Lean mass, and not fat mass, is an independent determinant of carotid intima media thickness in obese subjects

Abstract

Background and aimsObesity is an important determinant of increased cardiovascular risk. Increased fat mass has been assumed to constitute the main prominent contributor to changes in carotid intima-media thickness (c-IMT). MethodsIn 421 consecutive subjects (301 women), c-IMT was evaluated ultrasonographically in 6 independent territories and body composition was assessed by dual-energy X-ray absorptiometry. Resultsc-IMT was positively associated with lean body mass in both men (r = 0.328, p = <0.0001) and women (r = 0.268 p = <0.0001) and increased across lean mass quartiles (p = <0.0001 for linear-trend ANOVA). Stepwise linear regression analysis showed that age and lean mass (but not fat mass or traditional cardiovascular risk factors) contributed to 46.2% of c-IMT variance in men (p = <0.0001). Even within obese men, lean mass was an independent contributor to c-IMT variance. Among women, age, lean mass and ultrasensitive CRP levels contributed independently to 47.7% of c-IMT variance (p < 0.0001). ConclusionsLean mass, and not fat mass, might contribute to increase c-IMT in obese patients independently of classical atherosclerotic risk factors. These data reinforce the concept that the increase in metabolically fat-free mass that accompanies the body weight enlargement is closely related to the raise in blood pressure.