Vitamin D levels in idiopathic inflammatory myopathy patients: a meta-analysis.

PURPOSE: This meta-analysis aimed to explore correlations between vitamin D and idiopathic inflammatory myopathy (IIM). METHODS: A comprehensive database search was conducted on 13 October 2020. Mean differences (MDs) and aggregated risk ratios (RR) with 95% confidence intervals (CIs) were used to determine the correlation between vitamin D deficiency (VDD) and IIM. Statistical analysis was performed with RevMan 5.4 and Stata15, statistical significance was set at p < 0.05. RESULTS: Search revealed five studies with 286 IIM patients and 480 healthy controls. Results with random-effects modeling indicated that serum vitamin D levels were significantly lower in IIM patients than in healthy controls (MD = -13.10 ng/mL; 95% CI: -16.51 to -9.68; p < 0.00001). No differences were found between patients with IIM and other autoimmune diseases on vitamin D levels (MD =-2.65 ng/mL; 95% CI: -11.31-6.01; p = 0.55). In two studies with 185 IIM patients, those with low vitamin D levels exhibited higher creatine kinase levels (MD = 85.20 IU/L; 95% CI: 72.67-97.73; p < 0.00001) than those with normal vitamin D levels. VDD was correlated with an increased risk of IIM (RR = 3.24, 95% CI: 1.81-5.79; p < 0.0001). CONCLUSION: This meta-analysis showed correlations between vitamin D level and IIM. The results indicated, VDD may be a risk factor for IIM, a determinant of immune dysregulation in IIM, or a consequence of IIM. Also, it implied further research to determine whether vitamin D supplementation is beneficial for patients with IIM.

Vitamin A Oral Supplementation Induces Oxidative Stress and Suppresses IL-10 and HSP70 in Skeletal Muscle of Trained Rats.

Exercise training intensity is the major variant that influences the relationship between exercise, redox balance, and immune response. Supplement intake is a common practice for oxidative stress prevention; the effects of vitamin A (VA) on exercise training are not yet described, even though this molecule exhibits antioxidant properties. We investigated the role of VA supplementation on redox and immune responses of adult Wistar rats subjected to swimming training. Animals were divided into four groups: sedentary, sedentary + VA, exercise training, and exercise training + VA. Over eight weeks, animals were submitted to intense swimming 5 times/week and a VA daily intake of 450 retinol equivalents/day. VA impaired the total serum antioxidant capacity acquired by exercise, with no change in interleukin-1ß and tumor necrosis factor-α levels. In skeletal muscle, VA caused lipid peroxidation and protein damage without differences in antioxidant enzyme activities; however, Western blot analysis showed that expression of superoxide dismutase-1 was downregulated, and upregulation of superoxide dismutase-2 induced by exercise was blunted by VA. Furthermore, VA supplementation decreased anti-inflammatory interleukin-10 and heat shock protein 70 expression, important factors for positive exercise adaptations and tissue damage prevention. Our data showed that VA supplementation did not confer any antioxidative and/or protective effects, attenuating exercise-acquired benefits in the skeletal muscle.

DHA at nutritional doses restores insulin sensitivity in skeletal muscle by preventing lipotoxicity and inflammation.

Skeletal muscle plays a major role in the control of whole body glucose disposal in response to insulin stimulus. Excessive supply of fatty acids to this tissue triggers cellular and molecular disturbances leading to lipotoxicity, inflammation, mitochondrial dysfunctions, impaired insulin response and decreased glucose uptake. This study was conducted to analyze the preventive effect of docosahexaenoic acid (DHA), a long-chain polyunsaturated n-3 fatty acid, against insulin resistance, lipotoxicity and inflammation in skeletal muscle at doses compatible with nutritional supplementation. DHA (30 µM) prevented insulin resistance in C2C12 myotubes exposed to palmitate (500 µM) by decreasing protein kinase C (PKC)-θ activation and restoring cellular acylcarnitine profile, insulin-dependent AKT phosphorylation and glucose uptake. Furthermore, DHA protected C2C12 myotubes from palmitate- or lipopolysaccharide-induced increase in Ptgs2, interleukin 6 and tumor necrosis factor-α mRNA level, probably through the inhibition of p38 MAP kinase and c-Jun amino-terminal kinase. In LDLR -/- mice fed a high-cholesterol-high-sucrose diet, supplementation with DHA reaching up to 2% of daily energy intake enhanced the insulin-dependent AKT phosphorylation and reduced the PKC-θ activation in skeletal muscle. Therefore, DHA used at physiological doses participates in the regulation of muscle lipid and glucose metabolisms by preventing lipotoxicity and inflammation.

