal, à medida que se eleva a G2h, também aumenta o risco de morte. Glicação não-enzimática de componentes da parede arterial e oxidação de lipoproteínas aceleram o processo aterosclerótico. Associa-se a HPP a distúrbio de condução, facilitador da ocorrência de morte súbita. Disfunção endotelial também predispõe à vasoconstrição e isquemia miocárdica pós-refeição. A ADA recomenda que a GPP seja monitorada, especialmente quando GJ e A1c não forem proporcionais. Inibidores de alfa-glicosidase, glinidas e análogos de insulina de ação ultra-rápida são eficazes em reduzir a GPP, restando saber se diminuem complicações crônicas diabéticas.

Gender differences in the prevalence of impaired fasting glycaemia and impaired glucose tolerance in Mauritius. Does sex matter?

OBJECTIVE

To examine gender differences in the characteristics and prevalence of various categories of glucose tolerance in a population study in Mauritius.

RESEARCH DESIGN AND METHODS

In 1998, a community-based cross-sectional survey was conducted in Mauritius. Categories of glucose metabolism were determined in 5388 adults, with an oral glucose tolerance test given to those who did not have previously diagnosed diabetes (n=4036). Other cardiovascular risk factors were assessed among those without known diabetes.

RESULTS

For men and women the prevalence of diabetes (22.0 vs. 21.8%, respectively) and the prevalence of coexisting impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) (3.2 vs. 2.9%) were similar. However, men were twice as likely as women to have isolated IFG [5.1% (4.2-6.0) vs. 2.9% (2.3-3.5)], despite being younger, thinner and with lower plasma insulin but higher lipids. Conversely, the prevalence of isolated IGT was lower in men [9.0% (7.9-10.2) vs. 13.9% (12.6-15.1)]. Among non-diabetic individuals, fasting glucose was higher in men than women, whereas 2-h glucose was higher in women. In people without diabetes, women had significantly higher body mass index, beta cell function (HOMA-B), fasting and 2-h insulin than men and significantly lower waist-hip ratios, waist circumference, insulin sensitivity (HOMA-S) and triglycerides.

CONCLUSION

In Mauritius, the distribution of impaired glucose metabolism differs by sex. The observation that IFG is more prevalent in men and IGT more prevalent in women raises important questions about their underlying aetiology and the ability of the current glucose thresholds to equally identify men and women at high-risk of developing diabetes. IFG should be seen as a complimentary category of abnormal glucose tolerance, rather than a replacement for IGT.

High prevalence of diabetes in Adana, a southern province of Turkey

OBJECTIVE

To determine the prevalence of diabetes and glucose intolerance and their relationship with risk factors in Adana, a southern province of Turkey, where risk factors are more prominent, probably because of social and economic reasons.

RESEARCH DESIGN AND METHODS

The study population included 1637 randomly selected adults aged 20-79 years. Diagnosis of diabetes was based on plasma glucose values using the 1999 diagnostic criteria recommended by the World Health Organization.

RESULTS

The crude prevalence of diabetes was 12.9% in men and 10.9% in women (P = 0.207). Total prevalence of diabetes was 11.6%. The screening process identified previously undiagnosed diabetes in 4.2% of individuals and impaired glucose homeostasis (consisting of impaired glucose tolerance and impaired fasting glucose) in an additional 4.3% of subjects. The prevalence of hypertension was 26.4% among men and 36.6% among women (P < 0.0001). Total prevalence of hypertension was 32.9%, and prevalence of obesity was 43.4%. Age, sex, BMI, waist circumference, hypertension, family history of diabetes, and triglycerides were independently associated with diabetes.

CONCLUSIONS

The prevalence of diabetes in Adana is higher than expected in both urban and rural areas. Obesity and hypertension also seem to be common metabolic disorders in this area. Age, hypertension, obesity, high triglyceride level, and family history of diabetes are independently associated with diabetes. Therefore, primary prevention through lifestyle modifications may have a critical role in the control of diabetes.

Age, body mass index and Type 2 diabetes-associations modified by ethnicity

AIMS/HYPOTHESIS

The aim of this study was to assess the effect of ethnicity on the association between age and body mass index as well as the prevalence of diabetes.

