ABSTRACT
BACKGROUND: Enzalutamide, an androgen-receptor inhibitor, has been associated with improved overall survival in men with castration-resistant prostate cancer. It is not known whether adding enzalutamide to testosterone suppression, with or without early docetaxel, will improve survival in men with metastatic, hormone-sensitive prostate cancer. METHODS: In this open-label, randomized, phase 3 trial, we assigned patients to receive testosterone suppression plus either open-label enzalutamide or a standard nonsteroidal antiandrogen therapy (standard-care group). The primary end point was overall survival. Secondary end points included progression-free survival as determined by the prostate-specific antigen (PSA) level, clinical progression-free survival, and adverse events. RESULTS: A total of 1125 men underwent randomization; the median follow-up was 34 months. There were 102 deaths in the enzalutamide group and 143 deaths in the standard-care group (hazard ratio, 0.67; 95% confidence interval [CI], 0.52 to 0.86; P = 0.002). Kaplan-Meier estimates of overall survival at 3 years were 80% (based on 94 events) in the enzalutamide group and 72% (based on 130 events) in the standard-care group. Better results with enzalutamide were also seen in PSA progression-free survival (174 and 333 events, respectively; hazard ratio, 0.39; P<0.001) and in clinical progression-free survival (167 and 320 events, respectively; hazard ratio, 0.40; P<0.001). Treatment discontinuation due to adverse events was more frequent in the enzalutamide group than in the standard-care group (33 events and 14 events, respectively). Fatigue was more common in the enzalutamide group; seizures occurred in 7 patients in the enzalutamide group (1%) and in no patients in the standard-care group. CONCLUSIONS: Enzalutamide was associated with significantly longer progression-free and overall survival than standard care in men with metastatic, hormone-sensitive prostate cancer receiving testosterone suppression. The enzalutamide group had a higher incidence of seizures and other toxic effects, especially among those treated with early docetaxel. (Funded by Astellas Scientific and Medical Affairs and others; ENZAMET (ANZUP 1304) ANZCTR number, ACTRN12614000110684; ClinicalTrials.gov number, NCT02446405; and EU Clinical Trials Register number, 2014-003190-42.).
Subject(s)
Adenocarcinoma/drug therapy , Adenocarcinoma/secondary , Androgen Receptor Antagonists/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Phenylthiohydantoin/analogs & derivatives , Prostatic Neoplasms/drug therapy , Adenocarcinoma/mortality , Aged , Androgen Receptor Antagonists/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Benzamides , Bone Neoplasms/drug therapy , Bone Neoplasms/secondary , Digestive System Neoplasms/drug therapy , Digestive System Neoplasms/secondary , Fatigue/chemically induced , Follow-Up Studies , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Nitriles , Phenylthiohydantoin/adverse effects , Phenylthiohydantoin/therapeutic use , Progression-Free Survival , Prostatic Neoplasms/mortality , Prostatic Neoplasms/pathology , Seizures/chemically inducedABSTRACT
BACKGROUND: Efforts to increase transparency and accountability of nursing homes, and thus improve quality, now include information about changes in nursing home ownership. However, little is known about how change in ownership affects nursing home quality. METHODS: We conducted a retrospective cohort study of 15,471 U.S. nursing homes between January 2016 and December 2022, identifying all changes in ownership during that period. We used logistic regression to measure the association between nursing home characteristics and the odds of a change in ownership. A difference-in-differences model with multiple time periods was used to examine the impact of a change in ownership on the Medicare Nursing Home Compare 5-star ratings. RESULTS: One in five (23%) facilities changed ownership between 2016 and 2022. Nursing homes that were urban, for-profit, part of a chain, located in the South, had >50 beds, lower occupancy, higher percentage of stays covered by Medicaid, higher percentage of residents with non-white race, or a 1-star (poor) rating were more likely to undergo a change in ownership. There was a small statistically significant decrease in 5-star ratings after a change in ownership (-0.09 points on a 5-point scale; 95% CI -0.13 to -0.04; p < 0.001), driven primarily by a decrease in staffing ratings (-0.19 points; 95% CI -0.24 to -0.14; p < 0.001), and health inspections ratings (-0.07 points; 95% CI -0.11 to -0.03; p = 0.001). This was mitigated by an increase in quality measure ratings (0.15 points; 95% CI 0.10-0.20; p < 0.001). CONCLUSION: Nursing Home Compare ratings decreased slightly after a change in facility ownership, driven by lower staffing and health inspection ratings and mitigated somewhat by higher quality measure ratings. These conflicting trends underscore the need for transparency around changes in facility ownership and a better understanding of consequences of changes in ownership that are salient to patients and families.