Rituximab as an effective alternative therapy in refractory idiopathic inflammatory myopathies.

OBJECTIVES: To assess the efficacy and safety of B-lymphocyte depletion therapy (BCDT) utilising rituximab in refractory idiopathic inflammatory myositis. METHODS: We retrospectively evaluated 16 adult patients with active dermatomyositis (DM) or polymyositis (PM) who received 1 gram rituximab intravenous infusions two weeks apart after failing to respond to conventional therapy. The clinical and biochemical response were analysed by the Myositis Intention to Treat index (MITAX) and the serum creatine kinase (CK) levels at baseline and 6 and 12 months after treatment. The primary efficacy outcome was 20% improvement in the MITAX index and 30% reduction in CK. RESULTS: Eight patients responded to treatment and achieved both the MITAX and CK levels objectives within 6 months of rituximab therapy. Five out of these 8 responders remained clinically stable at 12 months and CK levels were still reduced or normalised. Of note, 4 patients who did not respond were re-assessed and had their diagnoses corrected. All patients showed adequate B cell depletion (BCD) with re-population occurring for a 15.4 months average (range 3-42 months). Those simultaneously treated with cyclophosphamide achieved more long-lasting depletion (average 18.6 months). CONCLUSIONS: The heterogeneous clinical and serological characteristics of patients diagnosed with IIM probably explain why some, but not all patients respond to rituximab. Myositis overlap and anti-synthetase syndromes seem to respond better than other patient subsets.

Effect of a single dose of green tea polyphenols on the blood markers of exercise-induced oxidative stress in soccer players.

PURPOSE: To evaluate the effect of acute ingestion of green tea polyphenols (GTP) on blood markers of oxidative stress and muscle damage in soccer players exposed to intense exercise. METHODS: This randomized, double-blinded study was conducted on 16 players during a general preparation period, when all athletes participated in a strength-training program focused on the development of strength endurance. After ingestion of a single dose of GTP (640 mg) or placebo, all athletes performed an intense muscle-endurance test consisting of 3 sets of 2 strength exercises (bench press, back squat) performed to exhaustion, with a load at 60% 1-repetition maximum and 1-min rests between sets. Blood samples were collected preexercise, 5 min after the muscle-endurance test, and after 24 hr of recovery. Blood plasma was analyzed for the concentrations of thiobarbituric acid-reacting substances (TBARS), uric acid (UA), total catechins, total antioxidant status (TAS), and activity of creatine kinase (CK); at the same time, erythrocytes were assayed for the activity of superoxide dismutase (SOD). RESULTS: In both groups, plasma TBARS, UA, and TAS increased significantly postexercise and remained elevated after a 24-hr recovery period. SOD activity in erythrocytes did not change significantly in response to the muscle-endurance test, whereas in both groups plasma CK activity increased significantly after 24 hr of recovery. Acute intake of GTP cased a slight but significant increase in total plasma catechins. However, GTP was found not to exert a significant effect on measured parameters. CONCLUSIONS: Acute ingestion of GTP (640 mg) does not attenuate exercise-induced oxidative stress and muscle damage.

Effect of blueberry ingestion on natural killer cell counts, oxidative stress, and inflammation prior to and after 2.5 h of running.

