Canadian Cardiovascular Society Position Statement on Familial Hypercholesterolemia: Update 2018

Familial hypercholesterolemia (FH) is the most common monogenic disorder causing premature atherosclerotic cardiovascular disease. It affects 1 in 250 individuals worldwide, and of the approximately 145,000 Canadians estimated to have FH, most are undiagnosed. Herein, we provide an update of the 2014 Canadian Cardiovascular Society position statement on FH addressing the need for case identification, prompt recognition, and treatment with statins and ezetimibe, and cascade family screening. We provide a new Canadian definition for FH and tools for clinicians to make a diagnosis. The risk of atherosclerotic cardiovascular disease in patients with "definite" FH is 10- to 20-fold that of a normolipidemic individual and initiating treatment in youth or young adulthood can normalize life expectancy. Target levels for low-density lipoprotein cholesterol are proposed and are aligned with the Canadian Cardiovascular Society guidelines on dyslipidemia. Recommendation for the use of inhibitors of proprotein convertase kexin/subtilisin type 9 are made in patients who cannot achieve therapeutic low-density lipoprotein cholesterol targets on maximally tolerated statins and ezetimibe. The writing committee used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology in the preparation of the present document, which offers guidance for practical evaluation and management of patients with FH. This position statement also aims to raise awareness of FH nationally, and to mobilize patient support, promote knowledge translation, and availability of treatment and health care resources for this under-recognized, but important medical condition.

Relating network connectivity to dynamics: opportunities and challenges for theoretical neuroscience

We review recent work relating network connectivity to the dynamics of neural activity. While concepts stemming from network science provide a valuable starting point, the interpretation of graph-theoretic structures and measures can be highly dependent on the dynamics associated to the network. Properties that are quite meaningful for linear dynamics, such as random walk and network flow models, may be of limited relevance in the neuroscience setting. Theoretical and computational neuroscience are playing a vital role in understanding the relationship between network connectivity and the nonlinear dynamics associated to neural networks.

Childhood Motor Coordination and Adult Affective Experience Among Extremely Low Birth Weight Survivors

Poor motor coordination in childhood has been associated in adulthood with more negative affect, less positive affect, and an increased risk of psychopathology. While survivors of extremely low birth weight (ELBW; < 1,000 grams) are more likely to manifest poor motor coordination than people born at normal birth weight (NBW; > 2,500 g), they have had better mental health outcomes than those with NBW who have motor difficulties. How emotion is experienced is an important risk factor for mental illness; yet, little is known about the affective experience of survivors of ELBW who also have poor motor coordination. In this longitudinal study, we examined interactions between birth weight status and childhood motor coordination on affective experience among 88 ELBW and 89 NBW participants. We first assessed childhood motor coordination at eight years of age, using the Bruininks-Oseretsky Test of Motor Proficiency, and we later gathered self-report data regarding affective style, using the Positive and Negative Affect Scedule and the Affective Styles Questionnaire, when these participants were 30-35 years of age. We found a statistically significant interaction between motor coordination and birth weight status. As motor coordination worsened among ELBW survivors, positive affect increased, while we observed the opposite trend in NBW participants (p < 0.05). There was no interaction for negative affect. Positive affect may contribute to previous findings of better relative adult mental health among ELBW survivors with poor childhood motor coordination. Strategies aimed at optimizing positive affect may be fruitful for optimizing mental health outcomes among preterm survivors and others with reduced motor proficiency.

Employers' Perspectives on Accommodating and Retaining Employees with Newly Acquired Disabilities: An Exploratory Study

Introduction Timely and appropriate accommodations can help employees who experience disabilities stay at work instead of exiting the labor force. Employers can play a critical role in connecting such workers with the accommodations they need. This qualitative study seeks to inform policy makers who want to improve workforce retention outcomes by uncovering factors that affect whether employers provide accommodations to, and ultimately retain, employees with disabilities. Methods We conducted semistructured interviews with a convenience sample of human resources professionals in 14 Arkansas-based employers, yielding detailed information on 50 cases in which an employee developed or disclosed a disability. We analyzed the interviews using a grounded theory approach and compared cases to identify key themes emerging across subgroups of cases. Results Two organization-level factors and four employee-level factors influenced employers' efforts to accommodate and retain employees with disabilities: employer resources; employers' communication with the employee and other stakeholders; employee tenure; employee work performance; active/sedentary nature of employee role; and the severity and type of employees' health conditions. Conclusions Consistent with prior literature, employers with greater access to resources and better ability to communicate generally made greater effort to accommodate and retain employees with disabilities. However, employers in the study did not deploy these resources and processes consistently when making decisions about whether and how to provide accommodations to workers with disabilities; employee-level characteristics affected their actions. Policy makers should consider intervention approaches that reach workers who may be overlooked by employers with scarce resources.

