Diabetes risk score: towards earlier detection of type 2 diabetes in general practice

Biomedical, lifestyle and psychosocial characteristics of people newly diagnosed with Type 2 diabetes: baseline data from the DESMOND randomized controlled trial

AIMS

To describe the characteristics of newly diagnosed people with Type 2 diabetes (T2DM) and compare these with published studies.

METHODS

Baseline data of participants recruited to the DESMOND randomized controlled trial conducted in 13 sites across England and Scotland were used. Biomedical measures and questionnaires on psychological characteristics were collected within 4 weeks of diagnosis.

RESULTS

Of 1109 participants referred, 824 consented to participate (74.3%). Mean (+/- sd) age was 59.5 +/- 12 years and 54.9% were male. Mean HbA(1c) was 8.1 +/- 2.1% and did not differ by gender. Mean body mass index (BMI) was significantly higher in women (33.7 vs. 31.3 kg/m2; P < 0.001); 69% of women and 54% of men were obese (BMI > 30 kg/m2). Total cholesterol was significantly higher in women (5.6 vs. 5.2 mmol/l; P < 0.001). Overall, 14.7% reported smoking. Percentages reporting recommended levels of vigorous activity (> or = 3 times/week) and moderate activity (> or = 5 times/week) were 10.6 and 16.0%, respectively, and were lower in women. Specific illness beliefs included 73% being unclear about symptoms and only 54% believing diabetes is a serious condition. Symptoms indicative of depression were reported by significantly more women than men (16.1% vs. 8.2%; P = 0.001).

CONCLUSION

Data from this large and representative cohort of newly diagnosed people with T2DM show that many have modifiable cardiovascular risk factors. Comparison with the literature suggests that the profile of the newly diagnosed may be changing, with lower HbA1c and higher prevalence of obesity. Many expressed beliefs about and poor understanding of their diabetes that need to be addressed in order for them to engage in effective self-management.

How much might cardiovascular disease risk be reduced by intensive therapy in people with screen-detected diabetes?

AIMS

To assess the cardiovascular disease (CVD) risk of people with screen-detected Type 2 diabetes and to estimate the risk reduction achievable through early intensive pharmacological intervention.

METHODS

In ADDITION-Cambridge, diabetic patients were identified among people aged 40-69 years through a stepwise screening procedure including a risk score, random and fasting capillary blood glucose, HbA(1c) and oral glucose tolerance test. In those without prior macrovascular disease, 10-year CVD risk was computed using UK Prospective Diabetes Study (UKPDS) and Framingham engines. The absolute risk reduction achievable and its plausible range were predicted using relative risk reductions for individual therapies from published trials and sensitivity analysis.

RESULTS

Of the 867 individuals with undiagnosed diabetes, 19% had pre-existing CVD, 97% were overweight or obese, 86% had hypertension, 75% had dyslipidaemia, 20% had microalbuminuria and 18% were smokers. Of those with hypertension, 35% were not prescribed drugs and 42% were suboptimally treated. Of participants with dyslipidaemia, 68% were not prescribed medications and 22% were poorly controlled. Median 10-year CVD risk was 34.0%[interquartile range (IQR) 26.2-44.6] in men and 21.5% (IQR 15.7-28.7) in women using the UKPDS engine; 38.6% (IQR 27.8-53.0) in men and 24.6% (IQR 17.2-32.9) in women using Framingham equations. In the most conservative scenario (no additive effect of therapies), the absolute risk reduction achievable through multifactorial therapy ranged from 4.9 to 9.5% (UKPDS) and from 5.4 to 10.5% (Framingham). The corresponding ranges of numbers needed to treat were 11-20 and 10-19.

CONCLUSIONS

People with screen-detected diabetes have an adverse cardiovascular risk profile, which is potentially modifiable through application of existing treatment recommendations.

Screening for type 2 diabetes is feasible, acceptable, but associated with increased short-term anxiety: a randomised controlled trial in British general practice

Background

To assess the feasibility and uptake of a diabetes screening programme; to examine the effects of invitation to diabetes screening on anxiety, self-rated health and illness perceptions.

Methods

Randomised controlled trial in two general practices in Cambridgeshire. Individuals aged 40–69 without known diabetes were identified as being at high risk of having undiagnosed type 2 diabetes using patient records and a validated risk score (n = 1,280). 355 individuals were randomised in a 2 to 1 ratio into non-invited (n = 238) and invited (n = 116) groups. A stepwise screening programme confirmed the presence or absence of diabetes. Six weeks after the last contact (either test or invitation), a questionnaire was sent to all participants, including non-attenders and those who were not originally invited. Outcome measures included attendance, anxiety (short-form Spielberger State Anxiety Inventory-STAI), self-rated health and diabetes illness perceptions.

Results

95 people (82% of those invited) attended for the initial capillary blood test. Six individuals were diagnosed with diabetes. Invited participants were more anxious than those not invited (37.6 vs. 34.1 STAI, p-value = 0.015), and those diagnosed with diabetes were considerably more anxious than those classified free of diabetes (46.7 vs. 37.0 STAI, p-value = 0.031). Non-attenders had a higher mean treatment control sub-scale (3.87 vs. 3.56, p-value = 0.016) and a lower mean emotional representation sub-scale (1.81 vs. 2.68, p-value = 0.001) than attenders. No differences in the other five illness perception sub-scales or self-rated health were found.

Conclusion

Screening for type 2 diabetes in primary care is feasible but may be associated with higher levels of short-term anxiety among invited compared with non-invited participants.

Trial registration

ISRCTN99175498

Detection of impaired glucose tolerance and undiagnosed type 2 diabetes in UK South Asians: an effective screening strategy

AIM

We tested a stepwise, community-based screening strategy for glucose intolerance in South Asians using a health questionnaire in conjunction with body mass index (BMI). Anthropometric measurements (waist and hip circumference, sagittal diameter and percentage body fat) were then conducted in a hospital setting followed by an oral glucose tolerance test (OGTT) to identify subjects at the highest risk and analyse the factors predicting that risk.

METHODS

A health questionnaire was administered to 435 subjects in a community setting and BMI was measured. Subjects were graded by a risk score based on the health questionnaire as high, medium and low. Subjects with high and medium risk scores and a representative sample of those with low scores had anthropometric measurements in hospital followed by an OGTT. In total, 205 (47%) of the subjects had an OGTT performed.

RESULTS

In total, 48.7% of the subjects tested with an OGTT had evidence of glucose dysregulation: 20% had diabetes and 28.7% had impaired glucose tolerance (IGT). Logistic regression model explained 49.1% of the total variability. The significant predictors of diabetes and IGT were Blood Glucose Monitoring Strips (BMI), random blood glucose (BM), sibling with diabetes and presence of diagnosed hypertension or ischaemic disease. Most of these predictors along with other heredity diabetes factors create a composite score, with high predictability, as the receiver operating curve analysis shows.

CONCLUSION

We describe a simple, stepwise strategy in a community setting, based on a health questionnaire and anthropometric measurements, to explain about 50% of cases with IGT and diabetes and diagnose about 50% of cases from the population screened. We have also identified factors that predict the risk.

Early diagnosis and prevention of diabetes in developing countries

Type 2 diabetes has an insidious onset with a long latent period of dysglycaemia. By the time the diagnosis of diabetes is made, diabetes-related tissue damage occurs in nearly half of the patients. Even after diagnosis, the glycaemic control is suboptimal in more than 50%, leading to the vascular complications. Evidences suggest that early detection of diabetes by appropriate screening methods, especially in subjects with high risk for diabetes will help to prevent or delay the vascular complications and thus reduce the clinical, social and economic burden of the disease. There are also evidences to show that intervention at the prediabetic stage is superior to diagnosis of diabetes.

Prevalence of diabetes mellitus and the performance of a risk score among Hindustani Surinamese, African Surinamese and ethnic Dutch: a cross-sectional population-based study

Background

While the prevalence of type 2 diabetes mellitus (DM) is high, tailored risk scores for screening among South Asian and African origin populations are lacking. The aim of this study was, first, to compare the prevalence of (known and newly detected) DM among Hindustani Surinamese, African Surinamese and ethnic Dutch (Dutch). Second, to develop a new risk score for DM. Third, to evaluate the performance of the risk score and to compare it to criteria derived from current guidelines.

