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Leucine zipper-like transcription regulator 1 (LZTR1) acts as a negative factor that suppresses RAS function and MAPK signaling; mutations in this protein may dysregulate RAS ubiquitination and lead to impaired degradation of RAS superfamily proteins. Germline LZTR1 variants are reported in Noonan syndrome, either autosomal dominant or autosomal recessive, and in susceptibility to schwannomatosis. This article explores the genetic and phenotypic diversity of the autosomal dominant LZTR1-related disorders, compiling a cohort of previously published patients (51 with the Noonan phenotype and 123 with schwannomatosis) and presenting two additional adult-onset cases: a male with schwannomatosis and Parkinson's disease and a female with Noonan syndrome, generalized joint hypermobility, and breast cancer. This review confirms that autosomal dominant LZTR1-related disorders exhibit an extreme phenotypic variability, ranging from relatively mild manifestations to severe and multi-systemic involvement, and offers updated frequences of each clinical feature. The aim is to precisely define the clinical spectrum of LZTR1-related diseases, using also two new emblematic clinical cases. Gaining insight into the mechanisms underneath this variability is crucial to achieve precision diagnostics and the development of therapeutic interventions.
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Neurilemoma , Síndrome de Noonan , Fenotipo , Humanos , Masculino , Femenino , Síndrome de Noonan/genética , Síndrome de Noonan/patología , Adulto , Neurilemoma/genética , Neurilemoma/patología , Neurofibromatosis/genética , Neurofibromatosis/patología , Transactivadores/genética , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Edad de Inicio , Factores de Transcripción/genética , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/patología , Persona de Mediana Edad , Genes Dominantes , MutaciónRESUMEN
Background: Extended half-life (EHL) factor IX (FIX) concentrates allow for prophylaxis with prolonged dosing intervals and high bleeding protection in persons with hemophilia B. Long-term real-world studies are lacking. Methods: In a retrospective-prospective study, the six-year use of prophylaxis with the EHL recombinant FIX-albumin fusion protein (rIX-FP) was analyzed, comparing outcomes with previous standard half-life (SHL) FIX in patients already on prophylaxis. Results: Prophylaxis with rIX-FP was prescribed in 15 patients (10 severe, 5 moderate; follow-up: 57 ± 17 months). Based on a pharmacokinetic assessment and clinical needs, the first regimen was 47 ± 7 IU/Kg every 9 ± 2 days. All but one patient remained on rIX-FP prophylaxis, adjusting infusion frequency and/or dose; the last prescribed frequency was ≥10 days in 10/13 patients, being reduced in seven and increased in four vs. the first regimen. The weekly FIX dose was unchanged; FIX trough levels were >5% in all patients. The annual infusion number and FIX IU/Kg significantly decreased (~60%) in eight patients previously on SHL FIX prophylaxis, with similar concentrate costs. Very low bleeding rates (most traumatic bleeds and the last quartile of the infusion interval), improved orthopedic and pain scores, unchanged HEAD-US scores and problem joints, and high treatment adherence (>90%) and satisfaction were registered. Conclusions: Personalized, carefully adjusted rIX-FP regimens contribute to the diffusion and optimization of prophylaxis in persons with severe and moderate hemophilia B, with long-term favorable bleeding, joint, and patient-reported outcomes.
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INTRODUCTION: Haemophilias are X-linked inherited bleeding disorders, due to de novo F8/F9 gene variants in 30-50% of cases. The identification of causative variant in index cases (IC) is crucial for genetic counselling in related women. Over the last 20 years the Emilia-Romagna Regional Haemophilia Registry documented high proportions of sporadic severe haemophilia. AIM: To clarify if carriers' reproductive choices influence the sporadic/familial ratio of severe haemophilia. METHODS: Genetic counselling and genotyping in 221 relatives of severe IC were retrospectively reviewed, retrieving reproductive choices and pregnancy history of childbearing-age carriers from familial and sporadic pedigrees and according to the IC degree of relationship (mothers, daughters, II/other). RESULTS: Carriers' identification rates were lower in sporadic women and in other-degree relatives. Among childbearing age women (n = 140), carriers were 37/48 (77%) and 57/92 (62%) of familial and sporadic relatives, respectively. Forty-five/57 sporadic carriers experienced 67 pregnancies, while 21/37 familial carriers had 39 pregnancies (four voluntary terminations), with a significantly higher number of affected sons in the former (40/67 vs. 12/35, P = .025). Prenatal diagnosis was chosen by 40% and 47% of sporadic and familial aware carriers, respectively. Sporadic mothers often avoided further pregnancies (17/38, 45%) after a firstborn affected child, while familial mothers tended to face pregnancies without prenatal approaches (6/10, 60%). CONCLUSION: In this cohort sporadic offspring account for more than 70% of severe haemophilia cases. This increasing proportion is likely to reflect the influence in reproductive choices of awareness of carriers' status, particularly in sporadic mothers, and of prenatal diagnosis options.