Fixed Points of Competitive Threshold-Linear Networks

Threshold-linear networks (TLNs) are models of neural networks that consist of simple, perceptron-like neurons and exhibit nonlinear dynamics determined by the network's connectivity. The fixed points of a TLN, including both stable and unstable equilibria, play a critical role in shaping its emergent dynamics. In this work, we provide two novel characterizations for the set of fixed points of a competitive TLN: the first is in terms of a simple sign condition, while the second relies on the concept of domination. We apply these results to a special family of TLNs, called combinatorial threshold-linear networks (CTLNs), whose connectivity matrices are defined from directed graphs. This leads us to prove a series of graph rules that enable one to determine fixed points of a CTLN by analyzing the underlying graph. In addition, we study larger networks composed of smaller building block subnetworks and prove several theorems relating the fixed points of the full network to those of its components. Our results provide the foundation for a kind of graphical calculus to infer features of the dynamics from a network's connectivity.

Understanding paediatric patients' attitudes toward obesity and expectations prior to entering a weight management program

Objective

This qualitative study explored attitudes toward weight management and knowledge of healthy, active living among paediatric patients referred to a weight management program. The objective of this study was to determine the emotional state and attitudes of patients entering into a paediatric weight management program.

Methods

Study participants (aged 7 to 17 years old) were recruited during clinic orientation. Semistructured interviews were conducted, audiotaped and transcribed verbatim. Qualitative content analysis generated a thematic coding scheme, identifying concepts and linkages in the data. Study rigour was achieved collaboratively through an audit trail, and data triangulation.

Results

Fifteen patients (median age 11 years) consented to interviews. Three recurring themes emerged: emotions, motivation and learning. A total of nine subthemes were identified. Four key spheres of influence (family, peers, school and health care providers) affected the patient's outlook on obesity positively by providing support or negatively by adversely influencing their emotions and motivation. The level of individual motivation to engage in the weight management program varied. A positive outlook toward learning about obesity from school officials and health care providers emerged.

Conclusions

This study provided insight regarding paediatric attitudes related to entering a weight management program. The negative emotional state and sometimes fear of the program expressed should be considered by the referring physician and by clinicians in weight management programs engaging in their care.

Causes and consequences of gestational diabetes in South Asians living in Canada: results from a prospective cohort study

BACKGROUND

The reasons for the increased risk of gestational diabetes among South Asian women are not well understood. We sought to identify the determinants of gestational diabetes and its impact on newborn health in a prospective birth cohort of South Asian women and their babies.

METHODS

As part of the South Asian Birth Cohort (START) prospective birth cohort study in Ontario, we recruited 1012 South Asian women with singleton pregnancies in the second trimester of pregnancy between July 11, 2011, and Nov. 10, 2015. We collected health information and physical measurements and administered an oral glucose tolerance test. Birth weight and skinfold thickness measurements were obtained from their newborns, and cord blood glucose and insulin levels were measured.

RESULTS

The incidence of gestational diabetes was 36.3% (95% confidence interval [CI] 33.3%-39.3%); the age-standardized rate was 40.7%. Factors associated with gestational diabetes included maternal age (odds ratio [OR] 1.08 [95% CI 1.04-1.12]), family history of diabetes (OR 1.65 [95% CI 1.26-2.17]), prepregnancy weight (OR 1.025 [95% CI 1.01-1.04]) and low diet quality (OR 1.57 [95% CI 1.16-2.12]). Maternal height was protective against gestational diabetes (OR 0.97 [95% CI 0.95-0.99]). The population attributable risk due to prepregnancy body mass index and low diet quality was 37.3%. Compared to newborns of women without gestational diabetes, those of women with gestational diabetes had a significantly higher birth weight (3267 [standard error (SE) 23] g v. 3181 [SE 17] g, p = 0.005), greater skinfold thickness (11.7 [SE 0.1] mm v. 11.2 [SE 0.1] mm, p = 0.007) and lower insulin sensitivity (glucose/insulin ratio 0.092 [SE 0.009] mmol/pmol v. 0.129 [SE 0.006] mmol/pmol, p = 0.001).

