Publications by authors named "Silmara Gusso"

20 Publications

  • Page 1 of 1

Exercise Cardiac Magnetic Resonance Imaging in Boys With Duchenne Muscular Dystrophy Without Cardiac Disease.

Pediatr Neurol 2021 Apr 30;117:35-43. Epub 2020 Dec 30.

Paediatric Neurology Department, Starship Children's Hospital, Auckland, New Zealand. Electronic address:

Background: Duchenne muscular dystrophy is caused by mutations in the DMD gene, resulting in cardiomyopathy in all affected children by 18 years. Although cardiomyopathy is now the leading cause of mortality in these children, there is ongoing debate regarding timely diagnosis, secondary prevention, and treatment of this condition. The purpose of this study was to use exercise cardiac magnetic resonance imaging in asymptomatic young boys with Duchenne muscular dystrophy to describe their heart function and compare this with healthy controls.

Methods: We studied 11 boys with Duchenne muscular dystrophy aged 8.6 to 13.9 years and 11 healthy age- and sex-matched controls.

Results: Compared with the controls, boys with Duchenne muscular dystrophy had lower ejection fraction at rest (57% versus 63%; P = 0.004). During submaximal exercise, they reached similar peak tachycardia but increased their heart rate and cardiac output only half as much as controls (P = 0.003 and P = 0.014, respectively). End-systolic volume remained higher in boys with Duchenne muscular dystrophy both at rest and during exercise. When transthoracic echocardiography was compared with cardiac magnetic resonance imaging, 45% of the echocardiograms had suboptimal or poor views in the Duchenne muscular dystrophy group.

Conclusions: Boys with Duchenne muscular dystrophy had abnormalities in left ventricular systolic function that were exaggerated by exercise stress. Exercise cardiac magnetic resonance imaging is feasible in a select population of children with Duchenne muscular dystrophy, and it has the potential to unmask early signs of cardiomyopathy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.pediatrneurol.2020.12.011DOI Listing
April 2021

The Effect of the COVID-19 Pandemic Movement Restrictions on Self-Reported Physical Activity and Health in New Zealand: A Cross-Sectional Survey.

Int J Environ Res Public Health 2021 02 10;18(4). Epub 2021 Feb 10.

Department of Exercise Sciences, Faculty of Science, University of Auckland, Auckland 1023, New Zealand.

This study describes self-reported physical activity (PA), motivation to exercise, physical and mental health and feelings towards PA during the March-May 2020 COVID-19 lockdown in New Zealand. Adults over the age of 18 years (n = 238; 80.2% female) completed the International Physical Activity Questionnaire (IPAQ), the Behavioural Regulation in Exercise Questionnaire 3, the Short Form-36 and open-ended questions about PA through an anonymous online survey. Regular exercise was undertaken by 85% of respondents prior to lockdown, but only 49.8% were able to maintain their usual level of PA. Although respondents were considered sufficiently physically active from the IPAQ, 51.5% reported not being able to maintain their usual level of PA primarily due to the closure of their gym facilities. Sixty percent of respondents reported that PA had a positive effect on their overall wellbeing. When asked to specify which aspects of wellbeing were affected, the effect on mental health was reported the most while the effect on body image or fitness was reported the least. Strategies to increase or maintain engagement in physical activity during lockdowns should be encouraged to promote positive mental health during the COVID-19 pandemic.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijerph18041719DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7916664PMC
February 2021

The Effect of Vibration Therapy on Walking Endurance in Children and Young People With Cerebral Palsy: Do Age and Gross Motor Function Classification System Matter?

Arch Rehabil Res Clin Transl 2020 Sep 20;2(3):100068. Epub 2020 Jun 20.

Exercise Sciences Department, University of Auckland, Auckland, New Zealand.

Objective: To investigate the effect of age and Gross Motor Function Classification System (GMFCS) level on walking endurance after 20 weeks of vibration therapy in children and young people with cerebral palsy (CP).

Design: The study was a clinical trial without control group comparing baseline and postintervention outcomes within participants.

Setting: Vibration therapy was performed at school or at home. Assessments took place in a clinical research unit.

