HDL-C (High-Density Lipoprotein Cholesterol)

• Low blood level of HDL-C (<40 mg/dL and in men HDL <50 mg/dL in women) is an independent risk factor for morbidity and mortality from cardiovascular disease (CVD) such as heart attack, stroke, peripheral arterial disease.

• Low HDL-C is associated with  an increased risk of coronary artery disease (CAD) even if  LDL-C levels are not elevated.¹ A 10 mg/dL decrease in HDL-C confers the same risk for CAD as 30 mg/dL increase in LDL-C.^{2 3}

• When combined with a high total/HDL-C ratio (>3), low HDL-C is a potent predictor of coronary plaque burden and progression leading to prematurity and severity of CAD including left main and 3-vessel coronary disease and proximal disease of the left anterior descending artery (widow maker).^4-8

• Low blood level of HDL-C is also a powerful prognosticator with a poor outcome following coronary angioplasty and bypass surgery including repeat revascularization and periprocedural heart attack, long term prognosis and death.^9-15

• For every 1% increase in HDL achieves a 2% decrease in cardiac events such as heart attack.¹⁶ However, the greatest benefit occurs in people with LDL-C < 130 mg/dl.¹⁷

• Low HDL-C often with high triglyceride is very common among Indians and genetic factors may be involved in addition to high glycemic load.^{18, 19} The prevalence of low HDL-C is as high as 50% 90% compared to 15-20% among Americans.^20-22

• Asian Indians not only have low levels of protective HDL-C but also have a preponderance of small dense dysfunctional HDL particles which are less protective and pro-inflammatory even at normal levels.^22-27 (Also See HDL-raising Therapy and Is very high HDL good for you?)

Sources 

1. Lien W, Lai L, Shyu K, et al. Low serum, high-density lipoprotein cholesterol concentration is an important coronary risk factor in Chinese patients with low serum levels of total cholesterol and triglyceride. Am J Cardiol. 1996;77:1112-1115.

2. Jacobs DR Jr, Mebane IL, Bangdiwala SI, Criqui MH, Tyroler HA. High density lipoprotein cholesterol as a predictor of cardiovascular disease mortality in men and women: the follow-up study of the Lipid Research Clinics Prevalence Study. Am J Epidemiol. 1990;131(1):32-47.

3. Toth PP. When high is low: raising low levels of high-density lipoprotein cholesterol. Current cardiology reports. Nov 2008;10(6):488-496.

4. Alber HF, Wanitschek MM, de Waha S, et al. High-density lipoprotein cholesterol, C-reactive protein, and prevalence and severity of coronary artery disease in 5641 consecutive patients undergoing coronary angiography. Eur J Clin Invest. Jun 2008;38(6):372-380.

5. Lan Hsia S, Duncan R, Schob AH, et al. Serum levels of high-density lipoprotein phospholipids correlate inversely with severity of angiographically defined coronary artery disease. Atherosclerosis. Oct 2000;152(2):469-473.

6. Roemer R, Taylor A, Lariviere J. Origins of the WHO Framework Convention on Tobacco Control. Am J Public Health. Jun 2005;95(6):936-938.

7. Hausmann D, Johnson J, Sudhir K, et al. Angiographically silent atherosclerosis detected by intravascular ultrasound in patients with familial hypercholesterolemia and familial combined hyperlipidemia: correlation with high density lipoproteins. J Am Coll Cardiol. 1996;27(7):1562-1570.

8. Nair D, Carrigan TP, Curtin RJ, et al. Association of total cholesterol/ high-density lipoprotein cholesterol ratio with proximal coronary atherosclerosis detected by multislice computed tomography. Prev Cardiol. Winter 2009;12(1):19-26.

9. Foody JM, Ferdinand FD, Pearce GL, Lytle BW, Cosgrove DM, Sprecher DL. HDL cholesterol level predicts survival in men after coronary artery bypass graft surgery: 20-year experience from The Cleveland Clinic Foundation. Circulation. 2000;102(19 Suppl 3):III90-94.

10. Goldbourt U, Cohen L, Neufeld HN. High density lipoprotein cholesterol: prognosis after myocardial infarction. The Israeli Ischemic Heart Disease Study. Int J Epidemiol. Mar 1986;15(1):51-55.