METHODS

We selected population-based studies carried out after 1980 in the DECODE/A studies representing different ethnic groups: 11 European, 1 Maltese, 3 Indian, 2 Chinese and 3 Japanese surveys. The total numbers of subjects were 14,240 men and 15,129 women who were 30 to 89 years of age. Diabetes was diagnosed according to the 1999 World Health Organization criteria based on a standard 75 g OGTT. Sex-specific prevalence of diabetes by age and BMI was stratified by ethnic group, in particular the interaction of ethnicity on the associations between age/BMI and the prevalence of diabetes.

RESULTS

The prevalence of diabetes was higher in studies from India and Malta compared to Japan, China, and the rest of Europe. The association between BMI and diabetes, adjusted for age, showed noticeable differences between the ethnic groups with an increase in prevalence starting at a BMI between 15 and 20 kg/m(2) in the Maltese and Indian populations compared to 25 kg/m(2 )in Europeans.

CONCLUSION/INTERPRETATION

The effect of BMI on the age-adjusted prevalence of Type 2 diabetes was modified by ethnicity with considerably lower thresholds in Indian and Maltese subjects compared to those from the rest of Europe. This difference should be reflected in national and international recommendations regarding "optimal" BMI.

Age- and sex-specific prevalence of diabetes and impaired glucose regulation in 11 Asian cohorts

OBJECTIVE

To report the age- and sex-specific prevalence of diabetes and impaired glucose regulation (IGR) according to revised World Health Organization criteria for diabetes in Asian populations.

RESEARCH DESIGN AND METHODS

We performed 11 studies of 4 countries, comprising 24,335 subjects (10,851 men and 13,484 women) aged 30-89 years who attended the 2-h oral glucose tolerance test and met the inclusion criteria for data analysis.

RESULTS

The prevalence of diabetes increased with age and reached the peak at 70-89 years of age in Chinese and Japanese subjects but peaked at 60-69 years of age followed by a decline at the 70 years of age in Indian subjects. At 30-79 years of age, the 10-year age-specific prevalence of diabetes was higher in Indian than in Chinese and Japanese subjects. Indian subjects also had a higher prevalence of IGR in the younger age-groups (30-49 years) compared with that for Chinese and Japanese subjects. Impaired glucose tolerance was more prevalent than impaired fasting glycemia in all Asian populations studied for all age-groups.

CONCLUSIONS

Indians had the highest prevalence of diabetes among Asian countries. The age at which the peak prevalence of diabetes was reached was approximately 10 years younger in Indian compared with Chinese and Japanese subjects. Diabetes and IGR will be underestimated in Asians based on the fasting glucose testing alone.

Impaired fasting glucose and impaired glucose tolerance in urban population in India

AIMS

To study prevalence of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) in urban Indians and their demographic and anthropometric characteristics.

METHODS

Data on capillary blood glucose (OGTT), anthropometric and demography details were available in 10 025 subjects (M : F 4711 : 5314) aged > or = 20 years. Glucose tolerance was categorized as normal, isolated IFG, isolated IGT, IFG + IGT and diabetes using the fasting and 2-h blood glucose (2hBG; 75-g glucose load) values. Subjects with known diabetes were excluded.

RESULTS

Age-standardized prevalences of IFG, IGT and newly detected diabetes were 8.7%, 8.1% and 13.9%, respectively. IFG was more prevalent in women (9.8%) than in men (7.4%) (chi2 = 13.62, P = 0.0002), while the gender differences in IGT (men 8.4%, women 7.9%) and diabetes (men 13.3%, women 14.3%) were not significant. Body mass index and waist circumference were higher in glucose-intolerant groups than in normal glucose tolerance (NGT). Prevalence of diabetes, IGT and IFG + IGT increased with age. Among the IFG, 4% had diabetes and 27.1% had IGT using 2hBG criteria. In IFG, the fasting and 2hBG values were not correlated.

CONCLUSIONS

Prevalences of IFG and IGT were similar in urban Indians and an overlap occurred in only less than half of these subjects. IFG was more common in women. Subjects with IFG were older and had more adverse anthropometric characteristics in comparison with NGT. IFG did not show an increasing trend with age.

