Waist circumference is an indirect marker of intra abdominal fatty tissues, usually called visceral fat.
Scientifically, Waist circumference is measured by a tape placing it over the Iliac crest (the upper most part of your both the hip bones) along with your naval.
The accurate point to measure waist circumference is midway between the upper hipbone and the uppermost border of the right iliac crest. A tape of accurate measurement should be placed in the region of the abdomen at the level of this middle point and a reading taken when the tape is comfortably placed but does not compress the skin. In practice, it may be tricky for extremely overweight persons precisely palpating those bony landmarks. In that case placing the tape at the level of the belly button (Umbilicus) is recommended.
The measurement of waist circumference gives us useful information regarding the distribution of body fat and is a tool to evaluate the risks for conditions such as high blood pressure, different cardiovascular diseases including coronary heart disease (CHD). It is now acclaimed that people who mainly carry their excess fat in the central part of the body (within the abdominal cavity) are at increased risk to suffer the consequences of being overweight. It is also associated with the metabolic syndrome like diabetes and pancreatitis.
You have a potential risk factor for various health problems if you are-
A man with a waist circumference more than 40 inches (101.6 cm)
A woman with a waist circumference more than 35 inches (88.9 cm)
The WHO (World Health Organization) definition for metabolic syndrome is -
Type 2 diabetes, impaired glucose tolerance or normal glucose tolerance with insulin resistance, together with two or more of the following:
Elevated blood pressure
Abdominal obesity and/or BMI >30kg/m2
Low HDL cholesterol
People with metabolic syndrome are at an increased risk of cardiovascular disease equivalent to people with frank Type-II diabetes (Non-Insulin Dependent Diabetes Mellitus).
Doctors are likely to diagnose a case of metabolic syndrome on a regular basis. It is estimated in America that 47 million people - about 1 in 4 adults (23%) - have metabolic syndrome. The incidence of metabolic syndrome in adults is comparable to that of hypertension (24%).
Aims of treating metabolic syndrome are averting of development to overt Type-II Diabetes and averting of premature death due to cardiovascular disease achieved through lifestyle adjustment and the sensible use of drugs and in extreme cases surgery.
The reference waist circumference measurement for men and women population at which there is an increased relative risk is defined as follows.
≥ 94 cm
≥ 102 cm
≥ 80 cm
≥ 88 cm
In some populations, waist circumference may be a better marker of risk factor than Body Mass Index (BMI) e.g. in persons of Asian descent.
In patients with a BMI in the range of 25–35 kg/m2 extra measurements of waist circumference may provide supplementary information about risk and can be used an added measure of progress with weight loss.