Timing and duration of obesity in relation to diabetes: findings from an ethnically diverse, nationally representative sample

Maximum BMI and microvascular complications in a cohort of Japanese patients with type 2 diabetes: the Japan Diabetes Complications Study

AIMS

The aim of this study was to examine the associations between possible indices of obesity based on information on weight history and the incidence of microvascular complications.

METHODS

A cohort of individuals with type 2 diabetes from 59 institutes in Japan was followed for 8years. Patients were classified into three categories according to weight at entrance and past maximum weight: normal (BMI at baseline <25kg/m(2) and maximum BMI <25kg/m(2)), past obesity (BMI at baseline <25kg/m(2) and maximum BMI ≥25kg/m(2)), and current obesity (BMI at baseline ≥25kg/m(2)) groups. The outcomes were diabetic retinopathy and overt nephropathy.

RESULTS

BMI at maximum and baseline of the 1809 patients was 26.5±3.5 and 23.1±3.0kg/m(2) (p<0.01), respectively (23.0±1.6 and 20.6±1.9kg/m(2) for normal, 27.4±2.0 and 22.8±1.4kg/m(2) for past obesity, and 30.1±2.9 and 27.0±1.8kg/m(2) for current obesity). The hazard ratios of past and current obesity compared to normal were 1.92 (95% CI, 1.08-3.41; p=0.03) and 2.21 (1.16-4.22; p=0.02), respectively, for overt nephropathy and 1.38 (1.05-1.83; p=0.02) and 1.64 (1.18-2.28; p<0.01), respectively, for diabetic retinopathy after adjustment for confounders.

CONCLUSIONS

Past obesity as well as current obesity were associated with increased risks of microvascular complications. Further identification of high-risk populations may be possible by classifying normal weight patients by past obesity.

The High Prevalence of Diabetes in a Large Cohort of Patients Drawn From Safety Net Clinics

Introduction

Underserved populations have been overlooked or underrepresented in research based on data from diabetes registries. We estimated diabetes prevalence using a cohort developed from the electronic health records of 3 networks of safety net clinics that provide care to underserved populations.

Methods

ADVANCE (Accelerating Data Value Across a National Community Health Center Network) is a partnership of the OCHIN Community Health Information Network (OCHIN), the Health Choice Network (HCN), and the Fenway Health Institute (FHI), representing 97 federally qualified health centers (FQHCs) and 744 clinic sites in 22 US states. Among 952,316 adults with a body mass index (BMI) measurement and at least 2 outpatient visits in 2012 to 2014, we calculated diabetes prevalence using outpatient diagnoses, diagnostic laboratory results, or dispenses of anti-hyperglycemic agents no more than 730 days apart. We calculated prevalence by age, sex, race, Hispanic ethnicity, and BMI class.

Results

The crude prevalence of diabetes was 14.4%. Men had a higher prevalence than women (16.5% vs 13.2%); diabetes prevalence increased across age categories. White patients had the lowest prevalence (11.4%) and Hawaiian/Pacific Islanders, the highest prevalence (21.9%), with prevalence ranging from 15.2% to 16.5% for other race/ethnicities. The association between BMI class and diabetes prevalence was similar across all racial/ethnic groups.

Conclusion

The ADVANCE diabetes cohort offers an opportunity to conduct epidemiologic and comparative effectiveness research on underserved and underrepresented individuals, who have a higher prevalence of diabetes than the general US population.

