Primary prevention of non-insulin-dependent diabetes mellitus

The Portfolio Diet and Incident Type 2 Diabetes: Findings From the Women's Health Initiative Prospective Cohort Study

OBJECTIVE

A plant-based dietary pattern, the Portfolio Diet, has been shown to lower LDL cholesterol and other cardiovascular disease risk factors. However, no study has evaluated the association of this diet with incident type 2 diabetes.

RESEARCH DESIGN AND METHODS

This analysis included 145,299 postmenopausal women free of diabetes at baseline in the Women's Health Initiative (WHI) Clinical Trials and Observational Study from 1993 to 2021. Adherence to the diet was assessed with a score based on six components (high in plant protein [soy and pulses], nuts, viscous fiber, plant sterols, and monounsaturated fat and low in saturated fat and cholesterol) determined from a validated food-frequency questionnaire. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% CIs of the association of the Portfolio Diet, alongside the Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets, with incident type 2 diabetes, with adjustment for potential confounders.

RESULTS

Over a mean follow-up of 16.0 years, 13,943 cases of incident type 2 diabetes were identified. In comparisons of the highest with the lowest quintiles of adherence, the HRs for risk of incident type 2 diabetes were 0.77 (95% CI 0.72, 0.82) for the Portfolio Diet, 0.69 (0.64, 0.73) for the DASH diet, and 0.78 (0.74, 0.83) for the Mediterranean diet. These findings were attenuated by 10% after additional adjustment for BMI.

CONCLUSIONS

Greater adherence to the plant-predominant Portfolio, DASH, and Mediterranean diets was prospectively associated with lower risk of type 2 diabetes in postmenopausal women.

The Diabetes Prevention Program: headline results

The Diabetes Prevention Program (DPP) was a trial of over 3,000 people with impaired glucose tolerance (IGT) to assess the effect of different interventions on their progression to type 2 diabetes. During an average follow-up period of three years, intensive lifestyle intervention with regular exercise and weight loss reduced the risk of progression to type 2 diabetes by 58%. Treatment with the antihyperglycaemic agent metformin reduced progression to type 2 diabetes by 31%. The DPP has therefore confirmed that rigorous lifestyle management can reduce the risk of type 2 diabetes and also shown that metformin therapy can reduce diabetes risk.

WITHDRAWN: Dietary advice for the prevention of type 2 diabetes mellitus in adults

Review status was set to withdrawn. The review is out of date and does not meet current Cochrane standards. It will be superseded by a new expanding Cochrane review on 'Diet, physical activity or both for the prevention or delay of type 2 diabetes mellitus and its associated complications in persons at increased risk'.

The editorial group responsible for this previously published document have withdrawn it from publication.

The effect of community-based education for lifestyle intervention on the prevalence of metabolic syndrome and its components: tehran lipid and glucose study

BACKGROUND

It has been shown that life style modification may decrease the prevalence of metabolic syndrome, but this intervention has not been reported in community setting.

OBJECTIVES

Effect of lifestyle modification on prevalence of metabolic syndrome and its components were assessed in an urban population.

MATERIALS AND METHODS

In 6870 participants of Tehran Lipid and Glucose Study aged 20-74 years, the prevalence of metabolic syndrome and its components were measured before and after a 3.6 years interval. Lifestyle intervention was employed at a community level including 2961 individuals and also 3909 subjects which were recruited as controls. Logistic regression analysis was adjusted for age, sex and medications.

RESULTS

After 3.6 years, the rise in the prevalence of metabolic syndrome was less prominent in intervention than control group (P < 0.002 for increase of metabolic syndrome prevalence between groups), with an OR of 0.84 (confidence interval 0.75-0.95). After intervention the prevalence of abdominal obesity, elevated fasting glucose levels, elevated triglyceride and low HDL cholesterol were more prominent in control group, as compared to intervention group.

CONCLUSIONS

Community based lifestyle modifications in Tehranian adults delayed rise in the prevalence of metabolic syndrome and some of its components.

Preventive pharmacotherapy in type 2 diabetes mellitus

Over the last few decades certain demographic changes have been observed worldwide, which have led to an increase in the prevalence of chronic non-communicable diseases. Type 2 diabetes mellitus and associated cardiovascular disease are major contributors to this disease burden leading to rising morbidity and mortality. It is worrisome to see that type 2 diabetes with its micro- and macrovascular complications is occurring in younger populations where it was hitherto unseen. Prevention appears to be an important strategy to reduce the burden of disease. Along with inculcating healthy lifestyle habits across populations, it may be suitable to use preventive pharmacotherapy in those with pre-diabetes and / or other risk factors like obesity, hypertension, and on the like. Metformin, alpha glucosidase inhibitors like acarbose, miglitol, and voglibose, and pioglitazone have all been used with success. The issues of compliance and adverse effects during long-term use have tempered the use of these drugs. The best approach would be to motivate the patient for effective lifestyle changes, and pharmacological management if the lifestyle changes are not successful in achieving their goals.

Prevention of non-communicable disease in a population in nutrition transition: Tehran Lipid and Glucose Study phase II

BACKGROUND

The Tehran Lipid and Glucose Study (TLGS) is a long term integrated community-based program for prevention of non-communicable disorders (NCD) by development of a healthy lifestyle and reduction of NCD risk factors. The study begun in 1999, is ongoing, to be continued for at least 20 years. A primary survey was done to collect baseline data in 15005 individuals, over 3 years of age, selected from cohorts of three medical heath centers. A questionnaire for past medical history and data was completed during interviews; blood pressure, pulse rate, and anthropometrical measurements and a limited physical examination were performed and lipid profiles, fasting blood sugar and 2-hours-postload-glucose challenge were measured. A DNA bank was also collected. For those subjects aged over 30 years, Rose questionnaire was completed and an electrocardiogram was taken. Data collected were directly stored in computers as database software- computer assisted system. The aim of this study is to evaluate the feasibility and effectiveness of lifestyle modification in preventing or postponing the development of NCD risk factors and outcomes in the TLGS population.

DESIGN AND METHODS

In phase II of the TLGS, lifestyle interventions were implemented in 5630 people and 9375 individuals served as controls. Primary, secondary and tertiary interventions were designed based on specific target groups including schoolchildren, housewives, and high-risk persons. Officials of various sectors such as health, education, municipality, police, media, traders and community leaders were actively engaged as decision makers and collaborators. Interventional strategies were based on lifestyle modifications in diet, smoking and physical activity through face-to-face education, leaflets & brochures, school program alterations, training volunteers as health team and treating patients with NCD risk factors. Collection of demographic, clinical and laboratory data will be repeated every 3 years to assess the effects of different interventions in the intervention group as compared to control group.

