Clinical value of the metabolic syndrome for long term prediction of total and cardiovascular mortality: prospective, population based cohort study
BMJ 2006; 332 doi: https://doi.org/10.1136/bmj.38766.624097.1F (Published 13 April 2006) Cite this as: BMJ 2006;332:878All rapid responses
Rapid responses are electronic comments to the editor. They enable our users to debate issues raised in articles published on bmj.com. A rapid response is first posted online. If you need the URL (web address) of an individual response, simply click on the response headline and copy the URL from the browser window. A proportion of responses will, after editing, be published online and in the print journal as letters, which are indexed in PubMed. Rapid responses are not indexed in PubMed and they are not journal articles. The BMJ reserves the right to remove responses which are being wilfully misrepresented as published articles or when it is brought to our attention that a response spreads misinformation.
From March 2022, the word limit for rapid responses will be 600 words not including references and author details. We will no longer post responses that exceed this limit.
The word limit for letters selected from posted responses remains 300 words.
Sundström and al. found that a diagnosis of metabolic syndrome better
predicts cardiovascular mortality when considered in addition to four
«established» risk factors (smoking, diabetes, hypertension and serum
cholesterol) (1).
Most of the components of the metabolic syndrome (NCEP or WHO
criteria), e.g. HDL-cholesterol, microalbuminuria, or impaired glucose
metabolism, are however also established independent cardiovascular risk
factors or markers (2,3). Hence, the incremental cardiovascular risk
attributed to the metabolic syndrome may well reflect the cumulative
effect of these components, and not the risk cluster defining the
syndrome. In addition, the paper uses cut offs of ≥140/90 mmHg to
define hypertension in the “4 risk factors” model and ≥130/85 mmHg
as part of the metabolic syndrome in the “4 risk factors + metabolic
syndrome” model: inclusion of high normal blood pressure in the latter
improves the prediction of cardiovascular mortality (4).
Invalid comparisons have often flawed research in this area and
assertions on the significance of the metabolic syndrome have been
consequently more speculative than adequately demonstrated (5). Moreover,
we are concerned by the practical consequences of these results based on
invalid premises. According to the paper, one would imply that,
conditional to same smoking habits, diabetes status, blood pressure and
total cholesterol levels, a doctor should treat more aggressively a
patient with low HDL-cholesterol, high triglyceride, and/or impaired
glucose metabolism in presence of the metabolic syndrome (which is
appropriate) but not in absence of the metabolic syndrome (which is
inappropriate). As a matter of fact, the use of other tools (e.g. the
hazard ratio for the metabolic syndrome adjusting for all independent
effects, including its components) might well reverse the conclusion of
the paper.
1) Sundström J, Risérus U, Byberg L, Zethelius B, Lithell B, Lind L.
Clinical value of the metabolic syndrome for long term prediction of total
and cardiovascular mortality: prospective, population based cohort study.
BMJ 2006;332;878-2.
2) 2003 World Health Organization (WHO)/International Society of
Hypertension (ISH) statement on management of hypertension. J Hypertension
2003;21:1983-92.
3) Lawes CM, Parag V, Bennett DA, Suh I, Lam TH, Whitlock G, et al: Asia
Pacific Cohort Studies Collaboration. Blood glucose and risk of
cardiovascular disease in the Asia Pacific region. Diabetes Care
2004;27:2836-42.
4) Vasan RS, Larson MG, Leip EP, Evans JC, O'Donnell CJ, Kannel WB et al.
Impact of high-normal blood pressure on the risk of cardiovascular
disease. N Engl J Med 2001;345:1291-7.
5) Kohli P, Greenland P. Role of the metabolic syndrome in risk assessment
for coronary heart disease. JAMA 2006;295:819-21 [Commentary].
