Statin-associated muscle symptoms: A comprehensive exploration of epidemiology, pathophysiology, diagnosis, and clinical management strategies.

Statins are the first line of treatment for both primary and secondary prevention of atherosclerotic cardiovascular disease. Despite the positive effects of statins on cardiovascular events, not all patients can use them at an optimized dose. The reason for this is the skeletal muscle side effects, termed statin-associated muscle symptoms (SAMS). Despite extensive research, the precise pathophysiology of SAMS remains unclear and multiple mechanisms may contribute to this phenomenon. Various therapeutic options are available for the management of SAMS, ranging from rechallenging with the same or a different statin to utilizing non-statin therapeutic alternatives in patients intolerant to statins. However, the lack of consensus on the definition of SAMS, the absence of a definitive diagnostic test, and lack of a universally accepted management algorithm pose a great challenge in dealing with this entity. This review aims to explore the various pathophysiological mechanisms involved in SAMS and understand the difference between self-limited toxic myopathy and immune-mediated myopathy requiring immunomodulatory therapy. The conundrum of statin withdrawal, tapering, and rechallenge in SAMS will also be explored in detail along with the newer non-statin therapies that are available.

Screening primary carnitine deficiency in 10 million Chinese newborns: a systematic review and meta-analysis.

BACKGROUND: Primary carnitine deficiency (PCD) is a rare autosomal recessive fatty acid oxidation disorder caused by variants in SLC22A5, with its prevalence and SLC22A5 gene mutation spectrum varying across races and regions. This study aimed to systematically analyze the incidence of PCD in China and delineate regional differences in the prevalence of PCD and SLC22A5 gene variants. METHODS: PubMed, Embase, Web of Science, and Chinese databases were searched up to November 2023. Following quality assessment and data extraction, a meta-analysis was performed on screening results for PCD among Chinese newborns. RESULTS: After reviewing 1,889 articles, 22 studies involving 9,958,380 newborns and 476 PCD cases were included. Of the 476 patients with PCD, 469 underwent genetic diagnosis, revealing 890 variants of 934 alleles of SLC22A5, among which 107 different variants were detected. The meta-analysis showed that the prevalence of PCD in China was 0.05‰ [95%CI, (0.04‰, 0.06‰)] or 1/20 000 [95%CI, (1/16 667, 1/25 000)]. Subgroup analyses revealed a higher incidence in southern China [0.07‰, 95%CI, (0.05‰, 0.08‰)] than in northern China [0.02‰, 95%CI, (0.02‰, 0.03‰)] (P < 0.001). Furthermore, the result of the meta-analysis showed that the frequency of the variant with c.1400C > G, c.51C > G, c.760C > T, c.338G > A, and c.428C > T were 45% [95%CI, (34%, 59%)], 26% [95%CI, (22%, 31%)], 14% [95%CI, (10%, 20%)], 6% [95%CI, (4%, 8%)], and 5% [95%CI, (4%, 8%)], respectively. Among the subgroup analyses, the variant frequency of c.1400C > G in southern China [39%, 95%CI, (29%, 53%)] was significantly lower than that in northern China [79‰, 95%CI, (47‰, 135‰)] (P < 0.05). CONCLUSIONS: This study systematically analyzed PCD prevalence and identified common SLC22A5 gene variants in the Chinese population. The findings provide valuable epidemiological insights and guidance for future PCD screening effects in newborns.

Epidemiología y caracterización molecular de las miopatías genéticas en adultos en una región del sureste de España / Epidemiology and molecular characterization of adult genetic myopathies in a southeastern region of Spain

Introducción Las miopatías genéticas constituyen un conjunto de enfermedades raras que impactan significativamente en la funcionalidad y la calidad de vida del paciente. Un diagnóstico temprano de las miopatías genéticas puede prevenir complicaciones futuras y proporcionar a las familias asesoramiento genético. A pesar del impacto sustancial de las miopatías genéticas en población adulta, la epidemiología global de estos trastornos está inadecuadamente abordada en la bibliografía.ObjetivosMejorar el entendimiento tanto de la epidemiología como de la genética de estos trastornos en la provincia de Alicante, situada en el sureste de España. Material y métodos. Entre 2020 y 2022, se llevó a cabo un estudio observacional prospectivo en el área de salud Alicante-Hospital General, que incluyó a pacientes de 16 años o más con sospecha de miopatías genéticas. Se recopilaron datos sociodemográficos, clínicos y genéticos. La fecha de referencia para el cálculo de la prevalencia se estableció el 31 de diciembre de 2022. Se utilizaron datos demográficos oficiales del área de salud para establecer la población en riesgo.ResultadosEn total, se identificó a 83 pacientes con miopatía genéticamente confirmada, lo que dio lugar a una prevalencia total de 29,59 casos por cada 100.000 habitantes. El rendimiento diagnóstico de las pruebas genéticas moleculares fue del 69,16%. Las miopatías genéticas más frecuentes incluyeron la distrofia miotónica (27,5%), las distrofinopatías (15,7%) y la distrofia facioescapulohumeral (15,7%).ConclusiónLa prevalencia de las miopatías genéticas puede variar considerablemente dependiendo de la región geográfica y la población estudiada. El análisis del rendimiento diagnóstico sugiere que los estudios genéticos deberían considerarse útiles en el diagnóstico de las miopatías genéticas. (AU)