CONCLUSION

This controlled community intervention will test the possibility of preventing or delaying the onset of non-communicable risk factors and disorders in a population in nutrition transition.

TRIAL REGISTRATION

ISRCTN52588395.

Dietary advice for the prevention of type 2 diabetes mellitus in adults

BACKGROUND

Prevention of type 2 diabetes in adults is a far better option than treatment, to alleviate pressure on health care providers and resources. However, there is no current review of the evidence regarding the efficacy of a diet-only intervention for prevention.

OBJECTIVES

To assess the effects of type and frequency of dietary advice for the prevention of type 2 diabetes mellitus.

SEARCH STRATEGY

We carried out a comprehensive search of The Cochrane Library, MEDLINE, EMBASE, CINAHL, AMED, bibliographies and contacted relevant experts.

SELECTION CRITERIA

All randomised controlled trials, of twelve months or longer, in which dietary advice for the prevention of type 2 diabetes was the only intervention in adults.

DATA COLLECTION AND ANALYSIS

The lead investigator performed all data extraction and quality scoring with duplication being carried out by one of the other four investigators independently with discrepancies resolved by discussion and consensus. Authors were contacted for missing data. Change data are presented.

MAIN RESULTS

Two trials which randomised 358 people to dietary treatment and control groups were identified. Longest duration of follow-up was six years. In the 6-year Da Qing IGT & Diabetes study, the incidence of type 2 diabetes in the control group was 67.7% (95% confidence interval (CI) 59.8% to 75.2%) which was reduced to 43.8% (95% CI 35.5% to 54.7%) in the diet group. Overall, the dietary intervention group had a 33% reduction in the incidence of diabetes after six years (P < 0.03). The Oslo Diet & Exercise Study (ODES) found significant (P<0.05) reductions in insulin resistance, fasting insulin (pmol/L), fasting C-peptide (pmol/L), fasting proinsulin (pmol/L), fasting blood glucose (mmol/L), BMI (kg/m(2)), mBP (mmHg) and fasting triglycerides (mmol/L), and a significant increase in fasting HDL cholesterol (mmol/L) and PAI-1 (U/ml) after 12 months of dietary intervention. Data on mortality, morbidity, health-related quality of life, adverse effects, costs were not reported in either study.

AUTHORS' CONCLUSIONS

There are no high quality data on the efficacy of dietary intervention for the prevention of type 2 diabetes. More well-designed, long-term studies, providing well-reported, high-quality data are required before proper conclusions can be made into the best dietary advice for the prevention of diabetes mellitus in adults.

Prediabetes in rural and urban children in 3 states in Mexico

The authors studied the frequency, distribution, and factors associated with prediabetes (fasting glucose, 100-125 mg/dL) in rural and urban children from San Luis Potosí, León, and Querétaro in central Mexico. Family history, somatometry, and levels of fasting insulin, glucose, and lipids were collected in 1238 children 6 to 13 years of age. The authors found no cases of type 2 diabetes and a 5.7% frequency of prediabetes. The group with prediabetes had higher homeostasis model assessment of insulin resistance scores and total cholesterol and high-density lipoprotein cholesterol levels. Prediabetes was more frequent in León, with similar distribution in rural and urban children. The frequency of insulin resistance was 24.1%, with higher figures in urban groups and in San Luis Potosí. In multivariate analysis, prediabetes was associated with insulin resistance and residence in León. The authors concluded that in central Mexico the frequency of prediabetes is significant, and it is associated with insulin resistance and a geographic location, but not with obesity or urban vs rural dwelling.

Dietary advice for treatment of type 2 diabetes mellitus in adults

BACKGROUND

While initial dietary management immediately after formal diagnosis is an 'accepted' cornerstone of treatment of type 2 diabetes mellitus, a formal and systematic overview of its efficacy and method of delivery is not currently available.

OBJECTIVES

To assess the effects of type and frequency of different types of dietary advice for adults with type 2 diabetes.

SEARCH STRATEGY

We carried out a comprehensive search of The Cochrane Library, MEDLINE, EMBASE, CINAHL, AMED, bibliographies and contacted relevant experts.

SELECTION CRITERIA

All randomised controlled trials, of six months or longer, in which dietary advice was the main intervention.

DATA COLLECTION AND ANALYSIS

The lead investigator performed all data extraction and quality scoring with duplication being carried out by one of the other six investigators independently with discrepancies resolved by discussion and consensus. Authors were contacted for missing data.

MAIN RESULTS

Thirty-six articles reporting a total of eighteen trials following 1467 participants were included. Dietary approaches assessed in this review were low-fat/high-carbohydrate diets, high-fat/low-carbohydrate diets, low-calorie (1000 kcal per day) and very-low-calorie (500 kcal per day) diets and modified fat diets. Two trials compared the American Diabetes Association exchange diet with a standard reduced fat diet and five studies assessed low-fat diets versus moderate fat or low-carbohydrate diets. Two studies assessed the effect of a very-low-calorie diet versus a low-calorie diet. Six studies compared dietary advice with dietary advice plus exercise and three other studies assessed dietary advice versus dietary advice plus behavioural approaches. The studies all measured weight and measures of glycaemic control although not all studies reported these in the articles published. Other outcomes which were measured in these studies included mortality, blood pressure, serum cholesterol (including LDL and HDL cholesterol), serum triglycerides, maximal exercise capacity and compliance. The results suggest that adoption of regular exercise is a good way to promote better glycaemic control in type 2 diabetic patients, however all of these studies were at high risk of bias.

AUTHORS' CONCLUSIONS

There are no high quality data on the efficacy of the dietary treatment of type 2 diabetes, however the data available indicate that the adoption of exercise appears to improve glycated haemoglobin at six and twelve months in people with type 2 diabetes. There is an urgent need for well-designed studies which examine a range of interventions, at various points during follow-up, although there is a promising study currently underway.

Abnormal glucose tolerance in Chinese women with polycystic ovary syndrome

BACKGROUND

The aims of this study were to analyse the prevalence of impaired glucose tolerance (IGT) and diabetes mellitus (NIDDM) in Chinese polycystic ovary syndrome (PCOS) patients and to assess the ability of screening tests to predict these abnormalities within this population.

METHODS

A total of 102 PCOS patients were evaluated. All patients underwent oral glucose tolerance tests (OGTTs) with blood samples taken at 0, 1 and 2 h. The 2-h plasma glucose level was used to categorize subjects as having IGT or NIDDM.