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Toma de Decisiones , Hemofilia A , Embarazo , Femenino , Hemofilia A/diagnóstico , Hemofilia A/epidemiología , Hemofilia A/genética , Heterocigoto , Humanos , Embarazo/psicología , Sistema de Registros , Historia Reproductiva , Estudios RetrospectivosAsunto(s)
Carcinoma Broncogénico , Deficiencia del Factor VII , Neoplasias Pulmonares , Carcinoma Broncogénico/complicaciones , Carcinoma Broncogénico/diagnóstico , Factor VII , Deficiencia del Factor VII/complicaciones , Deficiencia del Factor VII/diagnóstico , Humanos , Neoplasias Pulmonares/diagnósticoAsunto(s)
Betacoronavirus , Infecciones por Coronavirus/epidemiología , Hemofilia A/terapia , Hemofilia B/terapia , Pandemias , Neumonía Viral/epidemiología , Antiinflamatorios no Esteroideos/efectos adversos , Anticuerpos Biespecíficos/uso terapéutico , Anticuerpos Monoclonales Humanizados/uso terapéutico , COVID-19 , Ensayos Clínicos como Asunto , Comorbilidad , Continuidad de la Atención al Paciente , Contraindicaciones de los Medicamentos , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/prevención & control , Atención a la Salud , Manejo de la Enfermedad , Sustitución de Medicamentos , Factor IX/provisión & distribución , Factor IX/uso terapéutico , Factor VIII/provisión & distribución , Factor VIII/uso terapéutico , Fibrinolíticos/efectos adversos , Fibrinolíticos/uso terapéutico , Terapia Genética , Recursos en Salud/provisión & distribución , Hemofilia A/complicaciones , Hemofilia A/epidemiología , Hemofilia B/complicaciones , Hemofilia B/epidemiología , Hemorragia/etiología , Hemorragia/prevención & control , Humanos , Pandemias/prevención & control , Neumonía Viral/sangre , Neumonía Viral/complicaciones , Neumonía Viral/prevención & control , Relaciones Profesional-Paciente , SARS-CoV-2 , Medios de Comunicación Sociales , Telemedicina , Trombofilia/etiologíaRESUMEN
BACKGROUND: The recombinant factor VIII (rFVIII)-IgG1 Fc fusion protein (rFVIII-Fc) was the first available extended half-life rFVIII, shown to prolong dosing intervals of individualised prophylaxis in patients with severe haemophilia A, maintaining low bleeding rates and unchanged or lower FVIII dose versus standard half-life (SHL) rFVIII. Few data are available about real-world experience with rFVIII-Fc, including criteria for patient switching from SHL products, follow up and prophylaxis optimisation. MATERIALS AND METHODS: A single-centre retrospective study was designed to review patients switched to rFVIII-Fc, based on individual needs, after pharmacokinetic (PK) assessment, according to routine clinical practice. In patients with adequate post-switch follow up, data about rFVIII-Fc prophylaxis were compared with those from the last 18-months SHL rFVIII prophylaxis. RESULTS: Of 25 candidates, 18 patients (15 severe, 3 moderate; aged 9-62 years; 3 with inhibitor history) started rFVIII-Fc regimens, with comparable FVIII weekly dose and reduced infusion frequency (mean -30%) in all 17 patients previously on SHL rFVIII prophylaxis thrice weekly or every other day. Over a mean 18-month follow up in 13 patients, compared with SHL products, further reduced infusion frequency (mean -40%; p<0.001; interval ≥4 days in 9 patients), improved treatment satisfaction (Hemo-sat questionnaires), significantly lower FVIII weekly dose and annual consumption (mean -12%; p=0.019), comparable bleeding rates and FVIII trough levels, and improved management of breakthrough bleeding were observed. von Willebrand Factor Antigen (VWF:Ag) correlated to PK variables and both had relationships with rFVIII-Fc weekly dose, increasing statistical significance over the follow-up period. No inhibitors or drug-related adverse events were recorded. DISCUSSION: In this real-world series of patients, a switch to rFVIII-Fc, based on careful assessment of clinical needs, PK testing and treatment monitoring, was able to optimise individual convenience, efficacy and costs of prophylaxis.