11. Romm PA, Green CE, Reagan K, Rackley CE. Relation of serum lipoprotein cholesterol levels to presence and severity of angiographic coronary artery disease. Am J Cardiol. 1991;67(6):479-483.

12. Pearson TA, Bulkley BH, Achuff SC, Kwiterovich PO, Gordis L. The association of low levels of HDL cholesterol and arteriographically defined coronary artery disease. Am J Epidemiol. 1979;109(3):285-295.

13. Wolfram RM, Brewer HB, Xue Z, et al. Impact of low high-density lipoproteins on in-hospital events and one-year clinical outcomes in patients with non-ST-elevation myocardial infarction acute coronary syndrome treated with drug-eluting stent implantation. Am J Cardiol. Sep 15 2006;98(6):711-717.

14. Sattler KJ, Herrmann J, Yun S, et al. High high-density lipoprotein-cholesterol reduces risk and extent of percutaneous coronary intervention-related myocardial infarction and improves long-term outcome in patients undergoing elective percutaneous coronary intervention. Eur Heart J. Aug 2009;30(15):1894-1902.

15. Ghazzal ZB, Dhawan SS, Sheikh A, et al. Usefulness of serum high-density lipoprotein cholesterol level as an independent predictor of one-year mortality after percutaneous coronary interventions. Am J Cardiol. Apr 1 2009;103(7):902-906.

16. Devendra GP, Whitney EJ, Krasuski RA. Impact of increases in high-density lipoprotein cholesterol on cardiovascular outcomes during the armed forces regression study. J Cardiovasc Pharmacol Ther. Dec 2010;15(4):380-383.

17. Goldenberg I, Benderly M, Sidi R, et al. Relation of clinical benefit of raising high-density lipoprotein cholesterol to serum levels of low-density lipoprotein cholesterol in patients with coronary heart disease (from the Bezafibrate Infarction Prevention Trial). Am J Cardiol. Jan 1 2009;103(1):41-45.

18. Miller M, Rhyne J, Khatta M, Parekh H, Zeller K. Prevalence of the APOC3 promoter polymorphisms T-455C and C-482T in Asian Indians. Am J Cardiol. 2001;87(2):220-221.

19. Miller M. Current perspectives on the management of hypertriglyceridemia. Am Heart J. 2000;140(2):232-240.

20. Karthikeyan G, Teo KK, Islam S, et al. Lipid profile, plasma apolipoproteins, and risk of a first myocardial infarction among Asians: an analysis from the INTERHEART Study. J Am Coll Cardiol. Jan 20 2009;53(3):244-253.

21. Enas EA, Garg A, Davidson MA, Nair VM, Huet BA, Yusuf S. Coronary heart disease and its risk factors in first-generation immigrant Asian Indians to the United States of America. Indian heart journal. Jul-Aug 1996;48(4):343-353.

22. Superko HR, Enas EA, Kotha P, Bhat NK, Garrett B. High-density lipoprotein subclass distribution in individuals of asian Indian descent: the National Asian Indian Heart Disease Project. Prev Cardiol. Spring 2005;8(2):81-86.

23. Enas EA, Senthilkumar A, Chacko V, Puthumana N. Dyslipidemia among Indo-Asians: Strategies for identification and management. Brit J of Diabetes and Vascular Dis. 2005;5:81-90.

24. Enas EA, Chacko V, Pazhoor SG, Chennikkara H, Devarapalli HP. Dyslipidemia in South Asian patients. Curr Atheroscler Rep. Nov 2007;9(5):367-374.

25. 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.

26. Dodani S. Excess coronary artery disease risk in South Asian immigrants: can dysfunctional high-density lipoprotein explain increased risk? Vascular health and risk management. 2008;4(5):953-961.

27.Bhalodkar NC, Blum S, Rana T, Kitchappa R, Bhalodkar AN, Enas EA. Comparison of high-density and low-density lipoprotein cholesterol subclasses and sizes in Asian Indian women with Caucasian women from the Framingham Offspring Study. Clinical cardiology. May 2005;28(5):247-251.