Participants: Children and young people (N=59) with CP, aged 5-20 years, GMFCS level II, III, or IV, recruited through schools, physiotherapy services, and District Health Board clinics, Auckland, New Zealand.

Interventions: Participants performed side-alternating whole-body vibration therapy (WBVT) at 20 Hz and 3-mm amplitude, 9 minutes per day, 4 times per week for 20 weeks.

Main Outcome Measures: Distance walked in the 6-minute walk test (6MWT) was recorded before and after the intervention.

Results: Participants baseline results for the 6MWT were lower, independent of age or GMFCS, when compared to non-CP literature. On average, participants walked 12% further in the 6MWT after the intervention (<.001). There was significant improvement in 6MWT distance in all age groups (5-10y: 16%, <.001; 11-15y: 10%, =.001; 16-20y: 13%, <.001) and all GMFCS levels (level II: 10%, <.001, level III: 40%, =.013, level IV: 57%, =.007). There was a greater percentage improvement in the distance walked in those with GMFCS level III and level IV than level II (=.049 and <.001, respectively).

Conclusions: WBVT had a beneficial effect on walking endurance in children and young people with CP, independent of age and GMFCS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.arrct.2020.100068DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7853375PMC
September 2020

The effect of side-alternating vibration therapy on mobility and health outcomes in young children with mild to moderate cerebral palsy: design and rationale for the randomized controlled study.

BMC Pediatr 2020 11 5;20(1):508. Epub 2020 Nov 5.

Department of Exercise Sciences, University of Auckland, Auckland, New Zealand.

Background: Cerebral palsy (CP) is the most common cause of physical disability in early childhood. Vibration therapy (VT) is a promising rehabilitation approach for children with CP with potential to impact mobility, bone and muscle health as demonstrated by extant research. However, it is still unclear how long therapy must be conducted for and what the optimal vibration frequency is in order to gain health benefits.

Methods/design: The study is a randomized clinical trial evaluating and comparing the effects of two vibration frequency (20 Hz vs 25 Hz) and duration protocols (12 weeks vs 20 weeks) of side-alternating VT on mobility and other health parameters in children with CP. Children aged 5-12 years old with CP and GMFCS level I-III who are able to understand instruction and safely stand are eligible for the study. Exclusion criteria include bone fracture within 12 weeks of enrolment; acute conditions; the history of significant organic disease; the history of taking anabolic agents, glucocorticoids, growth hormone, and botulinum toxin injection into lower limbs within 3 months of enrolment. All participants will act as their own control with a 12-week lead-in period prior to intervention. The intervention period will consist of 20 weeks of home- or school-based VT 9 min per day, 4 times a week. After the baseline assessment, participants will be randomized to either a 20 Hz or 25 Hz vibration-frequency group. The primary outcome is mobility measured by a 6-min walking test, with analysis performed on the principle of intention to treat. Secondary outcomes include body composition, muscle strength, physical activity level, balance, gross motor function, respiratory function, and quality of life. Participants will undergo four assessment visits over the study period: baseline, at weeks 12, 24, and 32.

Discussion: The results of the study will provide evidence-based insights into the health benefits of side-alternating VT as a therapeutic tool in young children with cerebral palsy. The investigation of different vibration training protocols will help define the optimal parameters of intervention protocols (duration, frequency) of side-alternating VT to maximize outcomes on the health of 5-12-year-old children with CP.

Trial Registration: Australian New Zealand Clinical Trials Registry (ANZCTR): 12618002026202 (Registration date 18/12/2018).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12887-020-02377-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7643348PMC
November 2020

Safety, feasibility and efficacy of side-alternating vibration therapy on bone and muscle health in children and adolescents with musculoskeletal disorders: A pilot trial.

J Paediatr Child Health 2020 Aug 21;56(8):1257-1262. Epub 2020 May 21.

Liggins Institute, University of Auckland, Auckland, New Zealand.

Aims: A pilot study was performed to establish the safety, feasibility and efficacy of vibration therapy (VT) on bone and muscle health in children and adolescents with a range of musculoskeletal disorders.

Methods: Seventeen participants (15.7 years ± 2.9 years), with conditions that impacted on their musculoskeletal health, completed 20 weeks of side-alternating VT for 9 min/session, 4 times/week at 20 Hz. Data were collected at baseline and after 20 weeks of intervention. Assessments included whole-body dual-energyX-ray absorptiometry, muscle function (force plate) and 6-min walk test.