RESULTS

The prevalence of IGT was 20.5% and that of NIDDM was 1.9%. There was no significant relationship between BMI and 2-h plasma glucose levels. The areas under the receiver operating characteristic (ROC) curve for glucose to insulin ratio (G:I), homeostasis model assessment (HOMA) and quantitative insulin sensitivity check index (QUICKI) were 0.702, 0.734 and 0.733 respectively. ROC analysis suggested a threshold value of 10.7 in G:I ratio (73.9% sensitivity and 59.5% specificity), a value of 2.14 in HOMA (73.9% sensitivity and 73.4% specificity) and a value of 0.34 in QUICKI (73.9% sensitivity and 73.4% specificity) for the prediction of abnormal glucose tolerance (IGT and NIDDM).

CONCLUSIONS

Chinese women with PCOS are at increased risk of IGT and NIDDM. Even though G:I, HOMA and QUICKI are easier than OGTT, they could not replace the role of 2-h post-challenge plasma glucose level in the screening of IGT and NIDDM in PCOS women.

Prevention of type 2 diabetes by lifestyle intervention: a Japanese trial in IGT males

Prevention of type 2 diabetes by intensive lifestyle intervention designed to achieve and maintain ideal body weight was assessed in subjects with impaired glucose tolerance (IGT). Male subjects with IGT recruited from health-screening examinees were randomly assigned in a 4:1 ratio to a standard intervention group (control group) and intensive intervention group (intervention group). The final numbers of subjects were 356 and 102, respectively. The subjects in the control group and in the intervention group were advised to maintain body mass index (BMI) of <24.0 kg/m2 and of <22.0 kg/m2, respectively, by diet and exercise. In the intervention group, detailed instructions on lifestyle were repeated every 3-4 months during hospital visits. Diabetes was judged to have developed when two or more consecutive fasting plasma glucose (FPG) values exceeded 140 mg/dl. A 100g oral glucose tolerance test was performed every 6 months to detect improvement of glucose tolerance. The subjects were seen in an ordinary outpatient clinic. The cumulative 4-year incidence of diabetes was 9.3% in the control group, versus 3.0% in the intervention group, and the reduction in risk of diabetes was 67.4% (P < 0.001). Body weight decreased by 0.39 kg in the control group and by 2.18 kg in the intervention group (P < 0.001). The control group was subclassified according to increase and decrease in body weight. The incidence of diabetes was positively correlated with the changes in body weight, and the improvement in glucose tolerance was negatively correlated. Subjects with higher FPG at baseline developed diabetes at a higher rate than those with lower FPG. Higher 2h plasma glucose values and higher BMI values at baseline were also associated with a higher incidence of diabetes, but the differences were not significant. Subjects with a low insulinogenic index (DeltaIRI/DeltaPG 30 min after an oral glucose load) developed diabetes at a significantly higher rate than those with a normal insulinogenic index. Comparison of the BMI data and incidence of diabetes in five diabetes prevention studies by lifestyle intervention revealed a linear correlation between the incidence of diabetes and the BMI values, with the exception of the DaQing Study. However, the slope of the reduction in incidence of diabetes in the intensive intervention groups was steeper than expected simply on the basis of the reduction of BMI, suggesting that the effect of lifestyle intervention cannot be solely ascribed to the body weight reduction. We conclude that lifestyle intervention aimed at achieving ideal body weight in men with IGT is effective and can be conducted in an outpatient clinic setting.

The prevention of type 2 diabetes mellitus: recent advances

Diabetes is a major public health problem that is approaching epidemic proportions globally. There is an urgent need for strategies to curb the rising prevalence of this disease, and prevention appears a logical approach. Lifestyle modifications with weight loss and moderate exercise can reduce the incidence of diabetes by >50% in patients with impaired glucose tolerance (IGT). The use of metformin, acarbose and other agents have been shown in randomized prospective trials to prevent type 2 diabetes in high-risk subjects with IGT. Other pharmacological interventions are currently being examined in large prospective studies. It is likely that one or a combination of these approaches could make diabetes prevention a reality in the near future.

Long-term effects of a reduced fat diet intervention on cardiovascular disease risk factors in individuals with glucose intolerance

The long-term effects on cardiovascular disease risk factors of a reduced fat (RF), ad libitum diet were compared with usual diet (control, CD) in glucose intolerance individuals. Participants were 136 adults aged > or =40 years with 'glucose intolerance' (2h blood glucose 7-11.0 mmol/l) detected at a Diabetes Survey who completed at 1 year intervention study of reduced fat, ad libitum diet versus usual diet. They were re-assessed at 2, 3 and 5 years. Main outcome measures were blood pressure, serum concentrations of total cholesterol, HDL and LDL cholesterol, total cholesterol:HDL ratio, triglycerides and body weight. The reduced fat diet lowered total cholesterol (P<0.01), LDL cholesterol (P< or =0.05), total cholesterol:HDL ratio (P< or =0.05), body weight (P<0.01) and systolic blood pressure (P< or =0.05) initially and diastolic blood pressure (P<0.01) long-term. No significant changes occurred in HDL cholesterol or triglycerides. In the more compliant 50% of the intervention group, systolic and diastolic blood pressure levels and body weight were lower at 1, 2 and 3 years (P<0.05). It was concluded that a reduced fat ad libitum diet has short-term benefits for cholesterol, body weight and systolic blood pressure and long-term benefits for diastolic blood pressure without significantly effecting HDL cholesterol and triglycerides despite participants regaining their lost weight.

Ethnic specific recommendations in clinical practice guidelines: a first exploratory comparison between guidelines from the USA, Canada, the UK, and the Netherlands

OBJECTIVES

To investigate whether clinical practice guidelines in different countries take ethnic differences between patients into consideration and to assess the scientific foundation of such ethnic specific recommendations.

DESIGN

Analysis of the primary care sections of clinical practice guidelines.

SETTING

Primary care practice guidelines for type 2 diabetes mellitus, hypertension, and asthma developed in the USA, Canada, the UK, and the Netherlands.

MAIN OUTCOME MEASURES

Enumeration of the ethnic specific information and recommendations in the guidelines, and the scientific basis and strength of this evidence.

RESULTS

Different guidelines do address ethnic differences between patients, but to a varying extent. The USA guidelines contained the most ethnic specific statements and the Dutch guidelines the least. Most ethnic specific statements were backed by scientific evidence, usually arising from descriptive studies or narrative reviews.

CONCLUSION

The attention given to ethnic differences between patients in clinical guidelines varies between countries. Guideline developers should be aware of the potential problems of ignoring differences in ethnicity.