Introduction. Genetic myopathies constitute a collection of rare diseases that significantly impact patient functionality and quality of life. Early diagnosis of genetic myopathies can prevent future complications and provide families with genetic counselling. Despite the substantial impact of genetic myopathies on the adult population, the global epidemiology of these disorders is inadequately addressed in the literature.Aims. To enhance understanding of both the epidemiology and genetics of these disorders within the province of Alicante, situated in southeastern Spain.Material and methods. Between 2020 and 2022, a prospective observational study was conducted at the Alicante Health Area-General Hospital, enrolling patients aged 16 years or older with suspected genetic myopathies. Sociodemographic, clinical, and genetic data were collected. The reference date for prevalence calculation was established as December 31, 2022. Official demographic data of the health area were used to set the population at risk.Results. In total, 83 patients were identified with confirmed genetically related myopathy, resulting in an overall prevalence of 29.59 cases per 100,000 inhabitants. The diagnostic yield for molecular genetic testing was found to be 69.16%. The most prevalent genetic myopathies identified included myotonic dystrophy (27.5%), dystrophinopathies (15.7%), and facioscapulohumeral dystrophy (15.7%).Conclusion. The prevalence of GMs can vary considerably depending on the geographical region and the studied population. The analysis of diagnostic yield suggests that genetic studies should be considered useful in the diagnosis of genetic myopathies. (AU)

Evaluation of the frequency and risk factors of spontaneous intramuscular hemorrhage associated with dermatomyositis.

Dermatomyositis (DM) is an idiopathic inflammatory myositis (IIM) characterized by skin manifestations and muscle involvement. Spontaneous intramuscular hemorrhage (SIH) is a fatal complication that is very rare in the course of DM, but not well known to rheumatologists. Our aim was to determine the frequency and possible risk factors of DM-related SIH. A retrospective analysis was conducted on a cohort of DM patients who were observed in the rheumatology department of the university hospital between 1998 and January 2024. The clinical, laboratory, radiological data of the patients and the treatments they received during the follow-up were analyzed. To determine possible risk factors for the development of SIH in the course of DM, our patients with DM were analyzed together with other rare SIH cases in the literature. The study included 42 of our DM patients. 32 of the patients (76.2%) were female. The median age of the patients was 53 (24-82) years, the median age of DM diagnosis of the patients was 47 (18-75) years, and the median duration of DM of the patients was 36 (2-276) months. 7.1% of patients had dysphagia, and 16.7% had intertitial lung disease (ILD). 5 (11.9%) patients were diagnosed with malignancy. The incidence rate of SIH development in our DM cohort was 0.238/100 patient years (95% CI 0.006-1.256). We tried to identify independent risk factors for SIH development by comparing our 41 DM patients without SIH with the data of patients with 23 DM-related SIH collected from the literature by adding our 1 patient (24 pts). Male sex (OR 4.97, 95% CI 1.66-14.92, p = 0.003), ILD presence (OR 9.71, 95% CI 2.99-31.47, p < 0.001), anti-MDA5 positivity (OR 16.0, 95% CI 1.60-159.3, p = 0.006), anti-Ro52 positivity (OR 11.6, 95% CI 2.93-46.34, p < 0.001), heparin use (OR 4.42, 95% CI 2.68-7.24, p < 0.001), intravenous immunoglobulin (IVIG) use (OR 11.7, 95% CI 2.26-60.54, p < 0.001), and steroid dose (OR 1.03, 95% CI 1.00-1.05, p = 0.005) were identified as risk factors for the development of SIH in the univariate analysis. The death rate due to hemorrhage was 50%. No single risk factor was found to be associated with death. As a result, SIH may occasionally arise in patients with DM. Rheumatologists should be aware that patients with dysphagia and/or ILD, who are on heparin, getting high doses of steroids, and test positive for anti-MDA5 and/or anti-Ro52 antibodies may develop SIH in the early stages of DM.

Epidemiology and molecular characterization of adult genetic myopathies in a southeastern region of Spain. / Epidemiología y caracterización molecular de las miopatías genéticas en adultos en una región del sureste de España.

INTRODUCTION: Genetic myopathies constitute a collection of rare diseases that significantly impact patient functionality and quality of life. Early diagnosis of genetic myopathies can prevent future complications and provide families with genetic counselling. Despite the substantial impact of genetic myopathies on the adult population, the global epidemiology of these disorders is inadequately addressed in the literature. AIMS: To enhance understanding of both the epidemiology and genetics of these disorders within the province of Alicante, situated in southeastern Spain. MATERIAL AND METHODS: Between 2020 and 2022, a prospective observational study was conducted at the Alicante Health Area-General Hospital, enrolling patients aged 16 years or older with suspected genetic myopathies. Sociodemographic, clinical, and genetic data were collected. The reference date for prevalence calculation was established as December 31, 2022. Official demographic data of the health area were used to set the population at risk. RESULTS: In total, 83 patients were identified with confirmed genetically related myopathy, resulting in an overall prevalence of 29.59 cases per 100,000 inhabitants. The diagnostic yield for molecular genetic testing was found to be 69.16%. The most prevalent genetic myopathies identified included myotonic dystrophy (27.5%), dystrophinopathies (15.7%), and facioscapulohumeral dystrophy (15.7%). CONCLUSION: The prevalence of GMs can vary considerably depending on the geographical region and the studied population. The analysis of diagnostic yield suggests that genetic studies should be considered useful in the diagnosis of genetic myopathies.

TITLE: Epidemiología y caracterización molecular de las miopatías genéticas en adultos en una región del sureste de España.Introducción. Las miopatías genéticas constituyen un conjunto de enfermedades raras que impactan significativamente en la funcionalidad y la calidad de vida del paciente. Un diagnóstico temprano de las miopatías genéticas puede prevenir complicaciones futuras y proporcionar a las familias asesoramiento genético. A pesar del impacto sustancial de las miopatías genéticas en población adulta, la epidemiología global de estos trastornos está inadecuadamente abordada en la bibliografía. Objetivos. Mejorar el entendimiento tanto de la epidemiología como de la genética de estos trastornos en la provincia de Alicante, situada en el sureste de España. Material y métodos. Entre 2020 y 2022, se llevó a cabo un estudio observacional prospectivo en el área de salud Alicante-Hospital General, que incluyó a pacientes de 16 años o más con sospecha de miopatías genéticas. Se recopilaron datos sociodemográficos, clínicos y genéticos. La fecha de referencia para el cálculo de la prevalencia se estableció el 31 de diciembre de 2022. Se utilizaron datos demográficos oficiales del área de salud para establecer la población en riesgo. Resultados. En total, se identificó a 83 pacientes con miopatía genéticamente confirmada, lo que dio lugar a una prevalencia total de 29,59 casos por cada 100.000 habitantes. El rendimiento diagnóstico de las pruebas genéticas moleculares fue del 69,16%. Las miopatías genéticas más frecuentes incluyeron la distrofia miotónica (27,5%), las distrofinopatías (15,7%) y la distrofia facioescapulohumeral (15,7%). Conclusión. La prevalencia de las miopatías genéticas puede variar considerablemente dependiendo de la región geográfica y la población estudiada. El análisis del rendimiento diagnóstico sugiere que los estudios genéticos deberían considerarse útiles en el diagnóstico de las miopatías genéticas.

[RYR1 myopathies in childhood: phenotype-genotype correlation and incidence]. / Miopatías RYR1 en la infancia: correlación fenotipo-genotipo e incidencia.

INTRODUCTION: Ryanodine receptor type 1-related myopathies (RYR1-RM) represent the most prevalent category of congenital myopathies. The introduction of genetic techniques has shifted the diagnostic paradigm, suggesting the prioritization of molecular studies over biopsies. This study aims to explore the clinical and epidemiological characteristics of patients with RYR1 gene variants in a tertiary pediatric hospital, intending to enhance the understanding of the genotype-phenotype correlation in RYR1-RM. PATIENTS AND METHODS: An observational, descriptive, and cross-sectional study was conducted on patients under 14 years old with myopathic symptoms and potentially pathogenic RYR1 gene variants from January 2013 to December 2023. Variables such as gender, age, motor development, genetic variants, inheritance pattern, and other manifestations were considered. All variables were tabulated against the genetic variant. RESULTS: Of the nine included patients, the estimated incidence was approximately 1 in 10,000 live births. The median age at diagnosis was six years, with significant phenotypic variability. Common symptoms such as weakness and delayed motor development were observed. Genetic variants affected the RYR1 gene diversely, including five previously undescribed variants. Muscle biopsy was performed in five patients, revealing central core myopathy in two, multiminicore in one, congenital fiber-type disproportion in one, and a nonspecific pattern in another. CONCLUSIONS: RYR1-RM in our series exhibited phenotypic and involvement variability, with an incidence in our area of around 1 in 10,000 live births. Most cases were male, with dominant missense variants. We contribute five previously undescribed genetic variants.