Clinical Impact of the New Criteria for the Diagnosis of Diabetes Mellitus

In 1997 the American Diabetes Association lowered the threshold for diagnosis of diabetes from a fasting plasma glucose concentration of 7.8 mmol/l to 7.0 mmol/l and advised that the oral glucose tolerance test no longer be used in routine clinical practice. In 1999 the World Health Organization endorsed the reduction in fasting plasma glucose threshold but recommended retaining the oral glucose tolerance test for anyone with impaired fasting glucose (6.1 mmol/l-6.9 mmol/l). This Review discusses the impact of these changes on the prevalence of diabetes and examines the implications for individuals and specific high-risk groups. The phenotype of those diagnosed with diabetes and the predictive value for the development of complications according to the different criteria are compared. It is clear that these changes in diagnostic criteria have major importance both for individuals and for resource planning at a national level.

Age- and sex-specific prevalences of diabetes and impaired glucose regulation in 13 European cohorts

OBJECTIVE

To report the age- and sex-specific prevalences of diabetes and impaired glucose regulation (IGR) according to the revised 1999 World Health Organization criteria for diabetes in Europe.

RESEARCH DESIGN AND METHODS

A total of 13 studies from nine European countries with 7,680 men and 9,251 women aged 30-89 years were included in the data analysis.

RESULTS

In most of the study populations, the age-specific prevalences of diabetes were <10% in subjects younger than 60 years and between 10 and 20% at 60-79 years of age. Mean 2-h plasma glucose (2hPG) concentration increased linearly with age, but fasting plasma glucose (FPG) concentration did not. The increase in the prevalence of undiagnosed diabetes and IGR in the elderly was mainly a result of the large increase in 2hPG rather than FPG. Diabetes and impaired fasting glycemia defined by isolated fasting hyperglycemia was more common in men than in women 30-69 years of age, whereas the prevalence of isolated postload hyperglycemia, particularly impaired glucose tolerance, was higher in women than in men, especially in the elderly (individuals >70 years of age). More than half of the diabetes was undiagnosed in subjects younger than 50 years of age.

CONCLUSIONS

Most European populations have a moderate to low prevalence of diabetes and IGR. Diabetes and IGR will be underestimated in Europe, particularly in women and in elderly men, if diagnoses are based on fasting glucose determination alone.

Fasting criteria for screening: test properties and agreement with glucose tolerance

The objective of this study was to characterise test properties and agreement for fasting glucose cut-offs used for screening diabetes in Indigenous Australian communities, across a range of diabetes prevalence. The oral glucose tolerance test (OGTT) was administered to adult volunteers (n=3249) for community-based diabetes screening in isolated settlements (n=25). Two-hour post-load glucose concentration was the 'gold standard' against which test properties were characterised for fasting plasma glucose cut-offs at concentrations of > or = 7.0 mmol/l (ADA criterion) and > or = 7.8 mmol/l (WHO criterion). Test sensitivity (95% CI) was greater for the ADA (72.5%, 67.4-77.1%) versus the WHO criterion (61.5%, 56.1-66.6%). Specificity was high (>98%) using either criterion. The post-test likelihood of diabetes, given a population prevalence of 14.8%, was 89.1% using the ADA criterion, and 94.9% using the WHO criterion. The ADA criterion gave better agreement than did the WHO criterion for diabetes prevalence > or = 8.6%, and the probability of false results was lower using the ADA criterion, when diabetes prevalence was > or = 12.8%. According to the ADA criterion most individuals ascribed false negative results were aged > or = 35 years, overweight/obese, or had impaired fasting glucose. The fasting glucose criterion of 7.0 mmol/l was superior to 7.8 mmol/l in screening for diabetes.

Comparison of ADA and WHO criteria for the diagnosis of diabetes in elderly Koreans

AIMS

This study was conducted to compare the prevalence and cardiovascular risk factors of different categories of glucose tolerance in the elderly Korean population using World Health Organization (WHO) and American Diabetes Association (ADA) criteria.

METHODS

This study included 1456 non-diabetic subjects over the age of 60 years, selected from a cross-sectional study, which was conducted in 1999 in Seoul, Korea. Fasting and post-challenge 2-h plasma glucose, insulin levels, body mass index (BMI), waist-hip ratio (WHR), blood pressure, and lipid profiles were examined. Prevalence of glucose tolerance categories and the level of agreement (kappa statistics) were obtained using WHO 2-h criteria and ADA fasting criteria. Comparison of cardiovascular risk factors among several concordant and discordant glucose intolerance groups was done.

