It is true, 1/3 of Americans are obese. There is conflicting evidence regarding the mortality risk of obesity (defined as BMI>30 kg/m2) in critically ill patients.
It has been shown that abdominal fat has greater consequences than peripheral obesity, and based on this, a recent study has utilized the sagittal abdominal diameter (SAD) in ICU patients to show that abdominal obesity (as differentiated from BMI) poses an independent risk of death. The SAD detects visceral fat, which has been shown to have metabolic and immune health consequences, including the following:
-incidence and severity of certain infections is higher
-excess adipocytes are associated with elevated levels of proinflammatory factors that favor insulin resistance, diabetes, dyslipidemia and hypertension, all of which lead to microcirculatory dysfunction
-rates of required renal replacement therapy and abdominal compartment syndrome correlate to increased SAD
-there is also a trend toward a longer length of ventilator weaning
See you at the gym.
References
Paolini JM et al: Predictive value of abdominal obesity vs. body mass index for determining risk of intensive care unit mortality. Crit Care Med 2010; 38:1-7
