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Improvement in CV risk factors varies by socioeconomic status
The benefit of controlling CV risk factors has disproportionately affected U.S. adults by socioeconomic strata, according to two studies in JAMA Cardiology.
Ayodele Odutayo, MD , of the Applied Health Research Centre in the Li Ka Shing Knowledge Institute at St. Michael’s Hospital in Toronto, and colleagues analyzed data from 17,199 patients (mean age, 54 years; 8,828 women) from the National Health and Nutrition Examination Survey from 1999 to 2014.
Patients were categorized by years (1999-2004, 2005-2010 and 2011-2014) and socioeconomic status (high income, middle income and incomes at or below the federal poverty level), which was calculated by the family income to poverty ratio. Those who were pregnant or had a self-reported history of angina, CAD, stroke, acute MI or congestive HF were excluded.
Outcome variables included systolic BP, 10-year CV risk, diabetes, smoking and total cholesterol.
Income disparities
Patients with predicted CV risk above 20% decreased from 1999-2004 (13.1%; 95% CI, 12.3-14) to 2011-2014 (11.5%; 95% CI, 10.6-12.4), which differed by income strata (P = .02 for interaction between high income vs. at or below poverty level).
In those with high CV risk and incomes at or below poverty level, the percentage minimally changed within the period, from 14.9% (95% CI, 12.9-16.8) to 16.5% (95% CI, 13.7-19.2). Researchers also observed little difference in systolic BP in those with incomes at or below poverty level, as it decreased from 127.6 mm Hg (95% CI, 126.1-129) to 126.8 mm Hg (95% CI, 125.2-128.5). The percentage of current smokers minimally changed in this group from 1999 (36.5%; 95% CI, 32.1-41) to 2014 (36%; 95% CI, 31.1-40.8).
The number of patients with high incomes and increased CV risk decreased from 12% (95% CI, 10.7-13.3) to 9.5% (95% CI, 8.2-10.7). Systolic BP also decreased in this group, from 126 mm Hg (95% CI, 125-126.9) to 122.3 mm Hg (95% CI, 121.3-123.3). The percentage of current smokers decreased from 14.1% (95% CI, 12-16.2) to 8.8% (95% CI, 6.6-11).
The rate of diabetes increased, although it did not vary by income strata (P for interaction = .94), whereas mean total cholesterol decreased, but there was no significant variance by income (P for interaction = .44).
“Examining trends in [CV] risk factors among adults belonging to different socioeconomic strata is therefore an important element of any public health strategy to reduce income disparities in morbidity and mortality,” Odutayo and colleagues wrote.
Additional research
Adam L. Beckman, an initiatives fellow at Aledade Inc., and colleagues analyzed income disparities in 23,693 patients aged 25 years and older from NHANES between 2005 and 2014, according to a research letter published in JAMA Cardiology. Using the poverty to income ratio, risk factors including diabetes, hypertension, obesity, dyslipidemia and smoking were reviewed.
Hypertension increased in patients with the lowest poverty to income ratio and decreased in those with the highest ratio, which expanded the gap between the groups from 2005-2006 (absolute difference, 2.4%; 95% CI, –5.5 to 10.2) and 2013-2014 (absolute difference, 10.5%; 95% CI, 6.2-14.8). Controlled hypertension increased in both groups, but more so in those with the lowest poverty to income ratio, as the absolute difference of –0.1% (95% CI, –4.9 to 4.8) in 2005-2006 widened to 3.5% (95% CI, –0.8 to 8.8) in 2013-2014.
Uncontrolled diabetes was more prevalent in the group with the lowest poverty to income ratio compared with those with the highest ratio. Dyslipidemia increased in both the lowest and highest ratio groups, especially in the lowest ratio group, where prevalence increased by twofold. Obesity also increased more in those with the lowest poverty to income ratio, from 6.1% (95% CI, 1.1-11.2) in 2005-2006 to 9.1% (95% CI, 4.8-13.3) in 2013-2014.
The rates of patients who smoked declined in both groups, but a greater decrease in patients with the highest ratio broadened the gap between the groups.
“To reduce health disparities, there is an urgent need to identify and scale efforts that effectively target the [CV] health of low-income populations,” Beckman and colleagues wrote. – by Darlene Dobkowski
Disclosure: The researchers report no relevant financial disclosures.
Perspective
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The recent study on income disparities confirms what we have seen in previous data that there is a significant impact of socioeconomic status on CV risk. This particular study specifically looks at high-risk status and income, and relates that the declines that we see in smoking and BP are not equally distributed across the income strata.
Although the trends for diabetes and cholesterol do not appear to vary by income, across socioeconomic status, diabetes overall is increasing in the United States. The CV risk of diabetes is not manifested in a very short time, but it can be expected, with increasing rates of diabetes, obesity, physical inactivity and persistent high sodium intake that the downward trend in CV risk that we’ve seen over the last several decades in the U.S. may start to plateau or even reverse.
The lack of a variation in cholesterol levels by income potentially speaks to the fact that it is difficult to actually alter blood cholesterol significantly unless one adheres to a relatively strict diet low in animal products and saturated fat. So, for most Americans, especially those at high risk, medications and specifically statins will be needed if their calculated risk is high.