ABSTRACT
OBJECTIVES: To summarize current evidence regarding facility and prescriber characteristics associated with potentially harmful medication (PHM) use by residents in nursing homes (NHs), which could inform the development of interventions to reduce this potentially harmful practice. DESIGN: Scoping review. SETTING AND PARTICIPANTS: Studies conducted in the United States that described facility and prescriber factors associated with PHM use in NHs. METHODS: Electronic searches of PubMed/MEDLINE were conducted for articles published in English between April 2011 and November 2021. PHMs were defined based on the Beers List criteria. Studies testing focused interventions targeting PHM prescribing or deprescribing were excluded. Studies were characterized by the strengths and weaknesses of the analytic approach and generalizability. RESULTS: Systematic search yielded 1253 articles. Of these, 29 were assessed in full text and 20 met inclusion criteria. Sixteen examined antipsychotic medication (APM) use, 2 anticholinergic medications, 1 sedative-hypnotics, and 2 overall PHM use. APM use was most commonly associated with facilities with a higher proportion of male patients, younger patients, and patients with severe cognitive impairment, anxiety, depression, and aggressive behavior. The use of APM and anticholinergic medications was associated with low registered nurse staffing ratios and for-profit facility status. No studies evaluated prescriber characteristics. CONCLUSIONS AND IMPLICATIONS: Included studies primarily examined APM use. The most commonly reported facility characteristics were consistent with previously reported indicators of poor NH quality and NHs with patient case mix more likely to use PHMs.
Subject(s)
Antipsychotic Agents , Nursing Homes , Antipsychotic Agents/therapeutic use , Cholinergic Antagonists , Drug Prescriptions , Female , Humans , Inappropriate Prescribing/prevention & control , Male , United StatesABSTRACT
INTRODUCTION: Glioblastoma (GBM) is the most common malignant primary central nervous system cancer in adults. The objective of the Multi-Arm GlioblastoMa Australasia (MAGMA) trial is to test hypotheses in real world setting to improve survival of people with GBM. Initial experimental arms are evaluating the effectiveness of interventions in newly diagnosed GBM (ndGBM). This study will compare maximal surgical resection followed by chemoradiotherapy plus adjuvant chemotherapy for 6 months with the addition of (1) 'neoadjuvant' chemotherapy beginning as soon as possible after surgery and/or (2) adjuvant chemotherapy continued until progression within the same study platform. METHODS AND ANALYSIS: MAGMA will establish a platform for open-label, multiarm, multicentre randomised controlled testing of treatments for GBM. The study began recruiting in September 2020 and recruitment to the initial two interventions in MAGMA is expected to continue until September 2023.Adults aged ≥18 years with ndGBM will be given the option of undergoing randomisation to each study intervention separately, thereby giving rise to a partial factorial design, with two separate randomisation time points, one for neoadjuvant therapy and one for extended therapy. Patients will have the option of being randomised at each time point or continuing on with standard treatment.The primary outcome for the study is overall survival from the date of initial surgery until death from any cause. Secondary outcomes include progression-free survival, time to first non-temozolomide treatment, overall survival from each treatment randomisation, clinically significant toxicity as measured by grade 3 or 4 adverse events and health-related quality-of-life measures. Tertiary outcomes are predictive/prognostic biomarkers and health utilities and incremental cost-effectiveness ratio.The primary analysis of overall survival will be performed separately for each study intervention according to the intention to treat principle on all patients randomised to each study intervention. ETHICS AND DISSEMINATION: The study (Protocol version 2.0 dated 23 November 2020) was approved by a lead Human Research Ethics Committee (Sydney Local Health District: 2019/ETH13297). The study will be conducted in accordance with the principles of the Declaration of Helsinki and Good Clinical Practice. TRIAL REGISTRATION NUMBER: ACTRN12620000048987.