TITLE: Miopatías RYR1 en la infancia: correlación fenotipo-genotipo e incidencia.Introducción. Las miopatías relacionadas con el receptor de rianodina de tipo 1 (RYR1-RM) constituyen la categoría más frecuente de miopatías congénitas. La introducción de técnicas genéticas ha cambiado el paradigma diagnóstico y sugiere la prioridad de estudios moleculares sobre biopsias. Este estudio busca explorar las características clinicoepidemiológicas de pacientes con variantes del gen RYR1 en un hospital pediátrico de tercer nivel con el objetivo de ampliar la comprensión de la correlación genotipo-fenotipo en las RYR1-RM. Pacientes y métodos. Estudio observacional, descriptivo y transversal, de pacientes menores de 14 años con síntomas miopáticos y variantes potencialmente patógenas del gen RYR1 entre enero de 2013 y diciembre de 2023, considerando variables como sexo, edad, desarrollo motor, variantes genéticas, patrón de herencia y otras manifestaciones. Todas las variables fueron tabuladas frente a la variante genética. Resultados. De los nueve pacientes incluidos, la incidencia estimada fue de aproximadamente 1/10.000 nacidos vivos. La mediana en el momento del diagnóstico fue de 6 años, con una variabilidad fenotípica significativa. Se observaron síntomas comunes, como debilidad y retraso del desarrollo motor. Las variantes genéticas afectaron al gen RYR1 de manera diversa, y hubo cinco variantes previamente no descritas. La biopsia muscular se realizó en cinco pacientes, en dos de ellos de tipo miopatía central core; en uno, multiminicore; en uno, desproporción congénita de fibras; y en otro, de patrón inespecífico. Conclusiones. Las RYR1-MR de nuestra serie ofrecieron variabilidad fenotípica y de afectación, con una incidencia en nuestra área de en torno a 1/10.000 recién nacidos. La mayoría de los casos fueron varones, de variantes missense dominantes. Aportamos cinco variantes genéticas no descritas con anterioridad.

Incidence, characteristics, and risk factors of drug-associated muscle adverse reaction: a retrospective real-world study of inpatients.

OBJECTIVE: To analyze the clinical characteristics, incidence, and distribution of drug-associated muscle adverse reactions (DAMAR) in real-world inpatients, to provide valuable references for clinical medication use. METHODS: We conducted an automatic retrospective monitoring of inpatients from May 1, 2022, to April 30, 2023, to collect information on adverse drug reactions (ADR) of patients and conducted subsequent analyses. RESULTS: Among 102,430 hospitalizations, 1106 cases of DAMARs were identified, yielding an incidence of 1.08%, including 125 cases of rhabdomyolysis at an incidence of 0.12%. Seventy-five percent of the patients experienced muscle adverse reactions within 5 days after taking medication, with a median elevated creatine kinase (CK) value of 420.4 IU/L. Risk factors of DAMAR include age ≥ 65, male sex, obesity, hypertension, hepatic and renal insufficiency, and anemia. No significant correlation was observed between the duration of surgery and CK elevation, while the surgical procedure itself had an impact. The 114 drugs associated were predominantly nervous system drugs, anti-infectives for systemic use, and cardiovascular system drugs, with levofloxacin, pregabalin, and parecoxib being the most frequently associated drugs. CONCLUSION: Healthcare professionals should be vigilant with patients exhibiting the identified risk factors. Monitoring creatine kinase and related indices when using myotoxic drugs is crucial to preventing serious adverse reactions, ultimately preserving patients' quality of life.

The challenges faced by patients with hereditary myopathy during the COVID-19 pandemic.

BACKGROUND: Neuromuscular diseases are inherited and the prevalance of neuromuscular disease is estimated to be around 1:2000. METHODS: This cross-sectional research was conducted with a qualitative research model. Data were collected from patients with an online survey using the snowball sampling method. The study was conducted in accordance with the STROBE checklist methodology. Frequencies and percentages were used to analyse demographic data, and content analysis was used for qualitative opinions. RESULTS: Most of the participants were men and their education levels were low. Participants reported experiencing physical and socio-economic barriers to accessing healthcare. Participants also stated that these barriers have worsened since COVID-19. CONCLUSIONS: Patients with hereditary myopathy are stigmatised by society and face different problems depending on the type of disease and level of function. It is recommended that decision-makers enable patients with hereditary myopathy in exceptional situations to access healthcare services and take steps to resolve their problems.

