Professor Tabassome Simon said that the impact of obesity on long term mortality and cardiovascular complications in the general population has been the object of recent debate and much emphasis has also been given to the deleterious role of abdominal obesity.
Simon said that at the time of a heart attack, early mortality tends to be lower in obese patients, a phenomenon well known in critical care situations and described as the 'obesity paradox'.
At 5 years, absolute mortality was highest in the leanest patients (BMI less than 22 kg/m2) and lowest in patients with BMI between 25 and 35 kg/m2 (i.e. overweight and mild obesity). Patients with severe obesity (BMI = 35 kg/m2) had a markedly increased mortality after 3 years. Severe abdominal obesity (waist circumference more than 100 cm in women and more than 115 cm in men) was also associated with increased long-term mortality.
Simon said that as waist circumference is strongly linked to BMI, the researchers determined the upper quartile of waist circumference within each BMI category and used both variables together to determine their respective role in association with long-term mortality.
She added that they found that both lean patients (BMI less than 22 kg/m2) and very obese patients (BMI =35 kg/m2) had an increased risk of death at 5 years: + 41 percent and + 65 percent, respectively. Being in the upper quartile of waist circumference was also an indicator of increased mortality at 5 years (+ 44 percent).