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Seasonal variation in serum cholesterol levels may be another explanation for seasonal variation in acute myocardial infarction
International Journal of Cardiology 104 (2005) 101 www.elsevier.com/locate/ijcard
Letter to the Editor
Seasonal variation in serum cholesterol levels may be another explanation for seasonal variation in acute myocardial infarction Tsung O. Cheng George Washington University, Medical Center, Washington, DC 20037, United States Received 23 July 2004; accepted 27 July 2004 Available online 16 February 2005
Keywords: Serum cholesterol levels; Acuter myocardial infarction; Seasonal variation
The recent report of seasonal variation in serum cholesterol [1] not only has implications for lipid screening guidelines but also may serve as another explanation for seasonal variation in acute myocardial infarction [2]. It has been well established that there is an increase in acute myocardial infarction in winter months worldwide [2–6]. Several explanations have been offered [2,7], including meteorological [2,8] and infectious [3]. Obviously, whereas temperature may be a contributor to seasonal variation in acute myocardial infarction, it does not solely explain the winter increases [7]. There also seems to be a greater amplitude in seasonal variability in women [1]. According to Grech et al. [9], low winter temperatures may be more likely to trigger acute myocardial infarction in older patients, and as women tend to present with acute myocardial infarction at a later age than men, women will therefore tend to exhibit a more marked seasonal variation than men. Finally, more patients could have been diagnosed as having high blood lipids during the winter due to a possible selection bias because of more coronary events during the winter months [1]. On the other hand, these two findings might be causally related. This causality undoubtedly will have significant therapeutic implications. Obviously more research is needed to better understand the association between winter, increased serum cholesterol levels and acute myocardial infarction.
E-mail address: [email protected]. 0167-5273/$ - see front matter D 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2004.07.020
References [1] Ockene IS, Chiriboga DE, Stanek III EJ, Harmatz MG, Nicolosi R, Saperia G, et al. Seasonal variation in serum cholesterol levels. Treatment implications and possible mechanisms. Arch Intern Med 2004;164:863 – 70. [2] Cheng TO. Mechanism of seasonal variation in acute myocardial infarction. Int J Cardiol 2005;100:163–4. [3] Moschos N, Christoforaki M, Antonatos P. Seasonal distribution of acute myocardial infarction and its relation to acute infections in a mild climate. Int J Cardiol 2004;93:39 – 44. [4] Gonzalez Hernandez E, Cabades O’Callaghan A, Cebrian Domenech J, Lopez Merino V, Sanjuan Manez R, Echanove Errazti I, et al. Seasonal variations in admissions for acute myocardial infarction. The PRIMVAC study. Rev Esp Cardiol 2004;57:12 – 9. [5] Spencer FA, Goldberg RJ, Becker RC, Gore JM. Seasonal distribution of acute myocardial infarction in the second National Registry of Myocardial Infarction. J Am Coll Cardiol 1998;31:1226 – 33. [6] Wang CM, Ma S, Lam TH, Hedley AJ. Coronary artery disease varies seasonably in subtropics. BMJ 1999;319:1004. [7] Williams ES, Zipes DP. The winter’s tale—and toll. Am Heart J 2003; 146:941 – 3. [8] Cheng TO. Seasonal incidence of acute myocardial infarction in the Chinese population. Cardiology 1998;90:312. [9] Grech V, Aquilina O, Pace J. Gender differences in seasonality of acute myocardial infarction admissions and mortality in a population-based study. J Epidemiol Community Health 2001;55:147 – 8.
Letter to the Editor
Seasonal variation in serum cholesterol levels may be another explanation for seasonal variation in acute myocardial infarction Tsung O. Cheng George Washington University, Medical Center, Washington, DC 20037, United States Received 23 July 2004; accepted 27 July 2004 Available online 16 February 2005
Keywords: Serum cholesterol levels; Acuter myocardial infarction; Seasonal variation
The recent report of seasonal variation in serum cholesterol [1] not only has implications for lipid screening guidelines but also may serve as another explanation for seasonal variation in acute myocardial infarction [2]. It has been well established that there is an increase in acute myocardial infarction in winter months worldwide [2–6]. Several explanations have been offered [2,7], including meteorological [2,8] and infectious [3]. Obviously, whereas temperature may be a contributor to seasonal variation in acute myocardial infarction, it does not solely explain the winter increases [7]. There also seems to be a greater amplitude in seasonal variability in women [1]. According to Grech et al. [9], low winter temperatures may be more likely to trigger acute myocardial infarction in older patients, and as women tend to present with acute myocardial infarction at a later age than men, women will therefore tend to exhibit a more marked seasonal variation than men. Finally, more patients could have been diagnosed as having high blood lipids during the winter due to a possible selection bias because of more coronary events during the winter months [1]. On the other hand, these two findings might be causally related. This causality undoubtedly will have significant therapeutic implications. Obviously more research is needed to better understand the association between winter, increased serum cholesterol levels and acute myocardial infarction.
E-mail address: [email protected]. 0167-5273/$ - see front matter D 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2004.07.020
References [1] Ockene IS, Chiriboga DE, Stanek III EJ, Harmatz MG, Nicolosi R, Saperia G, et al. Seasonal variation in serum cholesterol levels. Treatment implications and possible mechanisms. Arch Intern Med 2004;164:863 – 70. [2] Cheng TO. Mechanism of seasonal variation in acute myocardial infarction. Int J Cardiol 2005;100:163–4. [3] Moschos N, Christoforaki M, Antonatos P. Seasonal distribution of acute myocardial infarction and its relation to acute infections in a mild climate. Int J Cardiol 2004;93:39 – 44. [4] Gonzalez Hernandez E, Cabades O’Callaghan A, Cebrian Domenech J, Lopez Merino V, Sanjuan Manez R, Echanove Errazti I, et al. Seasonal variations in admissions for acute myocardial infarction. The PRIMVAC study. Rev Esp Cardiol 2004;57:12 – 9. [5] Spencer FA, Goldberg RJ, Becker RC, Gore JM. Seasonal distribution of acute myocardial infarction in the second National Registry of Myocardial Infarction. J Am Coll Cardiol 1998;31:1226 – 33. [6] Wang CM, Ma S, Lam TH, Hedley AJ. Coronary artery disease varies seasonably in subtropics. BMJ 1999;319:1004. [7] Williams ES, Zipes DP. The winter’s tale—and toll. Am Heart J 2003; 146:941 – 3. [8] Cheng TO. Seasonal incidence of acute myocardial infarction in the Chinese population. Cardiology 1998;90:312. [9] Grech V, Aquilina O, Pace J. Gender differences in seasonality of acute myocardial infarction admissions and mortality in a population-based study. J Epidemiol Community Health 2001;55:147 – 8.