Competing interests:
None declared
Competing interests: No competing interests
Sundstrom et al (BMJ 15th April, p 878) claim that in their cohort of
50-year old men, the identification of the metabolic syndrome (as defined)
added to the prediction of total and cardiovascular mortality obtained
from classical risk factors. However, it is clear from the electronic
version of the article that this superiority only emerges after about 15
years of follow-up. As most guidelines for therapeutic intervention are
predicated upon ten year risk, the observation does not have pragmatic
value. Further, the relatively poor performance of the classical risk
factors appears to be due to the unusually low predictive power of total
cholesterol in this cohort, which suggests that the result would not be
generally applicable.
R J Jarrett
Competing interests:
None declared
Competing interests: No competing interests
We applaud Sundstrom et al in their efforts to link the metabolic
syndrome and its long-term predictive outcome with regard to
cardiovascular mortality [1]. The descriptive account of the intricacies
involved with different age groups of patients once again demonstrates
that we should perhaps regard this ‘syndrome’ with a cluster of
cardiovascular risk factors as a ‘description in evolution’, rather than
trying to reach a finale in this era of rapidly changing perceptions on
the search for a definition for this complex story.
If we take into consideration other concurrent risks, such as the
impact of ethnicity and the significance of body mass index [2], it makes
it all the more problematical and reiterates the joint accord from a
statement by the American Diabetes Association and the European
Association for the Study of Diabetes that clinicians should concentrate
on individual cardiovascular risk factors to tackle these patients [3].
This has particular bearing if one can estimate the future stance and
enormous vastness of the situation given the global prevalence of diabetes
and projections for 2030 [4], as well as the global challenge of
hypertension over the next couple of decades [5]. The ‘sine qua non’ is
that aggressive treatment is required taking into account the magnitude of
the circumstances and we should act swiftly.
1.Sundstrom J, Riserus U, Byberg L, Zethelius B, Lithell H, Lind L.
Clinical value of the metabolic syndrome for long term prediction of total
and cardiovascular mortality: prospective, population based cohort study.
BMJ 2006 Mar 1; [Epub ahead of print]
2.Snehalatha C, Viswanathan V, Ramachandran A. Cutoff values for
normal anthropometric variables in Asian Indian adults. Diabetes Care
2003; 26: 1380–1384.
3.Kahn R, Buse J, Ferrannini E, Stern M. The metabolic syndrome: time
for a critical appraisal. Joint statement from the American Diabetes
Association and the European Association for the Study of Diabetes.
Diabetologia 2005; 48(9): 1684-1699.
4.Wild S, Roglic G, Green A, Sicree R, King H. Global prevalence of
diabetes: estimates for the year 2000 and projections for 2030. Diabetes
Care 2004; 27(5): 1047-1053.
5.Kearney PM, Whelton M, Reynolds K, Muntner P, Whelton PK, He J.
Global burden of hypertension: analysis of worldwide data. Lancet 2005;
365: 217–223.
Competing interests:
GIV & HS work in Diabetes & Endocrinology and JVP is a Research Scientist in Metabolic Disorders & Cardiovascular Diseases
Competing interests: No competing interests
Early warning for use in primary care to inform patients of risk
Dear Sir,
I have almost completed 25 years in General Practice and have watched as
my rotund patients developed cardiac disease and strokes. I have
intervened to treat their blood pressure or lipids too little , too late.
Prof Sundstroms paper reinforces our present practice of encouraging
our clinical staff especially our nurses to do a waist circumference and
blood pressure followed by appropriate blood tests if indicated.
Based on our premise that patients need to be informed of risk and
stategies for reducing it, we then counsel patients on life style changes.
That the dangers may take 15 or even 20 years to manifest is not a reason
to delay and it is surprising that an epidemiologist like Professor
Jarrets should comment on the lack of pragmatic value. We are not talking
primarily about therapeutics but a means of informing patients that middle
age spread is not necessarily a benign condition that makes them cuddly.
Yours sincerely
Rupert Gude
Competing interests:
None declared
Competing interests: No competing interests