INTERPRETATION

The modifiable risk factors of prepregnancy weight and low diet quality accounted for 37% of the population attributable risk of gestational diabetes in our cohort. Intervention studies to lower prepregnancy weight and to prevent gestational diabetes among South Asian women in high-income countries are needed.

Pattern Completion in Symmetric Threshold-Linear Networks

Threshold-linear networks are a common class of firing rate models that describe recurrent interactions among neurons. Unlike their linear counterparts, these networks generically possess multiple stable fixed points (steady states), making them viable candidates for memory encoding and retrieval. In this work, we characterize stable fixed points of general threshold-linear networks with constant external drive and discover constraints on the coexistence of fixed points involving different subsets of active neurons. In the case of symmetric networks, we prove the following antichain property: if a set of neurons [Formula: see text] is the support of a stable fixed point, then no proper subset or superset of [Formula: see text] can support a stable fixed point. Symmetric threshold-linear networks thus appear to be well suited for pattern completion, since the dynamics are guaranteed not to get stuck in a subset or superset of a stored pattern. We also show that for any graph G, we can construct a network whose stable fixed points correspond precisely to the maximal cliques of G. As an application, we design network decoders for place field codes and demonstrate their efficacy for error correction and pattern completion. The proofs of our main results build on the theory of permitted sets in threshold-linear networks, including recently developed connections to classical distance geometry.

Why don't families initiate treatment? A qualitative multicentre study investigating parents' reasons for declining paediatric weight management

BACKGROUND

Many families referred to specialized health services for managing paediatric obesity do not initiate treatment; however, reasons for noninitiation are poorly understood.

OBJECTIVE

To understand parents' reasons for declining tertiary-level health services for paediatric weight management.

METHOD

Interviews were conducted with 18 parents of children (10 to 17 years of age; body mass index ≥85th percentile) who were referred for weight management, but did not initiate treatment at one of three Canadian multidisciplinary weight management clinics. A semi-structured interview guide was used to elicit parents' responses about reasons for noninitiation. Interviews were audio-recorded and transcribed verbatim. Data were managed using NVivo 9 (QSR International, Australia) and analyzed thematically.

RESULTS

Most parents (mean age 44.1 years; range 34 to 55 years) were female (n=16 [89%]), obese (n=12 [66%]) and had a university degree (n=13 [71%]). Parents' reasons for not initiating health services were grouped into five themes: no perceived need for paediatric weight management (eg, perceived children did not have a weight or health problem); no perceived need for further actions (eg, perceived children already had a healthy lifestyle); no intention to initiate recommended care (eg, perceived clinical program was not efficacious); participation barriers (eg, children's lack of motivation); and situational factors (eg, weather).

CONCLUSION

Physicians should not only discuss the need for and value of specialized care for managing paediatric obesity, but also explore parents' intention to initiate treatment and address reasons for noninitiation that are within their control.

Mental health of extremely low birth weight survivors in their 30s

OBJECTIVE

To determine the risk for psychiatric disorders among extremely low birth weight (ELBW) survivors in their early to mid-30s and to determine whether those born small for gestational age or those exposed to a full course of antenatal corticosteroids (ACS) were at particularly high risk.

METHODS

A prospective, longitudinal, population-based cohort of 84 ELBW survivors and 90 normal birth weight (NBW) control participants born in Ontario, Canada from 1977 to 1982 were assessed by interviewers naive to birth weight status using the Mini-International Neuropsychiatric Interview.

RESULTS

ELBW survivors had lower odds of an alcohol or substance use disorder but higher odds of current non-substance-related psychiatric problems (odds ratio [OR] = 2.47; 95% confidence interval [CI], 1.19-5.14). Those born ELBW and SGA exhibited the same patterns with larger effects. ACS-exposed ELBW survivors had even higher odds of any current non-substance-related psychiatric disorder (OR = 4.41; 95% CI, 1.65-11.82), particularly generalized anxiety disorder (OR = 3.42; 95% CI, 1.06-11.06), the generalized type of social phobia (OR = 5.80; 95% CI, 1.20-27.99), and the inattentive subtype of attention-deficit/hyperactivity disorder (OR = 11.45; 95% CI, 2.06-63.50).

