Race and ethnicity: vital constructs for diabetes research

Effect of lifestyle intervention on HbA1c levels in overweight and obese adults with type 2 diabetes across ethnicities: A systematic review and meta-analysis of randomized controlled trials

AIMS

Weight reduction is fundamental for the management and remission of diabetes. We aimed to assess ethnic differences in the effects of lifestyle weight-loss interventions on HbA1c levels in overweight or obese adults with type 2 diabetes mellitus (T2DM).

METHODS

We systematically searched PubMed/MEDLINE and Web of Science online databases up to 31 Dec 2022. Randomized controlled trials using lifestyle weight-loss interventions in overweight or obese adults with T2DM were selected. We performed subgroup analyses to explore the heterogeneity across different ethnicities (Asians, White/Caucasians, Black/Africans and Hispanics). A random effects model was applied to calculate weighted mean difference (WMD) with 95% confidence interval (CI).

RESULTS

Thirty studies including 7580 subjects from different ethnicities were identified according to the predefined inclusion and exclusion criteria. HbA1c levels were significantly reduced by lifestyle weight-loss intervention. Notably, a significantly beneficial effect on HbA1c was observed in White/Caucasians (WMD = -0.59, 95% CI: -0.90, -0.28, P < 0.001) and Asians (WMD = -0.48, 95% CI: -0.63, -0.33, P < 0.001), but not in the Black/African or Hispanic group (both P > 0.05). The findings remained essentially unchanged in the sensitivity analysis.

CONCLUSIONS

Lifestyle weight-loss interventions had distinct beneficial effects on HbA1c levels in different ethnic groups with T2DM, especially in Caucasians and Asians.

A mixed-methods approach to understanding the perspectives, experiences, and attitudes of a culturally tailored cognitive behavioral therapy/motivational interviewing intervention for African American patients with type 2 diabetes: a randomized parallel design pilot study

Background

African American (AA) adults are 60% more likely to be diagnosed with diabetes mellitus (DM) and experience more complications than non-Hispanic White adults. Cognitive behavioral therapy (CBT) has shown to be an effective modality for helping patients improve health behaviors and regulate emotional states. Motivational interviewing (MI) addresses participant engagement and motivation. Therefore, MI was combined with CBT as an approach to the process of learning using CBT skills to promote healthy lifestyle choices. We aimed to assess the effects of a culturally tailored CBT/MI intervention on glycemic control in AA participants and understand their perspectives, attitudes, and experiences while participating in this intervention.

Methods

Using a randomized, parallel design pilot study (web-based group vs in-person group), 20 participants aged ≥ 18 years, identifying as AA and having a glycosylated hemoglobin (HbA1c) > 8%, were recruited. A CBT/MI intervention was administered in six sessions over 3 months. Participants completed baseline and follow-up assessments on measures for diabetes control (HbA1c), self-efficacy, generalized anxiety, depression, perceived stress, health-related quality of life, and cognitive ability. Post-CBT/MI intervention focus groups were conducted to determine patient perspectives regarding the intervention.

Results

Fourteen participants completed the study, their mean HbA1c improved from 10.0 to 8.9% (t(26) = 0.5, p-value = 0.06). The Diabetes Distress Scale demonstrated decreased distress overall (t(26) = 2.6; p-value = 0.02). The Generalized Anxiety Disorder Scale demonstrated decreased generalized anxiety for all participants (t(26) = 2.2; p = 0.04). Themes identified in focus groups included (1) intervention group social support through information sharing, (2) mental health and personal identities in diabetes understanding and management, and (3) receptivity to CBT/MI intervention positively impacts self-efficacy through improved health literacy.

Conclusion

This group-based, culturally tailored CBT/MI intervention for type 2 DM care was positively received by AA participants and helped improve diabetes control, as demonstrated by the change in HbA1c. There were additional benefits of social support through group interactions and a stronger sense of self-efficacy due to health education. A comprehensive treatment plan using a CBT/MI intervention may be useful in promoting healthy diabetes self-management.