Results: Compliance with the prescribed VT training protocol was relatively high overall at 78% and there were no adverse events reported. After 20 weeks intervention, functional assessments showed time taken to perform the chair test was reduced by 15% (P = 0.018), leg balance improved with standard ellipse area decreasing by 88% (P = 0.006) and distance walked in the 6-min walk test improved by 9% (P = 0.002). Participants displayed increased total body mass (1.94 kg; P = 0.018) with increased lean mass (1.20 kg; P = 0.019) but not fat mass (P = 0.19). There was no change in total body bone mineral density (P = 0.44) or bone mineral content (P = 0.07).

Conclusions: Twenty weeks of side-alternating VT was a feasible protocol that was associated with improvements in physical function and no detrimental effects on lean mass, bone mass or density in children and adolescents with musculoskeletal disorders.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jpc.14913DOI Listing
August 2020

The Effects of 20 Weeks of Side-Alternating Vibration Therapy on Physical Function, Bone and Muscle Health in Adolescents with Down Syndrome.

Phys Occup Ther Pediatr 2021 28;41(1):44-55. Epub 2020 Apr 28.

Liggins Institute, University of Auckland, Auckland, New Zealand.

Aims: To evaluate the effects of side-alternating vibration therapy on physical function and body composition in adolescents with Down syndrome.

Methods: Fourteen adolescents (8 males) with Down syndrome (mean ± SD age: 15.5 ± 2.3 years) performed vibration treatment nine minutes daily, four times per week, for 20 weeks on a Galileo vibration platform. Data were collected at baseline and after 20 weeks of intervention. Assessments included six-minute walk test, muscle function (force plate), whole-body dual-energy X-ray absorptiometry and peripheral quantitative computed tomography of the non-dominant tibia.

Results: After 20 weeks, participants increased their distance walked in the six-minute walk test ( = 0.009), 2-leg single jump efficiency ( = 0.024) and jump velocity ( = 0.046). Participants also increased their power ( = 0.034) and reduced the time taken during the chair rise test ( < 0.001). At the total body level, increases were seen in bone mineral density ( = 0.004), bone mineral content ( = 0.043), fat free mass ( = 0.013) and lean mass ( = 0.021).

Conclusion: Side-alternating vibration therapy was associated with increases in physical function and muscle mass with no effects on bone health in adolescents with Down syndrome.

Clinical Trial Registration Number: Australian New Zealand Clinical Trial Registry (ACTRN12615000092594) - registered on 4 February 2015.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/01942638.2020.1758983DOI Listing
April 2020

Exercise Training as Part of Musculoskeletal Management for Congenital Myopathy: Where Are We Now?

Pediatr Neurol 2020 03 29;104:13-18. Epub 2019 Nov 29.

Department of Exercise Sciences, University of Auckland, Auckland, New Zealand.

Congenital myopathy is a heterogeneous group of muscle disorders characterized by muscle weakness and hypotonia. This condition is associated with a range of skeletal, respiratory, and ophthalmologic complications and requires a multidisciplinary therapeutic approach aimed at maximizing the function and independence of patients. One promising direction for therapeutic intervention is physical exercise rehabilitation, given its demonstrated ability to promote muscle and bone health of patients with a variety of neuromuscular conditions. However, there are few data to assist health care professionals identify the optimal physical activity levels and exercise type, including the intensity, frequency, and duration. This lack of empirical evidence is particularly problematic given the fact that inappropriate exercise modes can potentially cause muscle damage in patients with congenital myopathy. In this article, we discuss the rationale behind the incorporation of two types of physical exercises, strength and aerobic training, into the clinical care of patients with congenital myopathy. Given the paucity of literature on the management of congenital myopathy, we review the results of published research on the treatment of both congenital myopathy and other neuromuscular diseases that could provide helpful insights into the physical rehabilitation of patients with congenital myopathy. We also discuss the potential benefits of vibration therapy, which has been studied in patients with other neuromuscular disorders over the last two decades. We conclude by proposing directions for future research on physical rehabilitation of patients with congenital myopathy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.pediatrneurol.2019.10.008DOI Listing
March 2020

Exercise capacity and cardiac function in adolescents born post-term.