Obesity and Cardiovascular Disease

The prevalence of obesity has increased worldwide over the past few decades. In 2013, the prevalence of obesity exceeded the 50% of the adult population in some countries from Oceania, North Africa, and Middle East. Lower but still alarmingly high prevalence was observed in North America (≈30%) and in Western Europe (≈20%). These figures are of serious concern because of the strong link between obesity and disease. In the present review, we summarize the current evidence on the relationship of obesity with cardiovascular disease (CVD), discussing how both the degree and the duration of obesity affect CVD. Although in the general population, obesity and, especially, severe obesity are consistently and strongly related with higher risk of CVD incidence and mortality, the one-size-fits-all approach should not be used with obesity. There are relevant factors largely affecting the CVD prognosis of obese individuals. In this context, we thoroughly discuss important concepts such as the fat-but-fit paradigm, the metabolically healthy but obese (MHO) phenotype and the obesity paradox in patients with CVD. About the MHO phenotype and its CVD prognosis, available data have provided mixed findings, what could be partially because of the adjustment or not for key confounders such as cardiorespiratory fitness, and to the lack of consensus on the MHO definition. In the present review, we propose a scientifically based harmonized definition of MHO, which will hopefully contribute to more comparable data in the future and a better understanding on the MHO subgroup and its CVD prognosis.

Health Issues in Hispanic/Latino Youth

This review focuses on obesity, asthma and mental health functioning as salient health issues affecting Hispanic youth. Burden of these conditions and consequences for adult health are also discussed. Hispanic youth are affected by obesity at an early age; the prevalence of obesity among Hispanic children 6-11 years old is twice as high as the prevalence for non-Hispanic White children of the same age, but among 2-5 years old is 4 times higher. Asthma disproportionally affects certain Hispanic groups, notably children of Puerto Rican ancestry, and the comorbidity of asthma and obesity is an emerging health issue. Another area of concern is the scant data on mental health functioning among Hispanic youth. Research on Hispanic youth mental health have reported high rates of depressive symptomatology and high rates of alcohol use among Hispanic adolescents but despite these findings, they have inadequate access to mental health services. This review highlights the need for better data to gain a better understanding of the health status of Hispanic youth and help develop preventive programs that addresses the need of this population. Improving access to health services, in particular mental health services, is also a crucial aspect.

The influence of early-life conditions on cardiovascular disease later in life among ethnic minority populations: a systematic review

Ethnic minority groups are disproportionately affected by cardiovascular diseases (CVDs). The reasons for the high prevalence of CVD in ethnic minority groups are not fully understood. Recently, the importance of early-life developmental factors and their impact on CVDs in adulthood is increasingly being recognised, but little is known about this among ethnic minority groups. Therefore, the current paper aimed to fill this knowledge gap by reviewing the available literature to assess the influence of early-life conditions on CVDs and its risk factors in ethnic minority populations residing in Western countries. A systematic search was performed in PubMed and EMBASE between 1989 and 2014. In total, 1418 studies were identified of which 19 met the inclusion criteria. Six studies investigated the relationship between early-life anthropometrics and CVD risk factors of which all except one found significant associations between the assessed anthropometric measures and CVD risk factors. Seven studies evaluated the influence of childhood socio-economic status (SES) on CVD and risk factors of which five found significant associations between childhood SES measures and CVD risk factors. Five studies investigated the relationship between other early-life conditions including early-life nutrition, physical development, and childhood psychosocial conditions, and CVD risk factors. Four of these studies found significant associations between the assessed childhood conditions and CVD risk factors. This review reinforces the importance of early-life conditions on adult CVD in ethnic minority groups. Improvement of early-life conditions among ethnic minority groups may contribute to reducing CVD risk in these populations.

Duration and Degree of Weight Gain and Incident Diabetes in Younger Versus Middle-Aged Black and White Adults: ARIC, CARDIA, and the Framingham Heart Study

OBJECTIVE

To determine whether duration and degree of weight gain are differentially associated with diabetes risk in younger versus middle-aged black and white adults.

RESEARCH DESIGN AND METHODS

We combined data from three cohort studies: Atherosclerosis Risk in Communities (ARIC), Coronary Artery Risk Development in Young Adults (CARDIA), and the Framingham Heart Study. A total of 17,404 participants (56% women; 21% black) were stratified by baseline age (younger: ≥30 and <45 years; middle-aged: ≥45 and <60 years) and examined for incident diabetes (median follow-up 9 years). Duration and degree of gain in BMI were calculated as "BMI-years" above one's baseline BMI.