Blueberries are rich in antioxidants known as anthocyanins, which may exhibit significant health benefits. Strenous exercise is known to acutely generate oxidative stress and an inflammatory state, and serves as an on-demand model to test antioxidant and anti-inflammatory compounds. The purpose of this study was to examine whether 250 g of blueberries per day for 6 weeks and 375 g given 1 h prior to 2.5 h of running at ∼72% maximal oxygen consumption counters oxidative stress, inflammation, and immune changes. Twenty-five well-trained subjects were recruited and randomized into blueberry (BB) (N = 13) or control (CON) (N = 12) groups. Blood, muscle, and urine samples were obtained pre-exercise and immediately postexercise, and blood and urine 1 h postexercise. Blood was examined for F2-isoprostanes for oxidative stress, cortisol, cytokines, homocysteine, leukocytes, T-cell function, natural killer (NK), and lymphocyte cell counts for inflammation and immune system activation, and ferric reducing ability of plasma for antioxidant capacity. Muscle biopsies were examined for glycogen and NFkB expression to evaluate stress and inflammation. Urine was tested for modification of DNA (8-OHDG) and RNA (5-OHMU) as markers of nucleic acid oxidation. A 2 (treatment) × 3 (time) repeated measures ANOVA was used for statistical analysis. Increases in F2-isoprostanes and 5-OHMU were significantly less in BB and plasma IL-10 and NK cell counts were significantly greater in BB vs. CON. Changes in all other markers did not differ. This study indicates that daily blueberry consumption for 6 weeks increases NK cell counts, and acute ingestion reduces oxidative stress and increases anti-inflammatory cytokines.

Vitamin D deficiency, myositis-myalgia, and reversible statin intolerance.

OBJECTIVE: In 150 hypercholesterolemic patients, unable to tolerate ≥1 statin because of myositis-myalgia, selected by low (<32 ng/ml) serum 25 (OH) vitamin D, we prospectively assessed whether vitamin D supplementation with resolution of vitamin D deficiency would result in statin tolerance, free of myositis-myalgia. RESEARCH DESIGN AND METHODS: We studied 74 men, 76 women, median age 60, 131 white, 17 black and 2 other. On no statins, 50,000 units of vitamin D was given twice a week for 3 weeks, and then continued once a week. After 3 weeks on vitamin D, statins were restarted. Patients were re-assessed on statins and vitamin D every 3 to 4 months, with serial measures of serum 25 (OH) vitamin D, creatine phosphokinase (CPK), LDL cholesterol (LDLC) and assessment of myositis-myalgia. MAIN OUTCOME MEASURES: Percentage of patients myalgia-free on vitamin D plus reinstituted statins, serum 25 (OH) vitamin D, CPK, and LDLC on reinstituted statins and concurrent vitamin D supplementation. RESULTS: On vitamin D supplementation plus re-instituted statins for a median of 8.1 months, 131 of the 150 patients (87%) were free of myositis-myalgia and tolerated the statins well. Serum 25 (OH) vitamin D increased from median 21 to 40 ng/ml (p < 0.001), and normalized (≥32 ng/ml) in 117 (78%) of 150 previously vitamin D deficient, statin-intolerant patients. Median LDLC decreased from 146 mg/dl to 95 mg/dl, p < 0.001. CONCLUSION: Symptomatic myositis-myalgia in hypercholesterolemic statin-treated patients with concurrent serum 25 (OH) vitamin D deficiency may reflect a reversible interaction between vitamin D deficiency and statins on skeletal muscle causing myalgia.

Mycophenolate mofetil (CellCept): an alternative therapy for autoimmune inflammatory myopathy.

OBJECTIVES: Mycophenolate mofetil (MMF) is a new immunosuppressive agent currently being used for the prevention of renal allograft rejection. MMF is a specific inhibitor of lymphocytes and is well tolerated leading to its use in other autoimmune diseases. We have used MMF for the treatment of seven patients with inflammatory myopathy and are hereby reporting our results. CASE SERIES: All of our patients were females (age 17-65 yr). They were symptomatic upon presentation and met classification criteria for idiopathic inflammatory myopathy. Inflammatory markers such as erythrocyte sedimentation rate and C-reactive protein as well as creatine kinase were significantly elevated in all the patients, indicating active disease. Corticosteroids were concomitantly being administered (20-60 mg/day of prednisone). Initial therapy with conventional immunosuppressives was either ineffective or had significant adverse effects leading to their discontinuation. MMF was started in doses of 500 mg twice a day and titrated up to 1 g twice a day. RESULTS: Our patients have exhibited an impressive serological response to therapy with MMF and six patients had a marked improvement in their weakness. One patient had incomplete improvement in her weakness and has required additional therapies. MMF has been well tolerated during the treatment period (12-36 months). CONCLUSION: A striking clinical and laboratory response of active myositis in six out of seven patients in this series illustrates that MMF can be effectively used in management of autoimmune inflammatory myopathy and may be a suitable alternative to the conventional immunosuppressive agents.

