Montréal researchers find a link between pollutants and certain complications of obesity

This breakthrough could eventually help improve prevention, diagnosis and treatment of cardiometabolic complications associated with obesity

A team of researchers at the IRCM in Montre'al led by Re'mi Rabasa-Lhoret, in collaboration with Je'rome Ruzzin from the University of Bergen in Norway, found a link between a type of pollutants and certain metabolic complications of obesity. Their breakthrough, published online this week by The Journal of Clinical Endocrinology & Metabolism, could eventually help improve the prevention, diagnosis, and treatment of cardiometabolic risk associated with obesity, such as diabetes, hypertension and cardiovascular disease.

Although obesity is strongly linked to insulin resistance and type 2 diabetes, a subset of obese individuals, termed "metabolically healthy but obese", appears relatively protected from the development of such cardiometabolic complications. IRCM researchers are studying the factors that seem to protect obese individuals who remain metabolically healthy, in an attempt to find therapeutic avenues to prevent complications for others who are at risk.

"Recently, persistent organic pollutants (POPs) have been found to accelerate the development of prediabetes and obesity in mice, thereby mimicking the unfavourable cardiometabolic profile characteristic of certain obese individuals," says Re'mi Rabasa-Lhoret, MD, PhD, endocrinologist and Director of the Metabolic Diseases research unit at the IRCM. "As a result, the aim of our study was to test whether metabolically healthy but obese individuals have lower circulating levels of POPs than obese individuals with cardiometabolic complications."

Persistent organic pollutants are man-made chemicals used in agricultural, industrial and manufacturing processes. Due to their toxicity, POPs have been strictly and internationally regulated to ensure public health. However, because they have the ability to resist environmental degradation, POPs can still be found all around the world, even in areas where they have never been used, and remain omnipresent in our environment and food products. Thus, virtually all humans are exposed to POPs daily.

"Exposure to POPs comes primarily from the environment and the consumption of food such as fatty fish, meat and milk products," explains Je'rome Ruzzin, PhD, expert in the field of research on POPs. "One important characteristic of POPs is their lipid solubility, meaning they accumulate in the body’s fatty tissues. As their name suggests, they are also persistent so the body cannot easily eliminate them. POPs can therefore have significant impacts on human health, and have been shown to affect reproduction, promote cancer, and be involved in the development of metabolic diseases."

Complications of obesity The major diseases associated with obesity are hypertension, atherosclerosis, and diabetes, as well as certain types of cancer. Less well-known complications include A U- or J-shaped curve illustrates the relation between body mass index and the degree of these various complications. This relationship can be used to provide guidelines for assessing treatment of obesity.