K.M. Venkat Narayan

Impact of Recent Increase in Incidence on Future Diabetes Burden: U.S., 2005–2050

In an earlier study, we had forecasted 39 million with diagnosed diabetes in 2050 in the U.S. (1,2). However, since then, national diabetes incidence increased (3) and the relative risk of death among people with diabetes declined (4,5). These changes will impact future forecasts. Incorporating these changes, we now project 48.3 million people with diagnosed diabetes in the U.S. in 2050. We also present age-, sex-, and race/ethnicity-specific forecasts, with Bayesian CIs, of the number of people with diagnosed diabetes through 2050. We used a discrete-time (1-year intervals), incidence-based Markov model with three states (no diagnosed diabetes, diagnosed diabetes, and death) (1). In each cycle of the model, projections are developed for 808 population subgroups defined by age, sex, and race/ethnicity. We estimated the age-, sex-, and race/ethnicity-specific prevalence and incidence of diabetes from the U.S. National Health Interview Survey (6–9) and modeled data for 1984–2004 to improve the precision of 2004 estimates. Models were fit using Bayesian methods with improper flat priors applied to logistic regression. We assessed adequacy of model fit using posterior predictive P values (10). Estimated prevalence of diagnosed diabetes for 2000 and 2004 were 4.35 and 5.37%, respectively, and estimated incidence were 0.42 and 0.53% per year, respectively. The age-, sex-, and race/ethnicity-specific 2004 prevalence estimates were combined with U.S. population data for 2004 (11 …

Projection of Diabetic Retinopathy and Other Major Eye Diseases Among People With Diabetes Mellitus: United States, 2005-2050

OBJECTIVES To estimate the number of people with diabetic retinopathy (DR), vision-threatening DR (VTDR), glaucoma, and cataracts among Americans 40 years or older with diagnosed diabetes mellitus for the years 2005-2050. METHODS Using published prevalence data of DR, VTDR, glaucoma, and cataracts and data from the National Health Interview Survey and the US Census Bureau, we projected the number of Americans with diabetes with these eye conditions. RESULTS The number of Americans 40 years or older with DR and VTDR will triple in 2050, from 5.5 million in 2005 to 16.0 million for DR and from 1.2 million in 2005 to 3.4 million for VTDR. Increases among those 65 years or older will be more pronounced (2.5 million to 9.9 million for DR and 0.5 million to 1.9 million for VTDR). The number of cataract cases among whites and blacks 40 years or older with diabetes will likely increase 235% by 2050, and the number of glaucoma cases among Hispanics with diabetes 65 years or older will increase 12-fold. CONCLUSION Future increases in the number of Americans with diabetes will likely lead to significant increases in the number with DR, glaucoma, and cataracts. Our projections may help policy makers anticipate future demands for health care resources and possibly guide the development of targeted interventions. CLINICAL RELEVANCE Efforts to prevent diabetes and to optimally manage diabetes and its complications are needed.

Association of Intrauterine Exposure to Maternal Diabetes and Obesity with Type 2 Diabetes in Youth: The SEARCH Case-Control Study

OBJECTIVE—Limited data exist on the association between in utero exposure to maternal diabetes and obesity and type 2 diabetes in diverse youth. These associations were explored in African-American, Hispanic, and non-Hispanic white youth participating in the SEARCH Case-Control Study. RESEARCH DESIGN AND METHODS—A total of 79 youth with type 2 diabetes and 190 nondiabetic control youth aged 10–22 years attended a research visit. In utero exposures to maternal diabetes and obesity were recalled by biological mothers. RESULTS—Youth with type 2 diabetes were more likely to have been exposed to maternal diabetes or obesity in utero than were nondiabetic control youth (P < 0.0001 for each). After adjusting for offspring age, sex, and race/ethnicity, exposure to maternal diabetes (odds ratio [OR] 5.7 [95% CI 2.4–13.4]) and exposure to maternal obesity (2.8 [1.5–5.2]) were independently associated with type 2 diabetes. Adjustment for other perinatal and socioeconomic factors did not alter these associations. When offspring BMI was added, the OR for the association between in utero exposure to obesity and type 2 diabetes was attenuated toward the null (OR 1.1 [0.5–2.4]). Overall, 47.2% (95% CI 30.9–63.5) of type 2 diabetes in youth could be attributed to intrauterine exposure to maternal diabetes and obesity. CONCLUSIONS—Intrauterine exposures to maternal diabetes and obesity are strongly associated with type 2 diabetes in youth. Prevention efforts may need to target, in addition to childhood obesity, the increasing number of pregnancies complicated by obesity and diabetes.

Disparities in HbA1c levels between African-American and non-Hispanic white adults with diabetes: a meta-analysis.

