Not every person with obesity goes on to develop metabolic diseases, just as there are slim people who suffer from hypertension, diabetes and dyslipidemia. Scientists are baffled as to why this occurs and have researched the role fat cells play in metabolic diseases.
We are all aware that excess caloric intake (positive energy balance) results in excess fat and increased risk of cardio-metabolic diseases. Lipids accumulate mainly in subcutaneous fat, but they can accumulate and enlarge the visceral adipocytes (VF).
VF is associated to an increased risk of disease as observed more than 60 years ago by the French physician Jean Vague. Since then, imaging techniques have demonstrated that fat can accumulate also in the liver, pancreas or muscle (as ectopic fat). Ectopic fat is toxic for the organs since it impairs their function and promotes the development of metabolic diseases.
Three shades of fat
It has been found that fat cells are not all alike, not only in shape but also in colors: while the majority of fat cells are white, there are also beige or brown fat cells.
© Amalia Gastaldelli/De Gruyter
White adipocytes are mainly for energy storage; beige and brown fat cells instead burn lipids for the production of energy, especially heat. The amount of brown/beige fat cells in humans is quite limited and more importantly brown fat need to be activated. Several conditions can activate brown fat, in particular during cold weather, whilst exercising and through stress.
The baffling question
The question that baffles scientists, is why subjects accumulate visceral and ectopic fat instead of increasing subcutaneous fat? In their research article published in the journal Hormone Molecular Biology and Clinical Investigation, scientists give their interpretation to why this occurs.
One explanation is that in these subjects subcutaneous fat cells cannot store the excess energy either because they have a limit or an impediment (possibly genetic) in augmenting their size.
The authors of the paper and researchers continue to study the mechanisms that cause metabolic diseases, the origin and role of ectopic fat and ways to prevent and cure this phenomenon – not only to prevent and reduce obesity, but also to improve the cardiometabolic status of patients (either obese or non obese).
In their paper, the researchers reviewed the origin and role of ectopic fat and ways to prevent and cure this phenomenon with the aim of not only to prevent and reduce obesity, but also to improve the cardiometabolic status of patients, whether obese or not.