Rapid Responses to:
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Rapid Responses: Rapid Responses published:
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![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Genetic Epidemiology
- Pradeep Paul, Lingam Vijaya, Ronnie George,Rajiv Raman, Tarun Sharma (6 May 2005)
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Putting Racial Drugs in Context
- Jonathan D. Kahn, JD, Ph.D. (7 May 2005)
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Statistics and Incentives
- Ms Shefaly Yogendra (7 May 2005)
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Re: Statistics and Incentives
- Dr JK Anand (8 May 2005)
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Nothing new under the Sun.
- Ivor Hughes (10 May 2005)
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Pradeep Paul, Epidemiologist Vision Research Foundation, Sankara Nethralaya, Chennai - 600006., Lingam Vijaya, Ronnie George,Rajiv Raman, Tarun Sharma
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Genetic epidemiology as a science is more complete as it acknowledges the host role in the disease process, thereby completing the triad of agent - host - environment.Traditionally Randomized Clinical Trials have ignored the host differences while a new drug has been marketed.Now people have started to notice that some drugs works good for some while not the other, this has alereted scientists across the globe to seriously think about pharmacogenomics , mendelian randomization for RCT's ,Personalised care and personalised therapy based on a person's genetic constitution. Gregor Mendel without being really noticed by contemporary scientists, described his observations on the inheritance of various characteristics ("factors") in cross-bred pea plants as manifested in the phenotypes of subsequent generations.Indian systems of Medicine (ISM), disease classfication is based on the three humor theory (Vata, Pitha and Kapha) and personalised care based on alterations of the humor.We know that several diseases have a reasonable genotype and phenotype correlation,so any changes in the genetic composition will be reflected as a phenotypic expression of the resultant disease. ISM practitioner understands the patient phenotypic consitution based on the his nadi (pulse), skin colour,hair,ear lobe, appetite, personality,sleep, temperament and several other chararecteristics pertaining to the three humors.They seem to get some idea of the persons underlying genotype based on his phenotypic characteristics and they prescribe the appropriate treatment regiment for them. Great to see an interesting debate on the racial and ethinicity based differences and Pharmacogenomics.Obervational epidemiologic studies have established some differences across race and ethinicity.Modern epidemiology is undergoing a transformation from the abstract observational epidemiology into the realm Genetic epidemiology.Genetic epidemiological studies with race and ethinicity component can give us a clear picture about the value of race and ethinicity over genetics. Competing interests: None declared |
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Jonathan D. Kahn, JD, Ph.D., Assistant Professor of Law Hamline University School of Law, 1526 Hewitt Ave., St. Paul, MN 55104 USA
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Raj Bhopal and Taslin Rahemtulla focus on the heart failure drug BiDil to explore the “resurgence of the role of biology in concepts of race and ethnicity.” BiDil, a combination of two generic drugs (hydralazine and isosorbide dinitrate) that have been used for years to treat heart failure, is currently undergoing review by the U.S. Food and Drug Administration for approval as the first ever drug with a race- specific indication – to treat heart failure in African-Americans. Bhopal and Rahemtulla assert that “the major implication of BiDil is that differential responses to treatment between racial groups. . . are attributed primarily to genetic differences.” Unfortunately, this is precisely not the major medical implication of BiDil, but rather the major popular misreading of BiDil. The A-HeFT trials, upon which the BiDil submission is based, enrolled only self-identified African-Americans.(1) There was no comparison population, therefore the results say nothing about whether BiDil works differently or better in African-Americans than in anyone else. Moreover, the report makes no claims regarding purported race-specific genetic differences underlying response to BiDil, but merely hypothesizes that such differences may exist. The trial results seem to show that BiDil works to treat heart failure – full stop. The medical evidence from A-HeFT supports no claims regarding racial variation in response. As Bhopal and Rahemtulla note, “a historical perspective is likely to be helpful” in evaluating “claims of racial or ethnic variations in health and disease.” The history of BiDil shows the race-specific design of its clinical trial and marketing to be driven more by considerations of commerce than medicine. NitroMed, the corporate sponsor of the BiDil trials, holds at least two patents to BiDil. One is not race-specific, but it expires in 2007. The other, is race-specific; it does not expire until 2020. (2) NitroMed therefore has a vested interest in framing BiDil as a race-specific drug – regardless of the limitations imposed by the actual evidence. For example, given the relatively small numbers enrolled in the trial (about 1000), it could have designed the trial to include an additional 1,000 non-African-American subjects for comparison. Considering that estimates of the annual revenue stream from BiDil range up to $700 Million (US), this would seem a reasonable added expense. It could also break down its analysis of BiDil’s efficacy by non-racial base- line variables, such as ischemic v. non-ischemic heart failure. But, doing so before the FDA acts might severely compromise the value of NitroMed’s race-specific patent to BiDil. In evaluating claims and counterclaims regarding relations between race and genetic, it is imperative that such background interests be brought to light. (1) Taylor A, et al. 2004. “Combination of Isosorbide Dinitrate and Hydralazine in Blacks with Heart Failure.” N. Engl. J. Med. 351: 2049 -2057. (2) Kahn J. 2004. “How a Drug Becomes “Ethnic”: Law, Commerce, and the Production of Racial Categories in Medicine.” Yale. J. Health Pol’y, L. & Ethics 4: 1-46. Available at http://papers.ssrn.com/sol3/papers.cfm?abstract_id=515942 Competing interests: None declared |
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Ms Shefaly Yogendra, Doctoral Scholar University of Cambridge, CB2 1AG
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WHO experts believe that a lower risk threshold of BMI = 23 should be used for Asians, compared to Caucasians. Another reference from the House of Commons Health Committee's report on obesity is that a BMI of 27.5 triggers the same morbidities in Asians as a BMI of 30 in Caucasians. So perhaps fine difference based on ethnicity do exist. But from policy and strategy point of view, I see 2 key questions: 1. How statistically significant are these 'ethnic' differences? And what is the opportunity cost of making investment in this line of research than in broader, population-level interventions? 2. Many have argued that research money goes more and more into lifestyle diseases of the 'west', as it were. From the (public or private) investor's perspective, there has to be an incentive to invest. The promise of a market, a need backed by purchasing power, is that incentive. If the world's purchasing power is concentrated in certain geographical markets with certain ethnic majorities, where are the incentives? The broader debate in science and research cannot be separated from the question of allocating scarce resources and scientists will have to inform the 'lay' for us all to make the right choices. Note: I am an Asian British person but write this as a researcher of policy and strategy issues in obesity. Competing interests: None declared |
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Dr JK Anand, Retired doctor N/A
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Asian? Do the experts believe that: Turks, Arabs, Chinese, Japanese, Pashtoons, Gurkhas, Malays, Punjabees, Tamils, Bhils are a homogeneous entity? From such experts may the Good Lord deliver us. JK Anand Retired Competing interests: Have written in the past about the absurdity of using the term "Asian" in Medicine. |
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Ivor Hughes, Herbalist www.herbdatanz.com
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To give to each Nation its own type of medicine, the theoricam best suited to it, as it behooves. For I can well realize that my prescriptions may turn out to be ineffectual among the foreign Nations, and that foreign recipes may turn out to be ineffectual in our Nation. That is to say that I write for Europe, and I do not know whether Asia and Africa may profit from it. Paracelsus. Competing interests: None declared |
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