Hospital admissions from the emergency department of adult patients affected by myopathies.

BACKGROUND AND PURPOSE: Myopathies are associated with classic signs and symptoms, but also with possible life-threatening complications that may require assistance in an emergency setting. This phenomenon is understudied in the literature. We aimed to assess the presentation, management, and outcomes of clinical manifestations potentially related to a muscle disorder requiring referral to the adult emergency department (ED) and hospitalization. METHODS: Anonymized patient data retrieved using the International Classification of Diseases, Ninth Revision codes related to muscle disorders over 4 years were retrospectively analyzed. Medical reports were evaluated to extract demographic and clinical variables, along with outcomes. Two groups were defined based on the presence (known diagnosis [KD] group) or absence (unknown diagnosis [UD] group) of a diagnosed muscle disorder at arrival. RESULTS: A total of 244 patients were included, 51% of whom were affected by a known myopathy, predominantly limb-girdle muscular dystrophies and myotonic dystrophies. The main reasons for ED visits in the KD group were respiratory issues, worsening of muscle weakness, and gastrointestinal problems. Heart complications were less prevalent. In the UD group, 27 patients received a new diagnosis of a specific primary muscle disorder after the ED access, mostly an inflammatory myopathy. Death during hospitalization was recorded in 26 patients, with a higher rate in the KD group and in patients affected by mitochondrial and inflammatory myopathies. Sepsis and dyspnea were associated with increased death risk. CONCLUSIONS: Respiratory complications are the most common reason for myopathic patients accessing the ED, followed by gastrointestinal issues. Infections are severe threats and, once hospitalized, these patients have relatively high mortality.

Exploring signals of myopathy associated with statin and contraindicated comedications in the realworld.

BACKGROUND: Using statins in combination with other drugs was reported to increase the risk of myopathy. However, there was a sparse number of studies on the incidence of adverse events (AEs) associated with the concomitant use of statin and contraindicated drugs in the real world. OBJECTIVES: This study aimed to identify the risk of concomitant use of statins with contraindicated drugs by exploring signals related to statin-drug interactions. METHODS: We performed a disproportionality analysis for drugs and AEs by applying the case/non-case study using the KIDS-KAERS database (KIDS-KD), 2016-2020. A case was defined as an individual case safety reports (ICSRs) including "rhabdomyolysis/myopathy." A non-case was defined as an ICSR, including all other AEs. We applied Ω shrinkage measure model, chi-square statics model, additive model, multiplicative model, and combination risk ratio model to detect signals of myopathy due to statin with concomitant drugs including antiviral agents, immunosuppressants, and antifungals. RESULTS: Among 1 011 234 ICSRs, 2708 were cases, with 861 cases of statin monotherapy and 1248 of concomitant uses of statin. The adjusted reporting odds ratios were 3.27 (95% confidence interval [CI]: 3.11-3.43), 8.70 (95% CI: 8.04-9.40), and 1.83 (95% CI: 1.73-1.94), respectively. Several combinations of signals were detected through an additive model or multiplicative model. CONCLUSION: Signals of an increased risk of myopathy associated with the use of statins with concomitant drugs, including contraindicated drugs, were confirmed in a real-world setting.

Patient-reported muscle symptoms and their characterization in a hypertensive population eligible for statin therapy: An exploratory study.

BACKGROUND AND AIMS: Statin-associated muscle symptoms (SAMS) are claimed to be frequent in clinical practice. We evaluated the prevalence and characteristics of patient-reported muscle symptoms (PRMS) attributed to drugs/nutraceuticals in hypertensive patients, focusing the attention on statin treatment. METHODS AND RESULTS: Observational study on 390 consecutive outpatients. All patients were asked the following question: "Have you ever taken a drug/nutraceutical that you think gave you muscle symptoms?". Patients who answered "yes" were evaluated with a modified version of the SAMS-clinical index (SAMS-CI). Mean age: 60.5 ± 13.5 years (males 53.8%.). Patients who have ever taken a statin: 250. Patients who have never taken a statin: 140. Prevalence of PRMS (48.5% of the entire study population) did not differ between groups (p = 0.217). Only age, followed by number of drugs taken, was significantly associated with PRMS at multivariate analysis. A high prevalence of low scores to all the questions of "modified" SAMS-CI was found in both groups. Localization and pattern of PRMS did not differ between groups (p = 0.170). Timing of PRMS onset after starting the drug (p = 0.036) and timing of improvement after withdrawal (p = 0.002) were associated with statin therapy. CONCLUSION: PRMS are highly prevalent among the hypertensive population and are believed to be drug-related, especially with aging and regardless of whether the drug taken is a statin or not. These findings are in line with the growing evidence that subjective muscle symptoms are often misattributed to statins, while they may more likely be related to the nocebo/drucebo effect or to other common undiagnosed conditions.

