Advances in Diabetes for the Millennium: Diabetes in Minorities

Abstract

Diabetes shows an increased prevalence among minority groups, including Asians, African Americans, Hispanics, Native Americans, and Pacific Islanders. The sedentary lifestyle and high-fat diet of modern industrialized societies promote obesity at an early age. There is a strong correlation between the development of diabetes and increased visceral adiposity in American minority groups. This review focuses on the 2 largest minority groups in the United States, African Americans and Hispanics. The risk of diabetes is 20% to 50% greater in African American men and twice as great in African American women as well as twice as high in Hispanic adults than in whites. Furthermore, the prevalence of diabetes-associated complications, such as retinopathy and amputations, is 50% to 100% higher in African Americans and Hispanics.

The unfavorable consequences of diabetes in African American and Hispanic individuals do not seem to be due to inherent biological differences. Rather, it appears that differences in medical care and self-management of diabetes may be the major factor. The key to improving outcomes in these minority groups lies in enhancement of communication to overcome barriers to self-care. It is important to better understand the cultural milieu in minority communities to enhance patient involvement in their own management. Where this has been done, marked improvements in diabetes healthcare have occurred.

Diabetes in Ethnic Minorities

Diabetes is increasing in prevalence among minority groups in the United States.[1] Data from the 2001 Behavioral Risk Factor Surveillance System (BRFSS) suggest that as compared with whites, the odds ratios (95% confidence intervals [CIs]) for diabetes (adjusted for age, sex, and body mass index [BMI]) were 1.6 (1.2-2.3) for Asians, 1.9 (1.7-2.2) for African Americans, 1.9 (1.6-2.1) for Hispanics, 1.8 (1.3-2.5) for Native Americans, and 3.0 (1.4-6.7) for Pacific Islanders. Among Native Americans, about 15% of the population, receiving care from Indian Health Services (IHS), has diabetes, varying from a diabetes prevalence of 6.8% among Alaska Natives to 27% among Native Americans in the southeastern United States.[2] The increased incidence of diabetes is accompanied by a higher rate of end organ disease.[2] The rate of diabetic end-stage renal disease is 6 times higher among Native Americans. Amputation rates among Native Americans are 3-4 times higher than the general population. Diabetic retinopathy occurs in about 20% of southwestern Native Americans.

There is a strong association between the development of diabetes and increased visceral adiposity,[3-5] and it appears to correlate with a shift toward a more sedentary lifestyle with a higher-fat diet resulting in obesity.[6,7] The development of obesity begins early in childhood in the minority populations.[8]

In what follows, we review the lessons learned in the management of diabetes in the 2 largest minority populations in the United States. We each have special expertise in dealing with diabetes in each population, Dr. Harrison in African Americans and Dr. Jovanovic in Hispanics. We hope that these lessons will apply in general to the growing problem of diabetes in the expanding minority populations at risk in the United States.

Diabetes in African Americans

Data from studies of nationally representative samples indicate that as compared with their white counterparts, African American men are 20% to 50% more likely and African American women more than 100% more likely to develop diabetes.[9,10]

In the Atherosclerosis Risk in Communities (ARIC) study carried forward on 15,792 adults aged 45-64 years at baseline, the excess risk of diabetes in African Americans vs non-Hispanic whites was greater in women (absolute risk difference, 14.7 per 1000 person-years; risk ratio = 2.41) than in men (absolute risk difference, 7.5 per 1000 person-years; risk ratio = 1.47).[11] Apart from age, the profile of established risk factors for diabetes was clearly worse in African American women than in their white counterparts. In particular, African American women had fewer years of formal education, were more likely to report a family history of diabetes, had greater measures of adiposity (including BMI and the ratio of hip-to-waist circumference), and reported less physical activity during leisure time. A similar racial disparity of established diabetes risk factors prevailed in men, with the notable exception of adiposity, which was similar in African American and white men. Thus, the increased susceptibility to diabetes in African Americans appears to be related to associated risk factors rather than intrinsic biological differences.