OBJECTIVE—Among individuals with diabetes, a comparison of HbA1c (A1C) levels between African Americans and non-Hispanic whites was evaluated. Data sources included PubMed, Web of Science, the Cumulative Index to Nursing and Allied Health, the Cochrane Library, the Combined Health Information Database, and the Education Resources Information Center. RESEARCH DESIGN AND METHODS—We executed a search for articles published between 1993 and 2005. Data on sample size, age, sex, A1C, geographical location, and study design were extracted. Cross-sectional data and baseline data from clinical trials and cohort studies for African Americans and non-Hispanic whites with diabetes were included. Diabetic subjects aged <18 years and those with pre-diabetes or gestational diabetes were excluded. We conducted a meta-analysis to estimate the difference in the mean values of A1C for African Americans and non-Hispanic whites. RESULTS—A total of 391 studies were reviewed, of which 78 contained A1C data. Eleven had data on A1C for African Americans and non-Hispanic whites and met selection criteria. A meta-analysis revealed the standard effect to be 0.31 (95% CI 0.39–0.25). This standard effect correlates to an A1C difference between groups of ∼0.65%, indicating a higher A1C across studies for African Americans. Grouping studies by study type (cross-sectional or cohort), method of data collection for A1C (chart review or blood draw), and insurance status (managed care or nonmanaged care) showed similar results. CONCLUSIONS—The higher A1C observed in this meta-analysis among African Americans compared with non-Hispanic whites may contribute to disparity in diabetes morbidity and mortality in this population.

Glucose-Independent, Black–White Differences in Hemoglobin A1c Levels: A Cross-sectional Analysis of 2 Studies

BACKGROUND A previous study of participants with prediabetes found that hemoglobin A(1c) (HbA(1c)) levels differed between black and white participants with no differences in glucose concentration. OBJECTIVE To determine whether black-white differences in HbA(1c) level are present in other populations and across the full spectrum of glycemia. DESIGN Cross-sectional, retrospective. SETTING Outpatient. PARTICIPANTS 1581 non-Hispanic black and white participants between 18 and 87 years of age without known diabetes in the SIGT (Screening for Impaired Glucose Tolerance) study and 1967 non-Hispanic black and white participants older than 40 years without known diabetes in the NHANES III (Third National Health and Nutrition Examination Survey). MEASUREMENTS HbA(1c) levels, anthropometry, and plasma glucose levels during oral glucose tolerance testing. RESULTS Hemoglobin A(1c) levels were higher in black than in white participants with normal glucose tolerance (0.13 percentage point [P < 0.001] in the SIGT sample and 0.21 percentage point [P < 0.001] in the NHANES III sample), prediabetes (0.26 percentage point [P < 0.001] and 0.30 percentage point [P < 0.001], respectively), or diabetes (0.47 percentage point [P < 0.020] and 0.47 percentage point [P < 0.013], respectively) after adjustment for plasma glucose levels and other characteristics known to correlate with HbA(1c) levels. LIMITATION The mechanism for the differences is unknown. CONCLUSION Black persons have higher HbA(1c) levels than white persons across the full spectrum of glycemia, and the differences increase as glucose intolerance worsens. These findings could limit the use of HbA(1c) to screen for glucose intolerance, indicate the risk for complications, measure quality of care, and evaluate disparities in health.

Health of foreign-born people in the United States: a review.

This paper identifies the overarching patterns of immigrant health in the US. Most studies indicate that foreign-born individuals are in better health than native-born Americans, including individuals of the same race/ethnicity. They tend to have lower mortality rates and are less likely to suffer from circulatory diseases, overweight/obesity, and some cancers. However, many foreign-born groups have higher rates of diabetes, some infections, and occupational injuries. There is heterogeneity in health among immigrants, whose health increasingly resembles that of natives with duration of US residence. Prospective studies are needed to better understand migrant health and inform interventions for migrant health maintenance.

TYPE 2 DIABETES IN CHILDREN

Type 2 diabetes mellitus in children is an emotionally charged issue and an emerging public health problem. 1 2 Until recently most children with diabetes mellitus had type 1, one of the most common3 and increasingly prevalent4 chronic diseases in children. Increasingly, however, type 2 diabetes is being reported in children from the United States, Canada, Japan, Hong Kong, Australia, New Zealand, Libya, and Bangladesh.5 The prevalence of type 2 diabetes in children ranges from 4.1 per 1000 12-19 year olds in the US to 50.9 per 1000 15-19 year old Pima Indians of Arizona. 1 2 Between 8% and 45% of recently diagnosed cases of diabetes among children and adolescents in the United States is type 2, and the magnitude of this disease may be underestimated. 1 2 The prevalence of the disease is on the rise in North America, and its incidence almost doubled in Japan between 1976-80 and 1991-5—from 7.3 to 13.9 per 100 000 junior high school children.5 These trends coincide with the rising prevalence of overweight and physical …

Prevalence of impaired fasting glucose and its relationship with cardiovascular disease risk factors in US adolescents, 1999-2000.

