Vitamin D has been reported to lower blood pressure in vivo by regulating the renin-angiotensin system; however, there are limited clinical studies to support this finding in humans. We investigated the effect of vitamin D treatment on hypertension in a three-arm randomized placebo controlled pilot and feasibility study. We tested placebo with two forms of vitamin D: cholecalciferol (vitamin D3) and the active form of vitamin D, calcitriol. Subjects were recruited from the Atlanta Veterans Affairs Medical Center in Decatur, GA between April and August 2008. Subjects received 200,000 IU of vitamin D3 (n = 3) weekly for 3 weeks or matching placebo (n = 3) weekly for 3 weeks (n = 3) or 0.5 μg calcitriol (n = 2) taken twice daily for one week. Our primary endpoint was blood pressure measured by 24 h ambulatory blood pressure monitor. Subjects receiving calcitriol experienced a 9% decrease in mean systolic blood pressure (SBP) compared placebo (p < 0.001). One week after conclusion of calcitriol therapy SBP returned to pre-treatment levels. There was no reduction in blood pressure in the placebo or vitamin D3 groups. Results from this pilot study suggests that active vitamin D therapy may be an effective short-term intervention for reducing blood pressure and needs to be explored further in larger controlled studies.
Objective
To determine the sensitivity and specificity of ultrasound imaging (USI) compared to the reference‐standard of MRI in the diagnosis of bone stress injury (BSI).
Methods
A prospective blinded cohort study was conducted. Thirty seven patients who presented to an academic sports medicine clinic from 2016 to 2020 with suspected lower‐extremity BSI on clinical exam underwent both magnetic resonance imaging (MRI) and USI. Participant characteristics were collected including age, gender and sport. Exclusion criteria included contraindication for dedicated MRI, traumatic fracture, or severe tendon or ligamentous injury. The primary outcome measure was BSI diagnosis by USI. An 8‐point assessment system was utilized on USI for diagnosis of BSI, and the Fredericson and Nattiv22 criteria were applied to classify MRI findings.
Results
Thirty seven participants who met study criteria were consented to participate. All participants completed baseline measures. Using MRI, there were 30 (81%) athletes with a positive and seven participants with a negative BSI diagnosis. The most common BSIs in the study were in the metatarsal (54%) and tibia (32%). Compared to MRI, USI demonstrated 0.80 sensitivity (95% confidence interval [CI], 0.61–0.92) and 0.71 specificity (95% CI, 0.29–0.96) in detecting BSI, with a positive predictive value of 0.92 (95% CI, 0.75–0.99) and negative predictive value of 0.45 (95% CI, 0.17–0.77).
Conclusions
USI is a potentially useful point‐of‐care tool for practicing sports medicine providers to combine with their clinical evaluation in the diagnosis of BSIs. Further research is ongoing to determine the role of USI in follow‐up care and return‐to‐play protocols.
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