Dataset Information

Dominant and nondominant distal radius microstructure: Predictors of asymmetry and effects of a unilateral mechanical loading intervention.

ABSTRACT: Most information about distal radius microstructure is based on the non-dominant forearm, with little known about the factors that contribute to bilateral asymmetries in the general population, or what factors may influence bilateral changes over time. Here, we analyzed bilateral high resolution peripheral quantitative computed tomography (HRpQCT) data collected over a 12-month period as part of a clinical trial that prescribed a well-controlled, compressive loading task to the nondominant forearm. Baseline data from 102 women age 21-40, and longitudinal data from 66 women who completed the 12-month trial, were examined to determine factors responsible for side-to-side asymmetries in bone structure and change in structure over time. Cross-sectionally, the dominant radius had 2.4%-2.7% larger cross-sectional area, trabecular area, and bone mineral content than the nondominant radius, but no other differences were noted. Those who more strongly favored their dominant arm had significantly more, thinner, closely spaced trabecular struts in their dominant versus nondominant radius. Individuals assigned to a loading intervention had significant bilateral gains in total bone mineral density (2.0% and 1.2% in the nondominant versus dominant sides), and unilateral gains in the nondominant (loaded) cortical area (3.1%), thickness (3.0%), bone mineral density (1.7%) and inner trabecular density (1.3%). Each of these gains were significantly predicted by loading dose, a metric that included bone strain, number of cycles, and strain rate. Within individuals, change was negatively associated with age, meaning that women closer to age 40 experienced less of a gain in bone versus those closer to age 21. We believe that dominant/nondominant asymmetries in bone structure reflect differences in habitual loads during growth and past ability to adapt, while response to loading reflects current individual physiologic capacity to adapt.

SUBMITTER: Troy KL

PROVIDER: S-EPMC7994725 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:PurposeCarpal tunnel syndrome (CTS) can present following distal radius fracture (DRF) and may progress to require carpal tunnel release (CTR). The primary aim of this study was to determine the incidence of CTS within 6 months of a DRF and the rate of CTR in this population.MethodsWe used the PearlDiver national insurance database to determine the incidence of CTS after DRF. Patients were identified by International Classification of Diseases-10 codes, and treatment modalities for DRF and CTS were determined by respective Current Procedural Terminology codes. Patients with less than 6 months of follow-up, bilateral DRF, or preexisting CTS were excluded. Patient demographic characteristics were recorded. The time from DRF diagnosis to CTS diagnosis and CTR was determined. A multivariable analysis was performed to determine the differences between patients who underwent a CTR compared with those who were treated conservatively.ResultsWe identified 23,733 patients (6,015 men; 17,718 women) who sustained a DRF. Of these patients, 79.1% were treated nonsurgically and 20.9% underwent surgical fixation. In total, 9.2% (N = 2,179) were diagnosed with CTS in their ipsilateral extremity within 6 months of sustaining the DRF. Of the patients whose DRF was treated nonsurgically, 6.3% (N = 1,198) developed CTS and 2.9% (N = 546) required CTR. Of those patients whose DRF was treated surgically, 19.8% (N = 981) developed CTS and 13.3% (N = 661) required CTR. Of those patients with symptoms severe enough to warrant CTR, 18.5% required a second surgical intervention for the CTR.ConclusionsDistal radius fractures severe enough to require surgical fixation are associated with a higher incidence of perioperative CTS. Accordingly, careful evaluation for and counseling on CTS during surgical fixation may decrease the chance of a second surgery. We have identified a cohort of patients with DRFs who may benefit from prophylactic CTR.Type of study/level of evidenceDiagnostic IV.

Project description:Biotic and abiotic factors interact with dominant plants-the locally most frequent or with the largest coverage-and nondominant plants differently, partially because dominant plants modify the environment where nondominant plants grow. For instance, if dominant plants compete strongly, they will deplete most resources, forcing nondominant plants into a narrower niche space. Conversely, if dominant plants are constrained by the environment, they might not exhaust available resources but instead may ameliorate environmental stressors that usually limit nondominants. Hence, the nature of interactions among nondominant species could be modified by dominant species. Furthermore, these differences could translate into a disparity in the phylogenetic relatedness among dominants compared to the relatedness among nondominants. By estimating phylogenetic dispersion in 78 grasslands across five continents, we found that dominant species were clustered (e.g., co-dominant grasses), suggesting dominant species are likely organized by environmental filtering, and that nondominant species were either randomly assembled or overdispersed. Traits showed similar trends for those sites (<50%) with sufficient trait data. Furthermore, several lineages scattered in the phylogeny had more nondominant species than expected at random, suggesting that traits common in nondominants are phylogenetically conserved and have evolved multiple times. We also explored environmental drivers of the dominant/nondominant disparity. We found different assembly patterns for dominants and nondominants, consistent with asymmetries in assembly mechanisms. Among the different postulated mechanisms, our results suggest two complementary hypotheses seldom explored: (1) Nondominant species include lineages adapted to thrive in the environment generated by dominant species. (2) Even when dominant species reduce resources to nondominant ones, dominant species could have a stronger positive effect on some nondominants by ameliorating environmental stressors affecting them, than by depleting resources and increasing the environmental stress to those nondominants. These results show that the dominant/nondominant asymmetry has ecological and evolutionary consequences fundamental to understand plant communities.

Dataset Information

Dominant and nondominant distal radius microstructure: Predictors of asymmetry and effects of a unilateral mechanical loading intervention.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets