Treating Type 2 Diabetes in Diverse Populations
San Francisco—Type 2 diabetes disproportionally affects ethnic minorities. Nonwhite populations have a greater susceptibility to the disease, and Hispanic and black patients often have poorer outcomes than their white counterparts, leading to increased healthcare utilization costs. Disparities in type 2 diabetes arise from various genetic, cultural, and socioeconomic differences, but can be successfully overcome by approaches that put the patient at the center of the management effort, according to a panel of diabetes experts who discussed this topic during the ADA meeting at a satellite symposium, which was supported by an educational grant from Boehringer Ingelheim.
Presentations were given by Vivian Fonseca, MD, professor of medicine and pharmacology, Tulane University Health Sciences Center; Joseph R. Betancourt, MD, MPh, director, The Disparities Solutions Center, associate professor of medicine, Harvard Medical School; Samuel Dagogo-Jack, MD, professor of medicine, chief, division of endocrinology, diabetes, and metabolism, University of Tennessee Health Science Center; and Allison B. Goldfine, MD, associate professor of medicine, Harvard Medical School, head of clinical research, Joslin Diabetes Center.
Diabetes Overview
“Diabetes is rapidly increasing, and it is a major global problem,” said Dr. Fonseca, who opened the symposium with diabetes statistics. Dr. Fonseca highlighted a study by Boyle et al published in Population Health Metrics in 2010 that projected prevalence of individuals diagnosed with diabetes will increase to 37.9 million in 2020, and by 2050 that figure will reach 86.6 million. According to the Centers for Disease Control and Prevention’s (CDC) National Diabetes Fact Sheet, 2011, 35% of the US population have prediabetes. The CDC also examined racial and ethnic differences in diagnosed diabetes. Among individuals ≥20 years of age in the United States in 2010, the data showed 16.1% of
Native Americans, 12.6% of non-Hispanic blacks, 11.8% of Hispanics, 8.4% of Asian Americans, and 7.1% of non-Hispanic whites had diagnosed diabetes.
Dr. Betancourt continued the forum with a discussion of disparities in healthcare, its root causes, and strategies to address disparities. “We are a nation becoming increasingly diverse,” he said. “Science is going to be critical [in treating patients], but our ability to communicate with diverse populations is more critical.”
He referenced the 2002 Institute of Medicine (IOM) report, “Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care,” which found disparities across a wide range of healthcare settings, disease states, and clinical services, even when various confounders are considered. “Many sources contribute to disparities—no 1 suspect, no 1 solution,” said Dr. Betancourt, who was a member of the IOM committee that drafted the report.
He said minorities face greater difficulty communicating with physicians. A survey of adults with healthcare visits in the past 2 years found that 33% of Hispanics and 27% of Asian Americans reported ≥1 communication problem, such as understanding the doctor, feeling the doctor listened to everything they said, or had questions but did not ask them. A separate study by Peck et al published in SAGE Open in 2012 examined the effects of race and ethnicity on office visits. The findings showed that office visits with white patients lasted 20% longer than visits with nonwhite patients. Physicians, however, spent more time talking with nonwhite patients during office visits because this patient population tended to ask more questions. The researchers concluded, “Medical encounters differ in important ways depending on the patient and physician characteristics. These differences can create and contribute to health disparities.”
A growing body of evidence has identified disparities in diabetes and diabetes care. He said diabetes-related deaths vary by race and ethnicity, citing data from the National Center for Health Statistics that included the age-adjusted death rate per 100,000 population for diabetes in 2010. The death rate was highest among non-Hispanic black and American Indian/Alaskan Native populations (38.7 and 36.4, respectively).
Dr. Betancourt cited data from the 2013 Agency for Healthcare Research and Quality National Healthcare Disparities Report that examined 4 recommended annual diabetes interventions from 2008 to 2010: at least 2 hemoglobin A1c (HbA1c) tests, a foot examination, a dilated eye examination, and flu shot. The report found:
• In 2010, overall, among adults ≥40 years of age with diagnosed diabetes, only about one-fourth
reported receiving all 4 recommended services
• In 2009, blacks and Hispanics were less likely than whites to report receiving recommended care
for diabetes. However, in 2010, there were no statistically significant differences by race
• In 2008 and 2009, poor, low-income, and middle-income adults were less likely to receive
recommended care for diabetes than high-income adults. In 2010, there were no statistically
significant differences by income
Dr. Betancourt continued by identifying proven strategies to address disparities in diabetes care. An example is the Chelsea Diabetes Management Program that serves the needs of patients at Massachusetts General Hospital Chelsea location. The program’s 3 primary components include:
• Telephone outreach to increase rate of HbA1c testing
• Individual coaching to address patients’ needs and concerns regarding diabetes self-management
to improve HbA1c
• Communication with healthcare providers for specific, individualized treatment
He said the program has resulted in diabetes control improving for all ethnic groups. For example, patients with poorly controlled diabetes (HbA1c >8%) in 2008 were 34% Latinos and 24% whites. However, in 2009, the gap between Latinos and whites was closing (29% vs 20%, respectively). Dr. Betancourt mentioned that health information and testing are also promising strategies that may help to improve outcomes in underserved populations.
