Abstract
I
Although the pathogenetic mechanisms are still poorly elucidated, it is now well-recognized that the presence and persistence of lymphedema occasions progressive and often severe changes in the tissue composition of the affected segments of the body. 2 These tissue changes encompass both integumetary fibrosis 3 and pathological accumulation of excess subcutaneous adipose stores. 4 What has heretofore remained relatively unexplored is the relationship of limb dominance to the severity of this process.
In the current investigation, the authors have chosen to address this question in cohorts of women with and without breast cancer-associated lymphedema. The upper limbs were assessed with dual-energy X-ray absorptiometry (DXA), perometry and bioimpedance spectroscopy.5–7 They observed that, indeed, the direction and magnitude of limb composition changes in the lymphedema subjects were impacted by the dominance or non-dominance of the affected limb. Dominance also had an interactive impact on the severity of the condition. Of note, the control subjects had less fat and more lean tissue in the dominant limb when compared to the non-dominant one. In lymphedema subjects the accumulation of adipose tissue in the affected limb is unrelated to general adiposity when the dominant limb is affected by lymphedema.
These findings had an impact on the outcome of the limb measurements that are typically employed for the detection and staging of lymphedema. Comparison of the inter-limb BIS ratio with the inter-limb DXA ratios for those with lymphedema in the dominant limb revealed a moderate correlation for fat and lean tissue, but high correlation for the total limb volume; however, the correlation between the BIS ratio and fat ratio for lymphedema in the non-dominant limb was low, but high for lean and total limb volume. Given the growing emphasis upon bioimpedance spectroscopy in lymphedema assessment, the current observations of Dylke et al. are highly relevant and certainly deserve additional study.