In this cross-sectional study of 1,249 Afro-Caribbean men from the Tobago Health Study, a population of men > 40 years old with high prevalences of type 2 diabetes (>20%) and overweight or obesity (70%), Miljkovic-Gacic et al. tested the hypothesis that intramuscular adipose tissue (IMAT) is associated with diabetes, independent of total and subcutaneous fat. The authors reported that, with aging, IMAT increased, whereas subcutaneous adipose tissue and total muscle areas decreased. Moreover, greater accumulation of IMAT and, in contrast, lower accumulation of subcutaneous fat was associated with diabetes, independent of other risk factors. These findings stress the independent association of subcutaneous and IMAT among men of African ancestry, an effect that can be modified by a family history of diabetes. However, the authors acknowledged that additional studies are warranted to identify the specific genetic and physiological mechanisms that influence the distribution of adipose tissue in skeletal muscle. The article was accompanied by an editorial by Elbein and Rasouli. The editorial emphasized that the interaction of family history and IMAT found in the Miljkovic-Gacic study strongly suggests a gene X environment interaction specific to this population. However, the authors concluded that whether IMAT in this high-risk cohort represents a risk factor for diabetes, such as genetic susceptibility, or instead reflects the high prevalence of obesity in this elderly population remains to be determined.
Documentation centre