Addressing the burden of diabetes in the 21st century: better care and primary prevention

By the end of the 20th century, the worldwide diabetes pandemic had affected an estimated 151 million persons. Strategies to mitigate both the human and economic burden are urgently needed. Efficacious treatments are currently available but the quality of diabetes care being delivered is suboptimal in both developed and developing countries. Some progress to improve quality has been made thought national strategies. These efforts need two elements: "translation" research that will establish the methods needed to assure that clinical research findings are delivered effectively in every day practice settings; and development and implementation of quality improvement measures that will reliably track progress. New interventions that prevent diabetes among those at high risk also now hold much promise and need to be implemented.

Preparing nurses to face the pandemic of diabetes mellitus: a literature review

BACKGROUND

Diabetes constitutes a global public health problem. Today about 135 million people are affected and it is estimated that the number in 2025 will be 300 million.

AIMS

By reviewing existing literature the aim is to raise awareness among nurses, nurse educators and nursing students of the global epidemic of diabetes mellitus, its multiple underlying causes, especially social ones, and how to fight it. A further aim is to discuss the implications for future curriculum content in nurse education programmes.

FINDINGS

The main underlying causes of the disease are genetic and environmental factors, such as urbanization and industrialization, as well as increased longevity and changes in lifestyle from a traditional healthy and active life to a modern, sedentary, stressful life and over-consumption of energy-dense foods. This process, labelled 'coca-colonization', is evident all over the world, although more so in developing countries. The prevalence of diabetes mellitus varies among populations due to differences in genetic susceptibility and social risk factors such as change in diet, obesity, physical inactivity and, possibly, factors relating to intrauterine development. Migrants are especially affected. Diabetes mellitus needs to be treated by a holistic approach through dietary adjustment, exercise, medication (if needed), education and self-care measures. Type 2 diabetes mellitus is a preventable disease. The main implication for nurses and nursing curricula is to change the focus from the individual with diabetes mellitus and management to prevent deterioration of health (secondary prevention), to population-based community-intervention programmes. These need to focus on health promoting activities to raise awareness among healthy people of the risk factors for diabetes mellitus.

CONCLUSION

Nurses all over the world have an important role in fighting the diabetic pandemic by health promotion aimed to keep people healthy as long as possible.

Estimated number of adults with prediabetes in the US in 2000: opportunities for prevention

OBJECTIVE

To estimate the percent and number of overweight adults in the U.S. with prediabetes who would be potential candidates for diabetes prevention as per the American Diabetes Association Position Statement (12).

RESEARCH DESIGN AND METHODS

We analyzed data from the Third National Health and Nutrition Examination Survey (NHANES III; 1988-1994) and projected our estimates to the year 2000. We defined impaired glucose tolerance (IGT; 2-h glucose 140-199 mg/dl), impaired fasting glucose (IFG; fasting glucose 110-125 mg/dl), and prediabetes (IGT or IFG) per American Diabetes Association (ADA) criteria. The ADA recently recommended that all overweight people (BMI >or=25 kg/m(2)) who are >or=45 years of age with prediabetes could be potential candidates for diabetes prevention, as could prediabetic people aged >25 years with risk factors. In NHANES III, 2-h postload glucose concentrations were done only among subjects aged 40-74 years. Because we were interested in overweight people who had both the 2-h glucose and fasting glucose tests, we limited our estimates of IGT, IFG, and prediabetes to those aged 45-74 years. RESULTS-Overall, 17.1% of overweight adults aged 45-74 years had IGT, 11.9% had IFG, 22.6% had prediabetes, and 5.6% had both IGT and IFG. Based on those data, we estimated that in the year 2000, 9.1 million overweight adults aged 45-74 had IGT, 5.8 million had IFG, 11.9 million had prediabetes, and 3.0 million had IGT and IFG.

CONCLUSIONS

Almost 12 million overweight individuals aged 45-74 years in the U.S. may benefit from diabetes prevention interventions. The number will be substantially higher if estimation is extended to individuals aged >75 and 25-44 years.

The prevention of type 2 diabetes--lifestyle change or pharmacotherapy? A challenge for the 21st century

Diabetes mellitus is occurring in epidemic proportions in many countries. In Australia 7.4% of people over 25 years of age have diabetes (mostly type 2) and comparable or higher prevalences have been reported in the United States and a number of Asian countries. The enormous economic and social cost of this disease makes a compelling case for prevention. Epidemiological studies have shown clearly that type 2 diabetes results from an interaction between a genetic predisposition and lifestyle factors including obesity, sedentary behaviour and both calorie excess and various dietary constituents. The natural history of type 2 diabetes includes a preceding period of impaired glucose tolerance (IGT)/impaired fasting glucose (IFG) which provides an opportunity for targeted intervention within large communities. Lifestyle intervention studies have consistently shown that quite modest changes can reduce the progression from IGT to diabetes by 50-60%. It may, however, not be possible to translate these successful findings to larger cohorts or maintain the lifestyle changes longer term. This has lead to consideration of pharmacotherapy. While small studies with sulphonylureas are inconclusive, benefits have been found for metformin, acarbose and troglitazone. Big intervention studies with ramipril, rosiglitazone, valsartan and nateglinide are underway. Pharmacological intervention raises a whole range of ethical, economic and practical issues not the least of which is the problem of long term therapy of the 'otherwise well'.

Prevalence of impaired glucose tolerance among children and adolescents with marked obesity

BACKGROUND

Childhood obesity, epidemic in the United States, has been accompanied by an increase in the prevalence of type 2 diabetes among children and adolescents. We determined the prevalence of impaired glucose tolerance in a multiethnic cohort of 167 obese children and adolescents.

METHODS

All subjects underwent a two-hour oral glucose-tolerance test (1.75 g [DOSAGE ERROR CORRECTED] of glucose per kilogram of body weight), and glucose, insulin, and C-peptide levels were measured. Fasting levels of proinsulin were obtained, and the ratio of proinsulin to insulin was calculated. Insulin resistance was estimated by homeostatic model assessment, and beta-cell function was estimated by calculating the ratio between the changes in the insulin level and the glucose level during the first 30 minutes after the ingestion of glucose.

RESULTS

Impaired glucose tolerance was detected in 25 percent of the 55 obese children (4 to 10 years of age) and 21 percent of the 112 obese adolescents (11 to 18 years of age); silent type 2 diabetes was identified in 4 percent of the obese adolescents. Insulin and C-peptide levels were markedly elevated after the glucose-tolerance test in subjects with impaired glucose tolerance but not in adolescents with diabetes, who had a reduced ratio of the 30-minute change in the insulin level to the 30-minute change in the glucose level. After the body-mass index had been controlled for, insulin resistance was greater in the affected cohort and was the best predictor of impaired glucose tolerance.

