Suction-modified Bergström muscle biopsy technique: experience with 13,500 procedures.

INTRODUCTION: Bergström needle muscle biopsies have been used by exercise physiologists for over 35 years but have been less accepted by neuromuscular clinicians due to size concerns. METHODS: We retrospectively reviewed over 13,500 muscle Bergström needle biopsies done over a 21-year period to determine sampling success, patient/subject experience, and complications. We compared sample yield between two different needles (Bergström vs. UCH), with and without suction modifications. RESULTS: Needle biopsies adequate for histology and enzymology were obtainable from the vastus lateralis, deltoid, biceps brachii, soleus, and medial gastrocnemius muscles, with a success rate of >99.9% and a minor complication rate of 0.15%. Approximately 450 muscle fibers were submitted for histologic assessment; suction modification and use of the Bergström vs. UCH needle were associated with larger sample size (P < 0.05). CONCLUSIONS: The suction-modified Bergström needle muscle biopsy technique is safe and provides an adequate sample size for histologic, ultrastructural, DNA, and enzyme analysis.

Bacterial overgrowth syndrome in myotonic muscular dystrophy is potentially treatable.

Over one third of patients with myotonic muscular dystrophy type 1 (DM1) have gastrointestinal complaints. The cause is multifactorial, and treatment options are limited. Twenty DM1 patients with gastrointestinal symptoms were screened over a 2-year period using glucose breath hydrogen testing (GBHT) to evaluate the prevalence of small intestinal bacterial overgrowth (SIBO). Sixty-five percent of patients had a positive GBHT, and diarrhea was the most common presenting symptom. Ciprofloxacin was the most common antibiotic used for treatment, and 70% of patients reported a good response to the initial course of treatment. Although the causes of gastrointestinal symptoms in patients with DM1 are multifactorial, small intestinal bacterial overgrowth is an important diagnostic consideration that is easily diagnosed using glucose breath hydrogen testing and often shows a good response to treatment with common antibiotics.

Creatine monohydrate attenuates body fat accumulation in children with acute lymphoblastic leukemia during maintenance chemotherapy.

BACKGROUND: Corticosteroids are an important component of the treatment of acute lymphoblastic leukemia (ALL), with known significantly negative effects on bone and muscle. Creatine monohydrate (CrM) supplementation may be an adjunctive therapeutic strategy to attenuate some of these adverse effects. PROCEDURE: Nine children with ALL in the maintenance phase of treatment on the Dana-Farber Cancer Institute (DFCI) protocol 2000-2001 were treated with CrM (0.1 g/kg/day) for two sequential periods of 16 weeks (16 weeks treat > 6 weeks wash-out > 16 weeks treat). A cohort of children (N = 50) who were receiving the same chemotherapy at the same time served as natural history controls. Measurements included height, weight, body mass index (BMI), and lumbar spine bone mineral density (LS-BMD), whole body bone mineral content (WB-BMC), fat-free mass (FFM), and percent body fat (%BF) using dual-energy X-ray absorptiometry. RESULTS: Despite the long course of corticosteroid treatment for ALL, children showed significant increases in height, LS-BMD, WB-BMC and FFM over approximately 38 weeks (P < 0.05) during the study. There was an increase in BMI over time, but children taking CrM had a reduction, while the natural history group showed an increase in % BF (P < 0.05 for interaction). CONCLUSIONS: Children with ALL treated with corticosteroids as part of a maintenance protocol of chemotherapy showed an increase in % BF that was attenuated by CrM supplementation.

Creatine monohydrate and conjugated linoleic acid improve strength and body composition following resistance exercise in older adults.

Aging is associated with lower muscle mass and an increase in body fat. We examined whether creatine monohydrate (CrM) and conjugated linoleic acid (CLA) could enhance strength gains and improve body composition (i.e., increase fat-free mass (FFM); decrease body fat) following resistance exercise training in older adults (>65 y). Men (N = 19) and women (N = 20) completed six months of resistance exercise training with CrM (5g/d)+CLA (6g/d) or placebo with randomized, double blind, allocation. Outcomes included: strength and muscular endurance, functional tasks, body composition (DEXA scan), blood tests (lipids, liver function, CK, glucose, systemic inflammation markers (IL-6, C-reactive protein)), urinary markers of compliance (creatine/creatinine), oxidative stress (8-OH-2dG, 8-isoP) and bone resorption (Nu-telopeptides). Exercise training improved all measurements of functional capacity (P<0.05) and strength (P<0.001), with greater improvement for the CrM+CLA group in most measurements of muscular endurance, isokinetic knee extension strength, FFM, and lower fat mass (P<0.05). Plasma creatinine (P<0.05), but not creatinine clearance, increased for CrM+CLA, with no changes in serum CK activity or liver function tests. Together, this data confirms that supervised resistance exercise training is safe and effective for increasing strength in older adults and that a combination of CrM and CLA can enhance some of the beneficial effects of training over a six-month period. Trial Registration. ClinicalTrials.gov NCT00473902.