Subject(s)
Glioblastoma , Adolescent , Adult , Australasia , Chemoradiotherapy , Chemotherapy, Adjuvant , Glioblastoma/therapy , Humans , Progression-Free Survival , Randomized Controlled Trials as TopicABSTRACT
INTRODUCTION: Grades 2 and 3 gliomas (G2/3 gliomas), when combined, are the second largest group of malignant brain tumours in adults. The outcomes for G2/3 gliomas at progression approach the dismal outcomes for glioblastoma (GBM), yet there is a paucity of trials for Australian patients with relapsed G2/3 gliomas compared with patients with GBM. LUMOS will be a pilot umbrella study for patients with relapsed G2/3 gliomas that aims to match patients to targeted therapies based on molecular screening with contemporaneous tumour tissue. Participants in whom no actionable or no druggable mutation is found, or in whom the matching drug is not available, will form a comparator arm and receive standard of care chemotherapy. The objective of the LUMOS trial is to assess the feasibility of this approach in a multicentre study across five sites in Australia, with a view to establishing a national molecular screening platform for patient treatment guided by the mutational analysis of contemporaneous tissue biopsies METHODS AND ANALYSIS: This study will be a multicentre pilot study enrolling patients with recurrent grade 2/3 gliomas that have previously been treated with radiotherapy and chemotherapy at diagnosis or at first relapse. Contemporaneous tumour tissue at the time of first relapse, defined as tissue obtained within 6 months of relapse and without subsequent intervening therapy, will be obtained from patients. Molecular screening will be performed by targeted next-generation sequencing at the reference laboratory (PathWest, Perth, Australia). RNA and DNA will be extracted from representative formalin-fixed paraffin embedded tissue scrolls or microdissected from sections on glass slides tissue sections following a review of the histology by pathologists. Extracted nucleic acid will be quantified by Qubit Fluorometric Quantitation (Thermo Fisher Scientific). Library preparation and targeted capture will be performed using the TruSight Tumor 170 (TST170) kit and samples sequenced on NextSeq 550 (Illumina) using NextSeq V.2.5 hi output reagents, according to the manufacturer's instructions. Data analysis will be performed using the Illumina BaseSpace TST170 app v1.02 and a custom tertiary pipeline, implemented within the Clinical Genomics Workspace software platform from PierianDx (also refer to section 3.2). Primary outcomes for the study will be the number of patients enrolled and the number of patients who complete molecular screening. Secondary outcomes will include the proportion of screened patients enrolled; proportion of patients who complete molecular screening; the turn-around time of molecular screening; and the value of a brain tumour specific multi-disciplinary tumour board, called the molecular tumour advisory panel as measured by the proportion of patients in whom the treatment recommendation was refined compared with the recommendations from the automated bioinformatics platform of the reference laboratory testing. ETHICS AND DISSEMINATION: The study was approved by the lead Human Research Ethics Committee of the Sydney Local Health District: Protocol No. X19-0383. The study will be conducted in accordance with the principles of the Declaration of Helsinki 2013, guidelines for Good Clinical Practice and the National Health and Medical Research Council National Statement on Ethical Conduct in Human Research (2007, updated 2018 and as amended periodically). Results will be disseminated using a range of media channels including newsletters, social media, scientific conferences and peer-reviewed publications. TRIAL REGISTRATION NUMBER: ACTRN12620000087954; Pre-results.