Methods

We conducted a cross-sectional population based study among 336 Hindustani Surinamese, 593 African Surinamese and 486 Dutch, aged 35–60 years, in Amsterdam. Logistic regressing analyses were used to derive a risk score based on non-invasively determined characteristics. The diagnostic accuracy was assessed by the area under the Receiver-Operator Characteristic curve (AUC).

Results

Hindustani Surinamese had the highest prevalence of DM, followed by African Surinamese and Dutch: 16.7, 8.1, 4.2% (age 35–44) and 35.0, 19.0, 8.2% (age 45–60), respectively. The risk score included ethnicity, body mass index, waist circumference, resting heart rate, first-degree relative with DM, hypertension and history of cardiovascular disease. Selection based on age alone showed the lowest AUC: between 0.57–0.62. The AUC of our score (0.74–0.80) was higher than that of criteria from guidelines based solely on age and BMI and as high as criteria that required invasive specimen collection.

Conclusion

In Hindustani Surinamese and African Surinamese populations, screening for DM should not be limited to those over 45 years, as is advocated in several guidelines. If selective screening is indicated, our ethnicity based risk score performs well as a screening test for DM among these groups, particularly compared to the criteria based on age and/or body mass index derived from current guidelines.

Completing a postal health questionnaire did not affect anxiety or related measures: randomized controlled trial

OBJECTIVE

There is evidence from laboratory studies that anxiety scores are elevated by completing questionnaires about health problems for the first time. This limits interpretation of the common finding that people receiving risk information from screening programs show elevated anxiety (as assessed by questionnaire) in the short-term, which subsides over time. We examine the extent to which postal questionnaire studies are affected by this potential measurement artifact.

STUDY DESIGN AND SETTING

Participants were 964 patients at high risk of undiagnosed diabetes, registered at five general practices. A two-group randomized experimental design was used, with the experimental group (n=484) receiving an initial questionnaire concerning screening for diabetes, and the control group (n=480) not receiving this questionnaire. Outcomes were assessed by an identical questionnaire 3 months later.

RESULTS

There were no significant differences in questionnaire scores at three months between the two groups on any of the outcome measures, including anxiety, symptoms, perceptions of diabetes severity, and perceived diabetes risk.

CONCLUSION

These results suggest that the problems associated with the use of anxiety questionnaires that are found in laboratory studies do not occur in postal studies: the observed changes in anxiety after receiving screening results are therefore unlikely to be artifactual.

Stepwise screening for diabetes identifies people with high but modifiable coronary heart disease risk. The ADDITION study

AIMS/HYPOTHESIS

The Anglo-Danish-Dutch study of intensive treatment in people with screen-detected diabetes in primary care (ADDITION) is a pragmatic randomised controlled trial of the effectiveness of intensified multi-factorial treatment on 5 year cardiovascular morbidity and mortality rates in people with screen-detected type 2 diabetes in the Netherlands, UK and Denmark. This paper describes the baseline characteristics of the study population, their estimated risk of coronary heart disease and the extent to which that risk is potentially modifiable.

METHODS

Stepwise screening strategies were performed using risk questionnaires and routine general practice data plus random blood glucose, HbA(1c) and fasting blood glucose measurement. Diabetes was diagnosed using the 1999 World Health Organization criteria and estimated 10 year coronary heart disease risk was calculated using the UK Prospective Diabetes Study risk engine.

RESULTS

Between April 2001 and December 2006, 3,057 people with screen-detected diabetes were recruited to the study (mean age 59.7 years, 58% men) after a stepwise screening programme involving 76,308 people screened in 334 general practices in three countries. Their median estimated 10 year risk of coronary heart disease was 11% in women (interquartile range 7-16%) and 21% (15-30%) in men. There were differences in the distribution of risk factors by country, linked to differences in approaches to screening and the extent to which risk factors had already been detected and treated. The mean HbA(1c) at recruitment was 7.0% (SD 1.6%). Of the people recruited, 73% had a blood pressure > or =140/90 and of these 58% were not on antihypertensive medication. Cholesterol levels were above 5.0 mmol/l in 70% of participants, 91% of whom were not being treated with lipid-lowering drugs.

CONCLUSIONS/INTERPRETATION

People with type 2 diabetes detected by screening and included in the ADDITION study have a raised and potentially modifiable risk of CHD. ClinicalTrials.gov ID no.: NCT 00237549.

Novel biochemical risk factors for type 2 diabetes: pathogenic insights or prediction possibilities?

This review critically appraises studies examining the association of novel factors with diabetes. We show that many of the most studied novel and apparently 'independent' risk factors are correlated with each other by virtue of their common origins or pathways, and that residual confounding is likely. Available studies also have other limitations, including differences in methodology or inadequate statistical analyses. Furthermore, although most relevant work in this area has focused on improving our understanding of the pathogenesis of diabetes, association studies in isolation cannot prove causality; intervention studies with specific agents (if available) are required, and genetic studies may help. With respect to the potential value of novel risk factors for diabetes risk prediction, we illustrate why this work is very much in its infancy and currently not guaranteed to reach clinical utility. Indeed, the existence of several more easily measured powerful predictors of diabetes, suggests that the additional value of novel markers may be limited. Nevertheless, several suggestions to improve relevant research are given. Finally, we show that several risk factors for diabetes are only weakly associated with the risk of incident vascular events, an observation that highlights the limitations of attempting to devise unified criteria (e.g. metabolic syndrome) to identify individuals at risk of both CHD and diabetes.

A simple risk score identifies individuals at high risk of developing Type 2 diabetes: a prospective cohort study

BACKGROUND

Randomized trials have demonstrated that Type 2 diabetes is preventable among high-risk individuals. To date, such individuals have been identified through population screening using the oral glucose tolerance test.

OBJECTIVE

To assess whether a risk score comprising only routinely collected non-biochemical parameters was effective in identifying those at risk of developing Type 2 diabetes.

METHODS

Population-based prospective cohort (European Prospective Investigation of Cancer-Norfolk). Participants aged 40-79 recruited from UK general practices attended a health check between 1993 and 1998 (n = 25 639) and were followed for a mean of 5 years for diabetes incidence. The Cambridge Diabetes Risk Score was computed for 24 495 individuals with baseline data on age, sex, prescription of steroids and anti-hypertensive medication, family history of diabetes, body mass index and smoking status. We examined the incidence of diabetes across quintiles of the risk score and plotted a receiver operating characteristic (ROC) curve to assess discrimination.

RESULTS

There were 323 new cases of diabetes, a cumulative incidence of 2.76/1000 person-years. Those in the top quintile of risk were 22 times more likely to develop diabetes than those in the bottom quintile (odds ratio 22.3; 95% CI: 11.0-45.4). In all, 54% of all clinically incident cases occurred in individuals in the top quintile of risk (risk score > 0.37). The area under the ROC was 74.5%.

CONCLUSION

The risk score is a simple, effective tool for the identification of those at risk of developing Type 2 diabetes. Such methods may be more feasible than mass population screening with biochemical tests in defining target populations for prevention programmes.

Diabetes Risk Calculator: a simple tool for detecting undiagnosed diabetes and pre-diabetes

OBJECTIVE

The objective of this study was to develop a simple tool for the U.S. population to calculate the probability that an individual has either undiagnosed diabetes or pre-diabetes.

RESEARCH DESIGN AND METHODS

We used data from the Third National Health and Nutrition Examination Survey (NHANES) and two methods (logistic regression and classification tree analysis) to build two models. We selected the classification tree model on the basis of its equivalent accuracy but greater ease of use.

RESULTS

The resulting tool, called the Diabetes Risk Calculator, includes questions on age, waist circumference, gestational diabetes, height, race/ethnicity, hypertension, family history, and exercise. Each terminal node specifies an individual's probability of pre-diabetes or of undiagnosed diabetes. Terminal nodes can also be used categorically to designate an individual as having a high risk for 1) undiagnosed diabetes or pre-diabetes, 2) pre-diabetes, or 3) neither undiagnosed diabetes or pre-diabetes. With these classifications, the sensitivity, specificity, positive and negative predictive values, and receiver operating characteristic area for detecting undiagnosed diabetes are 88%, 75%, 14%, 99.3%, and 0.85, respectively. For pre-diabetes or undiagnosed diabetes, the results are 75%, 65%, 49%, 85%, and 0.75, respectively. We validated the tool using v-fold cross-validation and performed an independent validation against NHANES 1999-2004 data.

CONCLUSIONS

The Diabetes Risk Calculator is the only currently available noninvasive screening tool designed and validated to detect both pre-diabetes and undiagnosed diabetes in the U.S. population.

