May 16, 2013
Middle Age Could Be Tipping Point For Obesity-Related Cardiovascular Risk
redOrbit Staff & Wire Reports - Your Universe Online
While the cardiovascular system of a younger adult might be capable of compensating for the effects of obesity, new research published in the journal Hypertension suggests that the ability to adapt is lost after middle age, resulting to an increased risk of cardiovascular disease due to the relationship between body fat and aortic stiffness.
In the study, experts from the Medical Research Council (MRC) Clinical Sciences Centre at Imperial College London claim that their findings suggest that the harmful effects of body fat could be related to the total number of years that an individual is overweight during their adult years. However, they report that additional research is required to discover at what point obesity-related damage to the heart and arteries becomes irreversible.
The MRC researchers recruited 200 volunteers and conducted MRI scans in order to measure the speed of blood flow in the body´s largest artery, the aorta. They explained that, since blood travels more quickly in stiff blood vessels than in healthy elastic ones, they were able to calculate how stiff each individual´s aorta walls were.
Young adults with more body fat had less stiff arteries, they discovered. However, after the age of 50, increasing body fat was linked to stiffer arteries in both male and female study participants. Furthermore, body fat percentage was more closely related to arterial stiffness than body mass index. On average, men were approximately 21 percent fat while women were an average of 31 percent fat, the MRC team reported.
“The effects of having more fat seem to be different depending on your age,” study leader Dr. Declan O'Regan, MRC Senior Clinician Scientist and Consultant Radiologist working at the Robert Steiner MRI unit at Hammersmith Hospital, said in a statement. “It looks like young people may be able to adapt to excess body fat, but by middle age the cumulative exposure to years of obesity may start to cause permanent damage to the arteries.”
“One implication is that the potential beneficial effects of weight loss may depend on your age and how long you have been overweight. This is something we plan to study further,” he added. “We don´t know for sure how body fat makes arteries stiffer, but we do know that certain metabolic products in the blood may progressively damage the elastic fibers in our blood vessels. Understanding these processes might help us to prevent the harmful effects of obesity.”
The MRC, the National Institute for Health Research (NIHR) Imperial Biomedical Research Centre, and the British Heart Foundation funded the research.