The outcomes of diabetes mellitus in African Americans are suboptimal. In the Third National Health and Nutrition Examination Survey (NHANES III), the prevalence of diabetic retinopathy in people with diagnosed diabetes was 46% higher in non-Hispanic blacks and 84% higher in Mexican Americans as compared with non-Hispanic whites.[12] Clinical proteinuria was also more prevalent than in whites (11% to 14% vs 5%). African Americans and Mexican Americans had higher rates of moderate and severe retinopathy. In logistic regression, retinopathy in people with diagnosed diabetes was associated only with measures of diabetes severity (duration of diabetes, HbA1c, level, and treatment with insulin and oral agents) and systolic blood pressure. After adjustment for these factors, the risk of retinopathy in Mexican Americans was twice that of non-Hispanic whites, but non-Hispanic blacks were not at higher risk for retinopathy.[13]

In the NHANES Epidemiologic Followup Study, the 20-year age-adjusted rate of first lower extremity amputations for African American subjects was twice as high as in whites. Although preliminary analyses adjusted for age and diabetes indicated a significant association between race and amputation risk (relative risk [RR], 1.93 [95% CI, 1.26-2.96]), the effect of race diminished (RR, 1.49 [95% CI, .95-2.34]) following adjustment for education, hypertension, and smoking.[14] Lower proportions of African Americans and Mexican Americans self-monitored their blood glucose (insulin-treated, 27% vs 44% of whites) and had their cholesterol checked (62% to 68% vs 81%). African American and Mexican American patients had worse glucose control than white patients, with HbA1c >/=#x02265; 7% (58% to 66% vs 55%) and worse blood pressure control (>/=#x02265; 140/90 mm Hg: 60% to 65% vs 55%). There was no relationship of glycemic control to socioeconomic status or access to medical care in any racial or ethnic group.[15]

Decreased access to healthcare does not seem to be the problem. In the NHANES III study, almost all patients in each racial and ethnic group had 1 primary source of ambulatory medical care (92% to 97%), saw 1 physician at this source (83% to 92%), and had at least semiannual physician visits (83% to 90%). Almost all patients >/=#x02265; 65 years of age had health insurance (99% to 100%), and for those patients < 65 years of age, whites (91%) and African Americans (89%) had higher rates of coverage than Mexican Americans (66%). The rates of treatment with insulin or oral agents (71% to 78%), eye examination in the previous year (61% to 70%), blood pressure check in the previous 6 months (83% to 89%), and the proportion of hypertension that was diagnosed (84% to 91%) were similar for each racial and ethnic group. African American and Mexican American men were less overweight than white men (BMI >/=#x02265; 30) (34-37% vs 44%), although the opposite was true for women. In logistic regression analysis, there was little evidence that levels of blood glucose, blood pressure, lipids, or albuminuria were associated with access to or utilization of healthcare, or with socioeconomic status.[16]

Studies of ambulatory care for these patients suggest that the rates of visits to specialists for diabetes complications, physician testing of blood glucose, and screening for hypertension, retinopathy, and foot problems are not substantially different among African Americans, non-Hispanic whites, and Mexican Americans.[16]

Yet the same studies do show differences in treatment: African Americans were more likely to be treated with insulin (51.9%) than non-Hispanic whites (35.9%, P < .0001) and Mexican Americans (46.2%). Among insulin-treated subjects, African Americans were less likely to use multiple daily insulin injections (35.1% vs 53.8% of non-Hispanic whites [P < .0001] and 50.5% of Mexican Americans [P = 027]) and were less likely to self-monitor their blood glucose at least once per day (14 vs 29.8% of non-Hispanic whites [P < .0001] and 29% of Mexican Americans). A higher proportion of African Americans (43.3%) than non-Hispanic whites (31.5%, P < .0001) and Mexican Americans (25.6%, P = .001) had received patient education; however, the median number of hours of instruction was lower for African Americans.

Conventional belief suggests that these data indicate that African Americans are less compliant than other patients. However, compliance with blood glucose measurement after instruction is reportedly similar in African Americans and whites.[17,18]

Poor outcomes seem to be associated with minority patient status for most chronic diseases. For example, problems as diverse as congestive heart failure,[19] infertility,[20] hip fractures,[21] and transient ischemic attacks[22] are found to have outcomes that differ by race for no apparent biological reason. On the other hand, acute medical problems, which do not require behavioral modification, such as survival in an intensive care unit or cardiac arrest, often appear to show no such difference.[23,24]

Thus, there is little indication of biological racial difference in diabetes and its effects. It is the thesis of this study that optimal outcome in the management of a chronic condition, such as diabetes, is heavily dependent on the ability to develop effective self-care. To do so, it is vital to identify and eliminate barriers to behavioral change. The success in treatment of hypertension in our society is an example. Physician awareness of the importance of treating hypertension has led to considerable improvement in compliance in this area. Technical advances may also play an important role: For example, more effective drugs with less side effects have made antihypertensive treatment more acceptable to patients. The key to achieving compliance is for the healthcare provider to successfully transmit awareness. For example, smoking among healthcare providers has plummeted, and smoking in the general population has dropped by over 50% as a result of better communication on the risks of smoking.