The differences across sex or gender varies among the various risk factors. Nevertheless, it is important to recognize that because there are more older women than older men, the effects of disparate income on CV risk due to systolic BP may especially affect low-income women.
Systolic BP is a powerful predictor of CV morbidity and mortality, including MI, cerebrovascular events and HF, often underappreciated by clinicians. The fact that systolic BP was lower among high-income adults compared to adults with incomes at or below poverty level speaks directly to the multifactorial problem of controlling BP in poor individuals. Smoking also appears to have a more profound effect in low-income adults, and those two specific risk factors need to be focused on in patients with limited income.
Overall, in the U.S., the degree to which we diminish or decrease these disparities will have an impact in the overall CV health of our nation. While it is expected that the health care delivery system will be applied to all individuals equally, previous data have confirmed that adults with high incomes have greater life expectancy, and the gap between the richest and the poorest adults in the United States may actually be increasing in terms of life expectancy.
One of the concerns is that as we develop newer medications for the control of diabetes and lipids, including the PCSK9 inhibitors, those persons with limited resources will have less access and utilization of newer therapies with the unintended consequence that progress in medicine may lead to a widening of disparities, rich vs. poor.
This study has several limitations, however, and perhaps one of the most important shortcomings is that it measures certain risk factors for CVD, but does not examine other important factors such as BMI, glomerular filtration rate, physical activity and diet, all of which may also have a profound effect and should be examined in future studies.
A recent paper by Renee Hsia, MD, MSc, and colleagues (Hsia RY, et al. Health Affairs. 2017;doi:10.1377/hlthaff.2016.0925) demonstrates evidence of persistent inequities of health care. The researchers specifically examined California hospital-level data on ambulance diversion. They found that hospitals treating a high share of black patients with acute MI were more likely to experience diversion, and that black patients fared worse compared with white patients, experiencing the same level of ED crowding. Therefore, these become additional data to suggest that those hospitals serving especially disadvantaged populations and certain racial ethnic minorities need additional financial support and means to deliver care in the increasingly complex health care system to decrease CV death and disability.
A second recent publication in Health Affairs by Joachim O. Hero and colleagues (Hero JO, et al. Health Affairs. 2017;doi:10.1377/hlthaff.2017.0006) notes that in the U.S., compared with other middle-income and high-income countries worldwide, we have the unfortunate position of leading in differences in health care outcomes by income and in perceptions of health and health care. Specifically, the researchers suggested, although most Americans feel that income-based health care inequities are unfair, there is a relatively low level of moral discomfort over income-based health care disparities and outcomes. The authors note a clear unmet need to overcome public intolerance of health care inequities and that any replacements in health care delivery systems require attention to disparities and not take steps backwards in an area where the U.S. is in sore need of improvement.
For this reason, a coalition of individuals and myself published a paper in the Journal of the American College of Cardiology (Ferdinand KC, et al. J Am Coll Cardiol. 2017;doi:10.1016/j.jacc.2016.11.034) earlier this year focusing on the needs of improved medication adherence in cardiometabolic disease. Nonadherence is a major problem and may contribute to as much as 125,000 preventable deaths, with as much as one-half of persons with CVD not consistently taking medicines as prescribed after 2 years. The FDA and several public health organizations such as the National Forum for Heart Disease and Stroke Prevention and the Association of Black Cardiologists are specifically concerned because inadequate health care can be predicted with poor adherence.
Health literacy, especially in disadvantaged patients, is a strong underpinning of some of these difficulties. Health literacy is needed so that patients can read and understand their medications and the reasons to take medicines as prescribed to decrease CV risk. HHS has suggested that all people have the right to health information to help them make informed decisions, and that this information on medications and health services should be delivered in an easy to understand method so that they can improve their health longevity and quality of life.
Overall, these contemporary publications confirm the powerful predictor of the social determinative health in poor outcomes. Detailed description of the impact of these social disparities was described in a recent American Heart Association scientific statement (Havranek EP, et al. Circulation. 2015;doi:10.1161/CIR.0000000000000228) that notes that the underpinnings of CV outcomes can be affected by socioeconomic position, race, ethnicity, social support, culture and language, access to care and residential environment.
Especially for those clinicians who serve a significant proportion of disadvantaged patients, they should be aware of the difficulty in understanding and adhering to medications and the potential cost burdens, even with multiple generics. For instance, and elderly person with limited income who may be taking eight to nine cardiometabolic medications, even with apparently low copays, may be expected to expend $150 to $200 per month. Clinicians need to ask patients about their adherence and their ability to afford care.
America should keep the spotlight on disparities, and as we change our health care delivery system, either in a positive or negative manner, we need to make sure that we have developed means of insuring health equity, such that health care delivery and access is available and affordable for all regardless of socioeconomic status, race, ethnicity, geography, sex or gender.
Physicians and other clinicians have a responsibility to talk to patients about their understanding of their medications and their ability to afford therapy and access care, with the laudable goal to eliminate these disparities and achieve health equity.