Relationship of elevated casual blood glucose level with coronary heart disease, cardiovascular disease and all-cause mortality in a representative sample of the Japanese population. NIPPON DATA80

AIMS/HYPOTHESIS

High fasting blood glucose is one of the well-known risk factors for CHD. However, in certain settings, patients cannot always be expected to fast. For example, community screenings for cardiovascular disease (CVD) risk factors in Japan are performed under non-fasting conditions to achieve high participation rates. Thus, we examined a representative cohort of the Japanese population (n=9,444, follow-up period 17.3 years) to clarify whether high casual blood glucose (CBG) can predict CVD mortality.

METHODS

We defined CBG groups as follows: high CBG >or= 11.1 mmol/l or participants with a history of diabetes mellitus; borderline high, 7.77 <or= CBG<11.1 mmol/l; higher normal, 5.22 <or= CBG<7.77 mmol/l); and lower normal, CBG<5.22 mmol/l. The multivariate-adjusted hazard ratios (HRs) for CHD, CVD and all-cause mortality were calculated.

RESULTS

The crude CHD mortality rate was 0.84 per 1,000 person-years. Age- and sex-adjusted HRs for CHD mortality were high among participants with CBG levels >or= 7.77 mmol/l, regardless of time since last meal. Multivariate-adjusted HRs (95% CI) of CHD mortality in high and borderline high CBG groups were 2.62 (1.46-4.67) and 2.43 (1.29-4.58), respectively. Similar results were observed for both CVD and all-cause mortality. Even within the normal blood glucose range, each 1 mmol/l increase in CBG was associated with a statistically significant increase in the HR for CVD mortality (1.12, 95% CI 1.02-1.22). Population-attributable fractions of the combined groups of high and borderline high CBG for CHD, CVD and all-cause mortality were 12.0, 4.9 and 3.5%, respectively.

CONCLUSIONS/INTERPRETATION

Increases in CBG, even within the normal range, predict CVD mortality.

A simple clinical score for type 2 diabetes mellitus screening in the Canary Islands

AIM

To develop a straightforward risk score for type 2 diabetes (DM2) screening to use in clinical practice.

METHODS

A sample of 6237 adult inhabitants of the Canary Islands (Spain) was randomly divided into two subgroups: one yielded data used to develop the instrument, and the other yielded data used for validation testing. Performance of the instrument was compared in persons with clinically diagnosed DM2 and undiagnosed diabetes. The risk score, calculated by multivariate logistic regression, included the potential risk variables that yielded the highest odds ratio in the univariate analysis. A cut-off point for screening purposes was established at a 99% negative predictive value.

RESULTS

In men, variables included in the risk score were age, waist/height ratio, familial antecedents of diabetes, and systolic blood pressure (ROC curve 0.837, 95% CI: 0.803-0.871). In women, the risk score contained the same variables plus gestational diabetes history (ROC curve 0.874, 95% CI: 0.847-0901). Excluding systolic blood pressure from the score had no significant effect on the area under the curve. This instrument resulted valid only for people aged less than 55 years.

CONCLUSIONS

This simple risk score for DM2 would be easy to apply in clinical practice.

Patients' experiences of screening for type 2 diabetes: prospective qualitative study embedded in the ADDITION (Cambridge) randomised controlled trial

OBJECTIVES

To provide insight into factors that contribute to the anxiety reported in a quantitative study of the psychological effect of screening for type 2 diabetes. To explore expectations of and reactions to the screening experience of patients with positive, negative, and intermediate results.

DESIGN

Prospective qualitative interview study of patients attending a screening programme for type 2 diabetes.

SETTING

Seven general practices in the ADDITION (Cambridge) trial in the east of England.

PARTICIPANTS

23 participants (aged 50-69) attending different stages in the screening process.

RESULTS

Participants' perceptions changed as they progressed through the screening programme; the stepwise process seemed to help them adjust psychologically. The first screening test was typically considered unimportant and was attended with no thought about its implications. By the final diagnostic test, type 2 diabetes was considered a strong possibility, albeit a "mild" form. After diagnosis, people with screen detected type 2 diabetes tended to downplay its importance and talked confidently about their plans to control it. Participants with intermediate results seemed uncertain about their diagnosis, and those who screened negative were largely unaware of their remaining high risk.

CONCLUSIONS

This study helps in understanding the limited psychological impact of screening for type 2 diabetes quantified previously, in particular by the quantitative substudy of ADDITION (Cambridge). The findings have implications for implementing such a screening programme in terms of timing and content.

Psychological impact of screening for type 2 diabetes: controlled trial and comparative study embedded in the ADDITION (Cambridge) randomised controlled trial

OBJECTIVE

To quantify the psychological impact of primary care based stepwise screening for type 2 diabetes.

DESIGN

Controlled trial and comparative study embedded in a randomised controlled trial.

SETTING

15 practices (10 screening, five control) in the ADDITION (Cambridge) trial in the east of England.

PARTICIPANTS

7380 adults (aged 40-69) in the top fourth for risk of having undiagnosed type 2 diabetes (6416 invited for screening, 964 controls).

INTERVENTIONS

Invited for screening for type 2 diabetes or not invited (controls), incorporating a comparative study of subgroups of screening attenders. Attenders completed questionnaires after a random blood glucose test and at 3-6 months and 12-15 months later. Controls were sent questionnaires at corresponding time points. Non-attenders were sent questionnaires at 3-6 months and 12-15 months.

MAIN OUTCOME MEASURES

State anxiety (Spielberger state anxiety inventory), anxiety and depression (hospital anxiety and depression scale), worry about diabetes, and self rated health.

RESULTS

No significant differences were found between the screening and control participants at any time-for example, difference in means (95% confidence intervals) for state anxiety after the initial blood glucose test was -0.53, -2.60 to 1.54, at 3-6 months was 1.51 (-0.17 to 3.20), and at 12-15 months was 0.57, -1.11 to 2.24. After the initial test, compared with participants who screened negative, those who screened positive reported significantly poorer general health (difference in means -0.19, -0.25 to -0.13), higher state anxiety (0.93, -0.02 to 1.88), higher depression (0.32, 0.08 to 0.56), and higher worry about diabetes (0.25, 0.09 to 0.41), although effect sizes were small. Small but significant trends were found for self rated health across the screening subgroups at 3-6 months (P=0.047) and for worry about diabetes across the screen negative groups at 3-6 months and 12-15 months (P=0.001).

CONCLUSIONS

Screening for type 2 diabetes has limited psychological impact on patients. Implementing a national screening programme based on the stepwise screening procedure used in the ADDITION (Cambridge) trial is unlikely to have significant consequences for patients' psychological health.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN99175498 [controlled-trials.com].

Assessing risk for development of diabetes in young adults

PURPOSE

The prevalence of diabetes is increasing to epidemic levels. A multivariable risk score for the development of diabetes has been shown to be predictive for middle-aged adults; however, it is unclear how well it performs in a younger adult population. The purpose of this study was to evaluate a preexisting multivariable risk score for the development of diabetes in a young adult cohort.

METHODS

We analyzed the Coronary Artery Risk Development in Young Adults (CARDIA), a population-based observational study of participants aged 18 to 30 years recruited in 1985-1986. We observed individuals without diabetes at baseline for 10 years for the development of diabetes (n = 2,543). We computed receiver operating characteristic (ROC) curves for a diabetes risk score composed of the following 6 variables: elevated blood pressure, low high-density lipoprotein cholesterol levels, high triglyceride levels, body mass index, large waist circumference, and hyperglycemia.

RESULTS

The area under the ROC curve was .70 in this population, which was less than the .78 previously found among middle-aged adults. BMI alone (.67) was not significantly different from the risk score. Blacks (.72; 95% CI, .69-.74) and whites (.68; 95% CI, .66-.71) do not significantly differ in the area under the ROC curve for the risk score; however, the area under the ROC curve for BMI is significantly larger for blacks (.69; 95% CI, .66-.72) than for whites (.63; 95% CI, .60-.65).

CONCLUSION

An established risk score for the development of diabetes among middle-aged persons has limited utility in a younger population. Future research needs to focus on identifying novel factors that may improve the risk stratification for diabetes development among young adults.

Predicting glucose intolerance with normal fasting plasma glucose by the components of the metabolic syndrome

BACKGROUND

Surprisingly, it is estimated that about half of type 2 diabetics remain undetected. The possible causes may be partly attributable to people with normal fasting plasma glucose (FPG) but abnormal postprandial hyperglycemia. We attempted to develop an effective predictive model by using the metabolic syndrome (MeS) components as parameters to identify such persons.