Management of type 2 diabetes is difficult because it requires significant changes in behavior on the part of the patient. One of the key elements is the linkage of diabetes to obesity. Some studies report less success in dietary treatment of African Americans.[25]

However, it is difficult to assess whether the less favorable results in African Americans may be due to less effective communication and interaction techniques applied to this group. Perhaps one might gain an improved perspective of the difficulty of lifestyle change if one examines the success of weight management among healthcare providers. For example, a mail survey of 1200 physicians showed that family practitioners, internists, and endocrinologists reported treating obesity themselves in only about 50% of obese patients. Physicians reporting "any specialty training related to obesity" ranged from only 4.5% of family practitioners to 36.4% of endocrinologists.[26]

This problem is compounded when there is little familiarity with the social and economic issues governing dietary approaches in the African American population.[27] Recent advances in the treatment of diabetes and obesity offer better understanding of what lifestyle changes must be implemented. There are also now more effective pharmacologic agents, such as insulin sensitizers and anorexiants. Their use and more effective communication between the healthcare provider and the patient should result in improved management of type 2 diabetes mellitus in African Americans. If the issue is noncompliance with recommendations, we must make a special effort to communicate successfully. There are certain specific approaches that may help to improve communication.

Specific Approaches to Communication

The long legacy of unfavorable race relations in the United States has created barriers to communication. Patient self-esteem is more easily bruised than generally realized. A hurt, resentful patient will not cooperate with the healthcare provider. Try to imagine that the patient is a very powerful person, such as the President. Calling him by his first name would not occur to most of us no matter what our politics! (Nor would we ask, "May I call you by your first name?") Give each patient the appropriate honorific unless they explicitly ask otherwise. Whether seated or standing, make sure you are on the same level as the patient. Smile but do not joke.

Be clear that the patient knows the rationale for changing behavior. Concreteness and examples are very helpful. To explain why the glucose level and HbA1c is so important, I use the Amadori reaction as an example. This chemical reaction between glucose and protein makes bread crust and meat brown. I point out to the patient that bread crust is hard and easily broken because proteins are stiffened by the addition of sugar molecules. Thus, high glucose levels, as determined by the HbA1c, mean that the patient's proteins have become crusty. Crusty proteins are more easily broken and don't work as well as nice supple proteins. My patients do not want to be crusty.

The deliberately noncompliant patient is rare and obvious: For the remaining 99.99% of patients, it is poor planning skills rather than lack of motivation that lead to failure. For such people, we must ask how to change the results and not why. What is interfering and how can it be removed?

Most situations recur. Make concrete plans to cope better the next time. Plan a series of responses in case the first few don't work. Be sure the patient understands that you know that change is difficult. Sometimes it is helpful to assign the patient a concrete task, such as learning to brush their hair with the nondominant hand to give them a better idea of the difficulty of change (just remembering to do it is difficult). When organizing a plan, be as concrete as possible. Establish specific details: What time will you wake up? Where will you keep the glucose meter, lancets, record book, and pencil?

Set goals: If the goal is 28 fingersticks per week, will 24 be acceptable (no one is perfect)?

Make a record of whether the behavior was accomplished or not. Reinforce success and problem-solve nonadherence.

Be patient. Patients will struggle and they need to know that you will not give up on them.

There is emerging strong evidence that an aggressive approach to communication and interaction with African American diabetic patients can markedly improve glycemic control. At Grady Memorial Hospital in Atlanta, Georgia, such an approach led to a mean reduction of HbA1c levels of 1.4%.[28] Experience at the Kaiser Oakland Medical Center, Oakland, California, has shown no racial differences in either prevention practices or complication rates in their diabetic population.[29]

Diabetes is a disease that requires considerable self-management by the patient. By making the effort to communicate effectively with African American diabetic patients, the medical community can expect a substantial improvement in healthcare for this group.

Diabetes in Hispanics

Diabetes disproportionately affects the Hispanic population in the United States. The BRFSS to assess the prevalence of diabetes among Hispanic adults in the United States and Puerto Rico found that the age-adjusted prevalence of diabetes among Hispanic adults was twice that of non-Hispanic white adults (8% vs 4%; P < .001).[30] The NHANES III found that for every 2 Mexican Americans with diagnosed diabetes, 1 person had undiagnosed diabetes.[31] The prevalence of diabetes among Hispanic adults varied by geographic location: 10.7% in Puerto Rico, 5.8% in the West/Southwest, 4.9% (in the South/Southeast), and 4.1% in the Northeast/Midwest. Compared with non-Hispanic white adults in the United States, Hispanic adults in Puerto Rico were 2.9 times and Hispanic adults in the West/Southwest were 2 times more likely to have diabetes. Hispanic adults in the Northeast/Midwest and the South/Southeast were 1.4 times more likely to have diabetes than non-Hispanic white adults in the United States. After controlling for age, sex, education, and geographic location, Hispanic adults remained 1.8 times (95% CI = 1.6-1.9) more likely to have diabetes than non-Hispanic white adults. In African Americans, there has been no specific genetic locus identified to account for increased susceptibility to diabetes. There have been possible gene candidates identified in Hispanics, without conclusive results.[32,33]

