Defining Metabolic Syndrome: Which Kind of Causality, if any, is Required?

Open access

Abstract

The definition of metabolic syndrome (MetS) has been, and still is, extremely controversial. My purpose is not to give a solution to the associated debate but to argue that the controversy is at least partially due to the different ‘causal content’ of the various definitions: their theoretical validity and practical utility can be evaluated by reconstructing or making explicit the underlying causal structure. I will therefore propose to distinguish the alternative definitions according to the kinds of causal content they carry: (1) definitions grounded on associations, (2) definitions presupposing a causal model built upon statistical associations, and (3) definitions grounded on underlying mechanisms. I suggest that analysing definitions according to their causal content can be helpful in evaluating alternative definitions of some diseases. I want to show how the controversy over MetS suggests a distinction among three kinds of definitions based on how explicitly they characterise the syndrome in causal terms, and on the type of causality involved. I will call ‘type 1 definitions’ those definitions that are purely associative; ‘type 2 definitions’ the definitions based on statistical associations, plus generic medical and causal knowledge; and ‘type 3 definitions’ the definitions based on (hypotheses about) mechanisms. These kinds of definitions, although different, can be related to each other. A definition with more specific causal content may be useful in the evaluation of definitions characterised by a lower degree of causal specificity. Moreover, the identification of the type of causality involved is of help to constitute a good criterion for choosing among different definitions of a pathological entity.

In section (1) I introduce the controversy about MetS, in section (2) I propose some remarks about medical definitions and their ‘causal import’, and in section (3) I suggest that the different attitudes towards the definition of MetS are relevant to evaluate their explicative power.

Aguilar-Salinas, C.A.; Rojas, R.; Gómez-Pérez, F.J.; Mehta, R.; Franco, A.; Olaiz, G.; and Rull, J.A. 2005. The metabolic syndrome: a concept hard to define Archives of Medical Research 36(3):223–31.

Alberti, K.G. 2005. Introduction to the metabolic syndrome. European Heart Journal Supplements 7 (D): D3–D5.

Alberti, K. G.; and Zimmet, P. F. 1998. Definition, diagnosis and classification of diabetes mellitus and its complications. Part 1: diagnosis and classification of diabetes mellitus. Provisional report of a WHO consultation. Diabetic Medicine 15(7): 539–53.

Alberti, K.G.; Eckel, P.; Grundy, S.M. et al. 2009. Harmonizing the metabolic syndrome. A joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention, National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity. Circulation 120: 1640–5.

Alberti, K. G. M.; Zimmet, P.; Shaw, J. and IDF Epidemiology Task Force Consensus Group. 2005. The metabolic syndrome—a new worldwide definition. The Lancet 366(9491): 1059–62.

ATP III. 2001. Executive summary of the third report of the National Cholesterol Education Program (NCEP) expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (Adult Treatment Panel III). JAMA 285(19): 2486–7.

Balkau, B.; and Charles, M. A. 1999. Comment on the provisional report from the WHO consultation. Diabetic Medicine 16(5): 442–3.

Boyd, R. 1991. Anti-foundationalism and the enthusiasm for natural kinds. Philosophical Studies 61(1–2): 127–48.

Boyd, R. 1999. Homeostasis, species, and higher taxa. In Species: New Interdisciplinary Studies, ed. by R. Wilson. Cambridge, MA: MIT Press, 141–85.

Campaner, R. 2011. Understanding mechanisms in the health sciences. Theoretical Medicine and Bioethics. 32 (1): 5–17.

Craver, C. F. 2009. Mechanisms and natural kinds. Philosophical Psychology 22(5): 575–94.

Enzi, G.; Busetto, L.; Inelmen, E. M.; Coin, A.; and Sergi, G. 2003. Historical perspective: visceral obesity and related comorbidity in Joannes Baptista Morgagni’s ‘De Sedibus et Causis Morborum per Anatomen Indagata’. International Journal of Obesity 27(4): 534–5.

Eschwège, E. 2005. Metabolic syndrome: which definition(s) for which objective(s)?]. Annales d’Endocrinologie 66(2 Pt 2):1S32–44.

Federspil, G.; Nisoli, E.; and Vettor, R. 2006. A critical reflection on the definition of metabolic syndrome. Pharmacological Research 53: 449–56.

Fujioka, S.; Matsuzawa, Y.; Tokunaga, K.; and Tarui, S. 1987. Contribution of intra-abdominal fat accumulation to the impairment of glucose and lipid metabolism in human obesity. Metabolism 36: 54–9.

Grundy, S. M.; Cleeman, J. I.; et al. 2006. Diagnosis and management of the metabolic syndrome. An American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Current Opinion in Cardiology 21: 1–6.

Haller, H.; and Hanefeld, M. 1975. Synoptische Betrachtung Metabolischer Risikofaktoren. In Lipidstoffwechselstörungen, ed. by H. Haller, M. Hanefeld and W. Jaross. Jena: Gustav Fischer Verlag, 254–64.

Hitzenberger, K.; and Richter-Quittner, M. 1921. Ein Beitrag zum Stoffwechsel bei der vasculären Hypertonie. Wiener Archive für Innere Medizin 2: 189–216.

IDF (International Diabetes Federation). 2005. The IDF Consensus Worldwide Definition of the Metabolic Syndrome. Available at: www.idf.org/metabolic-syndrome.

Jørgensen, M.E.; and Borch-Johnsen, K. 2004. The metabolic syndrome—is one global definition possible? Diabetic Medicine 21(10):1064–5.

Kahn, R. 2006. The metabolic syndrome (emperor) wears no clothes. Diabetes Care 29(7): 1693–6.

