Body composition of patients with Duchenne muscular dystrophy: the Greek experience

Effect of Zinc Supplementation on Body Composition of Duchenne Muscular Dystrophy Patients: A Quasi-Experimental Study

Background

The study hypothesized that zinc supplementation would increase or preserve lean body mass in Duchenne muscular dystrophy (DMD) patients. Therefore, we aimed to evaluate the body composition of DMD patients before and after zinc supplementation.

Materials and Methods

The study is a clinical trial comprising 21 boys diagnosed with DMD. Dietary intake parameters were evaluated before zinc supplementation. Serum zinc levels, anthropometry, and body composition were measured in three moments, four months apart. The patients received 5, 10, or 15 mg of zinc bis-glycine supplementation according to age as an oral solution daily for four months. The sample was distributed into two groups according to serum zinc status: zinc deficiency (G1) or adequate zinc (G2).

Results

There was a significant difference in lean body mass between the groups: zinc deficiency (G1) or adequate zinc (G2), at three times (p=0.041, 0.016, and 0.009, respectively). After oral zinc supplementation, serum zinc levels were not different between groups. We did not observe differences when associating the parameters between times and groups.

Conclusion

Zinc supplementation was able to maintain lean body mass and fat mass in patients with DMD with previous deficiencies. Therefore, it is necessary to have a prior screening of serum zinc levels to observe changes after supplementation.

A systematic literature review and meta-analysis of the effectiveness of vitamin D supplementation for patients with Duchenne muscular dystrophy

We conducted a systematic literature review and meta-analysis on the effectiveness of vitamin D supplementation in maintaining or restoring vitamin D levels in Duchenne muscular dystrophy. Due to a lack of randomised controlled trials, cross-sectional and retrospective and prospective cohort studies were taken as the best available evidence. Inclusion criteria included reporting mean serum vitamin D levels in a supplement-taking group. After screening 102 records; 13 were included in a narrative synthesis and eight of these in a meta-analysis. We show that current dosing regimens are preventing severe deficiency but are not effective at maintaining sufficient vitamin D levels within the Duchenne population. Despite high levels of daily vitamin D supplementation (>1000 International Units), at least 20 % of people with Duchenne remain vitamin D deficient. No significant association between dose and serum vitamin D levels was found (r2 = 0.3, p = 0.237). A meta-analysis of mean serum vitamin D levels across eight studies also revealed substantial variability in response to vitamin D supplementation and high heterogeneity (I2 = 99.59 %). These data could impact on an individual's risk and severity of osteoporosis and vertebral fractures.

A Scoping Review of the Recent Clinical Practice Regarding the Evaluation of Bone Mineral Density in Children and Adolescents with Neuromuscular Diseases

Introduction: Neuromuscular Diseases (NMD) are associated with decreased bone strength due to altered muscle-bone interaction. However, the evaluation of bone quality remains a certain challenge in these patients. The purpose of this scoping review is to investigate the recent literature regarding the assessment of Bone Mineral Density (BMD) in this population. Methods: An electronic search of the PubMed and Scopus database was performed considering studies published in the English literature after 2007 that evaluated BMD in pediatric and adolescent patients with NMD. We excluded studies that evaluated patients > 20 years, studies not involving humans, and studies investigating bone mineral density in various pediatric conditions, but without specific data on NMD. Results: Overall, 19 studies were included that evaluated BMD in 1983 patients with NMD. Duchenne Muscular Dystrophy was the most widely studied disease (n = 11 studies). Dual energy X-ray absorptiometry (DEXA) was the most common diagnostic modality for BMD evaluation, while the most frequent site for BMD measurement was the lumbar spine (89.4%, n = 17 studies), followed by total body BMD (68.4%, n = 13 studies). Low BMD in children with NMD was demonstrated in all studies, especially after loss of ambulation. Moreover, a positive correlation between lower BMD and older age was shown. Conclusions: BMD evaluation in NMD remains a clinical challenge, as indicated by the high heterogeneity regarding the optimal site and technique for the evaluation of bone quality in these patients. Although DXA is currently the diagnostic modality of choice, a consensus regarding the optimal site for BMD measurement, and the adjustment method for its obtained measurements for parameters such as age and height is needed.

Dual-energy X-ray absorptiometry measures of lean body mass as a biomarker for progression in boys with Duchenne muscular dystrophy

We evaluated whether whole-body dual-energy X-ray absorptiometry (DXA) measures of lean body mass can be used as biomarkers for disease progression and treatment effects in patients with Duchenne muscular dystrophy. This post hoc analysis utilized data from a randomized, 2-period study of domagrozumab versus placebo in 120 ambulatory boys with DMD. DXA measures of lean body mass were obtained from the whole body (excluding head), arms, legs and appendicular skeleton at baseline and every 16 weeks. Treatment effects on DXA measures for domagrozumab versus placebo were assessed at Week 49. At Week 49, domagrozumab statistically significantly increased lean body mass versus placebo in the appendicular skeleton (p = 0.050) and arms (p < 0.001). The relationship between lean body mass at Week 49 and functional endpoints at Week 97 was evaluated. Changes in lean body mass at Week 49 in all regions except arms were significantly correlated with percent change from baseline in 4-stair climb (4SC) at Week 97. DXA-derived percent lean mass at Week 49 also correlated with 4SC and North Star Ambulatory Assessment at Week 97. These data indicate that whole-body DXA measures can be used as biomarkers for treatment effects and disease progression in patients with DMD, and warrant further investigation.Trial registration: ClinicalTrials.gov, NCT02310763; registered 8 December 2014.