Subject(s)
Antineoplastic Agents , Brain Neoplasms , Glioblastoma , Glioma , Adult , Humans , Antineoplastic Agents/therapeutic use , Australia , Brain Neoplasms/genetics , Brain Neoplasms/therapy , Brain Neoplasms/diagnosis , Glioblastoma/drug therapy , Glioblastoma/genetics , Glioma/drug therapy , Glioma/genetics , Multicenter Studies as Topic , Pilot Projects , Recurrence , Review Literature as TopicABSTRACT
Men who initially present with localized prostate cancer and later develop metachronous metastases have a better prognosis than men with de novo metastatic disease and often have a low burden of disease on conventional imaging. Some have disease amenable to metastasis-directed therapy for lymph node or bone metastases, a strategy used by some because no documented overall survival (OS) benefit of combination systemic therapy in this setting. We report data for patients prospectively classified as "M0" at initial diagnosis from the interim analysis of the ENZAMET trial, with 34 mo of median follow-up for survivors. A total of 312 (28%) of the 1125 enrolled patients were classified as M0 at diagnosis, and 205 (66%) of the 312 patients had low-volume disease at study entry as per the CHAARTED criteria. The hazard ratio for OS, that is, HR(OS), was 0.56 (95% confidence interval [CI]: 0.29-1.06) with the addition of enzalutamide for all patients with metachronous metastatic hormone-sensitive prostate cancer, and for the low-volume subset the HR(OS) was 0.40 (95% CI: 0.16-0.97). The 3-yr OS was 83% without and 89% with enzalutamide for all patients with metachronous metastases, and 83% and 92%, respectively, for the low-volume subset. Intensification of hormonal therapy should strongly be considered for these men. PATIENT SUMMARY: Many men present with prostate cancer that has spread to distant sites beyond the prostate gland years after their initial diagnosis and treatment, while others have distant spread at the time the cancer is diagnosed. On average, men whose cancer comes back years after the initial diagnosis often survive much longer than men whose cancer has been found to spread to distant sites when it is first diagnosed. In this report, we demonstrate strong evidence for the first time that the survival of men whose cancer comes back years later is improved when drugs such as enzalutamide or apalutamide are added to testosterone suppression in this setting.
Subject(s)
Androgen Antagonists , Antineoplastic Agents , Benzamides , Neoplasms, Second Primary , Nitriles , Phenylthiohydantoin , Prostatic Neoplasms , Thiohydantoins , Androgen Antagonists/therapeutic use , Antineoplastic Agents/therapeutic use , Benzamides/therapeutic use , Clinical Trials as Topic , Humans , Male , Neoplasms, Second Primary/drug therapy , Neoplasms, Second Primary/mortality , Nitriles/therapeutic use , Phenylthiohydantoin/therapeutic use , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/mortality , Prostatic Neoplasms/secondary , Prostatic Neoplasms, Castration-Resistant/drug therapy , Prostatic Neoplasms, Castration-Resistant/mortality , Prostatic Neoplasms, Castration-Resistant/secondary , Survival Analysis , Thiohydantoins/therapeutic useABSTRACT