RESULTS

The prevalence rates of newly diagnosed diabetes of elderly men defined by WHO 2-h criteria and ADA fasting criteria were 11.8% and 4.8%, respectively. That of elderly women was 8.1% by WHO 2-h criteria and 3.1% by ADA fasting criteria. The prevalence of impaired glucose tolerance (IGT) by WHO criteria was also higher than that of impaired fasting glucose (IFG) by ADA criteria (23.5% vs. 10.0% men, 23.7% vs. 7.5% women). The level of agreement between ADA fasting criteria and WHO 2-h criteria was low (weighted kappa = 0.228 men, weighted kappa = 0.301 women). The concordant diabetic women by both ADA fasting criteria and WHO 2-h criteria showed higher BMI, WHR, diastolic blood pressure, total cholesterol and triglyceride levels than concordant normal subjects. However, the isolated post-challenge hyperglycaemia (IPH) women group was not different significantly from the concordant normal women group except in BMI.

CONCLUSIONS

Our results clearly show that the 1997 ADA fasting criteria are less sensitive for diagnosing diabetes than oral glucose tolerance test (OGTT)-based WHO criteria in elderly Koreans. Also, there is a poor agreement of different categories of glucose tolerance between ADA and WHO criteria; therefore, the OGTT remains a valuable test in diagnosing diabetes and classifying various categories of glucose intolerance, especially in elderly Koreans.

Impaired glucose tolerance and impaired fasting glycaemia: the current status on definition and intervention

A workshop was convened by the International Diabetes Federation to review the latest information relating to the risks associated with impaired glucose tolerance (IGT) and impaired fasting glycaemia (IFG) for future diabetes and cardiovascular disease (CVD). The workshop sought to address three questions: (i) are the current definitions of IGT and IFG appropriate; (ii) are IFG and IGT risk factors, risk markers or diseases; (iii) what interventions (if any) should be recommended for people with IFG and IGT? The determinants of elevated fasting glucose and 2-h plasma glucose in an oral glucose tolerance test (2-HPG) levels differ. Raised hepatic glucose output and a defect in early insulin secretion are characteristic of the former, and peripheral insulin resistance is most characteristic of the latter. Therefore, it is not surprising that the concordance between the categories of IFG and IGT is limited. In all prevalence studies to date only half or less of people with IFG have IGT, and even a lower proportion (20-30%) with IGT also have IFG. In the majority of populations studied, IGT is more prevalent than IFG, and there is a difference in phenotype and gender distribution between the two categories. IFG is substantially more common amongst men and IGT slightly more common amongst women. The prevalence of IFG tends to plateau in middle age whereas the prevalence of IGT rises into old age. Both IFG and IGT are associated with a substantially increased risk of developing diabetes, with the highest risk in people with combined IFG and IGT. Because IGT is commoner than IFG in most populations it is more sensitive (but slightly less specific) for identifying people who will develop diabetes. In most populations studied, 60% of people who develop diabetes have either IGT or IFG 5 years or so before, with the other 40% having normal glucose tolerance at that time. The limited published data suggest that both isolated IFG (I-IFG) and isolated IGT (I-IGT) are similarly associated with cardiovascular risk factors, such as hypertension and dyslipidaemia, with the highest risk in those with combined IFG and IGT. However, some data have suggested that I-IGT is more strongly associated with hypertension and dyslipidaemia (features of the metabolic syndrome) than I-IFG. In unadjusted analyses both IFG and IGT are associated with CVD and total mortality. In separate analyses for fasting and 2-HPG adjusted for other cardiovascular risk factors (from the DECODE study) there remains a continuous relationship between 2-HPG and mortality, but an independent relationship with fasting glucose is only found above 7.0 mmol/l. Glycated haemoglobin (HbA1c) levels are continuously and positively associated with CVD and total mortality independent of other CVD risk factors. Life style interventions, including weight loss and increased physical activity, are highly effective in preventing or delaying the onset of diabetes in people with IGT. Two randomized controlled trials of individuals with IGT found that life style intervention studies reduce the risk of progressing to diabetes by 58%. The oral hypoglycaemic drugs metformin and acarbose have also been shown to be effective, but less so than the life style measures. Similar data do not yet exist for the effectiveness of such interventions in people with I-IFG. Larger studies are required to evaluate the effects of interventions on cardiovascular outcomes in people with IGT. Cost effective strategies to identify people with IGT for intervention should be developed and evaluated. The use of simple risk scores to assess who should undergo an oral glucose tolerance test is one promising approach, although these will need to be population-specific. In conclusion, IGT and IFG differ in their prevalence, population distribution, phenotype, and risk of total mortality and CVD. The consensus of the workshop was: 1. The diagnostic thresholds for all categories of glucose intolerance should be revisited in the light of the latest evidence. There was no clear consensus (with current evidence) on whether IFG and IGT should be classified as diseases, but they clearly represent risk factors and risk markers for diabetes and CVD, respectively. 2. Both IGT and IFG are similarly associated with an increased risk of diabetes, but IGT is more strongly associated with CVD outcomes. 3. Risks are higher when IGT and IFG coexist. 4. Life style interventions are highly effective in delaying or preventing the onset of diabetes in people with IGT and may reduce CVD and total mortality, but the latter requires formal testing.