SUBJECTS AND METHODS

All participants received a standard 75-g oral glucose tolerance test, which showed that 106 had normal glucose tolerance, 61 had impaired glucose tolerance, and 6 had diabetes-on-isolated postchallenge hyperglycemia. We tested five models, which included various MeS components. Model 0: FPG; Model 1 (clinical history model): family history (FH), FPG, age and sex; Model 2 (MeS model): Model 1 plus triglycerides, high-density lipoprotein cholesterol, body mass index, systolic blood pressure and diastolic blood pressure; Model 3: Model 2 plus fasting plasma insulin (FPI); Model 4: Model 3 plus homeostasis model assessment of insulin resistance. A receiver-operating characteristic (ROC) curve was used to determine the predictive discrimination of these models.

RESULTS

The area under the ROC curve of the Model 0 was significantly larger than the area under the diagonal reference line. All the other 4 models had a larger area under the ROC curve than Model 0. Considering the simplicity and lower cost of Model 2, it would be the best model to use. Nevertheless, Model 3 had the largest area under the ROC curve.

CONCLUSION

We demonstrated that Model 2 and 3 have a significantly better predictive discrimination to identify persons with normal FPG at high risk for glucose intolerance.

International Diabetes Federation: a consensus on Type 2 diabetes prevention

AIMS

Early intervention and avoidance or delay of progression to Type 2 diabetes is of enormous benefit to patients in terms of increasing life expectancy and quality of life, and potentially in economic terms for society and health-care payers. To address the growing impact of Type 2 diabetes the International Diabetes Federation (IDF) Taskforce on Prevention and Epidemiology convened a consensus workshop in 2006. The primary goal of the workshop and this document was the prevention of Type 2 diabetes in both the developed and developing world. A second aim was to reduce the risk of cardiovascular disease in people who are identified as being at a higher risk of Type 2 diabetes. The IDF plan for prevention of Type 2 diabetes is based on controlling modifiable risk factors and can be divided into two target groups: People at high risk of developing Type 2 diabetes. The entire population.

CONCLUSIONS

In planning national measures for the prevention of Type 2 diabetes, both groups should be targeted simultaneously with lifestyle modification the primary goal through a stepwise approach. In addition, it is important that all activities are tailored to the specific local situation. Further information on the prevention of diabetes can be found on the IDF website: http://www.idf.org/prevention.

Impact of the population at risk of diabetes on projections of diabetes burden in the United States: an epidemic on the way

AIMS/HYPOTHESIS

The aim of this study was to make projections of the future diabetes burden for the adult US population based in part on the prevalence of individuals at high risk of developing diabetes.

MATERIALS AND METHODS

Models were created from data in the nationally representative National Health and Nutrition Examination Survey (NHANES) II mortality survey (1976-1992), the NHANES III (1988-1994) and the NHANES 1999-2002. Population models for adults (>20 years of age) from NHANES III data were fitted to known diabetes prevalence in the NHANES 1999-2002 before making future projections. We used a multivariable diabetes risk score to estimate the likelihood of diabetes incidence in 10 years. Estimates of future diabetes (diagnosed and undiagnosed) prevalence in 2011, 2021, and 2031 were made under several assumptions.

RESULTS

Based on the multivariable diabetes risk score, the number of adults at high risk of diabetes was 38.4 million in 1991 and 49.9 million in 2001. The total diabetes burden is anticipated to be 11.5% (25.4 million) in 2011, 13.5% (32.6 million) in 2021, and 14.5% (37.7 million) in 2031. Among individuals aged 30 to 39 years old who are not currently targeted for screening according to age, the prevalence of diabetes is expected to rise from 3.7% in 2001 to 5.2% in 2031. By 2031, 20.2% of adult Hispanic individuals are expected to have diabetes.

CONCLUSIONS/INTERPRETATION

The prevalence of diabetes is projected to rise to substantially greater levels than previously estimated. Diabetes prevalence within the Hispanic community is projected to be potentially overwhelming.

Combined Use of Fasting Plasma Glucose and Glycated Hemoglobin A1c in a Stepwise Fashion to Detect Undiagnosed Diabetes Mellitus

Type 2 diabetes mellitus (DM) is a common and serious condition related with considerable morbidity. Screening for DM is one strategy for reducing this burden. In Japan National Diabetes Screening Program (JNDSP) guideline, the combined use of fasting plasma glucose (FPG) and glycated hemoglobin A1c (HbA1c) in a stepwise fashion has been recommended to identify the group of people needing life-style counseling or medical care. However, the efficacy of this program has not been fully evaluated, as an oral glucose tolerance test (OGTT) is not mandatory in the guideline. The aim of this study was to assess the validity of the screening test scenario, in which an OGTT would be applied to people needing life-style counseling or medical care on this guideline: FPG 110-125 mg/dl and HbA1c over 5.5%. Subjects were 1,726 inhabitants without a previous history of DM in the Funagata study, which is a population-based survey conducted in Yamagata prefecture to clarify the risk factors, related conditions, and consequences of DM. DM was diagnosed according to the 1999 World Health Organization criteria. The prevalence of undiagnosed DM was 6.6%. The tested screening scenario gave a sensitivity of 55.3%, a specificity of 98.4%, a positive predictive value of 70.8%, and a negative predictive value of 96.9% for undiagnosed DM. In conclusion, the screening test scenario, in which an OGTT would be followed by the combined use of FPG and HbA1c in a stepwise fashion according to the JNDSP guideline, was not effective in identifying people with undiagnosed DM.

Predictive validity of different definitions of hypertension for type 2 diabetes

BACKGROUND

Models to predict diabetes or pre-diabetes often incorporate the assessment of hypertension, but proposed definitions for 'hypertension' are inconsistent. We compared the classifications obtained using different definitions for 'hypertension'.

METHODS

We compared records for 5158 cases from 181 family practices, who were later diagnosed with diabetes and prescribed oral hypoglycaemic drugs, with 5158 controls, matched for age, sex and family practice, who were never diagnosed with diabetes. We compared classifications obtained using definitions of hypertension based on medical diagnoses, prescription of blood pressure lowering drugs or both. We compared family practices where diagnosis or prescribing varied systematically.

RESULTS

Classification of hypertension based on recorded medical diagnoses gave a sensitivity of 32.2% for diabetes (95% confidence interval from 30.4 to 34.1%). Prescription of blood pressure lowering drugs in the 12 months before diagnosis gave a sensitivity of 47.2% (45.7 to 48.7%). Combining either a medical diagnosis or a blood pressure lowering prescription gave a sensitivity of 52.8% (51.3 to 54.3%). In family practices where hypertension was least frequently recorded, a diagnosis of hypertension gave a sensitivity of 19.5% for diabetes (17.4 to 21.6%) compared with 50.8% (46.3 to 55.3%) in the highest quintile. Prescription of blood pressure lowering drugs gave a sensitivity of 36.1% (33.1 to 39.0%) in the lowest prescribing practices but 58.2% (55.5 to 61.0%) in the highest quintile.

CONCLUSIONS

Misclassification errors depend on the definition of hypertension and its implementation in practice. Definitions of hypertension that depend on access or quality in health care should be avoided.

Prescreening tools for diabetes and obesity-associated dyslipidaemia: comparing BMI, waist and waist hip ratio. The D.E.S.I.R. Study

OBJECTIVE

To compare the sensitivities of BMI, waist circumference and waist hip ratio (WHR) in identifying subjects who should be screened for diabetes and/or for obesity-associated dyslipidaemia.

DESIGN

Cross-sectional study.

SETTING

Central-western France.

PARTICIPANTS

More than 3000 men and women, aged 40-64 years, from the French study: data from an epidemiological study on the insulin resistance syndrome (D.E.S.I.R.).

MAIN OUTCOME MEASURES

Sensitivity and specificity for screened diabetes (fasting plasma glucose>or=7.0 mmol/l) and screened dyslipidaemia (triglycerides>or=2.3 mmol/l and/or HDL-cholesterol <0.9/1.1 mmol/l (men/women)) according to BMI, waist circumference and WHR.