As discussed by Dr. Harrison in this symposium, Hispanic patients with diabetes have shown worse control of glucose and more frequent and severe retinopathy than non-Hispanic whites. There is a substantial effort to deal with the problems caused by diabetes in the Hispanic population. In collaboration with Hispanic organizations, the US Centers for Disease Control and Prevention (CDC) and the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health (NIH) are developing a diabetes education campaign targeting persons of Hispanic origin. This campaign, which is part of the National Diabetes Education Program (NDEP), aims to increase public awareness of diabetes and promote self-management among persons with diabetes. CDC also is supporting 2 national Hispanic organizations to implement the NDEP at the local level and to develop partnerships for community interventions. In addition, CDC supports the National Hispanic/Latino Diabetes Initiative for Action to promote and evaluate interdisciplinary and culturally appropriate procedures to prevent diabetes and its complications in the US Hispanic community. Under this initiative, for example, CDC published the patient-care guide, "Take Charge of Your Diabetes," in Spanish after testing the publication among Hispanic persons. A copy of this guide is available from CDC in Spanish and English, telephone toll-free (877) 232-3422. Finally, CDC is working with diabetes-control programs in Arizona, California, New Mexico, and Texas to develop a community-based and culturally appropriate diabetes education program for the Hispanic population along the United States-Mexico border.

However, the key to success in managing diabetes in the Hispanic population as in the African American population remains the personal interaction between the patients and their healthcare providers. Improving awareness is the goal to help people take care of themselves. There is no doubt that compliance increases when the language barrier is overcome.[34] I learned to speak fluent Spanish, and this has definitely improved my relationship with my patients. However, communication requires more than linguistic skills; it is also important to understand the cultural issues that may affect therapy.[35-37] There are many issues that I have come to learn in my years of work in the Hispanic community. For example, to many older Mexican Americans, obesity is considered a sign of prosperity. It is important to continually stress that obesity is actually a sign of poor nutrition. Fortunately, the perception of obesity is changing as many new, thin role models are attaining success in the Hispanic community.

One of the greatest fears associated with diabetes among Hispanics is blindness.[38] Many have a family member who has gone blind. This fear is often directed at insulin, because blindness often occurred during a period of insulin treatment. This has led to the common and erroneous belief that insulin causes blindness, when in reality, insulin therapy is often saved for the sickest patients in Mexico. Most likely, insulin was administered too late in the natural history of the disease to prevent the complications. We have overcome the fear of insulin by the use of insulin pens. We simply call them "pens" ("la pluma") and we call the insulin "medicine."

Conversely, certain beliefs are quite helpful. Hispanics believe that nopales (the flower of cactus plants) helps diabetes. This belief is actually true for the nopales have very few calories and a high fiber content. Meals containing nopales tend to be filling and discourage the excess consumption of calories.

It is very important to be sensitive to financial issues in less-affluent communities. Diets can be undone by heavy carbohydrate consumption. Tortillas are a staple of the Mexican American diet but are very high in starches. Diets lower in carbohydrates and higher in proteins may improve glycemic control but are often too expensive. Conversely, beans are very popular in a variety of Hispanic recipes.[39] The protein and fiber content of beans are favorable to dietary control. We encourage the substitution of vegetables for starches and have had success with adherence to such dietary prescriptions.

It is critical to recognize the strength of the family in Hispanic society. Hispanics are brought up to believe that the role in life is to take care of others. They do not tend, therefore, to put themselves as priority. If the healthcare team becomes part of the family by speaking their language and understanding the family dynamics, then the patient cooperates to please the healthcare providers rather than disappoint them. To further integrate the healthcare experience into the Hispanic concept of family, it helps to have a clinic located in the Spanish neighborhoods. The waiting area needs to be conducive to interaction and the wait time can be used for education. We use Spanish Education video tapes, and educators can use the waiting room as a classroom to be able to increase awareness and interaction.

The goal is to improve patient self-management of diabetes. It has been gratifying for me to see how the efforts that I have made have succeeded in improving the lives of my patients in the Hispanic community.