Prevalence of overweight in urban Indian adolescent school children

The prevalence of diabetes mellitus (DM) and cardiovascular disease (CVD) is increasing in urban India. Overweight in adolescence is a marker of overweight in adult age, and it shows an association with the above diseases. There have been meagre data from India on the prevalence of childhood obesity. The objective of the study was to quantify the prevalence of overweight and its risk factors in adolescent children in urban India. School students in the age group of 13-18 years (n = 4700, M:F 2382:2318) were studied. Body mass index (BMI) was measured. Data on physical activity, food habits, occupation of parents and their economic status, birth weight of the children and age at menarche in girls were obtained by questionnaire. Age-adjusted prevalence of overweight was 17.8% for boys and 15.8% for girls. It increased with age and was higher in lower tertiles of physical activity and in higher socio-economic group. Birth weight and current BMI were positively associated. The study highlighted the high prevalence of overweight in adolescent children in urban India. Life style factors influenced BMI in adolescent age.

Cardiovascular risk profile assessment in glucose-intolerant Asian individuals--an evaluation of the World Health Organization two-step strategy: the DECODA Study (Diabetes Epidemiology: Collaborative Analysis of Diagnostic Criteria in Asia)

AIMS

To assess the cardiovascular (CVD) risk factor profile in individuals with diabetes and impaired glucose tolerance (IGT) identified by a one-step (fasting plasma glucose (FPG)) or a two-step strategy (including an oral glucose tolerance test (OGTT) in subjects with impaired fasting glucose (IFG)) as recommended by the World Health Organization (WHO).

METHODS

Twelve population-based studies in six countries (17 512 subjects, age 30-89 years, without known diabetes, with OGTT (fasting and 2-h plasma glucose (2-h PG))). Age, gender, and centre-adjusted means of CVD risk factors were compared according to the level of glucose intolerance.

RESULTS

Diabetes was found in 1270 individuals and IFG or IGT in 3158. In the diabetic group 55.1% had a FPG > or = 7.0 mmol/l (range between countries 36.2-67.0%), 20.5% were identified through the stepwise strategy (range 0-32%), while 24.4% would remain undiagnosed (FPG < 6.1 mmol/l) (range 9.0-40.0%). The two-step strategy identified 60-91% of all newly diagnosed diabetic subjects with 5-12% of the population requiring an OGTT. Mean body mass index (BMI), blood pressure, and total cholesterol did not differ between diabetic individuals diagnosed by FPG or OGTT. The step-wise strategy identified < 50% of the subjects with impaired glucose regulation, and the cardiovascular risk profile (BMI, blood pressure, and cholesterol) did not differ between those identified and those not identified in the screening process.

CONCLUSIONS

Applying an OGTT in subjects with IFG will fail to detect every fourth diabetic individual and every second individual with impaired glucose regulation. Individuals not diagnosed had a cardiovascular risk profile identical to those identified in the diagnostic process. Lower thresholds for an OGTT may be necessary in Asian populations.