Effect of Testosterone Treatment for Delayed Puberty in Duchenne Muscular Dystrophy

OBJECTIVE

To evaluate the impact of pubertal induction with testosterone on bone health, body composition, and motor function in boys with Duchenne muscular dystrophy (DMD) receiving long-term glucocorticoid.

STUDY DESIGN

A retrospective, observational, pre-post study investigating the impact of testosterone therapy on bone mass accrual, vertebral fracture incidence, body composition, motor function, and quality of life in boys with DMD. All those boys aged ≥14 years, on chronic steroid therapy, who had delayed puberty, and were receiving oral testosterone or oral and then transitioned to intramuscular testosterone, to complete virilization, were included. Prior/concomitant zoledronic acid use was included. The primary outcome was lumbar spine areal bone mineral density (BMD LS).

RESULTS

Puberty was induced, using oral testosterone undecanoate in 16 individuals, 10 of whom had transited to intramuscular testosterone at time of assessment. Median age at testosterone onset was 14.5 years (range 14-17.7). Median duration of testosterone therapy was 2.5 years (range 1.0-4.5). There was statistically significant increase in median BMD LS (0.523-0.700, p < 0.001) and median annualized percentage change of BMD LS (-1.34 to +10.08%, p < 0.001), with median Tanner stage 4 at evaluation (range 2-4). Ten of 14 assessed had no progression in vertebral fractures. Fat mass index (FMI) standard deviation score (SDS), lean body mass index (LBMI) SDS, and percentage change of FMI and LBMI were statistically unchanged. Cardiac function remained stable. Motor function in non-ambulatory individuals with Egen Klassifikation scores improved in 7 of 8.

CONCLUSION

Testosterone for delayed puberty acted as an adjunct to bisphosphonates to increase bone density and stabilize vertebral fracture in most boys with DMD.

Age-related changes in appendicular lean mass in males with Duchenne muscular dystrophy: A retrospective review

BACKGROUND

Appendicular lean mass (ALM) trajectory in males with Duchenne muscular dystrophy (DMD) has potential applicability for treatment and research and has not been characterized.

METHODS

This chart review included longitudinal data on 499 males with DMD receiving glucocorticoids and 693 controls, ages 5 to 22.9 y. ALM (kg) was measured by dual energy x-ray absorptiometry (DXA). Appendicular lean mass index (ALMI, kg/m² ) was calculated for height adjustment. Reference centiles were generated using data from healthy controls, and ALM and ALMI Z-scores were calculated for patients with DMD. Generalized linear models were used to estimate median Z-scores by age and functional mobility status (FMS) score. ALM velocity by age was modeled using superimposition, translation and rotation (SITAR).

RESULTS

Compared to controls, males with DMD had lower ALM from an early age. ALMI Z-scores dropped below 0 at age 8 y or FMS of 2, and below -2.0 at age 13 y or FMS of 3 (P < .05). Age at peak ALM velocity was similar in both groups, but the magnitude was higher in controls (3.5 vs. 0.7 kg/y, P < .0001). Patients with DMD had a transient loss of ALM around age 12 y, an increase at age 14 y, then a further decline at age 16 y, remaining low thereafter.

CONCLUSIONS

Males with DMD have progressive decline in lean mass with age and worsening functional mobility. DXA measurement of ALM may be useful for monitoring lean mass status in patients with DMD, providing valuable information for individual treatment plans and research endeavors.

Validity of bioelectrical impedance to estimate fat-free mass in boys with Duchenne muscular dystrophy

The evaluation of fat-free mass (FFM) in patients with Duchenne muscular dystrophy (DMD) is useful to investigate disease progression and therapeutic efficacy. This study aimed to validate the Bioelectrical impedance (BIA) method compared with the dual-energy X-ray absorptiometry (DXA) for estimating the %FFM in boys with DMD. This is a cross-sectional study performed with children and adolescents diagnosed with DMD. Resistance and reactance were measured with a BIA analyzer, from which eight predictive equations estimated the %FFM. The %FFM was also determined by DXA and its used as a reference method. Pearson correlation test, coefficient of determination, the root-mean-square error, the interclass correlation coefficient, and linear regression analysis were performed between %FFM values obtained by BIA and DXA. The agreement between these values was verified with the Bland-Altman plot analysis. Forty-six boys aged from 5 to 20 years were enrolled in the study. All the equations showed a correlation between the %FFM estimated by BIA and determined by DXA (p < 0.05). The Bland-Altman method indicated that two equations have a significant bias (p < 0.05) and six equations showed no significant bias of %FFM (p > 0.05). However, one of them has high variation and wide limits of agreement. Five of eight %FFM predictive equations tested in DMD were accurate when compared with the DXA. It can be concluded that BIA is a validity method to evaluate patients with DMD.