RESULTS

Diabetes incidence per 1,000 person-years in the younger and middle-aged groups was 7.2 (95% CI 5.7, 8.7) and 24.4 (22.0, 26.8) in blacks, respectively, and 3.4 (2.8, 4.0) and 10.5 (9.9, 11.2) in whites, respectively. After adjusting for sex, baseline BMI and other cardiometabolic factors, and age and race interaction terms, gains in BMI-years were associated with higher risk of diabetes in the younger compared with middle-aged groups: hazard ratios for 1-unit increase in log BMI-years in younger versus middle-aged blacks were 1.18 (P = 0.02) and 1.02 (P = 0.39), respectively (P for interaction by age-group = 0.047), and in whites were 1.35 (P < 0.001) and 1.11 (P < 0.001), respectively (P for interaction by age-group = 0.008).

CONCLUSIONS

Although middle-aged adults have higher rates of diabetes, younger adults are at greater relative risk of developing diabetes for a given level of duration and degree of weight gain.

Body mass index in early and middle adult life: prospective associations with myocardial infarction, stroke and diabetes over a 30-year period: the British Regional Heart Study

OBJECTIVES

Adiposity in middle age is an established risk factor for cardiovascular disease and type 2 diabetes; less is known about the impact of adiposity from early adult life. We examined the effects of high body mass index (BMI) in early and middle adulthood on myocardial infarction (MI), stroke and diabetes risks.

DESIGN

A prospective cohort study.

PARTICIPANTS

7735 men with BMI measured in middle age (40-59 years) and BMI ascertained at 21 years from military records or participant recall.

PRIMARY AND SECONDARY OUTCOME MEASURES

30-year follow-up data for type 2 diabetes, MI and stroke incidence; Cox proportional hazards models were used to examine the effect of BMI at both ages on these outcomes, adjusted for age and smoking status.

RESULTS

Among 4846 (63%) men (with complete data), a 1 kg/m(2) higher BMI at 21 years was associated with a 6% (95% CI 4% to 9%) higher type 2 diabetes risk, compared with a 21% (95% CI 18% to 24%) higher diabetes risk for a 1 kg/m(2) higher BMI in middle age (hazard ratio (HR) 1.21, 95% CI 1.18 to 1.24). Higher BMI in middle age was associated with a 6% (95% CI 4% to 8%) increase in MI and a 4% (95% CI 1% to 7%) increase in stroke; BMI at 21 years showed no associations with MI or stroke risk.

CONCLUSIONS

Higher BMI at 21 years of age is associated with later diabetes incidence but not MI or stroke, while higher BMI in middle age is strongly associated with all outcomes. Early obesity prevention may reduce later type 2 diabetes risk, more than MI and stroke.

Insulin resistance is associated with epigenetic and genetic regulation of mitochondrial DNA in obese humans

Background

Mitochondrial alterations have been observed in subjects with metabolic disorders such as obesity and diabetes. Studies on animal models and cell cultures suggest aberrant glucose and lipid levels, and impaired insulin signaling might lead to mitochondrial changes. However, the molecular mechanism underlying mitochondrial aberrance remains largely unexplored in human subjects.

Results

Here we show that the mitochondrial DNA copy number (mtDNAn) was significantly reduced (6.9-fold lower, p < 0.001) in the leukocytes from obese humans (BMI >30). The reduction of mtDNAn was strongly associated with insulin resistance (HOMA-IR: −0.703, p < 0.05; fasting insulin level: −0.015, p < 0.05); by contrast, the correlation between fasting glucose or lipid levels and mtDNAn was not significant. Epigenetic study of the displacement loop (D-loop) region of mitochondrial genome, which controls the replication and transcription of the mitochondrial DNA as well as organization of the mitochondrial nucleoid, revealed a dramatic increase of DNA methylation in obese (5.2-fold higher vs. lean subjects, p < 0.05) and insulin-resistant (4.6-fold higher vs. insulin-sensitive subjects, p < 0.05) individuals.

Conclusions

The reduction of mtDNAn in obese human subjects is associated with insulin resistance and may arise from increased D-loop methylation, suggesting an insulin signaling-epigenetic-genetic axis in mitochondrial regulation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0093-1) contains supplementary material, which is available to authorized users.