The fasting plasma glucose cut-point predicting a diabetic 2-h OGTT glucose level depends on the phenotype

To assess the use of fasting plasma glucose (FPG) alone for the screening of diabetes as defined by a 2-h plasma glucose (2-h PG) > or =11.1 mmol/l following a 75-g oral glucose tolerance test, we collated the results from 17512 subjects aged 30-89 years without a previous history of diabetes from 12 general population-based Asian studies. The performance of FPG corresponding to the 2-h PG > or =11.1 mmol/l was characterized. The prevalence of diabetes was 4.0% by the FPG criteria only and 6.0% by the 2-h PG criteria only. The FPG value of 7.0 mmol/l gave a sensitivity for diabetes as defined by a 2-h PG > or =11.1 mmol/l of 46% and specificity of 99%. The FPG associated with a 2-h PG > or =11.1 mmol/l with optimal sensitivity and specificity was 5.8 mmol/l (sensitivity 79%, specificity 85%). The optimal FPG cut-point was affected by gender, age, body mass index and the presence of hypertension, and the resulting sensitivity and specificity corresponding to each optimal cut-point changed. The FPG was a specific but insensitive screening test for diabetes defined by 2-h PG > or =11.1 mmol/l. There seems to be ethnic differences with respect to optimal FPG cut-point, and different screening strategies may be necessary in different parts of the world.

Report of the Committee on the classification and diagnostic criteria of diabetes mellitus

In 1995, the Japan Diabetes Society (JDS) appointed the Committee for the Classification and Diagnosis of Diabetes Mellitus. The Committee presented a final report in May 1999 in Japanese. This is the English version with minor modifications for readers outside Japan.

CONCEPT OF DIABETES MELLITUS

Diabetes mellitus represents a group of diseases of heterogeneous etiology, characterized by chronic hyperglycemia and other metabolic abnormalities, which are due to deficiency of insulin effect. After a long duration of metabolic derangement, specific complications of diabetes (retinopathy, nephropathy, and neuropathy) may occur. Arteriosclerosis is also accelerated. Depending on the severity of the metabolic abnormality, diabetes may be asymptomatic, or may be associated with symptoms (thirst, polyuria, and weight loss), or may progress to ketoacidosis and coma.

CLASSIFICATION

Both etiological classification and staging of pathophysiology by the degree of deficiency of insulin effect need to be considered. The etiological classification of diabetes and related disorders of glycemia includes, (1) type 1; (2) type 2; (3) those due to specific mechanisms and diseases; and (4) gestational diabetes mellitus. Type 1 is characterized by destructive lesions of pancreatic beta cells either by an autoimmune mechanism or of unknown cause. Type 2 diabetes is characterized by combinations of decreased insulin secretion and decreased insulin sensitivity (insulin resistance). Category (3) includes two subgroups; subgroup A is diabetes in which specific mutations have been identified as a cause of genetic susceptibility, while subgroup B is diabetes associated with other pathologic conditions or diseases. The staging of glucose metabolism includes normal, borderline and diabetic stages. The diabetic stage is further classified into three substages; non-insulin requiring, insulin-requiring for glycemic control, and insulin-dependent (ID) for survival. In each individual, these stages may vary according to the deterioration or the improvement of the metabolic state, either spontaneously or by treatment.

DIAGNOSIS

The confirmation of chronic hyperglycemia is a prerequisite for the diagnosis of diabetes mellitus. The state of glycemia may be classified within three categories, diabetic type; borderline type; and normal type. Diabetic type is defined when fasting plasma glucose (FPG) is 7.0 mmol/l (126 mg/dl) or higher, and/or plasma glucose 2 h after 75 g glucose load (2hPG) is 11.1 mmol/l (200 mg/dl) or higher. A casual plasma glucose (PG) > or =11.1 mmol/l (200 mg/dl) also indicates diabetic type. Normal type is defined when FPG is below 6.1 mmol/l (110 mg/dl) and 2hPG below 7.8 mmol/l (140 mg/dl). Borderline type includes those who are neither diabetic nor normal types. These cutoff values are for venous PG measurements. The persistence of 'diabetic type' in a subject indicates that he or she has diabetes. For children, a dose of 1.75 g/kg (maximum, 75 g) is used for oral glucose tolerance test (OGTT). The procedure for clinical diagnosis is as follows. Diabetes mellitus is diagnosed when hyperglycemia meeting the criteria for 'diabetic type' is shown on two or more occasions examined on separate days. Diabetes can be diagnosed by a single PG test of 'diabetic type' if one of the following three conditions co-exists, (1) typical symptoms of diabetes mellitus; (2) HbA1c > or =6.5% by a standardized method; or (3) unequivocal diabetic retinopathy. If the above conditions ((1) or (2)) have been present in the past and well documented, the subject is diagnosed either to have diabetes or to be suspected of diabetes, even if the present level of glycemia does not reach that of 'diabetic type'. If the diagnosis of diabetes cannot be established by these procedures, re-testing of PG is recommended after an appropriate interval. The physician should assess not only the presence or absence of diabetes, but also its etiology and glycemic stage, and the presence and absence of diabetic complications or associated conditions.

