Danish VISA-A questionnaire with validation and reliability testing for Danish-speaking Achilles tendinopathy patients

The VISA-A questionnaire has proven to be a valid and reliable tool for assessing severity of Achilles tendinopathy (AT). The aim was to translate and cross-culturally adapt the VISA-A questionnaire for a Danish-speaking AT population, and subsequently perform validity and reliability tests. Translation and following cross-cultural adaptation was performed as translation, synthesis, reverse translation, expert review, and pretesting. The final Danish version (VISA-A-DK) was tested for reliability on healthy controls (n = 75) and patients (n = 36). Tests for internal consistency, validity, and structure were performed on 71 patients. VISA-A-DK showed good reliability for patients (r = 0.80 ICC = 0.79) and healthy individuals (r = 0.98 ICC = 0.97). Internal consistency was 0.73 (Cronbach's alpha). The mean VISA-A-DK score in AT patients was 51 [47-55]. This was significantly lower than healthy controls with a score of 93 (90-95). Criterion validity was considered good when comparing the scores of the Danish version with the original version in both healthy individuals and patients. VISA-A-DK is a valid and reliable instrument and has shown compatible to the original version in assessment of AT patients. VISA-A-DK is a useful tool in the assessment of AT, both in research and in a clinical setting.

Does vitamin-D intake during resistance training improve the skeletal muscle hypertrophic and strength response in young and elderly men? - a randomized controlled trial

Introduction

Recent studies have shown that vitamin-D intake can improve skeletal muscle function and strength in frail vitamin-D insufficient individuals. We investigated whether vitamin-D intake can improve the muscular response to resistance training in healthy young and elderly individuals, respectively.

Methods

Healthy untrained young (n = 20, age 20–30) and elderly (n = 20, age 60–75) men were randomized to 16 weeks of daily supplementary intake of either 48 μg of vitamin-D + 800 mg calcium (Vitamin-D-group) or 800 mg calcium (Placebo-group) during a period and at a latitude of low sunlight (December-April, 56°N). During the last 12 weeks of the supplementation the subjects underwent progressive resistance training of the quadriceps muscle. Muscle hypertrophy, measured as changes in cross sectional area (CSA), and isometric strength of the quadriceps were determined. Muscle biopsies were analyzed for fiber type morphology changes and mRNA expression of vitamin-D receptor (VDR), cytochrome p450 27B1 (CYP27B1) and Myostatin.

Results

In the vitamin-D groups, serum 25(OH)D concentration increased significantly and at week 12 was significantly different from placebo in both young men (71.6 vs. 50.4 nmol/L, respectively) and elderly men (111.2 vs. 66.7 nmol/L, respectively). After 12 weeks of resistance training, quadriceps CSA and isometric strength increased compared to baseline in young (CSA p < 0.0001, strength p = 0.005) and elderly (CSA p = 0.001, strength p < 0.0001) with no difference between vitamin-D and placebo groups. Vitamin-D intake and resistance training increased strength/CSA in elderly compared to young (p = 0.008). In the young vitamin-D group, the change in fiber type IIa percentage was greater after 12 weeks training (p = 0.030) and Myostatin mRNA expression lower compared to the placebo group (p = 0.006). Neither resistance training nor vitamin-D intake changed VDR mRNA expression.

Conclusion

No additive effect of vitamin-D intake during 12 weeks of resistance training could be detected on either whole muscle hypertrophy or muscle strength, but improved muscle quality in elderly and fiber type morphology in young were observed, indicating an effect of vitamin-D on skeletal muscle remodeling.

Trial registration

ClinicalTrials with nr. NCT01252381

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-015-0029-y) contains supplementary material, which is available to authorized users.