RESULTS

Sensitivities increased as more corpulent subjects were screened, but they increased slowly after screening the top 30%: body mass index (BMI)>or=27/26 kg/m(2) (men/women) or waist >or=96/83 cm or WHR>or=0.96/0.83. These values were chosen as thresholds. In men, BMI had a nonsignificantly higher sensitivity than waist or WHR for both diabetes and dyslipidaemia (77 vs 74 and 66% P<0.3, 0.09; 56 vs 54 and 49% P<0.5, 0.16). For women, waist had a slightly higher sensitivity than BMI or WHR (82 vs 77 and 77% P<0.8, 0.7) for diabetes; for dyslipidaemia, waist and WHR had similar sensitivities, higher than for BMI (65 and 67 vs 54% P<0.16, 0.13).

CONCLUSIONS

We propose that for screening in a French population 40-64 years of age, the more obese 30% of the population, identified either by BMI, waist or WHR be screened for diabetes and obesity-associated dyslipidaemia.

High-risk individuals' willingness to pay for diabetes risk-reduction programs

OBJECTIVE

The purpose of this study was to estimate how much at-risk individuals are willing to pay for type 2 diabetes primary prevention programs.

RESEARCH DESIGN AND METHODS

An Internet-based, choice-format conjoint survey was presented to individuals at elevated risk for type 2 diabetes. Hypothetical diabetes risk-reduction programs included seven features: diet, exercise, counseling, medication, weight loss goal, risk reduction, and program costs. The sample included 582 individuals aged > or =45 years, two-thirds of whom were obese. Conditional logit models were used to calculate participants' willingness to pay for risk reduction programs. Each respondent's self-assessed risk of developing diabetes was compared with an objective measure based on a diabetes screening tool.

RESULTS

Many respondents underestimated their personal risk of developing diabetes. Those with a low perceived risk were less likely to indicate that they would participate in a diabetes prevention program. Individuals had the strongest preference for programs with large weight loss goals, fewer restrictions on diet, and larger reductions in the risk of diabetes. Respondents were willing to pay approximately $1,500 over 3 years to participate in a lifestyle intervention program similar to the Diabetes Prevention Program. Individuals with a high perceived risk were willing to pay more than individuals with lower perceived risk.

CONCLUSIONS

Many individuals will be willing to participate in interventions to delay or prevent diabetes if the interventions are subsidized, but most will be unwilling to pay the full program cost. Our results also offer insights for designing risk-reduction programs that appeal to potential participants.

Population impact of strategies for identifying groups at high risk of type 2 diabetes

BACKGROUND

To assess the incidence of diabetes among sub-groups of the population defined by the presence of one or more simple risk factors, and to investigate population stratification as a means of identifying groups at high risk of diabetes.

METHODS

Data from EPIC-Norfolk (1993-1998), a population-based cohort study of 24,714 men and women aged 40-78 years without self-reported diabetes at baseline, were analyzed. During 12 years of follow-up, 608 new cases of diabetes were recorded.

RESULTS

Age (RR 1.03; 95% CI 1.02, 1.04), parental history of diabetes (RR 2.15; 95% CI 1.80, 2.57), BMI (RR 1.76; 95% CI 1.53, 2.02) and physical activity (RR 0.72-0.77 (reference sedentary)) were independently related to risk of diabetes. Sedentary, obese individuals aged over 55 years, with a parental history of diabetes were 18 times more likely to develop diabetes than those in the lowest risk group.

CONCLUSION

Sedentary, obese men and women over 55 years with a parental history of diabetes form a readily identifiable group, which could be targeted for screening and primary prevention. Groups such as that defined by physical inactivity alone would be more suitable for population level approaches.

Validating the utility of the Spanish version of the American Diabetes Association Risk Test

The American Diabetes Association (ADA) Risk Test, often used for decisions to blood glucose screen or not, lacks studies reporting the reliability or validity for the Spanish version of the tool. The objective of this study is to further validate the utility of the Spanish version of the ADA's Risk Test for Latino Populations. A convenience sample of 316 Latinos participated in this study. A positive but weak statistical correlation was found between blood glucose and the Risk Test score (.138), suggesting low reliability and validity of the Spanish version of the instrument. Two internal consistency estimates of reliability techniques were computed for the Risk Test for diabetes scale items, indicating low reliability.

Risk scores for type 2 diabetes can be applied in some populations but not all

OBJECTIVE

Risk scores based on phenotypic characteristics to identify individuals at high risk of having undiagnosed diabetes have been developed in Caucasian populations. The impact of known risk factors on having undiagnosed type 2 diabetes differs between populations from different ethnic origin, and risk scores developed in Caucasians may not be applicable to other ethnic groups. This study evaluated the performance of one risk score in nine populations of diverse ethnic origin.

RESEARCH DESIGN AND METHODS

Data provided by centers from around the world to the DETECT-2 project were used. The database includes population-based surveys with information on at least 500 people without known diabetes having a 75-g oral glucose tolerance test. To date, 52 centers have contributed data on 190,000 individuals from 34 countries. In this analysis, nine cross-sectional studies were selected representing diverse ethnic and regional backgrounds. The risk score assessed uses information on age, sex, blood pressure treatment, and BMI.

RESULTS

This analysis included 29,758 individuals; 1,805 individuals had undiagnosed diabetes. The performance of the risk score varied widely, with sensitivity, specificity, and percentage needing further testing ranging between 12 and 57%, 72 and 93%, and 2 and 25%, respectively, with the worse performance in non-Caucasian populations. This variation in performance was related to differences in the association between prevalence of undiagnosed diabetes and components of the risk score.

CONCLUSIONS

A typical risk score developed in Caucasian populations cannot be applied to other populations of diverse ethnic origins.

The psychological impact of screening for type 2 diabetes

Until recently, there was little empirical data regarding the psychological impact of screening for type 2 diabetes. There is now some progress in this area, as evidenced by emerging population based studies reporting on the effects of screening for type 2 diabetes on perceived health status and well-being. Recent studies from our own and other groups show that the diagnosis type 2 diabetes has no substantial adverse or positive effect on the participants' perceived health status and well-being after notification of the test result. Importantly, screening-detected type 2 diabetes patients beforehand perceive their risk for type 2 diabetes to be low, despite the presence of risk factors, such as obesity, hypertension and a family history, and overall report low levels of diabetes-related symptom distress. Yet, screening-detected type 2 diabetes patients were bothered more by symptoms of hyperglycaemia and fatigue in the first year following diagnosis type 2 diabetes than non-diabetics. On the basis of research to date, we conclude that screening for type 2 diabetes in the general population has no serious psychological side effects. Whether lack of emotional response to screening, is because of unawareness or indifference, needs further investigation. Future studies should be aiming towards a better understanding of how to raise the awareness and understanding of type 2 diabetes and its risk factors in high-risk individuals, while avoiding or minimizing negative effects, such as emotional distress and denial. The growing number of younger people developing type 2 diabetes warrants further research into labeling effects of an early diagnosis.

Derivation and validation of diabetes risk score for urban Asian Indians

OBJECTIVE

Simple risk scores for identifying people with undiagnosed diabetes have been developed, mostly in Caucasian groups. This may not be suitable for Asian Indians, therefore this study was undertaken to develop and validate a simple diabetes risk score in an urban Asian Indian population with a high prevalence of diabetes. We also tested whether this score was applicable to South Asian migrants living in a different cultural context.

RESEARCH DESIGN AND METHODS

A population based Cohort of 10,003 participants aged >or=20 years was divided into two equal halves (Cohorts 1 and 2), after excluding people with known diabetes. Cohort 1 (n=4993) was used to derive the risk score. Validation of the score was performed in the other half of the survey population (Cohort 2) (n=5010). The validation was also done in a separate survey population in Chennai, India (Cohort 3) (n=2002) (diagnosis of diabetes was based on OGTT) and in the South Asian Cohort of the 1999 Health Survey for England (n=676) (fasting glucose value>or=7 mmol/l and HbA1c>or=6.5% were used for diagnosis). A logistic regression model was used to compute the beta coefficients for risk factors. The risk score value was derived from a receiver operating characteristic curve.

RESULTS

The significant risk factors included in the risk score were age, BMI, waist circumference, family history of diabetes and sedentary physical activity. A risk score value of >21 gave a sensitivity, specificity, positive predictive value and negative predictive value of 76.6%, 59.9%, 9.4% and 97.9% in Cohort 1, 72.4%, 59%, 8.3% and 97.6% in Cohort 2 and 73.7%, 61.0%, 12.2% and 96.9% in Cohort 3, respectively. The higher distribution of risk factors in the UK Cohort means that at the same cut point the score was much more sensitive but also less specific. (sensitivity 92.2%, specificity 25.7%, positive predictive value of 21.6% and negative predictive value of 93.7%).