CONCLUSIONS

Impaired glucose tolerance is highly prevalent among children and adolescents with severe obesity, irrespective of ethnic group. Impaired oral glucose tolerance was associated with insulin resistance while beta-cell function was still relatively preserved. Overt type 2 diabetes was linked to beta-cell failure.

Insulin, insulin-like growth factors and colon cancer: a review of the evidence

Insulin and insulin-like growth factor (IGF) axes are major determinants of proliferation and apoptosis and thus may influence carcinogenesis. In various animal models, modulation of insulin and IGF-1 levels through various means, including direct infusion, energy excess or restriction, genetically induced obesity, dietary quality including fatty acid and sucrose content, inhibition of normal insulin secretion and pharmacologic inhibition of IGF-1, influences colonic carcinogenesis. Human evidence also associates high levels of insulin and IGF-1 with increased risk of colon cancer. Clinical conditions associated with high levels of insulin (noninsulin-dependent diabetes mellitus and hypertriglyceridemia) and IGF-1 (acromegaly) are related to increased risk of colon cancer, and increased circulating concentrations of insulin and IGF-1 are related to a higher risk of colonic neoplasia. Determinants and markers of hyperinsulinemia (physical inactivity, high body mass index, central adiposity) and high IGF-1 levels (tall stature) are also related to higher risk. Many studies indicate that dietary patterns that stimulate insulin resistance or secretion, including high consumption of sucrose, various sources of starch, a high glycemic index and high saturated fatty acid intake, are associated with a higher risk of colon cancer. Although additional environmental and genetic factors affect colon cancer, the incidence of this malignancy was invariably low before the technological advances that rendered sedentary lifestyles and obesity common, and increased availability of highly processed carbohydrates and saturated fatty acids. Efforts to counter these patterns are likely to have the most potential to reduce colon cancer incidence, as well as cardiovascular disease and diabetes mellitus.

Long-term (5-year) effects of a reduced-fat diet intervention in individuals with glucose intolerance

OBJECTIVE

To determine whether reducing dietary fat would reduce body weight and improve long-term glycemia in people with glucose intolerance.

RESEARCH DESIGN AND METHODS

A 5-year Follow-up of a 1-year randomized controlled trial of a reduced-fat ad libitum diet versus a usual diet. Participants with glucose intolerance (2-h blood glucose 7.0-11.0 mmol/l) were recruited from a Workforce Diabetes Survey. The group that was randomized to a reduced-fat diet participated in monthly small-group education sessions on reduced-fat eating for 1 year. Body weight and glucose tolerance were measured in 136 participants at baseline 6 months, and 1 year (end of intervention), with follow-up at 2 years (n = l04), 3 years (n = 99), and 5 years (n = 103).

RESULTS

Compared with the control group, weight decreased in the reduced-fat-diet group (P < 0.0001); the greatest difference was noted at 1 year (-3.3 kg), diminished at subsequent follow-up (-3.2 kg at 2 years and -1.6 kg at 3 years), and was no longer present by 5 years (1.1 kg). Glucose tolerance also improved in patients on the reduced-fat diet; a lower proportion had type 2 diabetes or impaired glucose tolerance at 1 year (47 vs. 67%, P < 0.05), but in subsequent years, there were no differences between groups. However, the more compliant 50% of the intervention group maintained lower fasting and 2-h glucose at 5 years (P = 0.041 and P = 0.026 respectively) compared with control subjects.

CONCLUSIONS

The natural history for people at high risk of developing type 2 diabetes is weight gain and deterioration in glucose tolerance. This process may be ameliorated through adherence to a reduced fat intake

Walking campaign: a model for developing participation in physical activity? Experiences from three campaign periods of the Stockholm Diabetes Prevention Program (SDPP)

The Stockholm Diabetes Prevention Program (SDPP) is implementing a model for community-based intervention of type 2 diabetes in three municipalities, of which one has focused on increasing physical activity among the inhabitants. The purpose was to emphasize the integration of walking into daily routines. The campaign was promoted throughout residential areas, organizations and local media. Leaders for organized walking were recruited as volunteers by advertising in local media. After a short education in leadership, practice, and first aid, the 27 volunteers ran organized walking groups in several residential areas. During three of seven walking campaigns the participants were followed and evaluated. The study showed that those individuals who participated one to three times a week were predominantly married women with a good health and regular physical activity. Nevertheless, more important was that one third of the participants had never been exercising regularly before. Most remarkable was to find the voluntary leaders so easily recruited and their great interest to remain as leaders for walking tours.

Antihypertensive drugs as predictors of type 2 diabetes among subjects with impaired glucose tolerance

AIMS

to examine the incidence rate of progression to Type 2 diabetes and baseline prognostic risk factors, focusing on hypertension and antihypertensive medication, in a cohort (n=207) with impaired glucose tolerance (IGT).

METHODS

after 2 and 4.6 (1. 9-6.4) years new cases of diabetes were diagnosed by the oral glucose tolerance test (OGTT). Hypertension (BP 160/95 or antihypertensive medication) was included in multiple regression analyses to assess the effect of risk factors on the development of diabetes.

RESULTS

diabetes developed in 32 subjects (19%), an incidence of 41/1000 (95% CI 28-57/1000) person-years. In univariate analyses, progression to diabetes was associated with a high (>9.0 mmol/l) 2-h OGTT value (P=0.008), a high fasting insulin (>12.0 mU/l) level (P=0.000), a high triglyceride (>/=1.3 mmol/l) level (P=0.028), a high BMI (>/=28.0 kg/m(2)) (P=0.013) and hypertension (P=0.003). The risk for the development of diabetes was not increased in hypertensive subjects without antihypertensive medication compared with normotensive subjects (OR 0.8, 95% CI 0.3-2. 6). However, it was increased in subjects with on medication, especially diuretics alone or in combination with other drugs. Hypertensive subjects on diuretics had higher levels of fasting insulin and triglycerides and higher BMIs at baseline than normotensive subjects. After adjustment for 2-h OGTT, fasting insulin, triglycerides and BMI, the OR for diabetes was 7.7 (95% CI 2.1-28.2) in hypertensive subjects using diuretics alone or in combination with other drugs and 2.6 (95% CI 1.0-6.7) in those using other drugs compared with normotensive subjects. The OR of diabetes corresponding to a one-unit increase in the 2-h OGTT concentration was 2.5 (95% CI 1.6-4.0) in the whole cohort.

CONCLUSIONS

the rate of progression from IGT to Type 2 diabetes in this population was similar to that seen in other studies among Caucasian populations. The use of antihypertensive medication, especially diuretics, and a high 2-h OGTT level were significant predictors of subsequent deterioration to diabetes.

