Panel A shows MBF, which we quantified using positron emission tomography, in the 4 subject groups. The p values for the pairwise comparisons are shown. The obese women had the greatest MBF, which was significantly greater than in the nonobese women or the obese men. The nonobese women also had greater resting MBF than the nonobese men. Panel B shows MVO₂ levels in the groups, as determined with the utilization of positron emission tomography. Obese women had the greatest MVO₂, which was significantly greater than the nonobese women and the obese men. Nonobese women also had greater MVO₂ than the nonobese men. MBF = myocardial blood flow; MVO₂ = oxygen consumption.

This figure demonstrates the relationships between MBF, quantified using positron emission tomography, and BMI in men and in women. The correlations between BMI and MBF were only significant in the women. However, r values for the correlations of BMI with MBF in men and women were not statistically different. BMI = body mass index; MBF = myocardial blood flow.

These graphs show how MVO₂, quantified using positron emission tomography, relates to increasing BMI in men and in women. The correlation between MVO₂ and BMI was only significant in the women. However, r values for the correlations in men and women were not statistically different. BMI = body mass index; MVO₂ = oxygen consumption.

Top left, typical positron emission tomography (PET)-derived, horizontal long-axis image from the myocardium of a nonobese man in our study after injection with 1-¹¹C-acetate. Compared with the nonobese man, the PET-derived image after 1-¹¹C-acetate from an obese women's myocardium shows greater tracer accumulation in the myocardium (more white and red graphically indicate greater counts in the woman's myocardium, corresponding to greater tracer uptake). Bottom panels, blood (dashed lines) and myocardial time-activity curves (solid lines) from the corresponding PET images, which were used in conjunction with compartmental models to quantify MVO₂.

Panels A and B show the groups' myocardial glucose uptake and glucose utilization/plasma insulin, respectively. Glucose uptake and utilization were measured with positron emission tomography and insulin with a radioimmunoassay. Obesity's and gender's significant interaction in the prediction of glucose uptake (p < 0.05) is shown graphically because both the magnitude and direction of the effect of obesity on myocardial glucose uptake differ in men and women. Obese men have lower uptake than nonobese men; obese women, however, have greater uptake than nonobese women. Obesity and gender also interacted in determining glucose utilization/plasma insulin (p = 0.01), as shown by the magnitude of the difference between the obese and nonobese men and that between the obese and nonobese women.

Shown is a depiction of the groups' myocardial fatty acid (FA) uptake (A), utilization (B), and oxidation (C), which were quantified with positron emission tomography. Pairwise comparisons show no difference among the groups in FA uptake, but FA utilization was greater in the obese men compared with nonobese men. Fatty acid oxidation was greater in the obese men compared with nonobese men, and it was greater in the obese women compared with nonobese women.