Myosteatosis as a Shared Biomarker for Sarcopenia and Cachexia Using MRI and Ultrasound

Purpose

Establish bedside biomarkers of myosteatosis for sarcopenia and cachexia. We compared ultrasound biomarkers against MRI-based percent fat, histology, and CT-based muscle density among healthy adults and adults undergoing treatment for lung cancer.

Methods

We compared ultrasound and MRI myosteatosis measures among young healthy, older healthy, and older adults with non-small cell lung cancer undergoing systemic treatment, all without significant medical concerns, in a cross-sectional pilot study. We assessed each participant's rectus femoris ultrasound-based echo intensity (EI), shear wave elastography-based shear wave speed, and MRI-based proton density fat-fraction (PDFF). We also assessed BMI, rectus femoris thickness and cross-sectional area. Rectus femoris biopsies were taken for all older adults (n = 20) and we analyzed chest CT scans for older adults undergoing treatment (n = 10). We determined associations between muscle assessments and BMI, and compared these assessments between groups.

Results

A total of 10 young healthy adults, 10 older healthy adults, and 10 older adults undergoing treatment were recruited. PDFF was lower in young adults than in older healthy adults and older adults undergoing treatment (0.3 vs. 2.8 vs. 2.9%, respectively, p = 0.01). Young adults had significantly lower EI than older healthy adults, but not older adults undergoing treatment (48.6 vs. 81.8 vs. 75.4, p = 0.02). When comparing associations between measures, PDFF was strongly associated with EI (ρ = 0.75, p < 0.01) and moderately negatively associated with shear wave speed (ρ = −0.49, p < 0.01) but not BMI, whole leg cross-sectional area, or rectus femoris cross-sectional area. Among participants with CT scans, paraspinal muscle density was significantly associated with PDFF (ρ = −0.70, p = 0.023). Histological markers of inflammation or degradation did not differ between older adult groups.

Conclusion

PDFF was sensitive to myosteatosis between young adults and both older adult groups. EI was less sensitive to myosteatosis between groups, yet EI was strongly associated with PDFF unlike BMI, which is typically used in cachexia diagnosis. Our results suggest that ultrasound measures may serve to determine myosteatosis at the bedside and are more useful diagnostically than traditional weight assessments like BMI. These results show promise of using EI, shear wave speed, and PDFF proxies of myosteatosis as diagnostic and therapeutic biomarkers of sarcopenia and cachexia.

Can Community Gardens with Workshops Increase Gardening Behavior? A Navajo Wellness Collaboration

This project evaluated the potential efficacy of a community gardening intervention on the Navajo Nation to increase gardening and healthy eating behaviors, which are potentially important in preventing obesity and related health conditions. Rates of obesity are high among American Indians, including those living on Navajo Nation land. Eating fresh fruits and vegetables is part of healthy eating. However, availability and access to fresh fruits and vegetables are severely limited due to distance and cost. One way to increase both availability and consumption of fresh fruits and vegetables is through community gardening, yet many on the Navajo Nation have limited knowledge and capacity to garden.

METHODS

We used a quasi-experimental pre-post study design to estimate the effect of a community gardening intervention. Primary outcomes of interest were gardening frequency and fruit and vegetable consumption. Community gardens were constructed and planted in two communities on the Navajo Nation. In addition, a series of gardening workshops were held in each community. Community members were recruited to complete surveys at time points before and after the workshops. The time between baseline and follow-up was approximately one year.

RESULTS

We surveyed 169 participants at one time point at least, across both communities, and 25 of these participated in the gardening workshops. Within the 169, there was a cohort of 32 participants completing both baseline and follow-up surveys. For this cohort, interest in gardening increased from 78% to 97% (p=0.014), but none of the changes in gardening self-efficacy, knowledge or gardening frequency reached statistical significance. There were no measurable changes in reported fruit and vegetable consumption, self-efficacy or knowledge. Overall, the reported financial barriers to gardening increased from baseline to follow-up from 4.6 to 5.5 (p=0.035). Among those who completed follow-up, those who attended at least one workshop gardened more frequently than those who did not attend any workshops (21 times per month compared to 10 times per month (p=0.065).

CONCLUSION

Despite enthusiasm for the community garden in both the communities studied and the increased interest in gardening, workshop attendance and participant retention in the study were low. These factors limited our ability to evaluate the potential efficacy of the intervention on gardening and healthy eating behaviors. Nonetheless, we found some evidence that participating in gardening workshops may lead to increased gardening frequency. Future studies should augment the intervention to include explicit efforts to reduce barriers to long term engagement and extend intervention reach.

Gardening for Health: Patterns of Gardening and Fruit and Vegetable Consumption Among the Navajo

American Indians, including Navajo, are disproportionately affected by obesity and diabetes, in part due to diet-related health behaviors. The purpose of this study was to assess the patterns of gardening and fruit and vegetable (FV) consumption among residents in two communities on the Navajo Nation in order to inform a community gardening intervention. We analyzed survey data collected from participants in the Yéego Gardening study conducted in two communities in the Navajo Nation (N = 169). We found that 51% of the sample gardened, and on average participants gardened 8.9 times per month. Lack of time (53%) and financial barriers, such as gas for transportation or irrigation (51 and 49%, respectively), were reported as barriers to gardening. Most participants reported low levels of self-efficacy (80%) and behavioral capability (82%) related to gardening. Those with higher levels of gardening self-efficacy and behavioral capability reported more frequent gardening. Average daily FV consumption was 2.5 servings. Most participants reported high levels of self-efficacy to eat FV daily (64%) and high behavioral capability to prepare FV (66%). There was a positive association between FV consumption and gardening, with those gardening more than 4 times per month eating about 1 more serving of FV per day than those gardening 4 or fewer times per month. Further research is needed to better understand how gardening can increase fruit and vegetable availability and consumption among residents of the Navajo Nation.