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

• Body composition and c-IMT were evaluated in 421 subjects (301 women).
• In men, age and lean mass contributed to c-IMT variance but not fat mass.
• Even within obese men, lean mass was an independent contributor to c-IMT variance.
• Among women, age, lean mass and ultraCRP levels contributed independently to c-IMT variance.

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.