ASSOCIATION OF SOLUTE CARRIER ORGANIC ANION TRANSPORTER 1B1 GENE POLYMORPHISM WITH RESPONSE TO ATORVASTATIN AND ASSOCIATED MYOPATHY IN IRAQI DYSLIPIDEMIA PATIENTS.

OBJECTIVE: Aim: The study aims to investigate the effect of solute carriers organic anions transporters 1B1 (SLCO1B1) gene polymorphisms rs4149056, rs2306283, rs55901008, and rs729559745 in a sample of patients with dyslipidemia, and relate it to atorvastatin response and associated myopathy. PATIENTS AND METHODS: Materials and Methods: A cross sectional enrolled 200 patients both males and females of Arabic race, Iraqi nationality aged between 30-65 years. The patients were divided into two groups: Group 1 (Atorvastatin responders and tolerant), Group 2 (Atorvastatin non responder and intolerant). Blood samples collected from the patients for biochemical studies and analyzed statistically by Student T-test and Chi-square, and DNA extracted for polymerase chains reactions (PCR). RESULTS: Results: The results showed insignificant association P≥0.05 between the demographic characteristics of the study population with different genotypes, and significant difference P<0.05 in the biochemical parameters regarding (T-cholesterol, triglycerides, low density lipoproteins, and Creatine kinase-MM) when comparing the two groups. Odds ratio (OR) with confidence intervals CI (95%) used to evaluate the risk association to develop myopathy and poor response to atorvastatin therapy show relevant association for CC and CT genotype of rs4149056, while rs2306283 GG genotype show low association, also rs55901008 show low association for CC genotype, and moderate association for rs72559745 genotypes GG, AG. CONCLUSION: Conclusions: The mutant allele's genotypes of rs4149056, rs55901008, and rs72559745, and the wild allele genotype of rs2306283 show significant association with the development of poor response to atorvastatin and elevated the level of CK-MM plasma concentration.

The incidence and associated risk factors affecting myopathies in broiler chickens in Lithuania.

The objectives of this research were to highlight the main factors, which have relevant significance for etiology of myopathies and to assess the incidence of myopathies in a representative population of broilers raised in Lithuania. Eighteen flocks were evaluated to assess the incidence of musculus pectoralis major myopathies (PMM) (total 54,000 broilers) and dorsal cranial myopathy (DCM) (total 124,200 broilers). Thirteen flocks (total 19,500 broilers) were evaluated to find out deep pectoral myopathy (DPM) occurrence in Lithuania. Investigated parameters of each flock were: average broiler live body weight (BW) at slaughter, average slaughter age, treatment and seasons. A correlation analysis was used to measure the strength of the linear relationship between the investigated traits and incidence of these myopathies. Overall, the incidence of PMM in Lithuania was 18.19%. DCM and DPM were 5.16% and 0.27%, respectively. The percentage of PMM in flocks was strongly associated with average broiler live BW at slaughter (r=0.898, p<0.001) and age at slaughter (r=0.693, p<0.001). The percentage of PMM in flocks was negatively related with treatment of broilers (rs=-0.535, p<0.05). The percentage of DCM was positively associated with average broiler live BW at slaughter (r=0.537, p<0.05) and with seasons (rs=0.658, p<0.01). However, our study results revealed, that the analyzed parameters are not so important in DPM etiology. Furthermore, predisposing factors of PMM, DCM and DPM are different. These findings suggest that not only broiler's heavy weight and age at slaughter could have influence for etiology of myopathies.

Long-term Natural History of Pediatric Dominant and Recessive RYR1-Related Myopathy.

