Body composition (sarcopenia) in obese patients: implications for care in the intensive care unit

Abstract

The study of body composition is a rapidly evolving science. In today's environment, there is a great deal of interest in assessing body composition, especially in the obese subject, as a guide to clinical and nutrition interventions. There are some strikingly different compartments of body composition between the obese and the lean patient. We do have the ability to measure body composition accurately, although these techniques can be labor intensive and expensive. The recognition of patients with sarcopenic obesity has identified a potential high-risk patient population. These body composition abnormalities may have even greater importance in the intensive care patient.

Figure 1

Body composition in extremely obese and weight-reduced states compared with reference female values.^– All body compartments (except solids) are significantly different in the extremely obese state compared with the weight-reduced state (P < .05), and body compartments in extreme obesity (except solids) and weight-reduced state (except solids and extracellular water [ECW]) are significantly different from reference female values (P < .05). ICW, intracellular water. Reprinted with permission from Macmillan Publishers Ltd: Elia M, Stubbs RJ, Henry CJ. Differences in fat, carbohydrate, and protein metabolism between lean and obese subjects undergoing total starvation. Int J Obesity. 1999;7:6.

Figure 2

(a, b) Types of obesity in relation to fat distribution. Nonobese (left panel: BMI 22 kg/m², 22.7% fat), lower body obese (middle panel: BMI 36 kg/m², 33% fat), and upper body obese (right panel: BMI 37 kg/m², 47.3% fat). Images using a 3-dimensional photonic scanner (New York Obesity Nutrition Research Center, New York, New York). BMI, body mass index.

Figure 3

Cross-sectional images through the abdomen (centered at L4–L5) showing distribution of adipose tissue, before (upper panel) and 1-year post (lower panel) bariatric surgery (woman, age 36 years). Visceral adipose tissue (VAT, blue), subcutaneous adipose tissue (green), intermuscular adipose tissue (IMAT, pink), and skeletal muscle (red). Total VAT mass before surgery was 4.47 kg (body weight 133.4 kg, BMI 52 kg/m²) and 1 year postsurgery was 0.77 kg (body weight 74.3 kg, BMI 29 kg/m²). BMI, body mass index.