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Factor VIII , Hemofilia A , Hemorragia , Fragmentos Fc de Inmunoglobulinas , Proteínas Recombinantes de Fusión , Adolescente , Adulto , Niño , Costos y Análisis de Costo , Factor VIII/administración & dosificación , Factor VIII/economía , Factor VIII/farmacocinética , Estudios de Seguimiento , Hemofilia A/sangre , Hemofilia A/tratamiento farmacológico , Hemofilia A/economía , Hemorragia/sangre , Hemorragia/economía , Hemorragia/prevención & control , Humanos , Fragmentos Fc de Inmunoglobulinas/administración & dosificación , Fragmentos Fc de Inmunoglobulinas/economía , Masculino , Persona de Mediana Edad , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/economía , Proteínas Recombinantes de Fusión/farmacocinética , Estudios RetrospectivosRESUMEN
INTRODUCTION: Persons with haemophilia (PWH) experience recurrent joint bleeding which leads from early synovitis to irreversible joint damage. Pain strongly affects patients' quality of life, as PWH suffer from acute pain associated with haemarthroses and chronic pain due to arthritic and degenerative complications. AIM: To investigate pain issues among PWH and their treaters in Italy. METHODS: Persons with haemophilia and specialist physicians responded to a survey focused on pain characteristics, assessment, and management by phone call and online, respectively. RESULTS: One hundred and nineteen patients (76% severe haemophilia, 61% ≥18 years) and 44 physicians were involved. Pain was reported by 61% of PWH; among those who did not experience pain, 70% were children on prophylaxis. Patients described pain as chronic (71%), acute (69%) or postoperative (8%), and rated it as severe in 65% of cases. Clinicians reported lower percentages of patients with pain (46%), classified as chronic (58%), acute (33%) or postoperative (21%), half using specific scales. Pain was systematically investigated by treaters according to 36% of patients. Paracetamol was largely the most prescribed first-line pain therapy (89%), as well the most employed analgesic by PWH (51%), who also used non-steroidal anti-inflammatory drugs (24%), cyclo-oxygenase-2 inhibitors (21%) or opioids (26%). To manage pain, 61% of clinicians stated to collaborate with other specialists. Physiotherapy was often suggested but less frequently used by PWH. CONCLUSIONS: Pain is under-recognized and unsatisfactorily addressed by haemophilia treatment centre (HTC) clinicians, with discrepant management compared to PWH responses. Education in systematic pain assessment and multidisciplinary treatment and development of management guidelines are highly needed.
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Dolor Crónico/etiología , Hemofilia A/complicaciones , Manejo del Dolor/métodos , Dimensión del Dolor/métodos , Adolescente , Adulto , Anciano , Niño , Femenino , Hemofilia A/patología , Humanos , Italia , Masculino , Persona de Mediana Edad , Médicos , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Hemophilia B (HB) is an X-linked bleeding disorder caused by deficiency of factor IX (FIX). Patients with the severe form (FIX <1%) account approximately for 30 to 45% of persons with HB and usually suffer from recurrent joint, soft-tissue, and muscle bleeds. The availability of safe plasma-derived and recombinant products has virtually abolished the risk of viral infections and the adoption of prophylactic regimens has attenuated the impact of hemophilic arthropathy. Therefore, the development of an inhibitor against FIX is currently the most serious complication that can still occur in the new generations of HB patients. The development of an inhibitor in HB is a rare event (1.5-3% of all patients) but is associated with a significant morbidity, related not only to the bleeding risk but also to the frequent occurrence of allergic/anaphylactic reactions and nephrotic syndrome. Due to the relative rarity of this event, few data exist about risk factors, pathophysiology, and clinical aspects of inhibitors in HB. The induction of immune tolerance is often unsuccessful and can be otherwise affected by many complications in patients with history of allergy or anaphylaxis. Therefore, alternative therapeutic strategies and new approaches are developing. The aim of this narrative review is to discuss current knowledge about risk factors, pathophysiology, and clinical aspects of this rare but serious complication.