Sci Rep 2018 08 28;8(1):12963. Epub 2018 Aug 28.

Liggins Institute, University of Auckland, Auckland, New Zealand.

There is some evidence that children born post-term (≥42 weeks of gestation) have metabolic abnormalities that may be associated with an increased risk of adverse health outcomes in adulthood. However, there are no data as to whether adolescents born post-term display alterations in aerobic capacity or cardiovascular function. We studied 48 adolescents (56% males) in Auckland (New Zealand) with a mean age of 14.3 years (SD = 1.7): 25 born post-term and 23 born at term (37-41 weeks of gestation). Assessments included metabolic markers in blood, whole body DXA scans, 24-hour ambulatory blood pressure monitoring, maximal exercise capacity, as well as cardiac MRI scan at rest and during submaximal exercise. Exercise capacity was lower in the post-term than in control participants (44.5 vs 47.8 ml/kgffm/min; p = 0.04). There were no differences in left ventricular volumes at rest and during exercise between groups. The 24-hour ambulatory blood pressure monitoring also showed no differences between the two groups. Being born post-term was associated with reduced exercise capacity, but with no observed differences in central cardiac function. We speculate that the reduction in exercise capacity may be due to changes in the peripheral vascular system.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-018-31343-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6113248PMC
August 2018

Imaging the heart to detect cardiomyopathy in Duchenne muscular dystrophy: A review.

Neuromuscul Disord 2018 09 6;28(9):717-730. Epub 2018 Jun 6.

Paediatric Endocrinology Department, Starship Children's Hospital, Auckland, New Zealand; Liggins Institute, University of Auckland, Auckland, New Zealand.

Duchenne Muscular Dystrophy is the most common paediatric neuromuscular disorder. Mutations in the DMD gene on the X-chromosome result in progressive skeletal muscle weakness as the main clinical manifestation. However, cardiac muscle is also affected, with cardiomyopathy becoming an increasingly recognised cause of morbidity, and now the leading cause of mortality in this group. The diagnosis of cardiomyopathy has often been made late due to technical limitations in transthoracic echocardiograms and delayed symptomatology in less mobile patients. Increasingly, evidence supports earlier pharmacological intervention in cardiomyopathy to improve outcomes. However, the optimal timing of initiation remains uncertain, and the benefits of prophylactic therapy are unproven. Current treatment guidelines suggest initiation of therapy once cardiac dysfunction is detected. This review focuses on new and evolving techniques for earlier detection of Duchenne muscular dystrophy-associated cardiomyopathy. Transthoracic echocardiography or cardiac magnetic resonance imaging performed under physiological stress (dobutamine or exercise), can unmask early cardiac dysfunction. Cardiac magnetic resonance imaging can define cardiac function with greater accuracy and reliability than an echocardiogram, and is not limited by body habitus. Improved imaging techniques, used in a timely fashion, offer the potential for early detection of cardiomyopathy and improved long-term outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.nmd.2018.05.011DOI Listing
September 2018

Nulliparity is associated with subtle adverse metabolic outcomes in overweight/obese mothers and their offspring.

Clin Endocrinol (Oxf) 2017 Nov 22;87(5):545-551. Epub 2017 Aug 22.

Liggins Institute, University of Auckland, Auckland, New Zealand.

Background: We aimed to evaluate metabolic outcomes in overweight/obese nulliparous and multiparous women and their offspring.

Study Design: Seventy-two overweight and obese women who participated in a randomized controlled trial of exercise in pregnancy were included in the study, comparing 18 nulliparous and 54 multiparous women and their singleton offspring. Women were assessed at 19 and 36 weeks of gestation. Fetal growth was measured using standard obstetric ultrasound techniques. Cord blood was collected at birth. Maternal and offspring body composition was assessed using DXA ~2 weeks after delivery.

