‘Heart failure’ is a term used by doctors to describe a state where the heart muscle has become quite ineffective at pumping blood around the body. This problem can manifest in a variety of ways including fatigue, breathlessness, swelling (oedema) in the lower legs and fluid build-up in the lungs (pulmonary oedema). Ultimately, the condition can prove fatal. Heart failure can be caused by one or more of several factors including ‘heart disease’ (‘furring up’ of the arteries that supply blood to the heart muscle), persistently raised blood pressure and disease of the heart muscle itself (cardiomyopathy).
While raised cholesterol levels are often said to be bad news for the heart, I was interested to read a recently published piece of research which assessed the relationship between cholesterol levels and health outcomes in individuals suffering from heart failure. In this US-based study, about 2,500 people were assessed for an average of almost 3 years [1]. The researchers compared levels of supposedly unhealthy low-density lipoprotein cholesterol (LDL-C) and overall risk of death during the period of the study.
What the researchers found is that individuals with LDL-C cholesterol levels < 1.84 mmol/l (71 mg/dl ) were, overall, at a 68 per cent increased risk of death compared to individuals whose LDL-C levels were significantly higher (> 3.36 mmol/l = 130 mg/dl).
This study, though, is not a one-off. Previous research has also linked lower levels of cholesterol with worse outcomes in those suffering from heart failure. In one study published in 2006, lower levels of total cholesterol were found to be associated with increased risk of death in patients with heart failure. The authors of this study concluded that: “Further research is necessary to determine the nature of this relationship, optimal lipid levels, and the therapeutic role, if any, of statins in patients with established [heart failure].”
I think the caution these researchers advise in the use of statins in individuals with heart failure is relevant for two reasons. Firstly, statins may reduce cholesterol to levels associated with worse outcomes. Secondly, though, statins can deplete the body of the nutrient coenzyme Q10. Coenzyme Q10 contributes to muscle function, and low levels of it can conceivably compromise the functioning of the heart (the heart is a muscle, after all). The last thing we want to be doing, in my opinion, is weakening a muscle that is, by definition, already weakened.
References:
1. Kahn MR, et al. Low-Density Lipoprotein Levels in Patients With Acute Heart Failure. Congest Heart Fail 2012 Oct 16. [Epub ahead of print]
2. Afsarmanesh N, et al. Total cholesterol levels and mortality risk in nonischemic systolic heart failure. Am Heart J. 2006;152(6):1077-83
