Summary Although low doses of persistent organic pollutants (POPs), strong lipophilic chemicals with long half‐lives, have been linked to various endocrine, immune, nervous and reproductive system diseases, few obesity studies have considered adipose tissue as an important POPs exposure source. Because the toxicodynamics of POPs relate directly to the dynamics of adiposity, POPs might explain puzzling findings in obesity research. In two people exposed to the same amounts of environmental POPs, the one having more adipose tissue may be advantaged because POPs storage in adipose tissue can reduce burden on other critical organs. Therefore, adipose tissue can play a protective role against the POPs effects. However, two situations increase the POPs release from adipose tissue into the circulation, thereby increasing the risk that they will reach critical organs: (i) weight loss and (ii) insulin resistance. In contrast, weight gain reduces this possibility. Therefore, avoiding harmful health effects of POPs may mostly contradict conventional judgments about obesity and weight change. These contradictory situations can explain the obesity paradox, the adverse effects of intensive intentional weight loss and the protective effects of obesity against dementia. Future studies should consider that adipose tissue is widely contaminated with POPs in modern society.

Impaired fibrinolysis is a common finding in obese humans. This condition is now considered as an established risk factor for thromboembolic complications. Furthermore, obesity is characterized by a specific pattern of circulating concentrations of fat-cell products interleukin-6 (IL-6), leptin, and adiponectin. The aim of our study was to investigate the relationship between these proteins and selected variables of the fibrinolytic system in 74 mildly hypertensive, overweight subjects. Circulating IL-6 and leptin levels showed a positive association with BMI (r = 0.24, p = 0.04 and r = 0.70, p < 0.0001), whereas adiponectin was not correlated to BMI. Interestingly, IL-6 was also positively associated with t-PA/PAI-1 complexes after adjustment for BMI and other anthropometric variables. Leptin was positively correlated with PAI-1 activity and antigen (r = 0.32, p = 0.006 and r = 0.37, p < 0.001, respectively) and negatively with t-PA activity (r = -0.27, p = 0.03). However, these associations lost significance after correction for BMI or HOMA, an insulin sensitivity index. In contrast, adiponectin levels were independently and negatively correlated with PAI-1 antigen (r = -0.26, p = 0.04, after correction for BMI). In conclusion, our study provides further evidence that IL-6, leptin, and adiponectin are associated with impaired fibrinolysis in overweight hypertensive humans.