EPIDEMIOLOGICAL ASPECTS AND SCREENING

In order to determine the prevalence of diabetes in a population, 'diabetic type' may be regarded as 'diabetes'. The use of 2hPG cutoff level of > or =11.1 mmol/l (200 mg/dl) is recommended. If this is difficult, the FPG cutoff level of > or =7.0 mmol/l (126 mg/dl) can be used, but is likely to lead to under-ascertainment. For screening, the most important point is not to overlook 'diabetes'. In addition to parameters of hyperglycemia, clinical information such as family history, obesity etc., should be regarded as indications for further testing.

NORMAL TYPE AND BORDERLINE

Only FPG and 2hPG are adopted as cutoff values, but in clinical situations, it is recommended to measure PG also at 30 and 60 min during 75 g OGTT. Among people with normal type, those with 1hPG higher than 10.0 mmol/l (180 mg/dl) are at higher risk to develop diabetes than those with lower 1hPG. When OGTT is performed, the borderline type corresponds to the sum of impaired fasting glycemia (IFG) plus impaired glucose tolerance (IGT) according to the new WHO report. Subjects in this category are at higher risk of developing diabetes than those with 'normal type'. Those with low insulinogenic index (the ratio of increment of plasma insulin to that of PG at 30 min during OGTT) are at particularly high risk to develop diabetes. Microvascular complications are rare but arteriosclerotic complications are fairly frequent in this category.

GESTATIONAL DIABETES MELLITUS (GDM)

The current definition of GDM is ' any glucose intolerance developed or detected during pregnancy'. We adopt the proposal of the Japan Society of Gynecology and Obstetrics for the diagnosis of GDM (1984). GDM is defined when two or more values during a 75 g OGTT are higher than the following cutoff levels; FPG > or =5.5 mmol/l (100 mg/dl), 1hPG > or =10.0 mmol/l (180 mg/dl) and 2hPG > or =8.3 mmol/l (150 mg/dl). As a screening test, subjects with casual PG > or =5.5 mmol/l (100 mg/dl) are recommended for further testing. Patients who have had documented glucose intolerance before pregnancy, and who present as 'diabetic type' should be under closer supervision than those who develop GDM during pregnancy for the first time. HbA1c: There is a large overlap in the distribution of HbA1c between groups with 'normal type' and 'borderline type' and mild 'diabetic type'. Therefore, HbA1c is not a suitable parameter to detect mild glucose intolerance. HbA1c higher than 6.5% suggests diabetes, but HbA1c below 6.5% alone should not be taken as evidence against the diagnosis of diabetes. COMPARISON WITH REPORTS OF AMERICAN DIABETES ASSOCIATION (ADA) IN 1997 AND WHO IN 1999: The present report is unique in the following points when compared with those of the ADA 'Diabetes Care 20 (1997) 1183' and WHO 'Report of a WHO Consultation (1999)'. (1) Diabetes due to specific mechanisms and diseases is divided into two subgroups; diabetes in which genetic susceptibility is clarified at the DNA level and diabetes associated with other diseases or conditions. (2) Cutoff PG levels are the same as those of ADA and WHO, but a term 'type' is added to each glycemic category, because a single coding of 'diabetic type' hyperglycemia does not define diabetes. Diabetes is diagnosed when 'diabetic type' hyperglycemia is shown on two or more occasions. (3) A single 'diabetic type' hyperglycemia is considered sufficient for the diagnosis of diabetes, if the patient has typical symptoms, HbA1c > or =6.5%, or diabetic retinopathy. (4) OGTT is recommended for those with mild hyperglycemia, because FPG criteria alone would overlook many subjects with 'diabetic type' in Japan. High 1hPG without elevation of FPG and 2hPG is also considered to be a risk factor for future diabetes. (5) Borderline type in the present report corresponds to the sum of IFG and IGT by WHO when OGTT is performed. (6) New criteria for GDM by OGTT are proposed.