Fig. 1Pathogenesis of the metabolic syndrome as a special state of mitochondrial dysfunction. Various phenotypes, such as insulin deficiency and insulin resistance are pathophysiologically defined states, while type 2 diabetes, hypertension and obesity are well-defined specific disease states. Coronary heart disease and cancer might be considered either specific diseases or complications (or more appropriately, later stages) of preceding disease states. In this model, diabetes and CADs are not results of obesity, but its later stage phenotypes. CVD, cardiovascular disease; NMD, neuromuscular disease; NAFLD, nonalcoholic fatty liver disease.
Fig. 2Metabolic scaling relation between body size and metabolic rate. Panel (A) shows metabolic rate increases (watt) with increasing body mass (kg) across animal species, from mitochondrion to elephant. In Panel (B), the logarithm of the mass-specific metabolic rate, W/g, versus the body mass, M (g), for mammals is plotted in a logarithmic scale. The mass-specific metabolic rate declines as body mass increases. Panel (C) shows the relationship between changes in 24-hour energy expenditure (Δ 24-EE) and Δ weight after adjustment of 24-EE for fat-free mass (FFM), fat mass (FM), waist to thigh ratio (WTR), and age. Weight change is accompanied by a change in energy expenditure in Pima Indians. A long-term adaptation process normalizes the relationship between body mass and metabolic rate, suggesting that an adaptive process is operating (Panel D). Arrows 1A and 2A depicts metabolic adaptation, which leads to a quick decrease in the metabolic drive and a small weight change. Arrows 1B and 2B depict poor metabolic adaptation, which leads to a sustained metabolic drive and a larger weight change.
Fig. 3In whole-body metabolism, energy supply and energy demand are tightly linked, and the metabolism of its parts is quantitatively related (allometry) to whole-body mass. The larger the body, the bigger the parts, but the mass specific metabolic rate decreases (From Weibel ER. Nature 2002;417:131-2, with permission from Nature Publishing Group) [4].