Risk of type 2 diabetes mellitus in young adults from a biracial community: the Bogalusa Heart Study

BACKGROUND

Since type 2 diabetes has a strong familial component, characteristics of young adult offspring of type 2 diabetics were examined in a community sample to determine early abnormalities in black and white persons at risk.

METHODS

The sample consisted of 1,338 fasting young adults (72% white, 28% black) aged 19 to 37 years from a biracial community, including those with positive parental history of type 2 diabetes (one offspring per family, n = 230) or conditions of impaired fasting glucose and type 2 diabetes (n = 22).

RESULTS

Positive family history of diabetes or impaired fasting glucose and type 2 diabetes in young adults of both races were significantly associated with adverse profiles of measures of obesity and abdominal fat (body mass index, triceps and subscapular skinfolds, waist circumference, and abdominal height), systolic and diastolic blood pressures, serum total cholesterol, triglycerides, VLDL cholesterol, and HDL cholesterol, and indicators of glucose homeostasis (plasma glucose and insulin and insulin resistance index). The magnitude of the differences in obesity and abdominal fat measures and plasma glucose between individuals with and without parental diabetes was greater among blacks versus whites (P = 0. 047-0.004). Further, black offspring of both diabetics and non-diabetics had unfavorable profiles of obesity and abdominal fat measures, blood pressure, insulin, and insulin resistance index (P = 0.0001). In a multivariate analysis, adiposity measured as body mass index (P = 0.03) and plasma glucose (P = 0.003) emerged as the two independent characteristics that distinguished those with parental diabetes from those without parental disease. Insulin (P = 0.0001) and the insulin resistance index (P = 0.0001) were independently associated with conditions of impaired fasting glucose or type 2 diabetes.

CONCLUSIONS

The risk factors of young adults with parental type 2 diabetes or conditions of impaired fasting glucose and type 2 diabetes can be detected early. These observations have implications for early prevention and intervention, especially for blacks.

A risk-benefit assessment of metformin in type 2 diabetes mellitus

Metformin has been used for over 40 years as an effective glucose-lowering agent in type 2 (noninsulin-dependent) diabetes mellitus. Typically it reduces basal and postprandial hyperglycaemia by about 25% in more than 90% of patients when either given alone or coadministered with other therapies including insulin during a programme of managed care. Metformin counters insulin resistance and offers benefits against many features of the insulin resistance syndrome (Syndrome X) by preventing bodyweight gain, reducing hyperinsulinaemia and improving the lipid profile. In contrast to sulphonylureas, metformin does not increase insulin secretion or cause serious hypoglycaemia. Treatment of type 2 diabetes mellitus with metformin from diagnosis also offers greater protection against the chronic vascular complications of type 2 diabetes mellitus. The most serious complication associated with metformin is lactic acidosis which has an incidence of about 0.03 cases per 1000 patients years of treatment and a mortality risk of about 0.015 per 1000 patient-years. Most cases occur in patients who are wrongly prescribed the drug, particularly patients with impaired renal function (e.g. serum creatinine level > 130 micromol/L or > 1.5 g/L). Other major contraindications include congestive heart failure, hypoxic states and advanced liver disease. Serious adverse events with metformin are predictable rather than spontaneous and are potentially preventable if the prescribing guidelines are respected. Gastrointestinal adverse effects, notably diarrhoea, occur in less than 20% of patients and remit when the dosage is reduced. The life-threatening risks associated with metformin are rare and could mostly be avoided by strict adherence to the prescribing guidelines. Given the 4 decades of clinical experience with metformin, its antihyperglycaemic efficacy and benefits against Syndrome X, metformin offers a very favourable risk-benefit assessment when compared with the chronic morbidity and premature mortality among patients with type 2 diabetes mellitus.

Diabetes mellitus in the family: perceptions of offspring's risk

AIMS

The study aimed to explore the beliefs and concerns of people with Type 2 diabetes mellitus (DM) about their children's risk of developing the disease and the possibilities for prevention.

METHODS

Questionnaires were posted to all patients with Type 2 DM in four randomly selected general practices in South London. Two hundred and thirteen (73%) responded. The main outcome measures were: estimated risk of Type 2 DM in their offspring; worry about diabetes in their offspring; knowledge about the possibilities for prevention of Type 2 DM and its complications.

RESULTS

Of the 159 respondents with children, at least 35% and perhaps as many as 64% underestimated the risk of their offspring developing Type 2 DM; 44% thought it possible to reduce the risk of Type 2 DM and its complications; 28% thought altering diet and 6% taking exercise might be useful preventive strategies; 49% worried about their children developing diabetes.

CONCLUSIONS

Although risk of Type 2 DM was underestimated for their children and little was known about prevention, about half of the respondents worried about their children developing diabetes. Education and counselling about risk and prevention are needed. This is important in view of growing interest in and opportunities for both the primary and secondary prevention of Type 2 DM.

The Diabetes Prevention Program. Design and methods for a clinical trial in the prevention of type 2 diabetes

The Diabetes Prevention Program is a randomized clinical trial testing strategies to prevent or delay the development of type 2 diabetes in high-risk individuals with elevated fasting plasma glucose concentrations and impaired glucose tolerance. The 27 clinical centers in the U.S. are recruiting at least 3,000 participants of both sexes, approximately 50% of whom are minority patients and 20% of whom are > or = 65 years old, to be assigned at random to one of three intervention groups: an intensive lifestyle intervention focusing on a healthy diet and exercise and two masked medication treatment groups--metformin or placebo--combined with standard diet and exercise recommendations. Participants are being recruited during a 2 2/3-year period, and all will be followed for an additional 3 1/3 to 5 years after the close of recruitment to a common closing date in 2002. The primary outcome is the development of diabetes, diagnosed by fasting or post-challenge plasma glucose concentrations meeting the 1997 American Diabetes Association criteria. The 3,000 participants will provide 90% power to detect a 33% reduction in an expected diabetes incidence rate of at least 6.5% per year in the placebo group. Secondary outcomes include cardiovascular disease and its risk factors; changes in glycemia, beta-cell function, insulin sensitivity, obesity, diet, physical activity, and health-related quality of life; and occurrence of adverse events. A fourth treatment group--troglitazone combined with standard diet and exercise recommendations--was included initially but discontinued because of the liver toxicity of the drug. This randomized clinical trial will test the possibility of preventing or delaying the onset of type 2 diabetes in individuals at high risk.

