Differential effect of marrow adiposity and visceral and subcutaneous fat on cardiovascular risk in young, healthy adults

Background: Adipose tissue is an endocrine organ that influences many metabolic processes and accumulates in different depots, including the bone marrow. While the negative associations between visceral fat (VF) or subcutaneous fat (SF) and cardiovascular disease (CVD) risks are well known, the relation between marrow fat (MF) and metabolic risk is unexplored. Objectives: We examined the relations between these three fat depots and whether CVD risks are associated with marrow adiposity. Design: Observational cross-sectional study. Subjects and methods: Computed tomography was used to measure VF, SF and MF depots in 131 healthy young adults (60 females, 71 males; 16-25years of age). Weight, body mass index (BMI), waist and hip circumferences, blood pressure (BP), carotid intima-media thickness (CIMT) and serum levels of lipids, glucose and insulin were also measured. Results: Regardless of gender, MF was not associated with values of VF or SF, anthropometric measures, or lipid or carbohydrate serum levels (P > 0.05 for all). In contrast, VF was associated with SF (r values 0.74 for females, 0.78 for males; both P-values < 0.0001) and these depots were related to anthropometric parameters (r values between 0.69 and 0.87; all P-values < 0.0001) and to most measures of lipids, glucose or insulin (r values between 0.25 and 0.62). Conclusions: Marrow adiposity in young men and women is independent of VF and SF, and is not associated with CVD risk. These findings do not support the concept that marrow adiposity is involved in the comorbidities related to fat accumulation in other compartments.