Objective. PEDIATRICS (ISSN 0031 4005). Published in the public domain by the American Academy of Pediatrics.Several studies have reported increases in the occurrence of type 2 diabetes in youths. People with prediabetic states such as impaired fasting glucose (IFG) are at increased risk for developing diabetes and cardiovascular disease (CVD). The objective of this study was to examine the prevalence of IFG and its relationship with overweight and CVD risk factors in a nationally representative sample of US adolescents who were aged 12 to 19 years. Methods. We used data from the 1999–2000 National Health and Nutrition Examination Survey (NHANES). Adolescents who had fasted for 8 hours or more were included in the study (n = 915). IFG was defined as a fasting glucose of 100 to 125 mg/dL. Participants were classified as overweight when their age- and gender-specific BMI was ≥95th percentile and as at-risk for overweight when their BMI was ≥85th and <95th percentile. Results. In 1999–2000, the prevalence of IFG in US adolescents was 7.0% and was higher in boys than in girls (10.0% vs 4.0%). Prevalence of IFG was higher in overweight adolescents (17.8%) but was similar in those with normal weight and those who were at risk for overweight (5.4% vs 2.8%). The prevalence of IFG was significantly different across racial/ethnic groups (13.0%, 4.2%, and 7% in Mexican Americans, non-Hispanic black individuals, and non-Hispanic white individuals, respectively). Adolescents with IFG had significantly higher mean hemoglobin A1c, fasting insulin, total and low-density lipoprotein cholesterol, triglycerides, and systolic blood pressure and lower high-density lipoprotein cholesterol than those with normal fasting glucose concentrations. Conclusions. These data, representing 27 million US adolescents, reveal a very high prevalence of IFG (1 in 10 boys and 1 in 25 girls) among adolescents; the condition affects 1 in every 6 overweight adolescents. Adolescents with IFG have features of insulin resistance and worsened CVD risk factors. Evidence for prevention is still forthcoming in this age group.

Disparities in A1C Levels Between Hispanic and Non-Hispanic White Adults With Diabetes: A meta-analysis

OBJECTIVE—Hispanics have higher rates of diabetes and diabetes-related complications than do non-Hispanic whites. A meta-analysis was conducted to estimate the difference between the mean values of A1C for these two groups. RESEARCH DESIGN AND METHODS—We executed a PubMed search of articles published from 1993 through July 2007. Data sources included PubMed, Web of Science, Cumulative Index to Nursing and Allied Health, the Cochrane Library, Combined Health Information Database, and Education Resources Information Center. Data on sample size, age, sex, A1C, geographical location, and study design were extracted. Cross-sectional data and baseline data from clinical trials and cohort studies for Hispanics and non-Hispanic whites with diabetes were included. Studies were excluded if they included individuals <18 years of age or patients with pre-diabetes or gestational diabetes. RESULTS—A total of 495 studies were reviewed, of which 73 contained data on A1C for Hispanics and non-Hispanic whites, and 11 met the inclusion criteria. Meta-analysis revealed a statistically significant mean difference (P < 0.0001) of −0.46 (95% CI −0.63 to −0.33), correlating to an ∼0.5% higher A1C for Hispanics. Grouping studies by design (cross-sectional or cohort), method of data collection for A1C (chart review or blood sampling), and care type (managed or nonmanaged) yielded similar results. CONCLUSIONS—In this meta-analysis, A1C was ∼0.5% higher in Hispanic patients with diabetes than in non-Hispanic patients. Understanding the reasons for this disparity should be a focus for future research.

Trends in lifetime risk and years of life lost due to diabetes in the USA, 1985-2011: a modelling study.

BACKGROUND Diabetes incidence has increased and mortality has decreased greatly in the USA, potentially leading to substantial changes in the lifetime risk of diabetes. We aimed to provide updated estimates for the lifetime risk of development of diabetes and to assess the effect of changes in incidence and mortality on lifetime risk and life-years lost to diabetes in the USA. METHODS We incorporated data about diabetes incidence from the National Health Interview Survey, and linked data about mortality from 1985 to 2011 for 598 216 adults, into a Markov chain model to estimate remaining lifetime diabetes risk, years spent with and without diagnosed diabetes, and life-years lost due to diabetes in three cohorts: 1985-89, 1990-99, and 2000-11. Diabetes was determined by self-report and was classified as any diabetes, excluding gestational diabetes. We used logistic regression to estimate the incidence of diabetes and Poisson regression to estimate mortality. FINDINGS On the basis of 2000-11 data, lifetime risk of diagnosed diabetes from age 20 years was 40·2% (95% CI 39·2-41·3) for men and 39·6% (38·6-40·5) for women, representing increases of 20 percentage points and 13 percentage points, respectively, since 1985-89. The highest lifetime risks were in Hispanic men and women, and non-Hispanic black women, for whom lifetime risk now exceeds 50%. The number of life-years lost to diabetes when diagnosed at age 40 years decreased from 7·7 years (95% CI 6·5-9·0) in 1990-99 to 5·8 years (4·6-7·1) in 2000-11 in men, and from 8·7 years (8·4-8·9) to 6·8 years (6·7-7·0) in women over the same period. Because of the increasing diabetes prevalence, the average number of years lost due to diabetes for the population as a whole increased by 46% in men and 44% in women. Years spent with diabetes increased by 156% in men and 70% in women. INTERPRETATION Continued increases in the incidence of diagnosed diabetes combined with declining mortality have led to an acceleration of lifetime risk and more years spent with diabetes, but fewer years lost to the disease for the average individual with diabetes. These findings mean that there will be a continued need for health services and extensive costs to manage the disease, and emphasise the need for effective interventions to reduce incidence. FUNDING None.