Pharmacological management of diabetes: recent progress and future perspective in daily drug treatment

Glycaemic control in Type 1 diabetes has been proven efficient in preventing microvascular and neurological complications. The assumption that good control of hyperglycaemia may also have significant impact on alleviation of complications in Type 2 diabetes has gained growing support in recent years. Measures such as body weight reduction and exercise improve the metabolic defects, but pharmacological therapy is most frequently used. The sulphonylureas stimulate insulin secretion. Metformin and troglitazone increase glucose disposal and decrease hepatic glucose output without causing hypoglycaemia. Acarbose helps to spread the dietary carbohydrate challenge to endogenous insulin over time. These pharmacological treatments can improve blood glucose regulation in Type 2 diabetes patients. However, the key to strict glycaemic control with use of exogenous insulin lies in the creation of delivery methods that emulate physiologic insulin secretion. Insulin lispro, a recombinant insulin analogue, is identical to human insulin except for the transposition of proline and lysine at positions 28 and 29 in the C-terminus of the B chain. Evidence suggests that patients perceive their quality of life to be improved with insulin lispro when compared with regular human insulin, and that satisfaction with treatment is greater with the insulin analogue. Numerous new pharmacological approaches are under active investigation, with the aim of promoting insulin secretion, improving the action of insulin, or slowing carbohydrate absorption. With respect to continuous subcutaneous insulin infusion therapy and implantable pumps, despite that this approach is not widely utilised, it appears to bring us as close to achieving glycaemic control as is feasible with current treatment approaches. However, general application of such technology requires significant improvements in several areas, such as improvement of patency of catheter, pump failures due to early battery depletion incidents, and pump miniaturisation. Future perspective resides on insulin analogues with longer half-lives that would provide better basal insulin coverage in association with fast-acting analogues.

The Kahnawake Schools Diabetes Prevention Project: intervention, evaluation, and baseline results of a diabetes primary prevention program with a native community in Canada

OBJECTIVES

Kahnawake Schools Diabetes Prevention Project is a 3-year community-based, primary prevention program for non-insulin-dependent diabetes mellitus in a Mohawk community near Montreal, Canada. Objectives are to improve healthy eating and encourage more physical activity among elementary school children.

METHODS

Intervention incorporates behavior change theory, Native learning styles, the Ottawa Charter for Health Promotion, and a health promotion planning model. Evaluation uses a mixed longitudinal and cross-sectional design to measure obesity, fitness, eating habits, and physical activity of elementary school children in the experimental and comparison communities. Intermediate variables are self-efficacy and perceived parental support. Process evaluation provides feedback to the intervention.

RESULTS

During 3 years, 63 distinct interventions that included a Health Education Program reinforced by school events, a new Community Advisory Board, a recreation path, and community-based activities promoting healthy lifestyles were implemented. Baseline consent rates were 87 and 71% in the experimental and comparison schools. As expected, anthropometric data increase with age. Between 9 and 10 years there are increased weight, height, BMI, and skinfold thicknesses; decreased fitness; and increased television watching.

CONCLUSIONS

Implementing a Native community-based diabetes prevention program is feasible through participatory research that incorporates Native culture and local expertise.

Predictors of progression from impaired glucose tolerance to NIDDM: an analysis of six prospective studies

Risk factors associated with the progression from impaired glucose tolerance (IGT) to NIDDM were examined in data from six prospective studies. IGT and NIDDM were defined in all studies by World Health Organization (WHO) criteria, and baseline risk factors were measured at the time of first recognition of IGT. The studies varied in size from 177 to 693 participants with IGT, and included men and women followed from 2 to 27 years after the recognition of IGT. Across the six studies, the incidence rate of NIDDM was 57.2/1,000 person-years and ranged from 35.8/1,000 to 87.3/1,000 person-years. Although baseline measures of fasting and 2-h postchallenge glucose levels were both positively associated with NIDDM incidence, incidence rates were sharply higher for those in the top quartile of fasting plasma glucose levels, but increased linearly with increasing 2-h postchallenge glucose quartiles. Incidence rates were higher among the Hispanic, Mexican-American, Pima, and Nauruan populations than among Caucasians. The effect of baseline age on NIDDM incidence rates differed among the studies; the rates did not increase or rose only slightly with increasing baseline age in three of the studies and formed an inverted U in three studies. In all studies, estimates of obesity (including BMI, waist-to-hip ratio, and waist circumference) were positively associated with NIDDM incidence. BMI was associated with NIDDM incidence independently of fasting and 2-h post challenge glucose levels in the combined analysis of all six studies and in three cohorts separately, but not in the three studies with the highest NIDDM incidence rates. Sex and family history of diabetes were generally not related to NIDDM progression. This analysis indicates that persons with IGT are at high risk and that further refinement of risk can be made by other simple measurements. The ability to identify persons at high risk of NIDDM should facilitate clinical trials in diabetes prevention.

Reduction in body weight helps to delay the onset of diabetes even in non-obese with strong family history of the disease

Of the 1200 non-diabetic offspring of non-insulin-dependent diabetic patients registered under the prevention programme, 262 (M:F 189:73) were available for analysis with greater than or equal to 4 years of follow-up. All of them had been prescribed a calorie restricted diet to suit their body weight, occupation and age, and were advised to restrict the use of refined carbohydrates and fats. Regular exercise was also advised. Compliance with these prescriptions was assessed at each follow up. At the time of analysis, it was noted that only 14.5% had developed diabetes in a period of 8 +/- 4.2 years even though many of them had impaired glucose tolerance at entry in the programme. Multiple regression analysis showed that initial 2 h plasma glucose, initial glucose tolerance and gain in body weight were strong predictors of diabetes. Weight loss occurred in persons who adhered to diet and exercise programmes and conversion to diabetes was lower in them compared to those who gained weight (P < 0.002). Although the rate and degree of obesity is less among Indians, it has been observed in several earlier studies that even a minor increase in body mass index increased the risk of diabetes. This study highlights the fact that measures to control weight helps to delay the onset of diabetes even in the non-obese despite a strong family history of the disorder.