Results: Nulliparous women had higher HbA1c in the third trimester of pregnancy than multiparous women (5.48% vs 5.29%; P=.002) and were more insulin-resistant based on the surrogate marker sex hormone-binding globulin (354 vs 408 nmol/L; P=.047). Nulliparous women also had higher levels of the inflammatory marker tumour necrosis factor-alpha (4.74 vs 3.62 pg/mL; P=.025). At birth, the offspring of nulliparous women were on average 340 g (P=.013) and 0.69 standard deviation scores (P=.026) lighter than those born of multiparous women. Cord blood data showed lower insulin-like growth factor-II (P=.026) and higher IGF binding protein-1 (P=.002) levels in the offspring of nulliparous women. In addition, a less favourable metabolic profile was observed in the offspring of nulliparous women, as indicated by higher triglyceride (P<.001) and interleukin-6 (P=.039) concentrations.

Conclusions: Infants born of nulliparous overweight and obese women appear to be exposed to a less favourable metabolic environment in utero, with evidence of subtle adverse metabolic outcomes at birth compared to infants of overweight/obese multiparous women.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/cen.13426DOI Listing
November 2017

Exercise Training Improves but Does Not Normalize Left Ventricular Systolic and Diastolic Function in Adolescents With Type 1 Diabetes.

Diabetes Care 2017 09 18;40(9):1264-1272. Epub 2017 Jul 18.

Liggins Institute, University of Auckland, Auckland, New Zealand.

Objective: To determine the impact of 20 weeks of exercise training in aerobic capacity on left ventricular function and glycemic control in adolescents with and without type 1 diabetes.

Research Design And Methods: Fifty-three adolescents with type 1 diabetes (aged 15.6 years) were divided into two groups: exercise training ( = 38) and nontraining ( = 15). Twenty-two healthy adolescents without diabetes (aged 16.7 years) were included and, with the 38 participants with type 1 diabetes, participated in a 20-week exercise-training intervention. Assessments included VO and body composition. Left ventricular parameters were obtained at rest and during acute exercise using MRI.

Results: Exercise training improved aerobic capacity (10%) and stroke volume (6%) in both trained groups, but the increase in the group with type 1 diabetes remained lower than trained control subjects. Increased stroke volume in adolescents with type 1 diabetes resulted from greater left ventricular contractility (9% increase in ejection fraction and an 11% reduction in end-systolic volumes) and, to a lesser extent, improved left ventricular filling (6%), suggesting that impaired diastolic function can be affected by exercise training in adolescents with type 1 diabetes. Insulin use decreased by ∼10%, but no change in glycemic status was observed.

Conclusions: These data demonstrate that in adolescents, the impairment in left ventricular function seen with type 1 diabetes can be improved, although not normalized, with regular intense physical activity. Importantly, diastolic dysfunction, a common mechanism causing heart failure in older subjects with diabetes, appears to be partially reversible in this age group.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2337/dc16-2347DOI Listing
September 2017

The sex of the foetus affects maternal blood glucose concentrations in overweight and obese pregnant women.

J Obstet Gynaecol 2017 Jul 26;37(5):667-669. Epub 2016 Dec 26.

a Liggins Institute , University of Auckland , Auckland , New Zealand.

There is increasing evidence that the sex of the foetus may alter the maternal metabolic milieu during pregnancy. Following a randomized controlled trial of exercise in overweight and obese pregnant women, we assessed whether the sex of the foetus was associated with changes in maternal metabolism. Data were analysed on 74 randomized participants who completed the trial, including 38 mothers carrying males and 36 mothers carrying females. At 19 weeks of gestation, mothers carrying boys had higher blood glucose concentrations than those carrying girls (5.4 vs 4.9 mmol/l; p = .046). At 36 weeks of gestation, differences were more marked, with blood glucose concentrations 15% higher in mothers carrying females (5.7 vs 5.0 mmol/l; p = .004). In addition, mothers carrying girls had higher concentrations of hs-CRP across pregnancy (5.0 vs 3.6 mg/l; p = .029). Our findings provide further evidence that the sex of the foetus appears to influence maternal metabolism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/01443615.2016.1256970DOI Listing
July 2017

Effects of whole-body vibration training on physical function, bone and muscle mass in adolescents and young adults with cerebral palsy.

Sci Rep 2016 Mar 3;6:22518. Epub 2016 Mar 3.

Liggins Institute, University of Auckland, Auckland, New Zealand.