CONCLUSIONS

A diabetes risk score involving simple non-biochemical measurements was developed and validated in a native Asian Indian population. This easily applicable simple score could play an important role as the first step in the process of identifying individuals with an increased likelihood of having prevalent but undiagnosed diabetes. The different distribution of risk factors with the migrant Asian Indians living in England and the different relationship between sensitivity and specificity for the same score demonstrate that risk scores and cut-points developed and tested even within one ethnic group cannot be generalized to individuals of the same ethnic group living in a different cultural setting where the distribution of risk factors for diabetes is different.

'Coming down the line'-- patients' understanding of their family history of common chronic disease

PURPOSE

The family history is becoming an increasingly important feature of health promotion and early detection of common chronic diseases in primary care. Previous studies of patients from genetics clinics suggest a divergence between how persons with a family history perceive and understand their risk and the risk information provided by health professionals. This interview study aimed to explore how patients in primary care understand and come to terms with their family history of cancer, heart disease, or diabetes and how family history might affect consultations about disease risk and management.

METHODS

Thirty semistructured interviews were conducted with general practice patients who had a family history of cancer, heart disease, or diabetes. The transcript data underwent a qualitative constant comparative analysis.

RESULTS

What exactly constitutes having a family history of an illness varied among participants. The development of a personal sense of vulnerability to the illness in the family depended not only on the biomedical approach of counting affected relatives but also on a sophisticated interplay of other factors. The emotional impact of witnessing the illness in the family, particularly if the illness was sudden, premature, or fatal, and the nature of personal relationships within a family that determine a sense of emotional closeness and personal likeness with the affected relative, all contributed to the perception of disease risk. Different beliefs about the contributions of nature and nurture to disease can affect patients' views on the degree of control they can exert over their risk.

CONCLUSION

This study highlights potential differences between the way patients and medical professionals assess and understand familial risk of cancer, heart disease, and diabetes. Our previous systematic review findings are enhanced by showing that personal experience of disease and the emotional impact can also influence familial risk perceptions. Eliciting the patient's perspective when discussing risk of chronic disease, particularly in the context of a family history, could inform a more patient-centered approach to risk assessment and communication and support patients to make informed decisions about the management of their disease risk.

Use of the diabetes risk score for opportunistic screening of undiagnosed diabetes and impaired glucose tolerance: the IGLOO (Impaired Glucose Tolerance and Long-Term Outcomes Observational) study

OBJECTIVE

To evaluate an opportunistic screening strategy addressed to individuals with one or more cardiovascular risk factor, based on the Diabetes Risk Score (DRS) as the initial instrument, for the identification of individuals with type 2 diabetes or impaired glucose tolerance (IGT).

RESEARCH DESIGN AND METHODS

The DRS, a simple self-administered questionnaire, was completed by individuals identified by general practitioners and presenting with one or more cardiovascular risk factor. All patients underwent a 2-h oral glucose tolerance test (OGTT). The optimal DRS cutoff was calculated by applying the receiver-operating characteristic curve.

RESULTS

Overall, 1,377 individuals aged between 55 and 75 years received an OGTT and completed the DRS. Mean DRS values showed a marked variation according to glucose metabolism categories, as follows: 8.7 +/- 3.0 in normoglycemic individuals, 9.5 +/- 3.1 in individuals with impaired fasting glucose, 9.9 +/- 3.3 in individuals with IGT, and 12.0 +/- 3.5 in individuals with type 2 diabetes. The receiver-operating characteristic curve showed that, with a cutoff of 9, the sensitivity of DRS in detecting individuals with glucose abnormalities (type 2 diabetes or IGT) was 77% and the specificity 45%. The use of the DRS as an initial screening instrument, followed by the measurement of fasting blood glucose in individuals with a score > or =9 and by the OGTT in individuals with a fasting blood glucose between 5.6 and 6.9 mmol/l, would lead to the identification of 83% of the case subjects with type 2 diabetes and 57% of the case subjects with IGT, at a cost of an OGTT in 38% of the sample and a fasting blood glucose in 64%.

CONCLUSIONS

The DRS can represent a valid inexpensive instrument for opportunistic screening and a useful alternative to indiscriminate fasting blood glucose measurement, not readily available in general practice.

Cross-sectional evaluation of the Finnish Diabetes Risk Score: a tool to identify undetected type 2 diabetes, abnormal glucose tolerance and metabolic syndrome

The aim of this study was to assess the performance of the Finnish Diabetes Risk Score as a screening tool for undetected type 2 diabetes (T2D), abnormal glucose tolerance (AGT) and metabolic syndrome in the general population. In a cross-sectional, population-based survey, a total of 4,622 subjects aged 45-74 years were invited to a health examination that included an oral glucose tolerance test. Full data with risk score estimate and glucose tolerance status were available for 2,966 subjects without a prior history of diabetes. The risk score was associated with the presence of previously undiagnosed T2D, AGT, metabolic syndrome and cardiovascular risk factors. The area under the receiver operating curve for the prevalence of undiagnosed diabetes was 0.72 in men and 0.73 in women. The sensitivity using a cutoff risk score of 11 to identify undiagnosed diabetes was 66% in men and 70% in women; the corresponding false-positive rates were 31% and 39%, respectively. The area under the receiver operating curve for detecting the metabolic syndrome was 0.72 in men and 0.75 in women. The Finnish Diabetes Risk Score can be used as a self-administered test to screen subjects at high risk for T2D. It can also be used in the general population and clinical practice to identify undetected T2D, AGT and the metabolic syndrome.

TRAF4 functions as an intermediate of GITR-induced NF-kappaB activation

Members of the tumor necrosis factor receptor (TNFR) family regulate the activation, differentiation, and function of many cell types, including cells of the immune system. TNFR-associated factors (TRAFs) function as adapter molecules controlling signaling pathways triggered by TNFR family members, such as activation of nuclear factor kappaB (NF-kappaB). Despite intensive research, the function of TRAF4 in signaling pathways triggered by TNFR-related proteins remains enigmatic. Intriguingly, our functional studies indicated that TRAF4 augments NF-kappaB activation triggered by glucocorticoid-induced TNFR (GITR), a receptor expressed on T cells, B cells, and macrophages. Further analyses revealed that TRAF4-mediated NF-kappaB activation downstream of GITR depends on a previously mapped TRAF-binding site in the cytoplasmic domain of the receptor and is inhibited by the cytoplasmic protein A20. GITR is thought to inhibit the suppressive function of regulatory T cells (Treg cells) and to promote activation of T cells. Taken together, our studies provide the first indications that TRAF4 elaborates GITR signaling and suggest that TRAF4 can modulate the suppressive functions of Treg cells.

Strategies to identify adults at high risk for type 2 diabetes: the Diabetes Prevention Program

OBJECTIVE

The Diabetes Prevention Program (DPP) was a large, multicenter, randomized clinical trial testing interventions to prevent or delay type 2 diabetes. A major challenge was to identify eligible high-risk adults, defined by DPP as having both impaired glucose tolerance (IGT) (2-h glucose 140-199 mg/dl) and elevated fasting plasma glucose (EFG) (95-125 mg/dl).

RESEARCH DESIGN AND METHODS

We analyzed how screening yields would be affected by the presence of established risk factors such as age, sex, ethnicity, BMI, and family history of diabetes, and how much yields would be enhanced by preselecting individuals with elevated capillary blood glucose levels. Of 158,177 contacted adults, 79,190 were potentially eligible (no history of diabetes, age 25 years and older, BMI > or =24 kg/m2). We focus on the 30,383 participants who completed an oral glucose tolerance test (OGTT).

RESULTS

Based on OGTT, 27% had IGT with EFG, meeting DPP eligibility criteria for being at high risk of diabetes, and 13% had previously undiagnosed diabetes based on OGTT. Older age and higher BMI increased yield of high-risk individuals and those with newly discovered diabetes in most ethnic groups (whites, African Americans, Hispanics, and American Indians). In Asian Americans, age but not BMI predicted high risk and diabetes. Independent of age and BMI, the preliminary fasting capillary glucose predicted screening yield in all ethnic groups, with an inverted-U pattern defining DPP eligibility alone (IGT-EFG) and a steep curvilinear pattern defining either IGT-EFG or newly discovered diabetes. Fasting capillary glucose did not attenuate the affects of other participant characteristics in predicting IGT-EFG or the combination of IGT-EFG and newly discovered diabetes.

