Systematic review and meta-analysis: Associations of vitamin D with pulmonary function in children and young people with cystic fibrosis.

BACKGROUND: Increasing evidence suggests that vitamin D is associated with pulmonary health, which may benefit children and young people diagnosed with Cystic Fibrosis (cypCF). Therefore, the aim of this systematic review was to evaluate primary research to establish associations between 25OHD and pulmonary health in cypCF. METHODS: Electronic databases were searched with keywords related to CF, vitamin D, children/young people and pulmonary function. Included studies were cypCF (aged ≤21 years) treated in a paediatric setting. The primary outcome was lung function [forced expiratory volume in 1 s (FEV1% predicted)] and secondary outcomes were rate of pulmonary exacerbations, 25OHD status and growth. Evidence was appraised for risk of bias using the CASP tool, and quality using the EPHPP tool. A Meta-analysis was performed. RESULTS: Twenty-one studies were included with mixed quality ratings and heterogeneity of reported outcomes. The Meta-analysis including 5 studies showed a significantly higher FEV1% predicted in the 25OHD sufficiency compared to the deficiency group [FEV1% predicted mean difference (95% CI) was 7.71 (1.69-13.74) %; p = 0.01]. The mean ± SD FEV1% predicted for the sufficient (≥75 nmol/L) vs. deficient (<50 nmol/L) group was 94.7 ± 31.9% vs. 86.9 ± 13.2%; I2 = 0%; χ2 = 0.5; df = 4). Five studies (5/21) found significantly higher rate of pulmonary exacerbations in those who were 25OHD deficient when compared to the sufficient group and negative associations between 25OHD and FEV% predicted. The effects of vitamin D supplementation dosages on 25OHD status (10/21) varied across studies and no study (12/21) showed associations between 25OHD concentration and growth. CONCLUSION: This systematic review suggests that 25OHD concentration is positively associated with lung function and a concentration of >75 nmol/L is associated with reduced frequency of pulmonary exacerbations, which may slow lung function decline in cypCF. Future randomised clinical trials and mechanistic studies are warranted.

Categorizing 10 Sports According to Bone and Soft Tissue Profiles in Adolescents.

PURPOSE: Considering the different loading and training characteristics of the sports practiced during growth, it is important to specify and categorize the bone and soft tissue adaptations in adolescent athletes. This study aimed to categorize 10 different loading sports and a nonsport group and identify the differences in bone density and soft tissues. METHODS: The sample included 625 adolescents (10 to 17 yr of age) of 10 sports (soccer, basketball, volleyball, track and field, judo, karate, kung fu, gymnastics, baseball, and swimming) and a nonsport group. Dual-energy x-ray absorptiometry assessed areal bone mineral density (aBMD), bone mineral apparent density (BMAD), and soft tissues (lean soft tissue and fat mass). The results were adjusted for sex, peak height velocity status, lean soft tissue, fat mass, and weekly training volume. RESULTS: The comparisons among groups showed that soccer had the highest whole-body aBMD (mean ± SEM: 1.082 ± 0.007 g·cm) and lower limb aBMD (1.302 ± 0.010 g·cm). Gymnastics presented the highest upper limb aBMD (0.868 ± 0.012 g·cm) and whole-body BMAD (0.094 ± 0.001 g·cm). Swimming presented the lowest aBMD values in all skeletal sites (except at the upper limbs) and whole-body BMAD. The soft tissue comparisons showed that soccer players had the highest lean soft tissue (43.8 ± 0.7 kg). The lowest fat mass was found in gymnasts (8.04 ± 1.0 kg). CONCLUSION: The present study investigated and categorized for the first time 10 different sports according to bone density and soft tissue profiles. Soccer and gymnastics sport groups were found to have the highest bone density in most body segments, and both sports were among the groups with the lowest fat mass.

Bone accrual over 18 months of participation in different loading sports during adolescence.

This study investigated the impact and non-impact sports on bone mineral density accrual in adolescents over 18 months. The impact sports were beneficial for bone health (accrual of bone density). In contrast, swimmers had similar or lower bone mineral density compared with the control group depending on the skeletal site. PURPOSE: To investigate the impact and non-impact sports on bone mineral density (BMD) accrual in adolescents over a period of 18 months METHODS: The sample was composed of 71 adolescents, avarage age of 12.7 (± 1.7) years old at baseline. Bone outcomes were compared according to the loading of the sports practiced (impact sports, n = 33 [basketball, karate, and judo], non-impact sport, n = 18 [swimming], and control group, n = 20). Areal bone mineral density (aBMD) was measured by dual-energy X-ray absorptiometry (DXA) and bone mineral apparent density (BMAD) estimated through equation. The results were compared between the groups using analysis of variance and analysis of covariance. RESULTS: Adjusted aBMD at lower limbs, whole body less head (WBLH), and adjusted WBLH BMAD were significantly greater in the impact sport group than the non-impact sport group at all time points. Adjusted upper limbs aBMD was significantly higher at the impact sports group compared to the non-impact sport group at 9 months and 18 months, besides compared to the control group at baseline and 18 months. Non-impact sport group presented a significant lower adjusted aBMD compared with control group at lower limbs and WBLH at 9 months, and at 9 months and 18 months in WBLH BMAD. There was a significant interaction (time × sport group) at upper limbs (p = 0.042) and WBLH aBMD (p = 0.006), and WBLH BMAD (p < 0.001). CONCLUSION: Impact sports were more beneficial on accumulating aBMD and BMAD over a period of 18 months, while non-impact group (swimmers) had similar and lower aBMD and BMAD compared with the control group.

Effects of post exercise protein supplementation on markers of bone turnover in adolescent swimmers.

BACKGROUND: This study examined the effects of whey protein supplementation, compared with an isocaloric carbohydrate beverage and water, consumed immediately following an intense swimming trial on bone turnover in adolescent swimmers. METHODS: Fifty-eight (31 female, 27 male) swimmers (14.1 ± 0.4 years) were stratified into three groups matched for age, sex and body mass. The protein and carbohydrate groups consumed two isocaloric post-exercise beverages each containing 0.3 g.kg- 1 of whey protein (with ~ 6 mg of calcium) or maltodextrin while the control group consumed water. Participants provided a morning, fasted, resting blood sample, then performed an intense swimming trial consisting of a maximal 200 m swim followed by a high intensity interval swimming protocol (5x100m, 5x50m and 5x25m; 1:1 work-to-rest ratio). Following swimming, they consumed their first respective post-exercise beverage, and 2 h later, they performed a second maximal swim immediately followed by the second beverage. Approximately 3 h after the second beverage, two post-consumption blood samples were collected at 8 h and 24 h from baseline. Procollagen type 1 intact N-terminal propeptide (PINP) and carboxy-terminal collagen crosslinks (CTXI) were measured in serum. The multiples of medians of PINP and CTXI were also used to calculate bone turnover rate and balance. RESULTS: No significant changes were observed in PINP. CTXI increased (+ 11%) at 8 h in all groups, but then significantly decreased (- 22%) at 24 h in the protein group only. The protein group also had a significantly higher calculated rate of bone turnover at 8 h and 24 h compared to baseline, which was not observed in the other groups. CONCLUSIONS: These results shed light on the potential importance of protein consumed shortly after intense swimming in promoting positive bone turnover responses up to 24 h following exercise in adolescent athletes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov PRS; NCT04114045. Registered 1 October 2019 - Retrospectively registered.