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Factor IX/uso terapéutico , Hemofilia B/tratamiento farmacológico , Factor IX/farmacología , HumanosRESUMEN
Congenital factor VII (FVII) deficiency is a rare bleeding disorder caused by mutations in F7 gene with autosomal recessive inheritance. A clinical heterogeneity with poor correlation with FVII:C levels has been described. It was the objective of this study to identify genetic defects and to evaluate their relationships with phenotype in a large cohort of patients with FVII:C<50 %. One hundred twenty-three probands were genotyped for F7 mutations and three polymorphic variants and classified according to recently published clinical scores. Forty out of 123 patients (33 %) were symptomatic (43 bleedings). A severe bleeding tendency was observed only in patients with FVII:C<0.10 %. Epistaxis (11 %) and menorrhagia (32 % of females in fertile age) were the most frequent bleedings. Molecular analysis detected 48 mutations, 20 not reported in the F7 international databases. Most mutations (62 %) were missense, large deletions were 6.2 %. Compound heterozygotes/homozygotes for mutations presented lower FVII:C levels compared to the other classes (Chi2=43.709, p<0,001). The polymorphisms distribution was significantly different among the three F7 genotypic groups (Chi2=72.289, p<0,001). The presence of truncating mutations was associated with lowest FVII:C levels (Chi2=21.351, p=0.002). This study confirms the clinical and molecular variability of the disease and the type of symptoms. It shows a good correlation between the type of F7 mutation and/or polymorphisms and FVII:C levels, without a direct link between FVII:C and bleeding tendency. The results suggest that large deletions are underestimated and that they represent a common mechanism of F7 gene inactivation which should always be investigated in the diagnostic testing for FVII deficiency.
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Deficiencia del Factor VII/sangre , Deficiencia del Factor VII/genética , Factor VII/genética , Factor VII/metabolismo , Hemostasis/genética , Mutación , Polimorfismo Genético , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Pruebas de Coagulación Sanguínea , Niño , Preescolar , Análisis Mutacional de ADN , Deficiencia del Factor VII/diagnóstico , Femenino , Estudios de Asociación Genética , Marcadores Genéticos , Predisposición Genética a la Enfermedad , Heterocigoto , Homocigoto , Humanos , Italia , Masculino , Persona de Mediana Edad , Fenotipo , Adulto JovenRESUMEN
Treatment of patients with inherited bleeding disorders (PWIBD) in the emergency department (ED) is challenging. In 2010, a project was started involving all eight hemophilia centers (HC) and all 44 EDs of the Region of Emilia-Romagna (Italy) to improve emergency care for PWIBD. The project incorporates guidelines for emergency treatment, education for ED staff, and a dedicated Web site providing extensive information, proposing treatments, and sharing data with patients' electronic clinical records. A Web algorithm, accessible to PWIBD as well as ED and HC staff, suggests the first dose of concentrate for each type and severity of bleed or trauma. Following training courses in each ED, the network was activated. During 2012 and 2013, the site was visited 14,000 times, the EDs accessed the Web site 1,739 times, and used the algorithms 206 times. In two reference EDs, triage-assessment and triage-treatment times were reduced in 2013 and 2012 (27/20 and 110/71.5 minutes, respectively) and medical advice from the HC increased (54 vs. 24% cases). The main advantages of this system are better management of patients in ED (shorter triage-to-treatment times) and improved collaboration between HCs and EDs. The most critical point remaining is staff turnover in EDs, necessitating continual training.