Trial registration

ClinicalTrials.gov, NCT03562767. Registered on 19 June 2018

Racial/ethnic differences in the burden of type 2 diabetes over the life course: a focus on the USA and India

Type 2 diabetes is a common disease worldwide, but its prevalence varies widely by geographical region and by race/ethnicity. This review summarises differences in the frequencies of type 2 diabetes according to race, ethnicity, socioeconomic position, area of residence and environmental toxins. Type 2 diabetes susceptibility often begins early in life, starting with genetic susceptibility at conception and continuing in later life, via in utero, childhood and adult exposures. Early-life factors may lead to overt type 2 diabetes in childhood or in later life, supporting the concept of developmental origins of health and disease. The causes of the racial/ethnic differences in incidence of type 2 diabetes are not well understood. Specifically, the relative contributions of genetic and environmental factors to such differences are largely unknown. With a few exceptions in isolated populations, there is little evidence that differences in frequencies of known type 2 diabetes susceptibility genetic alleles account for racial/ethnic differences, although the search for genetic susceptibility has not been uniform among the world's racial/ethnic groups. In the USA, race/ethnicity is associated with many other risk factors for type 2 diabetes, including being overweight/obese, diet and socioeconomic status. Some studies suggest that some of these factors may account for the race/ethnic differences in prevalence of type 2 diabetes, although there is inadequate research in this area. A better understanding of the impact of these factors on type 2 diabetes risk should lead to more effective prevention and treatment of this disease. This has not yet been achieved but should be a goal for future research.

Diagnosis and surgical delays in African American and white women with early-stage breast cancer

BACKGROUND

Delays in diagnosis and treatment for breast cancer may contribute to excess deaths among African Americans. We examined racial differences in delays in diagnosis and surgical treatment for early-stage breast cancer and evaluated race-specific predictors associated with delay.

METHODS

A retrospective cohort study was conducted among 634 African American and white women diagnosed with invasive breast cancer between 2005 and 2010 in New Jersey. Detailed medical-chart abstraction and patient interviews were undertaken. Time intervals were calculated from symptom recognition to diagnosis (diagnosis delay) and from diagnosis to first operation (surgical delay). Binomial regression models were used to examine racial differences in delay and factors associated with ≥2 months delay in the overall population and stratified by race. Reasons responsible for diagnosis delay were also examined by race.

RESULTS

Compared to white women, African American women experienced significantly higher risk of ≥2 months delay in diagnosis and surgical treatment (adjusted relative risks=1.44 (1.12-1.86) and 3.08 (1.88-5.04), respectively). For the African Americans, predictors of diagnosis delay included mode of detection, insurance, and tumor size; for whites, mode of detection and tumor grade. Surgical delay was associated with operation type and education among African Americans but with operation type and tumor size for whites. Patient-related factors were commonly noted as reasons for diagnosis delay.

CONCLUSIONS

These findings emphasize the need to raise further awareness, especially among African American patients and their providers, of the importance of prompt evaluation and treatment of breast abnormalities. Research on effective ways to accomplish this is needed.

The potential for measuring ethnicity and health in a multicultural milieu--the case of type 2 diabetes in Australia

OBJECTIVE

Ethnicity influences health in many ways. For example, type 2 diabetes (T2DM) is disproportionately prevalent among certain ethnic groups. Assessing ethnicity is difficult, and numerous proxy measures are used to capture its various components. Australian guidelines specify a set of variables for measuring ethnicity, and how such parameters should be categorised. Using T2DM data collections as an illustrative example, this study sought to examine how ethnicity is measured in Australian health databases and, by comparing current practice with Australia's existing benchmark recommendations, to identify potential areas for improvement of the health data landscape.

DESIGN

We identified databases containing information from which ethnic group-specific estimates of T2DM burden may be gleaned. For each database, details regarding ethnicity variables were extracted, and compared with the Australian guidelines.

RESULTS

Data collection instruments for 32 relevant databases were reviewed. Birthplace was recorded in 27 databases (84%), but mode of birthplace assessment varied. Indigenous status was commonly recorded (78%, n=25), but only nine databases recorded other aspects of self-perceived race/ethnicity. Of 28 survey/audit databases, 14 accommodated linguistic preferences other than English, and 11 either excluded non-English speakers or those for whom a translator was not available, or only offered questionnaires in English.

CONCLUSIONS

Considerable variation exists in the measurement of ethnicity in Australian health data-sets. While various markers of ethnicity provide complementary information about the ethnic profile within a data-set, non-uniform measurement renders comparison between data-sets difficult. A standardised approach is necessary, and identifying the ethnicity variables that are particularly relevant to the health sector is warranted. Including self-identified ethnicity in Australia's set of recommended indicators and as a core component of the national census should be considered. Globalisation and increasing migration mean that these findings have implications internationally, including for multi-ethnic countries throughout North America and Europe.

