| Fat
skinny patients coming your way Are healthy thin women
concealing a fatter, sicker self beneath their trim faìades? A group of
Italian scientists say yes, and warn of a baffling new obesity epidemic looming
on the horizon. Obesity isn't just for the obese anymore, they say, arguing that
"normal-weight obese syndrome" (NWO) is putting women's lives at risk. A
woman who's of normal weight and body mass index could still be susceptible to
obesity-related diseases if her fat mass is >30% of her total body weight,
argue the researchers in the January issue of the American Journal of Clinical
Nutrition. The NWO woman is born. To verify the hypothesis,
the team measured concentrations of proinflammatory cytokines and cardiovascular
disease (CVD) risk factors in 20 NWO, 20 preobese-obese, and 20 non-obese women.
While they found no significant differences in body weight, lab values or CVD
risk factors between NWO and non-obese groups, the concentrations of interleukins
1, 1, 6, 8 and TNF- in the NWO women were significantly higher than in the nonobese
group. Elevated levels of these pro-inflammatory cytokines, they write "could
be regarded as significant prognostic indicators of the risk of obesity, CVD and
the metabolic syndrome in NWO women." | Metabolic
syndrome does exist, and it significantly increases the risk of cardiovascular
(CV) events, particularly in women. So concludes a new review in the January 30
issue of the Journal of the American College of Cardiology. The study is
the latest in a series aimed at proving (or disproving, as the case may be) the
merits of the relatively new syndrome, and seeks to draw special attention to
the clustering of known CV and diabetes risk factors. Since
the controversial diagnosis first emerged in 1999, metabolic syndrome has divided
clinicians and academics alike. Experts have argued about everything from the
syndrome's existence, to the criteria that define it, to its value as a diagnostic
tool. Conspiracy theorists have even suggested it's nothing more than a bid to
load people up with medications they don't need. Dr David C W Lau, chair of the
diabetes and endocrine research group at the University of Calgary, says that's
all stuff and nonsense. "As physicians, we're interested in the care of our patients.
That's all. This is about trying to harmonize all these factors for the clinician
to identify those patients that are most at risk." MORE
IS MORE
The meta-analysis, conducted by Dr Apoor S Gami at the Mayo
Clinic College of Medicine in Rochester, reviewed 37 studies published since 1998,
including over 170,000 patients. All were longitudinal studies assessing CV events
and/or death in patients with three or more coronary risk factors. Patients with
metabolic syndrome, they concluded, need to be identified and aggressively targeted
for interventions.
| Metabolic
syndrome:
Who fits the profile? According to the
new International Diabetes Federation definition, for a person to be defined as
having the metabolic syndrome they must have: - Central
obesity (defined as waist circumference >/= 94cm for Europid men and >/=
80cm for Europid women, with ethnicity specific values for other groups) plus
any two of the following four factors:
- Raised TG
level: >/= 1.7 mmol/L, or specific treatment for this lipid abnormality
- Reduced HDL cholesterol: < 1.03 mmol/L in
males and < 1.29 mmol/L in females, or specific treatment for this lipid abnormality
- Raised blood pressure: systolic BP>/= 130
or diastolic BP>/= 85 mm Hg, or treatment of previously diagnosed hypertension
- Raised fasting plasma glucose (FPG)>/= 5.6
mmol/L, or previously diagnosed type 2 diabetes. If above 5.6 mmol/L, OGTT is
strongly recommended but is not necessary to define presence of the syndrome.
| There's little doubt that
a combination of obesity, elevated triglycerides, high cholesterol, high blood
pressure and poor glucose control would put patients at high risk of developing
heart disease or diabetes. As Dr Lau puts it, "It doesn't take a rocket scientist
to say people with a paunch and elevated lipids and so on need to be paid special
attention." But opponents aren't convinced that the
presence of several of these risk factors at the same time confers a greater risk
than that associated with each individual symptom. "By grouping everything together
and calling it something else, you're basically inferring that when there's a
clustering of symptoms, you have to be more aggressive," Dr Lau explains. "These
people are saying 'why can't we just treat each individual symptom?'" DRAWING
THE LINE
Why indeed? Because it's getting more and more complicated
to just treat the individual symptoms. In the face of growing rates of heart disease
and diabetes, guidelines for the management of their associated risk factors are
becoming ever stricter. The American National Cholesterol Education Program recommended
even lower targets for LDL cholesterol last summer (see "Are new LDL criteria
too aggressive?" June 30, 2006, Vol 3, No 12, page 8), while tougher hypertension
guidelines were just issued by the Heart and Stroke Foundation (see "Older BP
meds up diabetes risk ," page 7). It can be a real challenge to keep up with which
patients need treatment, and which can get off with a warning. "That's the idea
behind the whole concept of metabolic syndrome: to make it simpler for physicians
to know who to treat and how," Dr Lau says. Metabolic
syndrome naysayers agree that all this is problematic, but say labelling patients
with a syndrome doesn't help. The cut-off points established in the criteria (see
IDF criteria, right) are just as arbitrary, they argue. "Generally speaking, a
patient is hypertensive if their systolic BP is above 140 and diastolic above
90," Dr Lau explains. "But if they're diabetic, the cut-off is 130/80. According
to the definition of metabolic syndrome, it's 130/85. That's the problem." MATHEMATICAL
FIX
Dr Lau says the solution may be yet another new concept —
namely cardiometabolic risk (CMR) assessment. The idea behind CMR is to break
everything down into a relatively simple calculation. "It's another way of getting
around it, by doing away with the criteria, which is what's troublesome," he says.
The advantage of this is that each of the risk factors can be weighed appropriately,
which doesn't happen when you assess a patient for metabolic syndrome. "The definition
[of metabolic syndrome] gives the same weight to each of the criteria, which is
not actually right. The risk of diabetes is actually greater for someone with
high glucose, for example, as opposed to their risk of cardiovascular disease.
CMR would take that into account." But while everyone's
quibbling over semantics, you need to know how to treat your patients. And luckily,
that hasn't changed. "The bottom line is that we recommend people get on the lifestyle
kick: trim off excess weight, especially the beer belly, and get healthy," affirms
Dr Lau. "If they have individual risk factors that need pharmacological treatment,
then consider that. That's really it." |