Long-term weight change: association with impaired glucose metabolism in young Austrian adults

Little is known about the associations between long-term weight change and the natural history of impaired fasting glucose (IFG) in young adults. We investigated the association between long-term body mass index (BMI) change and the risk of IFG using data of 24,930 20- to 40-year-old participants from the Vorarlberg Health Monitoring and Promotion Program (VHM&PP) cohort. Poisson models were applied to estimate the 10-year risk for new development of IFG (≥ 5.6 mmol/L), and persistence of IFG. Over 10 years, most men (68.2%) and women (70.0%) stayed within their initial BMI category. The risk for incident IFG was highest for men and women with persisting obesity (37.4% and 24.1%) and lowest with persisting normal weight (15.7% and 9.3%). Men transitioning from normal to overweight increased their risk of incident IFG by factor 1.45 (95%-CI: 1.31, 1.62), women by 1.70 (95%-CI: 1.50, 1.93), whereas transitioning from overweight to normal weight decreased the risk in men by 0.69 (95%-CI: 0.53, 0.90) and 0.94 (95%-CI: 0.66, 1.33) in women. Relative risks for men and women transitioning from obesity to overweight were 0.58 and 0.44, respectively. In conclusion, 10 year weight increase was associated with an increased IFG risk, weight decrease with a decreased risk of IFG in young adults.

The role of obesity duration on the association between obesity and risk of physical disability

OBJECTIVE

To relate measured obesity duration in mid-life with subsequent incidence of physical disability over and above body mass index (BMI) attained.

METHODS

Framingham Offspring Study is a longitudinal study that began in 1971. Examination 5 (1991-1995; "baseline") and disability onset ascertained from examinations 6-8 (2008) were used. About 2,095 disability-free participants aged 45-65 years at baseline were included. Obesity (BMI ≥ 30 kg/m(2) ) duration was calculated between examination 1 and examination 5. Cox regression was used to analyze time to disability.

RESULTS

204 participants developed disability (incidence rate=7.9 per 1,000 person-years). Obesity duration ranged from 0 to 22 years (mean of 2.0 years overall, 8.3 years for those with baseline obesity). Obesity duration increased risk of new disability (hazard ratio [HR] 1.07 per year of obesity; 95% confidence interval [CI] 1.05-1.09). This association was attenuated on further adjustment for baseline BMI (HR 1.03; 95% CI 1.00-1.06).

CONCLUSIONS

Being obese for longer during mid-life increases the risk of later-life disability over and above attained BMI. These results support the need for prevention of weight gain in young adults to avoid an increasing burden of physical disability in later life.

Childhood body mass index in relation to future risk of oesophageal adenocarcinoma

Background:

Middle-aged obese adults are at substantially elevated risk of oesophageal adenocarcinoma. It is unclear whether this risk originates earlier in life.

Methods:

We assessed associations between childhood body mass index (BMI) and height—measured annually between ages 7 and 13—with adult oesophageal adenocarcinoma in a cohort from the Copenhagen School Health Records Register. Analyses included 255 053 children born during 1930–1971. Danish Cancer Registry linkage provided outcomes. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression.

Results:

During 5.4 million person-years of follow-up, 254 (216 males) incident oesophageal adenocarcinomas occurred. At each examined age, cancer risk increased linearly per unit BMI z-score, although associations were only statistically significant for ages 9–13. The HR for the age of 13 years was 1.31 (95% CI: 1.13, 1.51) per unit BMI z-score. Associations were similar in men and women and across birth cohorts. Childhood height was not related to cancer risk in men but was in women, although these analyses included just 38 female cases. HRs per unit height z-score at the age of 13 years were 1.04 (0.90, 1.19) in males and 1.77 (1.27, 2.47) in females, with similar results observed at the other examined ages.

Conclusion:

Individuals with higher childhood BMI were at elevated risk of oesophageal adenocarcinoma, even though these cancers occurred many decades later in life. Although the mechanisms require further investigation, our findings provide additional evidence for the long-term health risks of childhood obesity.