BACKGROUND: Familial hypertrophic cardiomyopathy (FHC) is characterized by genetic and clinical heterogeneity. Five percent of FHC families have 2 FHC-causing mutations, which results in earlier disease onset, increased cardiac dysfunction, and a higher incidence of sudden death events. These observations suggest a relationship between the number of gene mutations and phenotype severity in FHC. METHODS AND RESULTS: We sought to develop, characterize, and investigate the pathogenic mechanisms in a double-mutant murine model of FHC. This model (designated TnI-203/MHC-403) was generated by crossbreeding mice with the Gly203Ser cardiac troponin I (TnI-203) and Arg403Gln alpha-myosin heavy chain (MHC-403) FHC-causing mutations. The mortality rate in TnI-203/MHC-403 mice was 100% by age 21 days. At age 14 days, TnI-203/MHC-403 mice developed a significantly increased ratio of heart weight to body weight, marked interstitial myocardial fibrosis, and increased expression of atrial natriuretic factor and brain natriuretic peptide compared with nontransgenic, TnI-203, and MHC-403 littermates. By age 16 to 18 days, TnI-203/MHC-403 mice rapidly developed a severe dilated cardiomyopathy and heart failure, with inducibility of ventricular arrhythmias, which led to death by 21 days. Downregulation of mRNA levels of key regulators of Ca(2+) homeostasis in TnI-203/MHC-403 mice was observed. Increased levels of phosphorylated STAT3 were observed in TnI-203/MHC-403 mice and corresponded with the onset of disease, which suggests a possible cardioprotective response. CONCLUSIONS: TnI-203/MHC-403 double-mutant mice develop a severe cardiac phenotype characterized by heart failure and early death. The presence of 2 disease-causing mutations may predispose individuals to a greater risk of developing severe heart failure than human FHC caused by a single gene mutation.
Subject(s)
Cardiomyopathy, Dilated/genetics , Cardiomyopathy, Hypertrophic, Familial/genetics , Disease Models, Animal , Mutation , Troponin I/genetics , Ventricular Myosins/genetics , Animals , Calcium Signaling , Cardiomyopathy, Dilated/pathology , Cardiomyopathy, Hypertrophic, Familial/physiopathology , Disease Progression , Female , Heterozygote , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Mutant Strains , Mutation, Missense , Paracrine Communication , Phenotype , Renin-Angiotensin System/physiology , STAT3 Transcription Factor/physiology , Signal Transduction , Ventricular Myosins/physiologyABSTRACT
Sudden unexpected death in epilepsy (SUDEP) is the most frequent epilepsy-related cause of death and is characterized by an absence of any identifiable cause of death at post-mortem, suggesting an underlying arrhythmogenic predisposition. This study sought to identify SUDEP cases in a review of post-mortem records and to undertake genetic studies in key familial long QT syndrome (LQTS) genes. All autopsies performed from 1993-2009 at a forensic centre in Sydney, Australia were reviewed and SUDEP cases identified. DNA was extracted from post-mortem blood and the three most common LQTS genes, ie, KCNQ1, KCNH2 (HERG) and SCN5A, were amplified and analyzed. Sixty-eight SUDEP cases were identified (mean age of 40 ± 16 years). Genetic analysis revealed 6 (13%) non-synonymous (amino acid changing) variants in KCNH2 (n = 2) and SCN5A (n = 4), all previously reported in LQTS patients. Specifically, KCNH2 Arg176Trp and SCN5A Pro1090Leu were identified once in SUDEP cases and absent in control alleles. Both DNA variants have been previously identified in the pathogenesis of LQTS. The cause of SUDEP is currently unknown. Our results indicate that investigation of key ion channel genes should be pursued in the investigation of the relationship between epilepsy and sudden death.