The global epidemiology of non-insulin-dependent diabetes mellitus and the metabolic syndrome

Non-insulin-dependent diabetes mellitus (NIDDM) constitutes about 85% of all cases of diabetes in developed countries and it has now reached epidemic proportions in many developing nations, as well as disadvantaged groups in developed countries, e.g., Mexican- and African-Americans and Australian Aborigines and Torres Strait Islanders. The diagnosis of NIDDM is usually made after the age of 50 years in Europids, but it is seen at much younger age in these high prevalence populations, which also include Pacific Islanders, Native Americans, and migrant Asian Indians and Chinese. There is enormous variation in NIDDM prevalence between populations, and exceptionally high rates have been documented in populations who have changed from a traditional to a modern lifestyle, e.g., American Pima Indians, Micronesians, and other Pacific Islanders, Australian Aborigines, migrant Asian Indians, and Mexican-Americans. Over the next decade, following the initial phase of the NIDDM epidemic, macro- and microvascular complications will emerge as a major threat to future public health throughout the world with huge economic and social costs. The major cause of death in NIDDM is macrovascular disease (coronary artery, peripheral vascular, and cerebrovascular), which accounts for at least two-thirds of NIDDM mortality. A key strategy in reducing macrovascular disease lies in the better understanding of the Deadly Quartet or Metabolic Syndrome. New data suggest that hyperleptinemia rather than hyperinsulinemia may play an important and central role in the genesis of the cardiovascular disease risk factor cluster that constitutes the Metabolic Syndrome.

Strategies for preventing type II diabetes. What can be done to stem the epidemic?

Non-insulin-dependent (type II) diabetes is a major target for prevention because of its staggering emotional and financial burdens on society. The theory behind preventive efforts is that individuals at high risk often show signs of impaired glucose tolerance before diabetes fully develops. Once identified, these patients may respond to several pharmacologic and nonpharmacologic interventions that lower blood glucose levels and improve cardiovascular fitness with few adverse effects. However, the long-term efficacy of these approaches is uncertain. Information from the National Institutes of Health Diabetes Prevention Program should help clarify the impact of preventive measures and their cost-effectiveness.

Oral antidiabetic drug use in the elderly

Non-insulin-dependent diabetes mellitus (NIDDM) is a metabolic disease that is common in the elderly, and is characterised by insulin insufficiency and resistance. Measures such as bodyweight reduction and exercise improve the metabolic defects, but pharmacological therapy is the most frequently used and successful therapy. The sulphonylureas stimulate insulin secretion. Metformin and troglitazone increase glucose disposal and decrease hepatic glucose output without causing hypoglycaemia. Acarbose is a dietary aid that spreads the dietary carbohydrate challenge to endogenous insulin over time. These pharmacological agents, either alone or in combination, should improve blood glucose regulation in patients with NIDDM.

Early lifestyle intervention in patients with non-insulin-dependent diabetes mellitus and impaired glucose tolerance

Non-insulin-dependent diabetes mellitus (NIDDM) is preceded by impaired glucose tolerance (IGT) lasting for years before manifesting as overt hyperglycaemia. Both genetic and environmental factors contribute to the development of IGT and NIDDM. Obesity, physical inactivity and high-fat diet have been found to predict IGT and NIDDM. Therefore, a diet and exercise intervention from diagnosis of NIDDM could improve the treatment outcome and prognosis of patients with NIDDM. Furthermore, because subjects with IGT are at increased risk for diabetes and atherosclerotic vascular disease, it is reasonable to assume that in terms of reducing the incidence and longterm consequences of NIDDM an intervention at this phase is more effective than in overt diabetes. Although the nonpharmacological approach is generally accepted as the first-line treatment of NIDDM its efficacy has often been questioned. Therefore, it is important to carry out long-term controlled studies to find out to what extent lifestyle modification could improve the metabolic control and level of major cardiovascular risk factors known to be associated with poor outcome in NIDDM. This kind of study also gave relevant experience in planning studies aiming at primary prevention of NIDDM. One-year dietary and exercise intervention on newly diagnosed NIDDM patients in Kuopio, Finland resulted in a better metabolic control and a moderate reduction in cardiovascular risk factors as compared to the conventional treatment group. After the second year of follow-up only 12.5% in the intervention group were receiving oral antidiabetic drugs vs. 34.8% in the conventional treatment group. Weight reduction and a reduced use of saturated fats appeared to be the main determinants of successful treatment results. Good aerobic capacity was associated with an increase in HDL cholesterol. A multicentre primary prevention study on IGT patients is continuing in Finland applying the same principles of intervention as used in the study on newly diagnosed NIDDM patients. Pilot results show that glucose tolerance can be improved by lifestyle changes.

Using central cancer-registry data to monitor progress in early detection of breast and cervical cancer (Illinois, United States)

Cases of breast and cervical cancer account for almost 40 percent of all cancers diagnosed in Illinois (United States) women. Information on screening rates, however, is not collected routinely for the populations at risk. This paper reports on surveillance indicators designed to identify target populations and evaluate programs. All cases of cancers of the breast (n = 38,824, including in situ) and invasive cervix (n = 2,763) with a known stage, among women aged 40 to 74, were identified through the population-based Illinois State Cancer Registry for 1986 to 1992. The proportion of breast cancer cases with in situ disease-stage and cervical cancer cases with a late invasive stage were selected as surveillance indicators. Differences by age and race were evaluated, as were age- and race-specific trends. The data suggest that Black women, aged 40 to 74 years, and White women, aged 65 to 74 years, should be targeted for breast-cancer-screening interventions. All women, aged 40 to 74, should be targeted for enhanced cervical-cancer-screening interventions. Significant trends in in situ breast cancer diagnoses were apparent in all age-race groups, however no significant decline in invasive cervical cancer was found for any age-race group. The indicators identified the age- and race-specific disparities among potential target populations for breast and cervical cancer screening.

Insulin and colon cancer

Some factors related to Westernization or industrialization increase risk of colon cancer. It is believed widely that this increase in risk is related to the direct effects of dietary fat and fiber in the colonic lumen. However, the fat and fiber hypotheses, at least as originally formulated, do not explain adequately many emerging findings from recent epidemiologic studies. An alternative hypothesis, that hyperinsulinemia promotes colon carcinogenesis, is presented here. Insulin is an important growth factor of colonic epithelial cells and is a mitogen of tumor cell growth in vitro. Epidemiologic evidence supporting the insulin/colon-cancer hypothesis is largely indirect and based on the similarity of factors which produce elevated insulin levels with those related to colon cancer risk. Specifically, obesity--particularly central obesity, physical inactivity, and possibly a low dietary polyunsaturated fat to saturated fat ratio--are major determinants of insulin resistance and hyperinsulinemia, and appear related to colon cancer risk. Moreover, a diet high in refined carbohydrates and low in water-soluble fiber, which is associated with an increased risk of colon cancer, causes rapid intestinal absorption of glucose into the blood leading to postprandial hyperinsulinemia. The combination of insulin resistance and high glycemic load produces particularly high insulin levels. Thus, hyperinsulinemia may explain why obesity, physical inactivity, and a diet low in fruits and vegetables and high in red meat and extensively processed foods, all common in the West, increase colon cancer risk.