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Algoritmos , Servicios Médicos de Urgencia/métodos , Servicio de Urgencia en Hospital , Hemofilia A , Internet , Sistemas de Registros Médicos Computarizados , Educación Médica Continua , Femenino , Hemofilia A/diagnóstico , Hemofilia A/tratamiento farmacológico , Humanos , Italia , MasculinoRESUMEN
Joint hemorrhages represent the most common type of bleeding episode in persons with hemophilia, and recurrent hemarthrosis triggers chronic arthropathy, which is the most frequent chronic complication in these patients. In recent years, in the frame of a comprehensive care approach, a growing attention has been given to the periodic assessment of the joint status in hemophilia patients with the aim to identify early arthropathic changes and to prevent the development of a clinically overt arthropathy. Besides clinical examination, X-ray and magnetic resonance imaging (MRI) are currently used to evaluate joint status and to monitor the disease progression in hemophilia. Considering the limitations of X-ray and MRI, growing interest has been given to ultrasound (US) as a possible tool to assess joint status and identify early arthropathic changes in hemophilia patients. In the present review, we summarize major literature evidence on the use of joint US for the evaluation of markers of disease activity (joint effusion and synovial hypertrophy) and of degenerative damages (osteochondral changes) in patients with hemophilia. On the whole, being able to identify the presence of intra- or extra-articular fluid, US examination is the fastest and most reliable technique to identify acute conditions, such as hemarthrosis. In addition, the information on joint involvement provided by US in the patient follow-up may influence treatment decisions on a personalized basis. The use of US as part of a routine clinical examination by hemophilia experts may optimize the diagnostic workflow, avoiding additional costs and long waiting lists for patients referred to imaging departments. In the frame of a comprehensive care approach, US might represent a strategy to early detect and monitor synovial hypertrophy and osteochondral changes in hemophilia, thus extending the clinical examination and helping identify joints to be studied with a second-level examination such as MRI.
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Hemofilia A , Hemorragia , Artropatías , Ultrasonografía , Hemofilia A/complicaciones , Hemofilia A/diagnóstico por imagen , Hemorragia/diagnóstico por imagen , Hemorragia/etiología , Humanos , Artropatías/diagnóstico por imagen , Artropatías/etiología , Membrana Sinovial/diagnóstico por imagen , Estados UnidosRESUMEN
Variations of DNA sequences in the human genome range from large, microscopically visible chromosome anomalies to single nucleotide changes. Submicroscopic genomic copy number variations, i.e. chromosomal imbalances which are undetectable by conventional cytogenetic analysis, play an intriguing clinical role. In this study, we describe the clinical consequences of the concurrent presence of an interstitial deletion in 13q34 and a terminal deletion in 4q35.2 in an Italian family. The index patient, a 19-year-old male, as well as his 12-year-old sister are carriers of both deletions, one of maternal and the other of paternal origin. The phenotype includes language delay, multiorgan involvement and bleeding diathesis with mild deficiency of factors X and VII. In the sister, the concomitant presence of Noonan syndrome may partly explain the clinical symptoms. The deleted region on chromosome 13 involves several genes (ATP11A, MCF2L, F7, F10, PROZ, PCID2, CUL4A, and LAMP1); some of these seem to play a role in the proband's phenotype. The terminal deletion in 4q35.2 contains other OMIM genes (FRG1, FRG2 and DBET); moreover, the 4q region is reported as a susceptibility locus for Crohn's disease, diagnosed in the proband's father. To our knowledge, this is the first report of a family with these 2 submicroscopic copy number changes. We tried to relate the clinical phenotype of the proband and his family to the molecular function of the involved genes.
