The 'Healthy Obese' and Their Healthy Fat Cells - NYTimes.com
Rohit Khare stashed this in Food
The 16 pairs were split evenly into two groups. In both, the average weight difference between the siblings was about 40 pounds. But in one group, the obese siblings had higher blood pressure, worse cholesterol levels and poorer measures of blood sugar and insulin production, as well as seven times the amount of fat in their livers. In the other group, the obese twins’ blood work and liver fat was similar to that of their lean twins.
Extensive tests of each person’s fat tissue revealed some other surprises. The healthy obese had 11 percent more adipocytes, or fat cells, in their subcutaneous fat tissue than their normal weight twins. But the unhealthy obese had 8 percent fewer fat cells than their leaner siblings, despite a higher body fat percentage.
The fat cells of the unhealthy obese were larger than those of any other group. They were swollen and riddled with inflammation. The breakdown and mobilization of their fat stores was suppressed, and a closer look showed that their mitochondria were malfunctioning. Their ability to burn fuel and produce adenosine triphosphate, or ATP, the body’s energy currency, was reduced.
Properly functioning mitochondria stimulate the creation of new fat cells, which may explain in part why the unhealthy obese had fat cells that were limited in number and bloated to extremes.
But it’s not clear what happens first. Is inflammation the initial stressor that impairs the mitochondria? Or do the mitochondria malfunction first, leading to inflammation that arrives to clear away the engorged and dying fat cells?