Trajectory of body mass index before the development of type 2 diabetes in Japanese men: Toranomon Hospital Health Management Center Study 15

Aims/Introduction

We aimed to investigate the long-term trajectory of general adiposity assessed by the body mass index (BMI) before the onset of type 2 diabetes in Japanese individuals.

Materials and Methods

We retrospectively examined data on 1,553 Japanese men without diabetes. Mean BMI and incident cases of diabetes (diabetes indicated by fasting glucose concentrations ≥7.0 mmol/L, a self-reported history of clinician-diagnosed diabetes, or glycated hemoglobin ≥6.5% (≥48 mmol/mol) were assessed on an annual basis over a 10-year period after the baseline examination.

Results

Mean (standard deviation) BMI at the time of diagnosis was 24.4 kg/m² (3.1 kg/m²) among cases of diabetes (n = 191). An increasingly high BMI was associated with the early stage of the disease development, such as an 8- to 10-year prediagnosis period; individuals who developed diabetes experienced a prolonged and stable elevated BMI of ≥24.4 kg/m² over the 8 years before the diagnosis of diabetes. The mean BMI among the non-cases of diabetes did not exceed 23.2 kg/m² throughout the period.

Conclusions

These results suggested that Japanese men who eventually developed diabetes during the 10-year observation period were not characterized as obese, but had stable high-normal BMIs before the onset of diabetes. Previous evidence showed that values for glycemic markers rapidly increased before the development of diabetes; however, the present study showed a slight gain in BMI in the earlier stage of the natural history of diabetes followed by a prolonged period of overweight.

Lifestyle interventions to reduce diabetes and cardiovascular disease risk among children

Diseases once associated with older adulthood, type 2 diabetes and cardiovascular disease, are increasingly diagnosed in children and adolescents. Interventions designed to assist adults in modifying dietary and physical activity habits have been shown to help prevent the development of type 2 diabetes and cardiovascular disease in adults. Given the unfortunate rise in both of these diseases in pediatric populations, it is increasingly important to begin prevention efforts in childhood or prenatally. There is strong empirical support for utilizing lifestyle interventions to prevent these diseases in adults; it is not clear whether the same holds true for pediatric populations. The present review examines lifestyle management efforts to prevent type 2 diabetes and cardiovascular disease in children across socioecological levels. Recommendations are made for expanding the traditional focus of lifestyle interventions from dietary and physical activity behaviors to target additional risks for these diseases such as smoking and depression in youth.

Status of cardiovascular disease and stroke in Hispanics/Latinos in the United States: a science advisory from the American Heart Association

BACKGROUND AND PURPOSE

This American Heart Association (AHA) scientific statement provides a comprehensive overview of current evidence on the burden cardiovascular disease (CVD) among Hispanics in the United States. Hispanics are the largest minority ethnic group in the United States, and their health is vital to the public health of the nation and to achieving the AHA's 2020 goals. This statement describes the CVD epidemiology and related personal beliefs and the social and health issues of US Hispanics, and it identifies potential prevention and treatment opportunities. The intended audience for this statement includes healthcare professionals, researchers, and policy makers.

METHODS

Writing group members were nominated by the AHA's Manuscript Oversight Committee and represent a broad range of expertise in relation to Hispanic individuals and CVD. The writers used a general framework outlined by the committee chair to produce a comprehensive literature review that summarizes existing evidence, indicate gaps in current knowledge, and formulate recommendations. Only English-language studies were reviewed, with PubMed/MEDLINE as our primary resource, as well as the Cochrane Library Reviews, Centers for Disease Control and Prevention, and the US Census data as secondary resources. Inductive methods and descriptive studies that focused on CVD outcomes incidence, prevalence, treatment response, and risks were included. Because of the wide scope of these topics, members of the writing committee were responsible for drafting individual sections selected by the chair of the writing committee, and the group chair assembled the complete statement. The conclusions of this statement are the views of the authors and do not necessarily represent the official view of the AHA. All members of the writing group had the opportunity to comment on the initial drafts and approved the final version of this document. The manuscript underwent extensive AHA internal peer review before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