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Deleción Cromosómica , Cromosomas Humanos Par 13 , Cromosomas Humanos Par 4 , Deficiencia del Factor VII/genética , Deficiencia del Factor X/genética , Trastornos Hemorrágicos/genética , Síndrome de Noonan/genética , Niño , Bandeo Cromosómico , Variaciones en el Número de Copia de ADN , Deficiencia del Factor VII/patología , Deficiencia del Factor X/patología , Femenino , Trastornos Hemorrágicos/patología , Humanos , Hibridación Fluorescente in Situ , Patrón de Herencia , Italia , Masculino , Síndrome de Noonan/patología , Linaje , Fenotipo , Adulto JovenRESUMEN
BACKGROUND: The prevalence of thrombophilic abnormalities in patients with cerebral vein thrombosis has been reported to be similar to that in patients with deep vein thrombosis of the lower limb. The role of gender-specific risk factors (pregnancy, oral contraceptives) is well established, whereas that of other acquired risk conditions is debated. MATERIALS AND METHODS: We screened 56 patients with cerebral vein thrombosis and 184 age- and sex-matched apparently healthy controls for prothrombin (factor II, FII) G20210A and factor V Leiden polymorphisms; protein S, protein C, and antithrombin deficiency; anticardiolipin antibodies; hyperhomocysteinaemia and other putative risk factors. RESULTS: The G20210A polymorphism was found in 29.1% of patients and in 5.7% of controls (odds ratio [OR] 7.1; P<0.0001; adjusted OR 12.67, P<0.0001). Frequencies of factor V Leiden and hyperhomocysteinaemia were not significantly different in patients and controls, nor were the other thrombophilic tests and some established cardiovascular risk factors, such as smoking, obesity or overweight and arterial hypertension. Conversely, 53.7% of the women who developed cerebral vein thrombosis did so while assuming oral contraceptives (OR 6.12; P<0.0001), with a further increase of risk in FII G20210A carriers (OR 48.533). Some associated diseases (onco-haematological disorders and infections) also had a significant role. Over a median 7-year follow-up, irrespective of the duration of antithrombotic treatment, 9/56 (16%) patients had further episodes of venous/arterial thrombosis. No significant risk factor for recurrent thrombosis was identified. DISCUSSION: In spite of the limitations of the sample size, our data confirm the role of FII G20210A mutation in this setting and its interactions with acquired risk factors such as oral contraceptives, also highlighting the risk of recurrent thrombosis in cerebral vein thrombosis patients.
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Venas Cerebrales , Trombosis de la Vena/epidemiología , Resistencia a la Proteína C Activada/epidemiología , Resistencia a la Proteína C Activada/genética , Adulto , Anticuerpos Anticardiolipina/sangre , Deficiencia de Antitrombina III/epidemiología , Deficiencia de Antitrombina III/genética , Enfermedades Autoinmunes/sangre , Enfermedades Autoinmunes/epidemiología , Enfermedades Cardiovasculares/epidemiología , Estudios de Casos y Controles , Comorbilidad , Anticonceptivos Hormonales Orales/efectos adversos , Factor V/genética , Femenino , Humanos , Hiperhomocisteinemia/epidemiología , Masculino , Persona de Mediana Edad , Neoplasias/sangre , Neoplasias/epidemiología , Obesidad/epidemiología , Regiones Promotoras Genéticas/genética , Deficiencia de Proteína C/epidemiología , Deficiencia de Proteína S/epidemiología , Protrombina/genética , Recurrencia , Factores de Riesgo , Fumar/epidemiología , Trombofilia/sangre , Trombofilia/epidemiología , Trombofilia/genética , Trombosis de la Vena/sangre , Trombosis de la Vena/etiología , Adulto JovenRESUMEN
OBJECTIVES: Left ventricular (LV) diastolic dysfunction is considered the earliest manifestation of diabetic cardiomyopathy. Whether LV abnormalities identified at rest by echocardiography predict peak exercise LV performance in uncomplicated type 1 diabetes mellitus (DM1) is largely unknown. RESEARCH DESIGN AND METHODS: We evaluated LV size, mass, and functions and peak exercise LV performance in 25 subjects with uncomplicated DM1 (median disease duration 13.5 years, 1-30 years) and in 56 non-DM subjects (24 hypertensive (HT) and 32 normotensive (NT)). Overt coronary heart disease, significant microangiopathy and central autonomic neuropathy were minimized by exclusion criteria. Peak exercise LV stroke index (SVi), cardiac index (COi), LV ejection fraction (EF), LV end-diastolic and end-systolic volumes were assessed noninvasively. No subject was on cardiovascular medications at the time of evaluation. RESULTS: In our study, DM1 did not show LV hypertrophy or impaired LV systolic function at rest. Prevalence of diastolic dysfunction was 8% among DM1, 18% among NT and 50% among HT. Pre-exercise heart rate, SVi, COi, and peak exercise blood pressure (BP) and heart rate were comparable among the three groups, but peak exercise LV EF, SVi and COi were lower in DM1 than in HT and NT independent to covariates (p<0.05). In separate analyses, DM1 predicted lower peak exercise SVi (B=-6.2) and COi (B=-1.6, both p<0.05) independently. Within DM1, glycated haemoglobin (HbA1c) and disease duration did not predict peak exercise LV systolic function. CONCLUSIONS: Our study suggests that uncomplicated DM1 may be associated with subnormal LV contractility reserve, which might not be predicted by LV dysfunction evaluated at rest.