BACKGROUND AND OBJECTIVES: RYR1-related myopathies are the most common congenital myopathies, but long-term natural history data are still scarce. We aim to describe the natural history of dominant and recessive RYR1-related myopathies. METHODS: A cross-sectional and longitudinal retrospective data analysis of pediatric cases with RYR1-related myopathies seen between 1992-2019 in 2 large UK centers. Patients were identified, and data were collected from individual medical records. RESULTS: Sixty-nine patients were included in the study, 63 in both cross-sectional and longitudinal studies and 6 in the cross-sectional analysis only. Onset ranged from birth to 7 years. Twenty-nine patients had an autosomal dominant RYR1-related myopathy, 31 recessive, 6 de novo dominant, and 3 uncertain inheritance. Median age at the first and last appointment was 4.0 and 10.8 years, respectively. Fifteen% of patients older than 2 years never walked (5 recessive, 4 de novo dominant, and 1 dominant patient) and 7% lost ambulation during follow-up. Scoliosis and spinal rigidity were present in 30% and 17% of patients, respectively. Respiratory involvement was observed in 22% of patients, and 12% needed ventilatory support from a median age of 7 years. Feeding difficulties were present in 30% of patients, and 57% of those needed gastrostomy or tube feeding. There were no anesthetic-induced malignant hyperthermia episodes reported in this cohort. We observed a higher prevalence of prenatal/neonatal features in recessive patients, in particular hypotonia and respiratory difficulties. Clinical presentation, respiratory outcomes, and feeding outcomes were consistently more severe at presentation and in the recessive group. Conversely, longitudinal analysis suggested a less progressive course for motor and respiratory function in recessive patients. Annual change in forced vital capacity was -0.2%/year in recessive vs -1.4%/year in dominant patients. DISCUSSION: This clinical study provides long-term data on disease progression in RYR1-related myopathies that may inform management and provide essential milestones for future therapeutic interventions.

Impact of metformin on statin-associated myopathy risks in dyslipidemia patients.

A growing number of patients with metabolic disorders are receiving statin and antidiabetic therapies as comedications. A signal of increased risk of myotoxicity due to potential interactions between antidiabetics and statins has been detected in previous studies. To investigate the effects of metformin on myopathy risks when added to preexisting statin therapy in dyslipidemia patients, we performed a retrospective cohort study using the Korean national health insurance data in statin-treated dyslipidemia patients with or without concomitant metformin use. We compared the risk of myopathy in statin + metformin users against statin-only users. Hazard ratios (HRs) and 95% confidence intervals (CIs) have been calculated following propensity score (PS) matching between study groups and subsequent stratification per patient factors. We included 4092 and 8161 patients in PS-matched statin + metformin and statin-only groups, respectively. The risk of myopathy decreased when metformin was used together with statins (adjusted HR 0.84; 95% CI 0.71-0.99). In subgroup analyses per individual statin agent and in stratified risk analyses, no specific statin agents or patient factors were associated with statistically significant myopathy risk. This study found that a comedication with metformin was associated with decreased myopathy risk in statin-treated dyslipidemia patients compared to statin-only users. Our findings suggest that metformin may provide protective effects on potential muscle toxicities induced by statin therapy.

Concomitant use of statins and sodium-glucose co-transporter 2 inhibitors and the risk of myotoxicity reporting: A disproportionality analysis.

AIMS: Recent case reports have suggested that sodium-glucose co-transporter 2 (SGLT2) inhibitors may interact with statins to increase their risk of myotoxicity. We assessed the risk of myotoxicity reporting associated with concomitant use of SGLT2 inhibitors and statins. METHODS: We queried the US Food and Drug Administration Adverse Event Reporting System (FAERS) from 2013 to 2021 for reports including SGLT2 inhibitors, statins or both. We estimated several measures of disproportionate reporting of myopathy and rhabdomyolysis associated with concomitant use of SGLT2 inhibitors and statins: reporting odds ratio (ROR) with 95% confidence interval (CI), Ω shrinkage measure (safety signal if >0) and an extension of the proportional reporting ratio (PRR) (two-criteria set, safety signal if both criteria are met), using the full FAERS dataset as the reference set. In sensitivity analyses, we focussed on specific SGLT2 inhibitor-statin pairs with higher interaction potential (canagliflozin-rosuvastatin, empagliflozin-rosuvastatin) and accounted for stimulated reporting. RESULTS: There were 456 myopathy and 77 rhabdomyolysis reports involving both an SGLT2 inhibitor and a statin. Concomitant use of SGLT2 inhibitors and statins was not associated with an increased risk of myopathy (ROR 0.79, 95% CI 0.70 to 0.89) or rhabdomyolysis (ROR 0.58, 95% CI 0.41 to 0.83) reporting. For both outcomes, the Ω shrinkage measure was negative and only one criterion of the PRR extension was met. SGLT2 inhibitor-statin pairs with higher interaction potential yielded potential signals for rhabdomyolysis; these signals disappeared after accounting for stimulated reporting. CONCLUSION: There was no increased risk of myotoxicity reporting associated with concomitant use of SGLT2 inhibitors and statins or for specific drug pairs.