CONCLUSIONS

The DPP screening approach identified adults with or at high risk for type 2 diabetes across various ethnic groups and provided guidance to more efficient use of OGTTs. Fasting capillary glucose is a useful adjunct in screening programs combined with data on age and adiposity.

Lay understanding of familial risk of common chronic diseases: a systematic review and synthesis of qualitative research

PURPOSE

Although the family history is increasingly used for genetic risk assessment of common chronic diseases in primary care, evidence suggests that lay understanding about inheritance may conflict with medical models. This study systematically reviewed and synthesized the qualitative literature exploring understanding about familial risk held by persons with a family history of cancer, coronary artery disease, and diabetes mellitus.

METHODS

Twenty-two qualitative articles were found after a comprehensive literature search and were critically appraised; 11 were included. A meta-ethnographic approach was used to translate the studies across each other, synthesize the translation, and express the synthesis.

RESULTS

A dynamic process emerged by which a personal sense of vulnerability included some features that mirror the medical factors used to assess risk, such as the number of affected relatives. Other features are more personal, such as experience of a relative's disease, sudden or premature death, perceived patterns of illness relating to gender or age at death, and comparisons between a person and an affected relative. The developing vulnerability is interpreted using personal mental models, including models of disease causation, inheritance, and fatalism. A person's sense of vulnerability affects how that person copes with, and attempts to control, any perceived familial risk.

CONCLUSIONS

Persons with a family history of a common chronic disease develop a personal sense of vulnerability that is informed by the salience of their family history and interpreted within their personal models of disease causation and inheritance. Features that give meaning to familial risk may be perceived differently by patients and professionals. This review identifies key areas for health professionals to explore with patients that may improve the effectiveness of communication about disease risk and management.

Genetics for targeting disease prevention: diabetes

This article provides an overview of current thinking regarding genetics and diabetes (type 1, type 2, and gestational diabetes mellitus),including a selective look at a few implicated gene variants. This article explores how this information might be applied in current and future clinical practice to (1) predict who is at risk for diabetes and its complications, (2) identify and intervene to prevent or delay the development of diabetes in persons at risk, (3) identify patients with diabetes in an early stage and intervene to prevent later complications,and (4) individualize therapy for patients with diabetes to improve outcomes. The article concludes with some general thoughts about genetics and diabetes prevention in the future.

No substantial psychological impact of the diagnosis of Type 2 diabetes following targeted population screening: The Hoorn Screening Study

AIMS

To examine the impact of the diagnosis of Type 2 diabetes on psychological well-being and perceived health status in subjects who participated in a targeted population-screening programme.

METHODS

This study was conducted within the framework of a screening project in the general (aged 50-75 years) Dutch population. The final study population consisted of 259 subjects with a high-risk score on the Symptom Risk Questionnaire; 116 of whom were subsequently detected with Type 2 diabetes and 143 who were non-diabetic. The impact was assessed approximately 2 weeks (shortly) and 6 and 12 months after the diagnosis, using the 12-item Well-Being Questionnaire (W-BQ12) and the Medical Outcomes Study Short Form 36 (SF-36), respectively. Analyses of co-variance (ancova) were used.

RESULTS

Approximately 2 weeks after the diagnosis, no significant mean differences were found on either the W-BQ12 or the SF-36, between the screening-detected Type 2 diabetes subjects and the non-diabetic subjects. Six months after the diagnosis, we found lower scores in the screening-detected Type 2 diabetes subjects compared with the non-diabetic subjects on the SF-36 dimensions Role Physical (mean difference (95% CI); -8.2 (-16.2; -0.1); P = 0.046) and Role Emotional (mean difference (95% CI); -7.9 (-15.3; -0.5); P = 0.038). One year after the test results, no significant mean differences were found between both groups on either instrument (W-BQ12; SF-36).

CONCLUSIONS

The diagnosis of Type 2 diabetes has no substantial adverse or positive effect on psychological well-being and perceived health status, shortly, and 6 and 12 months after the diagnosis.

Population-based stepwise screening for unrecognised Type 2 diabetes is ineffective in general practice despite reliable algorithms

AIMS/HYPOTHESIS

The yield of screening programmes for Type 2 diabetes in the existing healthcare setting might be lower than anticipated from tests of screening algorithms in data from epidemiological surveys. Our aims were to evaluate the reliability of the algorithms and the effectiveness of a proposed stepwise screening programme for Type 2 diabetes in general practice.

METHODS

The screening programme had four steps: (i) mail-distributed self-administered risk-chart; (ii) screening tests: random blood glucose (RBG) and HbA(1)c; (iii) diagnostic procedure 1 for fasting blood glucose (FBG) (if RBG >/=5.5 mmol/l or HbA(1)c >/=6.1%); and (iv) OGTT as diagnostic procedure 2 (if 5.6</=FBG<6.1 mmol/l or HbA(1)c >/=6.1%). Abnormalities of glucose metabolism were classified according to the WHO 1999 criteria, based on capillary whole blood. The subjects were all patients between 40 and 69 years of age ( n=60,926) who were registered in 88 general practices and had not been previously diagnosed with diabetes.

RESULTS

A total of 11,263 individuals had a high-risk risk-score and attended the screening consultation (step 1 test-positive). Of these, 30.1% needed diagnostic tests (step 2 test-positive) and 27.2% of these needed an OGTT (step 3 test-positive). The test-positive proportions were equal to the proportions obtained in data from a population-based survey from Step 2 onwards, and the algorithms were thus reliable. The identification rate was only 19% of all prevalent undiagnosed diabetes according to a recently published prevalence estimate. This was due to a large dropout rate among high-risk individuals prior to entry into the programme.

CONCLUSIONS/INTERPRETATION

Population-based mail-distributed stepwise screening for Type 2 diabetes in general practice is ineffective, despite reliable screening algorithms, primarily because many high-risk individuals fail to participate.

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.

A Danish diabetes risk score for targeted screening: the Inter99 study

OBJECTIVE

To develop a simple self-administered questionnaire identifying individuals with undiagnosed diabetes with a sensitivity of 75% and minimizing the high-risk group needing subsequent testing.

RESEARCH DESIGN AND METHODS

A population-based sample (Inter99 study) of 6,784 individuals aged 30-60 years completed a questionnaire on diabetes-related symptoms and risk factors. The participants underwent an oral glucose tolerance test. The risk score was derived from the first half and validated on the second half of the study population. External validation was performed based on the Danish Anglo-Danish-Dutch Study of Intensive Treatment in People with Screen Detected Diabetes in Primary Care (ADDITION) pilot study. The risk score was developed by stepwise backward multiple logistic regression.

RESULTS

The final risk score included age, sex, BMI, known hypertension, physical activity at leisure time, and family history of diabetes, items independently and significantly (P<0.05) associated with the presence of previously undiagnosed diabetes. The area under the receiver operating curve was 0.804 (95% CI 0.765-0.838) for the first half of the Inter99 population, 0.761 (0.720-0.803) for the second half of the Inter99 population, and 0.803 (0.721-0.876) for the ADDITION pilot study. The sensitivity, specificity, and percentage that needed subsequent testing were 76, 72, and 29%, respectively. The false-negative individuals in the risk score had a lower absolute risk of ischemic heart disease compared with the true-positive individuals (11.3 vs. 20.4%; P<0.0001).

CONCLUSIONS

We developed a questionnaire to be used in a stepwise screening strategy for type 2 diabetes, decreasing the numbers of subsequent tests and thereby possibly minimizing the economical and personal costs of the screening strategy.

Screening for type 2 diabetes and impaired glucose metabolism: the Australian experience

OBJECTIVE

To assess the Australian protocol for identifying undiagnosed type 2 diabetes and impaired glucose metabolism.

RESEARCH DESIGN AND METHODS

The Australian screening protocol recommends a stepped approach to detecting undiagnosed type 2 diabetes based on assessment of risk status, measurement of fasting plasma glucose (FPG) in individuals at risk, and further testing according to FPG. The performance of and variations to this protocol were assessed in a population-based sample of 10,508 Australians.

RESULTS

The protocol had a sensitivity of 79.9%, specificity of 79.9%, and a positive predictive value (PPV) of 13.7% for detecting undiagnosed type 2 diabetes and sensitivity of 51.9% and specificity of 86.7% for detecting impaired glucose tolerance (IGT) or impaired fasting glucose (IFG). To achieve these diagnostic rates, 20.7% of the Australian adult population would require an oral glucose tolerance test (OGTT). Increasing the FPG cut point to 6.1 mmol/l (110 mg/dl) or using HbA(1c) instead of FPG to determine the need for an OGTT in people with risk factors reduced sensitivity, increased specificity and PPV, and reduced the proportion requiring an OGTT. However, each of these protocol variations substantially reduced the detection of IGT or IFG.