We performed a clinical trial on the effects of whole-body vibration training (WBVT) on muscle function and bone health of adolescents and young adults with cerebral palsy. Forty participants (11.3-20.8 years) with mild to moderate cerebral palsy (GMFCS II-III) underwent 20-week WBVT on a vibration plate for 9 minutes/day 4 times/week at 20 Hz (without controls). Assessments included 6-minute walk test, whole-body DXA, lower leg pQCT scans, and muscle function (force plate). Twenty weeks of WBVT were associated with increased lean mass in the total body (+770 g; p = 0.0003), trunk (+410 g; p = 0.004), and lower limbs (+240 g; p = 0.012). Bone mineral content increased in total body (+48 g; p = 0.0001), lumbar spine (+2.7 g; p = 0.0003), and lower limbs (+13 g; p < 0.0001). Similarly, bone mineral density increased in total body (+0.008 g/cm(2); p = 0.013), lumbar spine (+0.014 g/cm(2); p = 0.003), and lower limbs (+0.023 g/cm(2); p < 0.0001). Participants reduced the time taken to perform the chair test, and improved the distance walked in the 6-minute walk test by 11% and 35% for those with GMFCS II and III, respectively. WBVT was associated with increases in muscle mass and bone mass and density, and improved mobility of adolescents and young adults with cerebral palsy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep22518DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4776132PMC
March 2016

Preliminary data on dermis and subcutis thickness in adults with type 1 and 2 diabetes mellitus.

Australas J Dermatol 2015 Nov 1;56(4):e93-5. Epub 2014 Sep 1.

Liggins Institute, University of Auckland, Auckland, New Zealand.

We compared the thickness of both dermis and subcutis (measured using ultrasound) in overweight and obese adults with type 1 (n = 10) or type 2 (n = 8) diabetes mellitus. When adjusted for confounding factors, patients with type 1 diabetes had thicker subcutis than those with type 2 diabetes, with this difference being particularly marked in the abdomen. There were no observed differences in dermal thickness between the groups.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/ajd.12177DOI Listing
November 2015

Antenatal exercise in overweight and obese women and its effects on offspring and maternal health: design and rationale of the IMPROVE (Improving Maternal and Progeny Obesity Via Exercise) randomised controlled trial.

BMC Pregnancy Childbirth 2014 Apr 26;14:148. Epub 2014 Apr 26.

Liggins Institute, University of Auckland, Auckland, New Zealand.

Background: Obesity during pregnancy is associated with adverse outcomes for the offspring and mother. Lifestyle interventions in pregnancy such as antenatal exercise, are proposed to improve both short- and long-term health of mother and child. We hypothesise that regular moderate-intensity exercise during the second half of pregnancy will result in improved maternal and offspring outcomes, including a reduction in birth weight and adiposity in the offspring, which may be protective against obesity in later life.

Methods/design: The IMPROVE (Improving Maternal and Progeny Risks of Obesity Via Exercise) study is a two-arm parallel randomised controlled clinical trial being conducted in Auckland, New Zealand. Overweight and obese women (BMI ≥25 kg/m2) aged 18-40 years, with a singleton pregnancy of <20 weeks of gestation, from the Auckland region, are eligible for the trial. Exclusion criteria are ongoing smoking or medical contra-indications to antenatal exercise.Participants are randomised with 1:1 allocation ratio to either intervention or control group, using computer-generated randomisation sequences in variable block sizes, stratified on ethnicity and parity, after completion of baseline assessments. The intervention consists of a 16-week structured home-based moderate-intensity exercise programme utilising stationary cycles and heart rate monitors, commencing at 20 weeks of gestation. The control group do not receive any exercise intervention. Both groups undergo regular fetal ultrasonography and receive standard antenatal care. Due to the nature of the intervention, participants are un-blinded to group assignment during the trial.The primary outcome is offspring birth weight. Secondary offspring outcomes include fetal and neonatal body composition and anthropometry, neonatal complications and cord blood metabolic markers. Maternal outcomes include weight gain, pregnancy and delivery complications, aerobic fitness, quality of life, metabolic markers and post-partum body composition.

Discussion: The results of this trial will provide valuable insights on the effects of antenatal exercise on health outcomes in overweight and obese mothers and their offspring.

Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12612000932864.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1471-2393-14-148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4002538PMC
April 2014

Systolic and diastolic abnormalities reduce the cardiac response to exercise in adolescents with type 2 diabetes.

Diabetes Care 2014 May 26;37(5):1439-46. Epub 2014 Feb 26.

Corresponding author: Paul L. Hofman,

Objective: To better understand the cardiac limitations during exercise in adolescents with type 2 diabetes mellitus (T2DM), we measured left ventricular performance with magnetic resonance imaging (MRI) during exercise in diabetic and nondiabetic adolescents.

Research Design And Methods: Thirteen subjects with T2DM, 27 overweight/obese nondiabetic (ObeseND) subjects, and 19 nondiabetic nonobese control subjects were recruited. Cardiac (left ventricular) MRI scans were performed at rest and during submaximal exercise.

Results: Vo2 peak indexed to fat-free mass was reduced in T2DM and ObeseND subjects compared with control subjects (P < 0.0001). Indexed cardiac output increased less during exercise and was 20% lower in T2DM subjects due to reduced stroke volume. This was a consequence of reduced ventricular filling with smaller end-diastolic volume, which decreased further during exercise in T2DM subjects, but not in ObeseND or control subjects. End-systolic volume was also smaller in T2DM subjects. These changes were associated with increased resting and exercise diastolic blood pressure, and total peripheral resistance in T2DM subjects.

Conclusions: Independently of obesity, T2DM impairs cardiac function during exercise in adolescents.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2337/dc13-2031DOI Listing
May 2014

Diastolic function is reduced in adolescents with type 1 diabetes in response to exercise.

Diabetes Care 2012 Oct 6;35(10):2089-94. Epub 2012 Jul 6.

Liggins Institute, University of Auckland, Auckland, New Zealand.

Objective: To determine whether adolescents with type 1 diabetes have left ventricular functional changes at rest and during acute exercise and whether these changes are affected by metabolic control and diabetes duration.

Research Design And Methods: The study evaluated 53 adolescents with type 1 diabetes and 22 control adolescents. Baseline data included peak exercise capacity and body composition by dual-energy X-ray absorptiometry. Left ventricular functional parameters were obtained at rest and during acute exercise using magnetic resonance imaging.

Results: Compared with nondiabetic control subjects, adolescents with type 1 diabetes had lower exercise capacity (44.7 ± 09 vs. 48.5 ± 1.4 mL/kg fat-free mass [FFM]/min; P < 0.05). Stroke volume was reduced in the diabetes group at rest (1.86 ± 0.04 vs. 2.05 ± 0.07 mL/kg FFM; P = 0.02) and during acute exercise (1.89 ± 0.04 vs. 2.17 ± 0.06 mL/kg FFM; P = 0.01). Diabetic adolescents also had reduced end-diastolic volume at rest (2.94 ± 0.06 vs. 3.26 ± 0.09 mL/kg FFM; P = 0.01) and during acute exercise (2.78 ± 0.05 vs. 3.09 ± 0.08 mL/kg FFM; P = 0.01). End-systolic volume was lower in the diabetic group at rest (1.08 ± 0.03 vs. 1.21 ± 0.04 mL/kg FFM; P = 0.01) but not during acute exercise. Exercise capacity and resting and exercise stroke volumes were correlated with glycemic control but not with diabetes duration.

Conclusions: Adolescents with type 1 diabetes have reduced exercise capacity and display alterations in cardiac function compared with nondiabetic control subjects, associated with reduced stroke volume during exercise.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2337/dc11-2331DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3447841PMC
October 2012

Design and testing of an MRI-compatible cycle ergometer for non-invasive cardiac assessments during exercise.

Biomed Eng Online 2012 Mar 18;11:13. Epub 2012 Mar 18.

Liggins Institute, University of Auckland, Auckland, New Zealand.

Background: Magnetic resonance imaging (MRI) is an important tool for cardiac research, and it is frequently used for resting cardiac assessments. However, research into non-pharmacological stress cardiac evaluation is limited.

Methods: We aimed to design a portable and relatively inexpensive MRI cycle ergometer capable of continuously measuring pedalling workload while patients exercise to maintain target heart rates.

