Also, certain types of blood pressure medications – ACE inhibitors, for example – lead to worse outcomes in African-Americans when used singularly as first-line therapy for high blood pressure, yet these medications work very well in Americans of European decent, a large study of hypertension therapy found.
A follow-up study that looked at subsequent clinical practices – which was done in response to changed recommendations based on race – showed nearly a third of African-American hypertensive patients continued to be prescribed medications that cause worse outcomes.
African-Americans also have a four-fold increased risk for renal disease leading to dialysis. Geneticists suspect that they have identified the gene that drives this difference yet most clinicians do not have the resources to test for this gene and identify the 30 percent of African-Americans that carry it.
And a gene that greatly increases the risk for Alzheimer’s disease, APOE-4, has also been identified and occurs disproportionately higher in European-Americans yet is almost nonexistent in African-Americans and is inconsistent in Hispanic-Americans. Great controversy exists surrounding the testing for this gene, given the devastating impact it could have on a patient or family. (Hispanic and African-Americans still have a very significant risk for Alzheimer’s disease, but it is not driven by this gene).
Genetically different responses to medications
Patient response to medications vary according to the presence or absence of genetic variants, which can impact the dose and the effect of many pharmaceuticals. Some of these differences can be anticipated based on race or ethnicity. For example, Warfarin is a commonly used medication in the treatment of a number of cardiovascular disorders including atrial fibrillation, deep vein thrombosis and heart valve replacement. It shows wide variations in dosing, with Americans of Asian descent requiring less medication and African-Americans requiring more to achieve equal effects. European-Americans have a variant gene that make having a major bleed on Warfarin much higher.
A popular cholesterol-lowering medication, Rosuvastatin, better known as trade name Crestor, is twice as powerful in patients of Asian descent, and their manufacturing label indicates starting at a much lower dose in this population. In fact, the highest manufactured pill dose of Crestor is “contraindicated in Asian patients.”
Patient-centered care is the key
Because of the “patient-centered” movement in hospitals, clinics and insurance plans, providers are now feeling increased pressure to improve the quality of care provided to individual patients. Many outcomes and patient cost of care are now tracked by providers. And countless well-designed studies have validated verified differences in the clinical care of a number of pervasive diseases based on ancestry.
Providers need to educate themselves about the important differences that exist in their patient populations. Health disparities, while driven by a number of social factors, are also the result of some clinicians not applying known nuances in the care of special populations.
As home genetic testing grows, patients will be bringing their results to physicians for reaction and response. Physicians will need to be proactively prepared.