By Dr Ananya Mandal, MD
Metabolic syndrome is linked to an increased risk of type 2 diabetes and cardiovascular disease. Metabolic syndrome is characterized by several features that are common with obesity and overweight individuals.
Features of metabolic syndrome
Metabolic syndrome is characterized by:-
increased waist circumference
high levels of triglycerides in the blood
low levels of high-density lipoprotein (HDL)-cholesterol in blood
high blood sugar (fasting state)
high blood pressure
Obesity usually is caused by the underlying pathology of accumulation of excess body fat. Obesity is defined as a Body mass index (BMI) exceeding 30 kg/m2. Obesity is a new epidemic that is affecting millions worldwide.
In England for example obesity rose between 13.2% to 23.6% in men and 16.4% to 23.8% in women between 1993 and 2004. In the United States the numbers rose from 23% in 1990 to 31% in 2000. In both countries present figures are nearly one third of the total population.
Central obesity (abdominal obesity) as well as obesity in general is associated with physiological changes that may cause the development of diseases like high blood pressure, heart disease, high blood cholesterol and type 2 diabetes.
Obesity also raises the risk of fatty liver disease, gall bladder disease, osteoarthritis and certain cancers. It is estimated that the cost of treating obesity related diseases contributes 2–7% of total national health care costs in developed countries.
Latest recommendations suggest measuring waist circumference rather than body mass index (BMI) in determining the risk of metabolic syndrome that is associated with abdominal obesity.
Studies have shown that the rise of obese and overweight individuals is attributed to affluent, sedentary lifestyle with excess consumption of highly processed, energy-dense food that has a poor nutritional value. This is accompanied by lack of exercise and physical activity.
Due to the rise of type 2 diabetes along with obesity at similar high and exponential rates, a term “diabesity” has been coined to emphasize the link between these two conditions.
However just high blood sugar is said to be the proverbial tip of the iceberg and underlying this is a host of metabolic imbalances associated with metabolic syndrome seen in overweight and obese patients with excess abdominal fat and insulin resistance.
Obesity and insulin resistance
Insulin resistance is considered a key factor connecting obesity and metabolic syndrome. However, not every obese patient is insulin resistant or at high risk of diabetes and heart disease.
This could explain why obesity could not be classified as a modifiable risk factor for heart disease that includes smoking, high blood pressure and cholesterol (high low-density lipoprotein (LDL)/low HDL).
This said, it must be remembered that individuals with abdominal obesity are at a greater risk of insulin resistance and metabolic syndrome than others.
Obesity and C-reactive protein
Obese individuals also have raised blood levels of C-reactive protein (CRP), an inflammatory marker that can predict the risk of heart attacks. These levels are raised in individuals with insulin resistance and metabolic syndrome as well.
The protein adiponectin is also abundant in the blood and comes from fatty tissues. These levels are reduced in obese individuals with excess abdominal obesity.
Adiponectin in normal individuals helps prevent insulin resistance and also protects against atherosclerosis. The reduced adiponectin levels in obese individuals could thus connect diabetes, obesity and metabolic syndrome.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)
Last Updated: Apr 8, 2013