Results: We constructed and tested an MRI-compatible cycle ergometer for a 1.5 T MRI scanner. Resting and sub-maximal exercise images (at 110 beats per minute) were successfully obtained in 8 healthy adults.

Conclusions: The MRI-compatible cycle ergometer constructed by our research group enabled cardiac assessments at fixed heart rates, while continuously recording power output by directly measuring pedal force and crank rotation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1475-925X-11-13DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3334686PMC
March 2012

Structural and functional cardiac abnormalities in adolescent girls with poorly controlled type 2 diabetes.

Diabetes Care 2009 May 5;32(5):883-8. Epub 2009 Feb 5.

Department of Medicine, Faculty of Medicine and Health Sciences, The University of Auckland, Auckland, New Zealand.

Objective: Type 2 diabetes is associated with left ventricular hypertrophy (LVH) and diastolic dysfunction, which may eventually lead to clinical heart failure. We sought to determine the cardiovascular effects of adolescent-onset type 2 diabetes.

Research Design And Methods: We recruited diabetic girls (8 with type 2 and 11 with type 1 diabetes) from a hospital diabetes service and nondiabetic control subjects (9 lean and 11 overweight) from the schools of the diabetic subjects. Echocardiography and measurements were performed by a single observer, blinded to subject group allocation, and included M-mode left ventricular dimensions, two-dimensional left ventricular mass, Doppler diastolic flows, estimation of left ventricular filling pressure, and systolic longitudinal motion. Left ventricular mass was indexed to height and fat-free body mass. ANOVA was used to compare the groups.

Results: The groups were similar in age and height, but significant differences in body composition were observed. Subjects with type 2 diabetes had larger left ventricular dimensions and left ventricular mass, which persisted when indexed to height. Diastolic filling was impaired in both diabetic groups, and systolic longitudinal function was lower in the type 2 diabetic group. Half of the group with type 2 diabetes met the published criteria for LVH and left ventricular dilatation; 25% had evidence of elevated left ventricular filling pressure in association with structural abnormalities.

Conclusions: This study has demonstrated preclinical abnormalities of cardiac structure and function in adolescent girls with type 2 diabetes, despite the short duration of diabetes and highlights the potential high cardiovascular risk occurring in adolescent type 2 diabetes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2337/dc08-2005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2671111PMC
May 2009

Reduced leg blood flow during submaximal exercise in type 2 diabetes.

Med Sci Sports Exerc 2008 Apr;40(4):612-7

Department of Sport and Exercise Science, University of Auckland, Auckland, New Zealand.

Unlabelled: It is unclear whether impaired cardiac and/or vascular function contribute to exercise intolerance in patients with type 2 diabetes.

Purpose: Magnetic resonance imaging (MRI) was used to determine whether reductions in cardiac output and/or femoral arterial blood flow contribute to reduced aerobic capacity in patients with type 2 diabetes.

Methods: Cardiac and femoral arterial blood flow MRI scans were performed at rest and during low-intensity leg exercise in eight patients with type 2 diabetes and 11 healthy individuals. Maximal aerobic capacity VO(2 max) and maximal oxygen pulse were also determined in all participants.

Results: V O(2 max) was 20% lower and maximal oxygen pulse was 16% lower in patients with type 2 diabetes (P < 0.05), whereas maximal heart rate was the same between groups. Low-intensity exercise induced a 20% increase in heart rate and cardiac output as well as a 60-70% increase in femoral blood flow in both groups (P < 0.05). Femoral arterial blood flow indexed to thigh lean mass was reduced during exercise in patients with type 2 diabetes compared with healthy individuals. Stroke volume indexed to fat-free mass was lower in patients with type 2 diabetes, but greater heart rate allowed cardiac output to be maintained during submaximal exercise.

Conclusions: These findings suggest that impaired femoral arterial blood flow, an indirect marker of muscle perfusion, affects low-intensity exercise performance in patients with type 2 diabetes. However, because of lower exercising stroke volume, we propose that femoral arterial blood flow and, possibly, cardiac output, limit V O(2 max) in patients with type 2 diabetes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1249/MSS.0b013e318161aa99DOI Listing
April 2008