Blood oxidative stress status in patients with macrophagic myofasciitis.

The study aimed at determining the presence of an oxidative stress in patients with macrophagic myofasciitis (MMF), a new inflammatory myopathy with suspected toxic etiology related to aluminium hydroxide-containing vaccines. A total of 30 MMF patients (nine males, 21 females; aged 42+/-14 years), whose diagnosis was confirmed by deltoid biopsy, have been included and compared to 38 sex- and age-matched healthy control subjects (10 males, 28 females; aged 43+/-8 years). The blood oxidative stress status has been evaluated by assaying six parameters: plasma lipid peroxidation products (thiobarbituric acid-reactive substances: TBARS) and antioxidant defense systems: plasma vitamin E and glutathione peroxidase (GSH-Px) activity, erythrocyte GSH-Px and Cu,Zn-superoxide dismutase (SOD) activities. Plasma selenium was also determined as a trace element essential to the activity of GSH-Px. Statistical significance was evaluated by the Mann-Whitney test. Plasma GSH-Px activity, selenium and vitamin E concentration were significantly lower in MMF group than in controls (P=0.004, P=0.003 and P=0.009, respectively), with a positive correlation in MMF patients between plasma GSH-Px activity and selenium concentration (rho=0.0001). The other parameters of oxidative stress did not significantly differ between both groups. A macrophage activation could occur in MMF, consequently to chronic stimulation by aluminium-containing vaccines, and could participate to the lower values of selenium and vitamin E observed in comparison with controls. Nevertheless, since no deficiency in these elements has been observed, no supplementation is to be considered.

The effects of fish oil and isoflavones on delayed onset muscle soreness.

INTRODUCTION/PURPOSE: Fish oils (FO) have been shown to modulate the inflammatory response through alteration of the eicosanoid pathway. Isoflavones (ISO) appear to reduce the inflammatory pathway through their role as a tyrosine kinase inhibitor. Delayed onset muscle soreness (DOMS) develops after intense exercise and has been associated with an inflammatory response. Therefore, we hypothesized that physical parameters associated with DOMS could be decreased via the modulation of the inflammatory response by supplementing subjects with either FO or ISO. METHODS: 22 subjects were recruited and randomly assigned to one of three treatment groups: FO (1.8 g of omega-3 fatty acids x d(-1)), ISO (120 mg soy isolate x d(-1)), or placebo (PL) (Western fat blend and/or wheat flour). All treatment groups received 100-IU vitamin E x d(-1) to minimize lipid peroxidation of more highly unsaturated fatty acids. Subjects were supplemented 30 d before the exercise and during the week of testing and were instructed to refrain from unusual exercise. DOMS was induced by 50 maximal isokinetic eccentric elbow flexion contractions. Strength parameters, pain, arm circumference, and relaxed arm angle (RANG) were measured at 48, 72, and 168 h post exercise. Cortisol, creatine kinase (CK), interleukin-6 (IL-6), tumor necrosis factor (TNFalpha), malondialdehyde (MDA), and serum iron were measured before supplementation, after supplementation, and post exercise. RESULTS: Significant decreases were observed in RANG and strength 48 h postexercise among all groups, and there were significant increases in pain and arm circumference. There were no significant changes among all groups from baseline at 168 h (7 d) post exercise. There were no significant treatment effects between groups for the physical parameters or for cortisol, CK, IL-6, TNFalpha, MDA, or serum iron. CONCLUSION: These data indicate FO or ISO, at the doses supplemented, were not effective in ameliorating DOMS with the above-cited protocol.