Subject(s)
Death, Sudden/etiology , Epilepsy/genetics , Ether-A-Go-Go Potassium Channels/genetics , Genetic Predisposition to Disease , KCNQ1 Potassium Channel/genetics , Sodium Channels/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Autopsy , Child , Child, Preschool , ERG1 Potassium Channel , Epilepsy/complications , Female , Humans , Long QT Syndrome/genetics , Male , Middle Aged , NAV1.4 Voltage-Gated Sodium Channel , Polymerase Chain Reaction , Polymorphism, Single Nucleotide , Young AdultABSTRACT
Sudden unexpected death in epilepsy (SUDEP) is the most common epilepsy-related cause of death, yet the cause is unknown. Our previous studies suggest a role for arrhythmia-related ion channel genes in the pathogenesis of SUDEP. Hyperpolarization-activated cyclic nucleotide-gated cation (HCN1-4) channels are ion channels involved in generating spontaneous rhythmic activity in cardiac pacemaker and neuronal cells. This study sought to determine the role of pathogenic DNA variants in the HCN1-4 genes in a large SUDEP cohort collected from 1993 to 2009. Post-mortem DNA samples were amplified and analyzed for each HCN exon. Genetic analysis in 48 SUDEP cases (age range 12-82 years) identified six novel and three previously reported nonsynonymous (amino acid changing) variants in HCN1 (n = 1), HCN2 (n = 2), HCN3 (n = 2) and HCN4 (n = 4). The Phe738Cys and Pro802Ser variants in HCN2, and Gly973Arg in HCN4 were absent in control alleles and affecting highly conserved residues in the carboxyl-cytoplasmic tail region. Our results support a pathogenic link between the heart and brain in SUDEP, mediated by the HCN neuro-cardiac ion channel genes.
Subject(s)
Cyclic Nucleotide-Gated Cation Channels/genetics , Death, Sudden/etiology , Epilepsy/genetics , Ion Channels/genetics , Muscle Proteins/genetics , Potassium Channels/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Amino Acid Sequence , Base Sequence , Child , Epilepsy/complications , Female , Genetic Predisposition to Disease , Humans , Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels , Male , Middle Aged , Molecular Sequence Data , Polymorphism, Single Nucleotide , Young AdultABSTRACT
Sudden cardiac death is an unpredictable and devastating event, particularly in the young. A significant proportion of sudden deaths in the young are unexplained-no cause is identified either during life or at post-mortem. This is seen in a subgroup of young patients with type 1 diabetes who have dead in bed syndrome, where these victims are in good health, retire to bed, only to be found dead the following morning in a bed which is undisturbed, suggesting no terminal struggle or seizure. The underlying cause of dead in bed syndrome remains unknown, but is likely to be due to a terminal malignant arrhythmia. A plausible hypothesis is that it may be secondary to QT interval prolongation (followed by a degenerate ventricular tachycardia), caused by a number of factors including acute hypoglycaemia, on a background of cardiac autonomic neuropathy, and possible genetic influences. It is envisaged that understanding the causes and triggers of dead in bed syndrome will allow appropriate therapeutic interventions to be initiated in high-risk patients with type 1 diabetes, with the ultimate goal to prevent sudden death.
Subject(s)
Death, Sudden/epidemiology , Diabetes Mellitus, Type 1/mortality , Hypoglycemia/mortality , Long QT Syndrome/mortality , Tachycardia, Ventricular/mortality , Adult , Humans , Risk Factors , Young AdultABSTRACT
Dead in bed syndrome is a poorly understood cause of sudden death in young people with type 1 diabetes. The underlying cause remains unknown. One possible explanation may involve prolongation of the QT interval followed by a terminal malignant arrhythmia. Risk factors associated with QT interval prolongation include hypoglycemia and cardiac autonomic neuropathy. We sought to identify myocardial cellular changes and genetic influences that may contribute to the pathogenesis of dead in bed syndrome. Post-mortem reports between 1994 and 2006 from the 2 largest Departments of Forensic Medicine in Australia were reviewed for dead in bed syndrome cases. Post-mortem heart sections were immunohistochemically stained for collagen types I and III and connective tissue growth factor (CTGF). Genomic DNA was prepared from post-mortem samples, and genetic analysis was performed in the SCN5A, G6PC, PHOX2B, and CTGF genes. Twenty-two dead in bed syndrome cases were identified and staining of heart sections for collagen I and III, and CTGF showed no differences between dead in bed syndrome cases and controls. Genetic screening of SCN5A revealed 3 silent polymorphisms A29A, E1061E, and D1819D and 1 protein-changing variant H558R. No genetic variants were found in G6PC, PHOX2B, and CTGF, and dead in bed syndrome cases were not associated with the G-945C CTGF promoter polymorphism. In conclusion, this study is the first to investigate potential pathogenic mechanisms underlying the dead in bed syndrome in type 1 diabetes with the results substantially adding to knowledge of this condition. Understanding the causes and triggers of dead in bed syndrome will be critical in facilitating the identification of patients with type 1 diabetes at highest risk of developing sudden death.
