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Overview

Cholesterol

  • World Health Report 2002 estimates that 60% of heart attacks and 40% of stroke (ischemic stroke) is due to a cholesterol level in excess of the optimum level of 150 mg/dl. 1 More recent European guidelines suggest a target cholesterol of less than 150 mg/dl (4 mmol/l) for people with or high risk of heart disease.2
  • A low total cholesterol value in midlife (<154 mg/dl) predicts both better survival and better physical functioning in old age according to a study that followed 1292 business men for 46 years.3
  • The INTERHEART study showed cholesterol to be the most important risk factor for heart disease across the globe2, 4, 5 Approximately, 44% of heart attack among South Asians is attributable to abnormal blood lipids.2, 4, 5
  • The risk of CAD (coronary artery disease) from high cholesterol as well as the benefit of lowering high cholesterol is greater at younger ages.6 A 40 mg/dL lower cholesterol level was associated with about 56% lower CAD mortality at ages 40-49, in both sexes but decreases to 34% at ages 50-69, and to 17% at ages 70-89 years.7, 8
  • Mortality rates due to CAD have declined by more than 43% in the U.S. from 1980 to 2000.9  About half of this decline is attributed to  reductions in risk factors.9  Decrease in cholesterol was the largest contributor (24%) followed by blood pressure control (20%) and smoking reduction (12%).9
  • Ever since it was first isolated from gallstones in 1784, cholesterol has exerted a hypnotic fascination for scientists from the most diverse domains of science and medicine.  Cholesterol is the most highly decorated small molecule in biology with 13 Nobel Prizes having been awarded to scientists who devoted major parts of their careers to cholesterol.
  • The long tradition of research on cholesterol has led to fundamental discoveries about a two-faced molecule: not only is it essential to life, but its excess in the vasculature underlies the major cause of death in the developed world. Progress in understanding both faces will come from continued research efforts, could lead to more Nobel prices for this “small molecule”  and  major advances in our understanding of its role in cardiovascular disease.
  • The elevated cholesterol can be reduced by drugs, and dietary changes, particularly with a reduction in the consumption of saturated fat. Cholesterol-lowering medications are widely available, highly effective and can play an essential role in reducing cardiovascular disease around the world.  Despite these facts, effective medication use and control of high cholesterol remains disappointingly low in both high and low income countries. Untreated high blood cholesterol represents a missed opportunity in the face of a global epidemic of cardiovascular diseases.10
  • A study of 79,039 adults aged 40-79 years from England, Germany, Japan, Jordan, Mexico, Scotland, Thailand and the United States found wide variation in undiagnosed high cholesterol (>240 mg/d) which ranged from 16% in the US to 78% in Thailand. The fraction of diagnosed but untreated ranged from 9% in Thailand to 53% in Japan. The proportion of those treated and attained the target ranged from 4% in Germany to 58% in Mexico.10
  • Time series estimates showed improved control of high total serum cholesterol over the past two decades in England and the United States.10
  • High cholesterol (>240 mg/dl) is found in 16% US adults >20 years of age and 10% of adolescents 12 to 19 years of age. Mean cholesterol is 165 mg/dl in children 4-11 years of age, 161 mg/dl in adolescents and 199 mg/dl in adults (198 in men and 202 in women).
  • In 2005–2006, approximately 65% of men and 70% of women had been screened for high cholesterol in the past 5 years.
  • Although a cholesterol level less than 200 mg/dl is generally considered a desirable level, this is not the case for Asian Indians for whom the desirable level is 20% lower or less than 160 mg/dl.8, 11-13
FAQ

Q.How common is undiagnosed and untreated elevated cholesterol? 

Untreated high blood cholesterol (>240 mg/dl) represents a missed opportunity in the face of a global epidemic of cardiovascular diseases and there is wide variation across the globe.14 The proportion of undiagnosed individuals with high TC was highest in Thailand (78%) and lowest in the United States (16%). The fraction diagnosed but untreated ranged from 9% in Thailand to 53% in Japan. The proportion being treated who had attained evidence of control ranged from 4% in Germany to 58% in Mexico. Thus, the percentage of people with high total serum cholesterol who are effectively treated remains small in many  high- and middle-income countries. Many of those affected are unaware of their condition.14

Sources

1. World Health Organization. Risk Management Package Geneva: World Health Organization;2002.

2. Joshi P, Islam S, Pais P, et al. Risk factors for early myocardial infarction in South Asians compared with individuals in other countries. Jama. Jan 17 2007;297(3):286-294.

3. Hyttinen L, Strandberg TE, Strandberg AY, et al. Effect of Cholesterol on Mortality and Quality of Life up to a 46-Year Follow-Up. Am J Cardiol. Sep 1 2011;108(5):677-681.

4. Pais P, Pogue J, Gerstein H, et al. Risk factors for acute myocardial infarction in Indians: A case-control study. Lancet. 1996;348(9024):358-363.

5. Yusuf S, Hawken S, Ounpuu S, et al. Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet. Sep 11 2004;364(9438):937-952.

6. Law MR, Wald NJ, Thompson SG. By how much and how quickly does reduction in serum cholesterol concentration lower risk of ischaemic heart disease? BMJ. 1994;308(6925):367-372.

7. Lewington S, Whitlock G, Clarke R, et al. Blood cholesterol and vascular mortality by age, sex, and blood pressure: a meta-analysis of individual data from 61 prospective studies with 55,000 vascular deaths. Lancet. Dec 1 2007;370(9602):1829-1839.

8. Enas E.A., Hancy Chennikkara Pazhoor MD, Arun Kuruvila MBBS, Krishnaswami Vijayaraghavan MD F. Intensive Statin Therapy for Indians:Part I Benefits. Indian Heart J 2011; 63: 211-227.

9. Ford ES, Ajani UA, Croft JB, et al. Explaining the decrease in U.S. deaths from coronary disease, 1980-2000. N Engl J Med. Jun 7 2007;356(23):2388-2398.

10. Roth G A, Fihn SD, Mokdad AH, Aekplakorn W, Hasegawa T, Lim SS. High total serum cholesterol, medication coverage and therapeutic control: an analysis of national health examination survey data from eight countries. Bull World Health Organ. Feb 1 2011;89(2):92-101.

11. Enas  EA, Singh V, Munjal YP, et al. Recommendations of the second Indo-U.S. health summit on prevention and control of cardiovascular disease among Asian Indians. Indian Heart J. May-Jun 2009;61(3):265-274.

12. Enas EA, Singh V, Munjal YP, Bhandari S, Yadave RD, Manchanda SC. Reducing the burden of coronary artery disease in India: challenges and opportunities. Indian Heart J. Mar-Apr 2008;60(2):161-175.

13. Enas EA. How to Beat the Heart Disease Epidemic among South Asians: A Prevention and Management Guide for Asian Indians and their Doctors. Downers Grove: Advanced Heart Lipid Clinic  USA; 2011.

14.Narayan K M, Aviles-Santa L, Oza-Frank R, et al. Report of a National Heart, Lung, And Blood Institute Workshop: heterogeneity in cardiometabolic risk in Asian Americans In the U.S. Opportunities for research. J Am Coll Cardiol. Mar 9 2010;55(10):966-973.

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