One in six Europeans, and up to one in three in some EU countries, have the metabolic syndrome, a condition that greatly increases the risk of type 2 diabetes, cardiovascular disease and stroke, and can lead to premature death. Rapid increases in the rates of overweight and obesity at increasingly earlier ages drive the massive prevalence of the syndrome. The metabolic syndrome even creeps up in geographical areas that were traditionally protected through healthy diets and lifestyle such as Greece or France. The impact on society is huge, with experts expecting health and social welfare costs to rise in Europe, in the near future.
A cluster of abnormalities in glucose and fat metabolism
The metabolic syndrome (also called Syndrome X or insulin resistance syndrome), is diagnosed when a person has three or more of the following conditions: abdominal obesity (waist circumference: men > 102 cm, women > 88 cm), high triglyceride levels, low HDL (high-density lipoprotein) cholesterol levels, high blood pressure, and high fasting blood sugar levels - although international and national health organizations differ somewhat in the exact criteria.
A cascade of adverse health effects
All the factors associated with the metabolic syndrome are interrelated. Obesity and lack of exercise lead to insulin resistance. Insulin resistance in turn increases LDL cholesterol (low-density lipoprotein - the "bad" cholesterol) and blood triglycerides, and decreases HDL cholesterol (high-density lipoprotein - the "good" cholesterol). This can lead to fatty plaque deposits in the arteries, which, over time, can cause cardiovascular disease, blood clots, and strokes. Insulin resistance also raises insulin and glucose levels in the blood. Chronically elevated glucose levels, in turn, damage blood vessels and organs such as the kidneys, and may lead to diabetes. Due to high insulin levels, the kidney retains too much sodium, which increases blood pressure and can lead to hypertension.
EU's efforts to curb the monster
The European Commission is running an ambitious 5-year research programme, LipGene, looking into the metabolic syndrome. This massive effort from 25 centres of excellence will help us understand how diet (especially dietary fat) and our individual genetic make-up contribute to the syndrome. The programme, which will also contribute to developing effective measures to fight the condition, includes: a large-scale human nutrition intervention study, development of new technologies to increase the content of 'good fat' such as the long-chain omega-3 fatty acids in foods, and an educational campaign.
What can we do to help ourselves?
The best way for someone to prevent or reduce insulin resistance is to keep a healthy weight, make healthy food choices and be active. If you are overweight, limiting caloric intake to lose 5-10% of body weight will help. Diet has also an effect independent from losing weight - there is evidence that the Mediterranean diet, and diets rich in long-chain omega-3 fatty acids (e.g. rich in fish) or wholegrains, all reduce the risk of the metabolic syndrome. Moderate physical activity for at least 30 min per day is also effective - for example, take the stairs instead of the lift; don't use the TV's remote control, or stand rather than sit whenever you can; walk to work.
Do we need to know about the metabolic syndrome? Better understanding of the metabolic syndrome has great value. It enables the identification of people who are at increased risk of disease and for whom more intensive interventions may be justified. From an epidemiological perspective, the metabolic syndrome confirms the link between lifestyle-associated disorders (obesity, insulin resistance, hyperglycaemia etc) and increased cardiovascular risk. In the end, it provides a powerful, central motive to improve the way we manage our health.
- Chaplin, S. Type 2 diabetes prevention and management. (2005) ILSI Europe concise monograph series.
- Pi-Sunyer, FX. Pathophysiology and long-term management of the metabolic syndrome. (2004) Obesity Research 12 Suppl:174S-80S.
- Buttriss, J and Nugent, A. LipGene: an integrated approach to tackling the metabolic syndrome. (2005) Proceedings of the Nutrition Society 64: 345-347. See also LipGene website on www.lipgene.tcd.ie.