CONCLUSIONS

The Australian screening protocol identified one new case of diabetes for every 32 people screened, with 4 of 10 people screened requiring FPG measurement and 1 in 5 requiring an OGTT. In addition, 1 in 11 people screened had IGT or IFG. Including HbA(1c) measurement substantially reduced both the number requiring an OGTT and the detection of IGT or IFG.

The performance of a risk score as a screening test for undiagnosed hyperglycemia in ethnic minority groups: data from the 1999 health survey for England

OBJECTIVE

To assess the performance of the Cambridge Risk Score (CRS) to predict undiagnosed hyperglycemia in Caribbean and South Asian people living in the U.K.

RESEARCH DESIGN AND METHODS

The CRS uses routinely available data from primary care records to identify people at high risk for undiagnosed type 2 diabetes. The sensitivity, specificity, and area under the receiver operator characteristic (ROC) curve for the CRS cut point of 0.199 were 77, 72, and 80% (95% CI 68-91), respectively. The risk score was calculated for 248 Caribbean and 555 South Asian participants aged 40-75 years in the 1999 Health Survey for England. Undiagnosed hyperglycemia was considered present if fasting plasma glucose was >/=7.0 mmol/l or HbA(1c) was >/=6.5%. Sensitivity, specificity, and predictive values were calculated for various cut points of the risk score, and ROC curves were constructed.

RESULTS

The area under the ROC curve was 67% (59-76) and 72% (67-78) for Caribbeans and South Asians, respectively. The optimal cut point in Caribbean participants was 0.236, sensitivity was 63% (46-77), and specificity was 63% (56-69). In the South Asian population, the optimal cut point was and 0.127, sensitivity was 69% (60-78), and specificity was 64% (60-69).

CONCLUSIONS

The CRS, using routinely available data, can be used in a strategy to detect undiagnosed hyperglycemia in Caribbean and South Asian populations. The existence of ethnic group-specific cut points must be further established in future studies.

Effectiveness of diabetes mellitus screening recommendations

Screening guidelines proposed by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus have been endorsed by several medical societies. However, one-third of cases are undiagnosed, and complications at the time of diagnosis indicate that disease may have been present for several years before diagnosis. This study evaluates the effectiveness of the guidelines for detecting new cases of diabetes mellitus. By using a cross-sectional, representative sample of the United States (National Health and Nutritional Examination Survey, NHANES III), the guidelines are tested on adults, 20 years and older without a prior diagnosis of diabetes. Individuals are classified as nondiabetics (n = 6,241) or as having undiagnosed diabetes (n = 274) based on their blood glucose. Screening when one risk factor is present, as stated in the guidelines, has a true-positive rate of 100% and would require that 83% of the population be tested. Screening when two risk factors are present is more efficient, with a comparable true-positive rate (98%), but requires that only 59% of the population be tested. A notable finding is the earlier age of onset among minorities, which may be associated with other health disparities. Because diabetes occurs at younger ages in minorities, screening whites who are > or =40 and minorities > or =30 years of age has a high true-positive rate (95%) and also reduces testing (60%). The screening guidelines would be effective, if followed, and would essentially eliminate undiagnosed cases of diabetes.

Detection of undiagnosed diabetes and other hyperglycemia states: the Atherosclerosis Risk in Communities Study

OBJECTIVE

To evaluate screening strategies based on fasting plasma glucose (FPG), clinical information, and the oral glucose tolerance test (OGTT) for detection of diabetes or other hyperglycemic states-impaired fasting glucose (IFG) and impaired glucose tolerance-meriting clinical intervention.

RESEARCH DESIGN AND METHODS

We studied 8,286 African-American and white men and women without known diabetes, aged 53-75 years, who received an OGTT during the fourth exam of the Atherosclerosis Risk in Communities Study. Using a split sample technique, we estimated the diagnostic properties of various clinical detection rules derived from logistic regression modeling. Screening strategies utilizing FPG, these detection rules, and/or the OGTT were then compared in terms of both the fraction of hyperglycemia cases detected and the sample fraction receiving different screening tests and identified as screen positive.

RESULTS

Screening based on the IFG cut point (> or =6.1 mmol/l), followed by a clinical detection rule for those below this value, detected 86.3% of diabetic case subjects and 66.0% of all hyperglycemia cases, identifying 42% of the sample as screen positive. Applying an OGTT for those positive by the rule provides diagnostic labeling and reduces the fraction that is screen positive to 29%. Another strategy, to apply an OGTT to those with an FPG cut point between 5.6 and 6.1 mmol/l, also identifies 29% of the sample as screen positive, although it detects slightly fewer hyperglycemia cases.

CONCLUSIONS

Screening strategies based on FPG, complemented by clinical detection rules and/or an OGTT, are effective and practical in the detection of hyperglycemic states meriting clinical intervention.

The diabetes risk score: a practical tool to predict type 2 diabetes risk

OBJECTIVE

Interventions to prevent type 2 diabetes should be directed toward individuals at increased risk for the disease. To identify such individuals without laboratory tests, we developed the Diabetes Risk Score.

RESEARCH DESIGN AND METHODS

A random population sample of 35- to 64-year-old men and women with no antidiabetic drug treatment at baseline were followed for 10 years. New cases of drug-treated type 2 diabetes were ascertained from the National Drug Registry. Multivariate logistic regression model coefficients were used to assign each variable category a score. The Diabetes Risk Score was composed as the sum of these individual scores. The validity of the score was tested in an independent population survey performed in 1992 with prospective follow-up for 5 years.

RESULTS

Age, BMI, waist circumference, history of antihypertensive drug treatment and high blood glucose, physical activity, and daily consumption of fruits, berries, or vegetables were selected as categorical variables. Complete baseline risk data were found in 4435 subjects with 182 incident cases of diabetes. The Diabetes Risk Score value varied from 0 to 20. To predict drug-treated diabetes, the score value >or=9 had sensitivity of 0.78 and 0.81, specificity of 0.77 and 0.76, and positive predictive value of 0.13 and 0.05 in the 1987 and 1992 cohorts, respectively.

CONCLUSIONS

The Diabetes Risk Score is a simple, fast, inexpensive, noninvasive, and reliable tool to identify individuals at high risk for type 2 diabetes.

Risk of new-onset diabetes in the Losartan Intervention For Endpoint reduction in hypertension study

BACKGROUND

There has been uncertainty about the risk of new-onset diabetes in hypertensive individuals treated with different blood pressure-decreasing drugs.

OBJECTIVES

To study this risk in hypertensive individuals who were at risk of developing diabetes mellitus in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study.

METHODS

In the LIFE study, with a double-masked, randomized, parallel-group design, 9193 patients (46% men) with hypertension (mean age 67 years, average pressure 174/98 mmHg after placebo run-in) and electrocardiogram-documented left ventricular hypertrophy were randomly assigned to once-daily losartan- or atenolol-based antihypertensive treatment and followed for at least 4 years (mean 4.8 years). At baseline, 7998 patients did not have diabetes mellitus and were thus at risk of developing this condition during the study. To demonstrate ability to predict new-onset diabetes, we developed a prediction score using the significant variables from multivariate analyses (serum glucose, body mass index, serum high-density lipoprotein cholesterol, systolic blood pressure and history of prior use of antihypertensive drugs).

RESULTS

There was a steadily increasing risk of diabetes with increasing level-of-risk score; patients in the highest quartile were at considerably greater risk than those in the three lower ones. Treatment with losartan was associated with lower risk of development of diabetes within each of the four quartiles of the risk score. As previously reported, new-onset diabetes mellitus occurred in 242 patients receiving losartan (13.0 per 1000 person-years) and 320 receiving atenolol (17.5 per 1000 person-years); relative risk 0.75 (95% confidence interval 0.63 to 0.88; P<0.001).

CONCLUSIONS

New-onset diabetes could be strongly predicted by a newly developed risk score using baseline serum glucose concentration (non-fasting), body mass index, serum high-density lipoprotein cholesterol concentration, systolic blood pressure and history of prior use of antihypertensive drugs. Independently of these risk factors, fewer hypertensive patients with left ventricular hypertrophy developed diabetes mellitus if they were treated with losartan than if they were treated with atenolol.