Body size preference among Yoruba in three Nigerian communities

Following our previous observation of an aversion to weight reduction in Nigerians with type 2 diabetes, we measured several parameters of body dimensions and preferences in otherwise healthy adults in three communities to study the phenomenon further. The study population of 524 participants (304 F) was 99.8% of Yoruba ethnic origin with a mean age of 43.9 ± 17.2 years. Females had a significantly (p > 0.001) higher body mass index (BMI), waist circumference, hip circumference compared to the males; the values being 24.55 ± 5.5 vs. 21.75 ± 3.71 kg/m(2); 84.98 ± 12.67 vs. 80.92 ± 9.85 cm; 96.32 ± 12.94 vs. 89.36 ± 8.06 cm, respectively. There was a high level of satisfaction amongst respondents with their body size (Kendall's t = 0.52, p < 0.001) which they also predicted with a high degree of certainty even without the prior use of a weighing scale. The relationship between current body size (CBI) and BMI emerged as CBI = 1.22 + 0.32 BMI. In the 41% of respondents who expressed unhappiness with their current body size, there was a strong aversion for a smaller body size and the preference was often for a bigger body figure. Strikingly, many more women than men were less dissatisfied with their bigger body sizes. Stepwise regression indicated that CBI and gender were the two most important variables that best related to casual blood sugar (RBS) among the factors entered. The mathematical relationship between these variables that emerged was: [Formula: see text] where gender = 0 for male and 1 for female. The results suggest that larger body sizes were positively viewed in these communities consistent with our previous observations in type 2 diabetes.

Race/ethnic difference in diabetes and diabetic complications

Health disparities in diabetes and its complications and comorbidities exist globally. A recent Endocrine Society Scientific Statement described the Health Disparities in several endocrine disorders, including type 2 diabetes. In this review, we summarize that statement and provide novel updates on race/ethnic differences in children and adults with type 1 diabetes, children with type 2 diabetes, and in Latino subpopulations. We also review race/ethnic differences in the epidemiology of diabetes, prediabetes, and diabetes complications and mortality in the United States and globally. Finally, we discuss biological, behavioral, social, environmental, and health system contributors to diabetes disparities to identify areas for future preventive interventions.

Assimilation and health service utilization of Korean immigrant women

In this case study, I present descriptive findings with regard to immigrant incorporation and health service utilization. Using focus groups and survey of Korean immigrant women in Wisconsin, I examine whether the ways in which they adapt to the U.S. society is relevant to their health services utilization and the alternatives they seek when available health services are less than satisfactory. The findings suggest that adherence to Korean identity appears to be associated with health service utilization. This is evident in the immigrants' evaluation of the U.S. health services as compared to those of Korea, and the consideration given by these immigrants to seeking health services in Korea instead of the United States. Such concerns on the part of these immigrants have important implications for health researchers, as they highlight the significance of immigrants' transnational experiences and their sense of personal agency in the use of health care.

Disparity implications of the Medicare medication therapy management eligibility criteria: a literature review

The emphasis on eliminating racial and ethnic disparities in healthcare has received national attention, with various policy initiatives addressing this problem and proposing solutions. However, in the current economic era requiring tight monetary constraints, emphasis is increasingly being placed on economic efficiency, which often conflicts with the equality doctrine upon which many policies have been framed. The authors' review aims to highlight the disparity implications of one such policy provision - the predominantly utilization-based eligibility criteria for medication therapy management services under Medicare Part D - by identifying studies that have documented racial and ethnic disparities in health status and the use of and spending on prescription medications. Future design and evaluation of various regulations and legislations employing utilization-based eligibility criteria must use caution in order to strike an equity-efficiency balance.

Elevated rates of diabetes in Pacific Islanders and Asian subgroups: The Diabetes Study of Northern California (DISTANCE)

OBJECTIVE

We estimated the prevalence and incidence of diabetes among specific subgroups of Asians and Pacific Islanders (APIs) in a multiethnic U.S. population with uniform access to care.