Treatment Options
Diabetes treatments should be selected based on the individual patient’s profile and risk of adverse events and complications, with consideration of the costs for these sequelae as well as the cost of medications. Medical comorbidities, such as obesity, hypertension, renal disease, and cardiovascular disease, should also be considered. Currently, there are >30 glucose-lowering agents to treat diabetes. “It is a cause for celebration but also reflection,” said Dr. Dagogo-Jack, who continued the presentation with a discussion of similarities and differences among 3 drugs classes.
Glucagon-like peptide-1 (GLP-1) receptor agonists provide a glucose-dependent insulinotropic effect, glucagon suppression, and gastric emptying. They target post-meal blood glucose and lower fasting plasma glucose (FPG). They are generally used in combination with 1 to 2 oral agents. Studies have found that GLP-1 receptor agonists lower HbA1c by approximately 1%, with associated weight loss and lower risk of hypoglycemia. The most common side effects are gastrointestinal-related, including nausea, vomiting, and diarrhea, usually occurring during initiation of therapy, according to Dr. Dagogo-Jack. FDA-approved GLP-1 receptor agonists include liraglutide, exenatide, and albigutide.
Similar to GLP-1 receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors target post-meal blood glucose and lower FPG. They also provide a glucose-dependent insulinotropic effect and glucagon suppression. Used in combination with 1 to 2 oral agents, studies have shown that DDP-4 inhibitors lower HbA1c by 0.5% to 0.9%, are weight neutral, and have low risk of hypoglycemia. The 4 FDA-approved DDP-4 inhibitors are sitagliptan, saxagliptin, linagliptin, and alogliptin. They are well-tolerated, with allergic reactions being the most notable side effect, explained Dr. Dagogo-Jack.
The final class of drugs Dr. Dagogo-Jack highlighted were sodium-glucose cotransporter-2 (SGLT-2) inhibitors. Currently, canagliflozin, dapagliflozin, and empagliflozin are the FDA-approved therapies in this class. SGLT-2 inhibitors work by blocking urinary glucose reabsorption. He referenced a study by Gerber et al published in Endocrine Practice in 2013 that assessed the advantages and disadvantages with this drug class. Advantages included that they were well-tolerated, had a low risk of hypoglycemia, were associated with weight loss, and decreased blood pressure. Disadvantages observed were modest increase in HbA1c, fungal infection, hypotension, and increased low-density lipoprotein cholesterol.
When treating patients with diabetes, he recommended clinicians reference the ADA and European Association for the Study of Diabetes position statement published in Diabetes Care in 2012, which proposed rational approaches to glucose lowering in patients with type 2 diabetes.
In summary, Dr. Dagogo-Jack said newer classes of antihyperglycemic medications offer glucose lowering with little to no risk of hypoglycemia when used as a monotherapy. Furthermore, DPP-4 inhibitors, GLP-1 receptor agonists, and SGLT-2 inhibitors have additional properties that may be tailored to specific patient profiles. Finally, lifestyle modification is the foundation on which to build an individualized platform of treatment in all patients with diabetes.
Dr. Goldfine concluded the symposium with a look at extraglycemic effects of recently developed pharmacotherapy. Studies on the effects of DDP-4 inhibitors on lipids and inflammatory factors found that DDP-4 inhibitors did not significantly affect lipids in pivotal monotherapy trials. No significant effects on lipids were observed when DDP-4 inhibitors were added to standard cardiovascular risk factor treatments. While no major effects on inflammatory factors were observed or reported in pivotal trials, they have been seen in other studies.
As for the same effects with SGLT-2 inhibitors, Dr. Goldfine said that studies have shown no significant effect on other lipid parameters, such as triglycerides and high-density lipoprotein cholesterol. She noted that no effects on inflammatory factors with SGLT-2 inhibitors have been reported.
To date, DDP-4 inhibitor outcome trials have not shown a macrovascular benefit. Lowering risk in patients with type 2 diabetes may require long-term studies. Also, cardiovascular safety trials are underway with incretin agents and SGLT-2 inhibitors, according to Dr. Goldfine.
“Extraglycemic effects of diabetes medications may help manage associated comorbid health conditions and inform clinical decisions and therapy selection,” she concluded.—Eileen Koutnik-Fotopoulos