This statement documents the status of knowledge regarding CVD among Hispanics and the sociocultural issues that impact all subgroups of Hispanics with regard to cardiovascular health. In this review, whenever possible, we identify the specific Hispanic subgroups examined to avoid generalizations. We identify specific areas for which current evidence was less robust, as well as inconsistencies and evidence gaps that inform the need for further rigorous and interdisciplinary approaches to increase our understanding of the US Hispanic population and its potential impact on the public health and cardiovascular health of the total US population. We provide recommendations specific to the 9 domains outlined by the chair to support the development of these culturally tailored and targeted approaches.

CONCLUSIONS

Healthcare professionals and researchers need to consider the impact of culture and ethnicity on health behavior and ultimately health outcomes. There is a need to tailor and develop culturally relevant strategies to engage Hispanics in cardiovascular health promotion and cultivate a larger workforce of healthcare providers, researchers, and allies with the focused goal of improving cardiovascular health and reducing CVD among the US Hispanic population.

The dynamics of diabetes among birth cohorts in the U.S

OBJECTIVE Using a nationally representative sample of the civilian noninstitutionalized U.S. population, we estimated trends in diabetes prevalence across cohorts born 1910-1989 and provide the first estimates of age-specific diabetes incidence using nationally representative, measured data. RESEARCH DESIGN AND METHODS Data were from 40,130 nonpregnant individuals aged 20-79 years who participated in the third National Health and Nutrition Examination Survey (NHANES III), 1988-1994, and the continuous 1999-2010 NHANES. We defined diabetes as HbA1c ≥6.5% (48 mmol/mol) or taking diabetes medication. We estimated age-specific diabetes prevalence for the 5-year age-groups 20-24 through 75-79 for cohorts born 1910-1919 through 1980-1989 and calendar periods 1988-1994, 1999-2002, 2003-2006, and 2007-2010. We modeled diabetes prevalence as a function of age, calendar year, and birth cohort, and used our cohort model to estimate age-specific diabetes incidence. RESULTS Age-adjusted diabetes prevalence rose by a factor of 4.9 between the birth cohorts of 1910-1919 and 1980-1989. Diabetes prevalence rose with age within each birth cohort. Models based on birth cohorts show a steeper age pattern of diabetes prevalence than those based on calendar years. Diabetes incidence peaks at 55-64 years of age. CONCLUSIONS Diabetes prevalence has risen across cohorts born through the 20th century. Changes across birth cohorts explain the majority of observed increases in prevalence over time. Incidence peaks between 55 and 64 years of age and then declines at older ages.

The association of depression and anxiety with glycemic control among Mexican Americans with diabetes living near the U.S.-Mexico border

BACKGROUND

The prevalence of diabetes is alarmingly high among Mexican American adults residing near the U.S.-Mexico border. Depression is also common among Mexican Americans with diabetes, and may have a negative influence on diabetes management. Thus, the purpose of the current study was to evaluate the associations of depression and anxiety with the behavioral management of diabetes and glycemic control among Mexican American adults living near the border.

METHODS

The characteristics of Mexican Americans with diabetes living in Brownsville, TX (N = 492) were compared by depression/anxiety status. Linear regression models were conducted to evaluate the associations of depression and anxiety with BMI, waist circumference, physical activity, fasting glucose, and glycated hemoglobin (HbA1c).

RESULTS

Participants with clinically significant depression and/or anxiety were of greater age, predominantly female, less educated, more likely to have been diagnosed with diabetes, and more likely to be taking diabetes medications than those without depression or anxiety. In addition, anxious participants were more likely than those without anxiety to have been born in Mexico and to prefer study assessments in Spanish rather than English. Greater depression and anxiety were associated with poorer behavioral management of diabetes (i.e., greater BMI and waist circumference; engaging in less physical activity) and poorer glycemic control (i.e., higher fasting glucose, HbA1c).

CONCLUSIONS

Overall, depression and anxiety appear to be linked with poorer behavioral management of diabetes and glycemic control. Findings highlight the need for comprehensive interventions along the border which target depression and anxiety in conjunction with diabetes management.

