Risks of Long Term, Abdominal Obesity
The rate of childhood obesity continues to climb, which means that more and more individuals are experiencing long term exposure to excess adiposity during their lifetime. Several new studies have examined how the risk of chronic conditions such as cardiovascular disease and type 2 diabetes is influenced by the cumulative effects of obesity over time and by the predominant location of excess fat tissue in the body.
Obesity is strongly linked with an increased risk of cardiovascular disease. A prospective study looking at the 25 year progression of coronary artery calcification (CAC), a predictor of coronary heart disease, found that the longer exposure to overall or abdominal obesity led to a higher risk of developing CAC.  Subjects that experienced more than 20 years of abdominal obesity had slightly higher progression of CAC compared to those with 20 or more years of overall obesity, but not at a significant level. Using the same group, duration of abdominal obesity was measured to determine if there was association with the development of diabetes.  For every year that a person was abdominally obese, there was a 4% higher risk in developing diabetes.
People tend to hold excess body fat in different areas, but research indicates that the most detrimental area may be in the abdomen. In a study comparing visceral adipose tissue (VAT) to subcutaneous adipose tissue (SAT), VAT was associated with cardiovascular disease and cancer, while SAT was not. These results were derived after adjusting for both waist measurements and BMI.
One hypothesis as to why abdominal obesity may pose more of a cardiovascular threat is that the fat cells produce a more toxic environment. When compared to SAT, VAT arterioles had severely impaired vasodilation. VAT also showed much higher expression of proinflammatory, oxidative stress-related, and proangiogenic genes.
These findings stress the importance of reducing the amount of excess fat in individuals, particularly in children and young adults, in order to reduce the incidence of chronic disease.