RESEARCH DESIGN AND METHODS

This prospective cohort analysis included 2,123,548 adult members of Kaiser Permanente Northern California, including 1,704,363 with known race/ethnicity (white, 56.9%; Latino, 14.9%; African American, 8.0%; Filipino, 4.9%; Chinese, 4.0%; multiracial, 2.8%; Japanese, 0.9%; Native American, 0.6%; Pacific Islander, 0.5%; South Asian, 0.4%; and Southeast Asian, Korean, and Vietnamese, 0.1% each). We calculated age-standardized (to the 2010 U.S. population) and sex-adjusted diabetes prevalence at baseline and incidence (during the 2010 calendar year). Poisson models were used to estimate relative risks.

RESULTS

There were 210,632 subjects with prevalent diabetes as of 1 January 2010 and 15,357 incident cases of diabetes identified during 2010. The crude diabetes prevalence was 9.9% and the incidence was 8.0 cases per 1,000 person-years and, after standardizing by age and sex to the 2010 U.S. Census, 8.9% and 7.7 cases per 1,000 person-years. There was considerable variation among the seven largest API subgroups. Pacific Islanders, South Asians, and Filipinos had the highest prevalence (18.3, 15.9, and 16.1%, respectively) and the highest incidence (19.9, 17.2, and 14.7 cases per 1,000 person-years, respectively) of diabetes among all racial/ethnic groups, including minorities traditionally considered high risk (e.g., African Americans, Latinos, and Native Americans).

CONCLUSIONS

High rates of diabetes among Pacific Islanders, South Asians, and Filipinos are obscured by much lower rates among the large population of Chinese and several smaller Asian subgroups.

Health disparities in endocrine disorders: biological, clinical, and nonclinical factors--an Endocrine Society scientific statement

OBJECTIVE

The aim was to provide a scholarly review of the published literature on biological, clinical, and nonclinical contributors to race/ethnic and sex disparities in endocrine disorders and to identify current gaps in knowledge as a focus for future research needs. PARTICIPANTS IN DEVELOPMENT OF SCIENTIFIC STATEMENT: The Endocrine Society's Scientific Statement Task Force (SSTF) selected the leader of the statement development group (S.H.G.). She selected an eight-member writing group with expertise in endocrinology and health disparities, which was approved by the Society. All discussions regarding the scientific statement content occurred via teleconference or written correspondence. No funding was provided to any expert or peer reviewer, and all participants volunteered their time to prepare this Scientific Statement.

EVIDENCE

The primary sources of data on global disease prevalence are from the World Health Organization. A comprehensive literature search of PubMed identified U.S. population-based studies. Search strategies combining Medical Subject Headings terms and keyword terms and phrases defined two concepts: 1) racial, ethnic, and sex differences including specific populations; and 2) the specific endocrine disorder or condition. The search identified systematic reviews, meta-analyses, large cohort and population-based studies, and original studies focusing on the prevalence and determinants of disparities in endocrine disorders. consensus process: The writing group focused on population differences in the highly prevalent endocrine diseases of type 2 diabetes mellitus and related conditions (prediabetes and diabetic complications), gestational diabetes, metabolic syndrome with a focus on obesity and dyslipidemia, thyroid disorders, osteoporosis, and vitamin D deficiency. Authors reviewed and synthesized evidence in their areas of expertise. The final statement incorporated responses to several levels of review: 1) comments of the SSTF and the Advocacy and Public Outreach Core Committee; and 2) suggestions offered by the Council and members of The Endocrine Society.

CONCLUSIONS

Several themes emerged in the statement, including a need for basic science, population-based, translational and health services studies to explore underlying mechanisms contributing to endocrine health disparities. Compared to non-Hispanic whites, non-Hispanic blacks have worse outcomes and higher mortality from certain disorders despite having a lower (e.g. macrovascular complications of diabetes mellitus and osteoporotic fractures) or similar (e.g. thyroid cancer) incidence of these disorders. Obesity is an important contributor to diabetes risk in minority populations and to sex disparities in thyroid cancer, suggesting that population interventions targeting weight loss may favorably impact a number of endocrine disorders. There are important implications regarding the definition of obesity in different race/ethnic groups, including potential underestimation of disease risk in Asian-Americans and overestimation in non-Hispanic black women. Ethnic-specific cut-points for central obesity should be determined so that clinicians can adequately assess metabolic risk. There is little evidence that genetic differences contribute significantly to race/ethnic disparities in the endocrine disorders examined. Multilevel interventions have reduced disparities in diabetes care, and these successes can be modeled to design similar interventions for other endocrine diseases.