Anoctamin-5 related muscle disease: clinical and genetic findings in a large European cohort.

Anoctamin-5 related muscle disease is caused by biallelic pathogenic variants in the anoctamin-5 gene (ANO5) and shows variable clinical phenotypes: limb-girdle muscular dystrophy type 12 (LGMD-R12), distal muscular dystrophy type 3 (MMD3), pseudometabolic myopathy or asymptomatic hyperCKaemia. In this retrospective, observational, multicentre study we gathered a large European cohort of patients with ANO5-related muscle disease to study the clinical and genetic spectrum and genotype-phenotype correlations. We included 234 patients from 212 different families, contributed by 15 centres from 11 European countries. The largest subgroup was LGMD-R12 (52.6%), followed by pseudometabolic myopathy (20.5%), asymptomatic hyperCKaemia (13.7%) and MMD3 (13.2%). In all subgroups, there was a male predominance, except for pseudometabolic myopathy. Median age at symptom onset of all patients was 33 years (range 23-45 years). The most frequent symptoms at onset were myalgia (35.3%) and exercise intolerance (34.1%), while at last clinical evaluation most frequent symptoms and signs were proximal lower limb weakness (56.9%) and atrophy (38.1%), myalgia (45.1%) and atrophy of the medial gastrocnemius muscle (38.4%). Most patients remained ambulatory (79.4%). At last evaluation, 45.9% of patients with LGMD-R12 additionally had distal weakness in the lower limbs and 48.4% of patients with MMD3 also showed proximal lower limb weakness. Age at symptom onset did not differ significantly between males and females. However, males had a higher risk of using walking aids earlier (P = 0.035). No significant association was identified between sportive versus non-sportive lifestyle before symptom onset and age at symptom onset nor any of the motor outcomes. Cardiac and respiratory involvement that would require treatment occurred very rarely. Ninety-nine different pathogenic variants were identified in ANO5 of which 25 were novel. The most frequent variants were c.191dupA (p.Asn64Lysfs*15) (57.7%) and c.2272C>T (p.Arg758Cys) (11.1%). Patients with two loss-of function variants used walking aids at a significantly earlier age (P = 0.037). Patients homozygous for the c.2272C>T variant showed a later use of walking aids compared to patients with other variants (P = 0.043). We conclude that there was no correlation of the clinical phenotype with the specific genetic variants, and that LGMD-R12 and MMD3 predominantly affect males who have a significantly worse motor outcome. Our study provides useful information for clinical follow up of the patients and for the design of clinical trials with novel therapeutic agents.

Osteomalacic myopathy: A re-emerging scourge hiding in plain sight.

We present a cluster of patients with osteomalacic myopathy in the aftermath of the COVID-19 pandemic. We believe that the home confinement of these children may have contributed to the resurgence of this condition. This deficiency is eminently reversible.

Characterization of dorsal recumbency syndrome associated with woody breast in broiler flocks from Ontario, Canada.

A dorsal recumbency syndrome (DRS) has been recently described in market-age broiler chickens. Affected broilers fall onto their backs, and are unable to right themselves, and eventually die of cardiopulmonary insufficiency. These broilers are referred to as turtle chickens. A previous report and anecdotal evidence suggest that breast myopathies, such as woody breast (WB), may be associated with DRS due to impaired contractility of the pectoral muscles. In this study, we aimed to provide additional evidence to document DRS in broilers, and its possible association with breast myopathies. A total of 64 broilers (Ross 708), 33 DRS-affected and 31 controls, were culled between 42 and 48 d of age from 3 different commercial farms over 4 visits. All broilers underwent postmortem analysis; breast muscles were scored grossly and/or histologically to determine the presence and severity of myopathies, and sera were used to determine the level of aspartate aminotransferase (AST) and creatine kinase (CK). A gross diagnosis of WB was moderately associated with DRS broilers, and DRS broilers displayed a greater microscopic severity of lesions (P < 0.001) in the Pectoralis major, as typically observed with WB. Levels of AST and CK were greater (P < 0.001) in the sera of DRS-affected compared to control broilers, consistent with muscular damage. The frequency of cardiac changes, such as mild hydropericardium and right ventricular dilation, or severity of microscopic pulmonary lesions, such as edema, were not significantly different between the 2 groups. The odds of DRS increased with the histology score of the P. major (OR = 1.37, 95% CI 1.02-1.85). The data presented in this study support an association between DRS and muscular damage of the P. major, suggesting that WB may predispose broilers to DRS. DRS might be a cause of broiler death, and this syndrome could be responsible for significant financial loss to the farmers and to the whole poultry industry.