THE METABOLIC SYNDROME
NEW PARMA – september/october 2010
About half the population over sixty suffers from obesity. Yet, obesity is increasing in young people as well.
Almost 7 million patients in Italy suffer from central or abdominal obesity. The so-called paunch affects 20% of our population. It is not just an aesthetic problem, since abdominal fat is the main indicator of the risk of suffering from the metabolic syndrome. This term refers to a series of problems whose main factor is a lack in insulin efficiency, also called insulin-resistance. The fact is that the metabolic syndrome is an early symptom of evident and severe diseases such as hypertension, heart attack, stroke, type II diabetes, tumours. The metabolic syndrome is becoming a real epidemic above all in old patients, since about half of the population over 60 suffers from it. However, it is also increasing in young people. The metabolic syndrome is diagnosed according to the following criteria.
1) According to the AMERICAN GUIDELINES:
A person is suffering from metabolic syndrome if at least 3 of the following risk-factors are present:
– Waistline: > 102 cm in men; >88 cm in women
– Triglycerides: > 150 mg/dl
– HDL cholesterol: < 50 mg/dl in men; <40 mg=”” dl=”” in=”” women=”” p=””>
– Arterial pressure: > 130/85 mm/Hg
– Glycaemia on an empty stomach: >110 mg/dl
(Grundy et al. Circulation, 18th October, 2005)
2) According to the INTERNATIONAL DIABETES FEDERATION:
A person is suffering from metabolic syndrome if suffering from ABDOMINAL OBESITY + 2 RISK FACTORS. Attention must be drawn to the fact that the International Diabetes Federation has reduced the waistline, so a person is suffering from abdominal obesity if the waist is over 94 cm in men and 80 cm in women.
Moreover, they have also reduced the threshold of glycaemia on an empty stomach. In fact, in this case if it is over 100 mg/dl it must be considered a risk factor. Risk factors such as arterial pressure, HDL cholesterol and triglycerides are the same as the American guidelines.
(International Diabetes Federation 2005, Ecket. Lancet; 356:1415, 2005)
I suppose that at this point many of you have already stopped reading this article to go and take a measuring tape to measure your waistline. Some of you have probably heaved a sigh of relief, while others are worried.
Wait a minute. First I would like to spend some words on the partial unsuitability of measuring one’s waistline to determine abdominal obesity. For example, it is quite obvious that the measurement has a different value on a person who is 1.90 m tall and on a person who is 1.65 m tall. This means that a measurement over 94 cm may not indicate abdominal obesity in a person who is 1.90 m tall. On the contrary, a measurement under 94 cm may correspond to abdominal obesity in a person who is 1.65 m tall. Therefore, it is better to use the BMI (Body Mass Index), which measures body weight based on a person’s weight and height. (BMI = weight/height2). A BMI over 25 indicates high excess weight, which must be then associated to the W/H ratio (waist/hips). This indicates abdominal obesity if it is over 0.9 in men and 0.85 in women (For example a 0.95 ratio corresponds to a waistline of 95 and hip measurement of 100).
The W/H ratio becomes important because it indicates a specific fat deposit at a central level rather than on the lower part of the body. Moreover, it prevents from considering those BMI over 25 and waistlines over 94 which are due to a high BMI caused by considerable muscle mass in association with high abdominal and lumbar muscle development. An athlete may have a BMI over 25 and a waistline over 95 without exceeding 0.9 in the W/H ratio, unless he/she is really fat.
Fat is, in fact, a problem. It is not just a deposit of cumulation but it is basically an endocrine organ producing hormones (above all estrogens) and inflammatory cytokines which worsen insulin resistance. The link between insulin-resistance and cardiovascular diseases is probably represented by oxidative stress, which can cause vascular damage. The same applies to the formation of arterial hypertension in patients suffering from metabolic syndrome. Hyperinsulinemia depending on insulin-resistance may determine both a stimulation of the sympathetic nervous system with a consequent vasoconstriction, and sodium retention, which is responsible for the increase in the pressure levels. Since the role of insulin in the beginning of hypertension is not normally recognised, this is treated with diuretics and Beta-blockers. Yet, the first increase the risk to develop diabetes of over 4.6 times more, while the second ones of 6.1 times more. Those who take both these medicines have a risk which is 11.5 times higher.
It is clear that if hypertension is caused by insulin resistance, first it is important to treat the latter. Yet how is insulin resistance formed? By an excessive consumption of sugars and refined carbohydrates, which can be also associated to an excess of saturated fats and salt. Therefore, a proper diet – eating well – is a fundamental help to treat the metabolic syndrome. But this will be dealt with next time.