You don’t have to wait too long before yet another study is published which is used to persuade us that cholesterol is a killer and cholesterol-reducing drugs are essential for keeping us from the mortal spectre of heart disease. The focus, for some time, has been on controlling so-called ‘low density lipoprotein (LDL) cholesterol’ ” the form of cholesterol we are told is responsible for gumming up our arteries and increasing risk of heart disease. Official recommendations regarding LDL levels come from a body known as the National Cholesterol Education Programme in the USA. The latest recommendations from this body emerged in 2004 when it advised that:
For patients at high risk of heart disease LDL should be lower than 2.59 mmol/l (100 mg/dL)
For patients at very high risk of heart disease LDL should be lower than 1.81 mmol/l (70 mg/dL)
The suggestion is that individuals whose cholesterol levels are above these thresholds should take enough statin (cholesterol reducing medication) to get them into the ‘desirable’ range.
However, not everyone agreed with these recommendations. The authors of an independent review of the basis for these recommendations which appeared in the Annals of Internal Medicine stated: In this review, we found no high-quality clinical evidence to support current treatment goals for [LDL] cholesterol. They also went on to say that the recommended practice of adjusting statin dose to achieve recommended cholesterol levels was not scientifically proven to be beneficial or safe [1]. After the guidelines were published it was subsequently revealed that of the 9 members of the NCEP panel, all but one of whom had potential financial conflicts of interest that you can read here. Also, see here for reasons why it might not be such a good idea to drive cholesterol levels too low (namely because low cholesterol levels are associated with an increased risk of cancer and, err, death).
You may need this background when you consider the conclusions drawn from a study published last week in the American Heart Journal [2]. In this study, cholesterol levels were measured in almost 137,000 individuals, soon after they had been admitted to hospital with a heart-disease related problem (e.g. heart attack). It was found that almost half (49.6 per cent, to be precise) of these individuals had LDL levels less than 2.59 mmol/l (100 mg/dl). And almost 18 per cent had cholesterol levels less than 1.81 mmol/l (70 mg/dL). The authors concluded that These findings may provide further support for recent guideline revisions with even lower LDL goals. This study is being used to suggest that the NCEP guidelines may simply not be low enough. See here for an example (originating from Reuters) of how this study is being reported.
Now, stepping aside from the science for just a moment, let’s view all of this from a common sense perspective. Cholesterol is a substance which, among other things, is essential for the production of steroid hormones in the body (e.g. cortisol and sex hormones). It also plays an essential role in the membranes of the body’s cells. Cholesterol is crucial to health. But the message appears to be that what are essentially ‘normal’ levels of cholesterol are somehow causing a disease i.e. heart disease. Some would say that the notion that an essentially body constituent at normal levels is putting us in mortal danger doesn’t really make sense.
But more importantly, perhaps, what of the science? Well, we’ve been here before: all this focus on heart disease neglects the fact that heart disease is not the only killer. Far better, I think, to focus on funeral rates (overall mortality, in medical parlance). And as stated above, here we see the idea of lowering cholesterol levels to death-defying levels might actually, ironically, be hastening individuals’ demise. More on the potential hazards of cholesterol reduction can be read here.
Read the Reuters report that I’ve linked to and you’ll see that one of the authors of this study, Dr Gregg Fonarow, has stated that: “The conventional cholesterol guidelines are missing the majority of patients” who have heart attacks and related problems. I feel it only fair to point out (unlike the Reuters piece) that Dr Fonarow does have some conflicts of interest to declare when it comes to receiving money from statin manufacturers. In the actual paper, these are listed as: research from Pfizer and GlaxoSmithKline; consultant and honorarium from Abbott, AstraZeneca, GlaxoSmithKline, Merck, Pfizer, and Schering Plough…”
Dr Fonarow and his co-authors clearly have a special interest in cholesterol and health, and so it seems a shame to me that at no point in their paper does the subject of cholesterol levels and its relationship to overall mortality or cancer come up. According to Dr Fonarow, the results of this study should serve as a wake-up call for anyone interested in reducing death and disability due to cardiovascular disease.” I say the evidence linking low cholesterol levels with an increased risk of death should serve as a wake-up call to Dr Fonarow and his co-authors.
References:
1. Hayward RA, et al. Narrative review: lack of evidence for recommended low-density lipoprotein treatment targets: a solvable problem. Ann Int Med 2006;145:520-530
2. Sachdeva A, et al. Lipid levels in patients hospitalized with coronary artery disease: An analysis of 136,905 hospitalizations in Get With The Guidelines. American Heart Journal.
2009;157(1) 111-117.