Relationship between glycated haemoglobin and subclinical atherosclerosis in obese children and adolescents

OBJECTIVE

To explore the relationship between glycated haemoglobin A1C (HbA1C) and subclinical atherosclerosis as assessed by carotid intima-media thickness (cIMT) in Chinese Han obese children and adolescents without diabetes.

METHODS

A total of 524 obese children and adolescents without diabetes were analysed. All participants underwent HbA1C measurements, oral glucose tolerance tests and ultrasound measurements of cIMT. The logistic regression models were implemented to evaluate the adjusted OR of HbA1C for increased cIMT.

RESULTS

In obese boys, HbA1C was associated with increased cIMT independently of age, measurements of anthropometry, blood pressure, plasma lipid and lipoprotein, fasting plasma glucose, 2 h postchallenge glucose, uric acid and hepatic function. After adjustment for all these risk factors, the OR of increased cIMT for every 1% (11 mmol/mol) increase in HbA1C was 2.702 (95% CI 1.640 to 4.452). However, in girls, the major risk factor independently associated with cIMT was measurement of abdominal obesity instead of HbA1C.

CONCLUSIONS

Our research suggests that the adoption of HbA1C as a diagnostic criterion of prediabetes and diabetes in obese boys may help to identify early macrovascular complications.

The growing prevalence of type 2 diabetes: increased incidence or improved survival?

Approximately 347 million persons were estimated to have diabetes worldwide in 2008, an increase of 194 million cases from 1980. Diabetes now affects both high- and low-income countries, with low-income countries bearing the majority of the burden. The epidemiologic transition from traditional health risks, such as poor hygiene, to modern health risks, such as sedentary lifestyle, has facilitated the increase in incidence in diabetes, especially in developing countries. The effect of these risk factors may be especially pronounced in some racial and ethnic populations. Increased surveillance for diabetes has contributed to increased diabetes prevalence in higher-income countries. Survival with and some risk factors for diabetes have improved in developed countries, but global diabetes mortality has increased by 20 % since 1990. Population growth and aging will only increase the burden of diabetes, and public health interventions are needed to address diabetes risk factors to stem the tide of this epidemic.

Cost analysis of maternal disease associated with suboptimal breastfeeding

OBJECTIVE

To estimate the U.S. maternal health burden from current breastfeeding rates both in terms of premature death as well as economic costs.

METHODS

Using literature on associations between lactation and maternal health, we modeled the health outcomes and costs expected for a U.S. cohort of 15-year-old females followed to age 70 years. In 2002, this cohort included 1.88 million individuals. Using Monte Carlo simulations, we compared the outcomes expected if 90% of mothers were able to breastfeed for at least 1 year after each birth with outcomes under the current 1-year breastfeeding rate of 23%. We modeled cases of breast cancer, premenopausal ovarian cancer, hypertension, type 2 diabetes mellitus, and myocardial infarction considering direct costs, indirect costs, and cost of premature death (before age 70 years) expressed in 2011 dollars.

RESULTS

If observed associations between breastfeeding duration and maternal health are causal, we estimate that current breastfeeding rates result in 4,981 excess cases of breast cancer, 53,847 cases of hypertension, and 13,946 cases of myocardial infarction compared with a cohort of 1.88 million U.S. women who optimally breastfed. Using a 3% discount rate, suboptimal breastfeeding incurs a total of $17.4 billion in cost to society resulting from premature death (95% confidence interval [CI] $4.38-24.68 billion), $733.7 million in direct costs (95% CI $612.9-859.7 million), and $126.1 million indirect morbidity costs (95% CI $99.00-153.22 million). We found a nonsignificant difference in number of deaths before age 70 years under current breastfeeding rates (4,396 additional premature deaths, 95% CI -810-7,918).

CONCLUSIONS

Suboptimal breastfeeding may increase U.S. maternal morbidity and health care costs. Thus, investigating whether the observed associations between suboptimal breastfeeding and adverse maternal health outcomes are causal should be a research priority.