New race and ethnicity standards: elucidating health disparities in diabetes

The concepts of race and ethnicity are useful for understanding the distribution of disease in the population and for identifying at-risk groups for prevention and treatment efforts. The U.S. Department of Health and Human Services recently updated the race and ethnicity classifications in order to more effectively monitor health disparities. Differences in chronic disease mortality rates are contributing to race and ethnic health disparities in life expectancy in the United States. The prevalence of diabetes is higher in African Americans and Hispanics compared to white Americans, and parallel trends are seen in diabetes risk factors, including physical inactivity, dietary patterns, and obesity. Further research is required to determine the extent to which the observed differences in diabetes prevalence are attributable to differences in lifestyle versus other characteristics across race and ethnic groups.

Medication adherence and racial differences in A1C control

OBJECTIVE

The purpose of this study was to examine medication adherence and other self-management practices as potential determinants of higher glycemic risk among black relative to white patients.

RESEARCH DESIGN AND METHODS

We used a retrospective, longitudinal repeated-measures design to model the contribution of medication adherence to black-white differences in A1C among type 2 diabetic patients at a large multispecialty group practice. We identified 1,806 adult (aged >/=18 at diagnosis) patients (467 black and 1,339 white) with newly initiated oral hypoglycemic therapy between 1 December 1994 and 31 December 2000. Race was identified using an electronic medical record and patient self-report. Baseline was defined as the 13 months preceding and included the month of therapy initiation. All patients were required to have at least 12 months of follow-up.

RESULTS

At initiation of therapy, black patients had higher average A1C values compared with whites (9.8 vs. 8.9, a difference of 0.88; P < 0.0001). Blacks had lower average medication adherence during the first year of therapy (72 vs. 78%; P < 0.0001). Although more frequent medication refills were associated with lower average A1C values, adjustment for adherence did not eliminate the black-white gap.

CONCLUSIONS

We found persistent racial differences in A1C that were not explained by differences in medication adherence. Our findings suggest that targeting medication adherence alone is unlikely to reduce disparities in glycemic control in this setting. Further research is needed to explore possible genetic and environmental determinants of higher A1C among blacks at diagnosis, which may represent a critical period for more intensive intervention.

The shape of inequality: racial disparities in age-specific mortality

There are significant mortality disparities across racial and socioeconomic (SES) groups. Although the mechanisms behind these disparities remain vague, there is a clear connection between the mortality disparities across racial and SES groups. It is less clear, though, if the relationship between SES and racial mortality disparities varies across the life course. Prior research indicates that both racial and SES mortality disparities decline over the life course. These results suggest that if we standardize mortality rates for age-variation in the SES-mortality relationship, then the age-pattern of racial mortality disparities will be attenuated. Using data from the National Longitudinal Mortality Study, I analyze the relationship between SES and racial disparities in age-specific mortality among adults aged 25 and over. The results suggest that racial differences in SES are most important early in the adult life, and are minimally related to the convergence in racial mortality disparities at the oldest ages.

Comparing diabetes prevalence between African Americans and Whites of similar socioeconomic status

OBJECTIVES

We investigated whether racial disparities in the prevalence of type 2 diabetes exist beyond what may be attributable to differences in socioeconomic status (SES) and other modifiable risk factors.

METHODS

We analyzed data from 34331 African American and 9491 White adults aged 40 to 79 years recruited into the ongoing Southern Community Cohort Study. Participants were enrolled at community health centers and had similar socioeconomic circumstances and risk factor profiles. We used logistic regression to estimate the association between race and prevalence of self-reported diabetes after taking into account age, SES, health insurance coverage, body mass index, physical activity, and hypertension.

RESULTS

Multivariate analyses accounting for several diabetes risk factors did not provide strong support for higher diabetes prevalence rates among African Americans than among Whites (men: odds ratio [OR]=1.07; 95% confidence interval [CI]=0.95, 1.20); women: OR=1.13, 95% CI=1.04, 1.22).

CONCLUSIONS

Our findings suggest that major differences in diabetes prevalence between African Americans and Whites may simply reflect differences in established risk factors for the disease, such as SES, that typically vary according to race.