Subject(s)
Death, Sudden/pathology , Diabetes Mellitus, Type 1/pathology , Myocardium/pathology , Adolescent , Adult , Analysis of Variance , Australia , Chi-Square Distribution , Collagen Type I/metabolism , Collagen Type III/metabolism , Connective Tissue Growth Factor/genetics , Connective Tissue Growth Factor/metabolism , Death, Sudden/etiology , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/metabolism , Genetic Predisposition to Disease , Glucose-6-Phosphatase/genetics , Homeodomain Proteins/genetics , Humans , Hypoglycemia/genetics , Hypoglycemia/metabolism , Hypoglycemia/pathology , Immunohistochemistry , Male , Myocardium/metabolism , NAV1.5 Voltage-Gated Sodium Channel , Polymorphism, Genetic/genetics , Retrospective Studies , Risk Factors , Sequence Analysis, DNA , Sodium Channels/genetics , Transcription Factors/geneticsABSTRACT
OBJECTIVE: To determine the causes of death in Australians with type 1 diabetes mellitus who died aged 40 years or younger. DESIGN AND SETTING: Retrospective review of autopsy reports at the Department of Forensic Medicine, Sydney, New South Wales, 1 January 1994-31 December 2006. MAIN OUTCOME MEASURE: Causes of mortality in people with type 1 diabetes aged <40 years. RESULTS: Of the 26 682 autopsy reports, 1914 were for individuals with diabetes (type 1, 400; type 2, 1514). Cardiovascular disease accounted for 51% of deaths (169/333) in people with type 1 diabetes aged >40 years, versus 13% among those aged Subject(s)
Death, Sudden/epidemiology
, Diabetes Mellitus, Type 1/mortality
, Adult
, Autopsy
, Cause of Death
, Female
, Humans
, Male
, Middle Aged
, New South Wales/epidemiology
, Retrospective Studies
ABSTRACT
Gene mutations in cardiac troponin I (cTnI) account for up to 5% of genotyped families with familial hypertrophic cardiomyopathy (FHC). Little is known about how cTnI mutations cause disease. Five lines of transgenic mice were generated which overexpress the human disease-causing cTnI gene mutation, Gly203Ser (designated cTnI-G203S), in a cardiac-specific manner. Mice were compared to transgenic mice that overexpress normal cTnI (cTnI-wt) and non-transgenic littermates (NTG). cTnI-G203S mice developed all the characteristic features of FHC by age 21 weeks. Left ventricular hypertrophy was observed on echocardiography (1.25+/-0.05 mm vs. 0.86+/-0.02 mm in cTnI-wt, P<0.01), associated with a significant 4-fold increase in RNA markers of hypertrophy, ANF and BNP. Myocyte hypertrophy, myofiber disarray and interstitial fibrosis were observed in cTnI-G203S mice. Expression of the cTnI-G203S mutation in neonatal cardiomyocytes resulted in a significant increase in myocyte volume, and reduced interactions with both troponins T and C. Ca2+ cycling was abnormal in adult cardiomyocytes extracted from cTnI-G203S mice, with a prolonged decay constant in Ca2+ transients and a reduced decay constant in response to caffeine treatment. Mice with the cTnI-G203S gene mutation develop all the phenotypic features of human FHC. The cTnI-G203S mutation disrupts interactions with partner proteins, and results in intracellular Ca2+ dysregulation early in life, suggesting a pathogenic role in development of FHC.