Kahn, R.; Buse, J.; Ferrannini, E.; and Stern, M. 2005. The metabolic syndrome: time for a critical appraisal. Joint statement from the American Diabetes Association and the European Association for the Study of Diabetes. Diabetes Care 28(9): 2289–304.

Kendler, K. S.; Zachar, P.; and Craver, C. 2011. What kinds of things are psychiatric disorders? Psychological Medicine 41(06): 1143–50.

Kincaid, H. 2008. Do we need theory to study disease? Lessons from cancer research and their implications for mental illness. Perspectives in Biology and Medicine 51(3): 367–78.

Kincaid, H. 2011. Causal modelling, mechanisms, and probability in epidemiology. In Causality in the Sciences, ed. Phyllis McKay Illari, Federica Russo and Ion Williamson. Oxford: Oxford University Press: 70–90.

Kincaid, H. 2012. Mechanisms, causal modeling, and the limitations of traditional regression. In The Oxford Handbook of Philosophy of Social Science, ed. Harold Kincaid. Oxford: Oxford University Press: 46–64.

Kissebah, A.H.; Vydelingum, N.; Murray, R.; Evans, D. J.; Kalkhoff, R. K.; and Adams, P. W. 1982. Relation of body fat distribution to metabolic complications of obesity. The Journal of Clinical Endocrinology and Metabolism 54 (2): 254–60.

Kitano, H.; Oda, K.; Kimura, T.; Matsuoka, Y.; Csete, M.; Doyle, J.; and Muramatsu, M. 2004. Metabolic syndrome and robustness tradeoffs. Diabetes 53 (suppl 3): S6–S15.

Kraja, A. T.; Province, M. A.; Huang, P.; Jarvis, J. P.; Rice, T.; Cheverud, J. M.; and Rao, D. C. 2008. Trends in metabolic syndrome and gene networks in human and rodent models. Endocrine, Metabolic and Immune Disorders-Drug Targets 8(3): 198–207.

Kylin, E. 1921. Hypertonie und Zuckerkrankenheit. Zentralblatt für innere Medizin 42: 873–7.

Kylin, E. 1923. Studien über das Hypertonie-Hyperglykämie-Hyperurikämie Syndrom. Zentralblatt für innere Medizin 44: 105–27.

Lam, D. W.; and LeRoith, D. 2015. Metabolic syndrome. In Endotext [Internet]. Ed. by L.J De De Groot, P. Beck-Peccoz, G. Chrousos et al. http://www.ncbi.nlm.nih.gov/pubmed/25905173.

Leśniak, W.; and Kolasińska-Kloch, W. 2003. Do syndromes X, cardiac and metabolic, have any similar characteristics?. Folia Medica Cracoviensia 44(1–2): 59–69.

Liberopoulos, E.N.; and Elisaf, M.S. 2005. Diagnosis of the metabolic syndrome: which definition should we use? The Hellenic Journal of Cardiology 46(4): 258–62.

Lim, H.S.; Patel, J.V.; Lip, G.Y. 2004. Metabolic syndrome: a definition in progress. Circulation 110(4):e35; author reply e35.

Marañon, G. 1922. Über Hypertonie und Zuckerkrankenheit. Zentralblatt für Innere Medizin 43: 169–76.

Mitka, M. 2005. Does the metabolic syndrome really exist? JAMA 294: 2010–3.

Ninomiya, J.K.; L’Italien, G.; Criqui, M.H.; Whyte, J.L.; Gamst, A.; Chen, R. 2004. Association of the metabolic syndrome with history of myocardial infarction and stroke in the third National Health and Nutrition Examination Survey. Circulation 109: 42– 6.

Oda, E. 2012. Metabolic syndrome: its history, mechanisms, and limitations. Acta Diabetologica 49(2): 89–95.

Pearl, J. 2000. Causality: Models, Reasoning, and Inference. Cambridge: Cambridge University Press. 2nd ed. 2010.

Real, J.T.; and Carmena, R. 2005. Relevance of metabolic syndrome and its definition depending on the criteria employed. Medicina Clinica 124(10): 376–8.

Reaven, G. M. 1988. Role of insulin resistance in human disease. Diabetes 37: 1595–607.

Reaven, G M. 2004. The metabolic syndrome or the insulin resistance syndrome? Different names, different concepts, and different goals. Endocrinology and Metabolism Clinics of North America 33(2): 283–303.

Reaven, G. M. 2005. The metabolic syndrome: requiescat in pace. Clinical Chemistry 51(6): 931–8.

Reaven, G. M. 2006. The metabolic syndrome: is this diagnosis necessary? The American Journal of Clinical Nutrition 83(6): 1237–47.

Reaven, G. M. 2011. The metabolic syndrome: time to get off the merry-go-round? Journal of Internal Medicine 269 (2): 127–36.

Rosas Peralta, M. 2005. Definition of metabolic syndrome: Tower of Babel. Archivos de cardiología de México 75(2): 230–3.

Shahar, E. 2010. Metabolic syndrome? A critical look from the viewpoints of causal diagrams and statistics. Journal of Cardiovascular Medicine 11(10): 772–9.

Spirtes, P.; Glymour, C. N.; and Scheines, R. 1993. Causation, Prediction, and Search. Lecture Notes in Statistics. 2nd ed. Cambridge: Cambridge University Press, 2009.

Vague, J. 1947. La différenciation sexuelle: facteur déterminant des formes de l’obesité. Presse Medicale 30: 339–40.

Zimmermann, J. G. 1763. Von der Erfahrung in der Arzneykunst. 2 Bde. Zürich: bey Heidegger und Compagnie.

Disputatio

International Journal of Philosophy

Journal Information

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 58 58 58
PDF Downloads 35 35 35