Systematic review identified suboptimal reporting and use of race/ethnicity in general medical journals

OBJECTIVE

Methods of reporting of race/ethnicity in biomedical journals are largely unknown. We aimed to systematically examine the reporting practice of race/ethnicity and socioeconomic status (SES) information in biomedical journals.

STUDY DESIGN AND SETTING

All primary research articles that reported more than one racial/ethnic group, published between 1999 and 2003 in Annals of Internal Medicine, JAMA, The Lancet, and The New England Journal of Medicine (n=1,152) were reviewed for their use of race/ethnicity and SES variables. Interobserver reliability was assessed by independent abstraction of 10% of study sample.

RESULTS

There were a total of 116 different terms used to describe various racial/ethnic groups. Assignment of race/ethnicity by self-report was stated in only 13% of papers; 52% of papers identifying race/ethnicity of study participants did not report any SES information. Overall, 16% of articles explicitly stated reasons for collecting information on race/ethnicity.

CONCLUSION

Our results suggest that race/ethnicity information was suboptimally reported in general medical journals. Terminology used was highly variable. Method of establishing racial/ethnic categories, rationale for collecting race/ethnicity data, and SES information were underreported.

Racial and ethnic disparities in pain management in the United States

PURPOSE

To critically examine research on racial and ethnic disparities in pain management with a focus on who has been studied, the magnitude of disparities, and potential explanations for those disparities.

DESIGN

A systematic literature review. Articles included were reports of original research in which at least two racial or ethnic groups were compared on adequacy of pain management.

METHODS

Review of research articles published between 1990 and 2004 with the primary aim of identifying the influence of race or ethnicity on pain management in the US. Databases were CINAHL, Medline, and Pubmed. Relevant articles were categorized by pain type. Effect sizes were calculated where sufficient data were provided.

FINDINGS

Studies were focused on Blacks or African Americans, Whites or non-Hispanic Whites, Hispanics, and Asians. Terms for describing these groups were neither well defined nor consistently used within and across studies. Disparities in pain management were reported in relation to minority status, but the magnitudes of these disparities were mostly small.

CONCLUSIONS

Greater clarity and consistency are needed in the use of the terms race, ethnicity, and minority. Groups were treated as if they were homogeneous, and details were lacking about whether subgroups of different races or ethnicities had been studied. Although reported disparities in pain management were small, they were consistent. Further research is needed to examine differences within groups and to explain possible reasons for disparities across groups.

Drugs and double binds: racial identification and pharmacogenomics in a system of binary race logic

People respond to drugs in different ways depending on their genotype. Some geneticists and medical researchers have suggested using race as a substitute for genotype in prescribing medication. Overall, individuals resist the prescription of medication based on race, but some minority individuals, although indicating resistance and suspicion, ultimately choose race-based medication. This can be explained by the operation of Burkean identification in a system of binary race logic. Although individuals resist race-based medication and recognize race is not a legitimate genetic category, their identification with a racial-ethnic group places them in a double bind between choosing race-based medication or denying their racial identification.

Racial disparities in risk factors for thrombosis

PURPOSE OF REVIEW

Until recently, the paucity of characterization of the epidemiology of venous thromboembolism among non-Caucasians has contributed to the misconception that race or ethnicity does not modify disease presentation. This review will describe the previously poorly documented magnitude of venous thromboembolism disease burden among four racial cohorts, by defining disease incidence and associated morbidity/mortality from available literature data.

RECENT FINDINGS

Emerging data suggest that African-Americans possess the highest burden of venous thromboembolism, and Asians the lowest, compared with the Caucasian population. In both racial groups, however, the inheritable thrombophilic risk factors prevalent in Caucasians (factor V Leiden, Prothrombin G20210A) are distinctly rare. The presence of yet undetermined modifiers of disease, conferring susceptibility or resistance to venous thromboembolism among these racial groups, is suspected and requires further investigation.

SUMMARY

Racial disparity in thrombotic disorders exists in the divergent patterns of disease incidence among different racial/ethnic cohorts, yet the genetic determinants of disease and modifiers of risk remain obscure. Further research focused on delineating the underlying etiologies of venous thromboembolism across different racial/ethnic groups promises to be a productive and much needed area of exploration.