CONCLUSIONS

In their early to mid-30s, ELBW survivors were less likely to have alcohol or substance use disorders but may be at greater risk for other psychiatric problems. Those exposed to ACS were at especially high risk and manifested no reduction in alcohol or substance use disorders. ELBW survivors exposed to ACS may be a special group at risk for psychopathology in adulthood.

Treatment of overweight and obesity in children and youth: a systematic review and meta-analysis

BACKGROUND

Childhood obesity is a public health concern. One-third of North American children and youth are overweight or obese. We reviewed the evidence of behavioural and pharmacological weight-management interventions on body mass index (BMI), BMI z-score and the prevalence of overweight and obesity in children and youth.

METHODS

We updated the search of a previous review. We searched 4 databases up to August 2013. We included randomized trials of primary care-relevant behavioural (diet, exercise, lifestyle) and pharmacological (orlistat) interventions for treating overweight and obesity in children and youth aged 2-18 years if 6-month post-baseline data were provided for BMI, BMI z-score or prevalence of overweight and obesity. In addition, we examined secondary health outcomes such as lipid and glucose levels, blood pressure, quality of life and physical fitness. We included any study reporting harms. We performed meta-analyses when possible, and we examined the features of interventions that showed benefits.

RESULTS

Thirty-one studies (29 behavioural, 2 pharmacological and behavioural) were included. Both intervention types showed a significant effect on BMI or BMI z-score in favour of treatment (behavioural: standardized mean difference [SMD] -0.54, 95% confidence interval [CI] -0.73 to -0.36; orlistat plus behavioural: SMD -0.43, 95% CI -0.60 to -0.25). Studies reported no significant difference between groups in the likelihood of reduced prevalence of overweight or overweight and obesity. Pooled estimates for blood pressure and quality of life showed significant benefits in favour of treatment (systolic blood pressure mean difference [MD] -3.42, 95% CI -6.65 to -0.29; diastolic blood pressure MD -3.39, 95% CI -5.17 to -1.60; quality of life MD 2.10, 95% CI 0.60 to 3.60). Gastrointestinal difficulties were more common in youth taking orlistat than in the control group (risk ratio 3.77, 95% CI 2.56 to 5.55). We saw much variability across efficacious interventions.

INTERPRETATION

Low- to moderate-quality evidence suggests behavioural treatments are associated with a medium effect in terms of reduced BMI or BMI z-score compared with a small effect shown by combined pharmacological-behavioural interventions. Future research should evaluate active weight maintenance interventions in adolescents with longer follow-up and examine the effectiveness of combined pharmacological and behavioural interventions.

REGISTRATION

PROSPERO no. CRD42012002754.

Prevention of overweight and obesity in children and youth: a systematic review and meta-analysis

BACKGROUND

One-third of Canadian children are overweight or obese. This problem carries considerable concern for negative impacts on current and future health. Promoting healthy growth and development is critical. This review synthesized evidence on the effectiveness of behavioural interventions for preventing overweight and obesity in children and adolescents.

METHODS

We updated the search of a previous Cochrane review. Five databases were searched up to August 2013. Randomized trials of primary care-relevant behavioural (diet, exercise and lifestyle) interventions for preventing overweight and obesity in healthy normal- or mixed-weight children or youth aged 0-18 years were included if 12-week postbaseline data were provided for body mass index (BMI), BMI z-score, or prevalence of overweight or obesity. Any study reporting harms was included. Meta-analyses were performed if possible. Features of interventions showing significant benefits were examined.

RESULTS

Ninety studies were included, all with mixed-weight populations. Compared with controls, interventions showed a small but significant effect on BMI and BMI z-score (standardized mean difference -0.07, 95% confidence interval [CI] -0.10 to -0.03, I (2) = 74%), a reduction in BMI (mean difference -0.09 kg/m(2), 95% CI -0.16 to -0.03, I (2) = 76%) and a reduced prevalence of overweight and obesity (risk ratio [RR]; RRintervention - RRcontrol 0.94, 95% CI 0.89 to 0.99, I (2) = 0%; number needed to treat 51, 95% CI 29 to 289). Little evidence was available on harms. There was variability across efficacious interventions, although many of the interventions were short-term, involved school-aged children and were delivered in educational settings.

INTERPRETATION

Behavioural prevention interventions are associated with small improvements in weight outcomes in mixed-weight populations of children and adolescents. No intervention strategy consistently produced benefits.

REGISTRATION

PROSPERO no. CRD42012002754.

Combinatorial neural codes from a mathematical coding theory perspective

Shannon's seminal 1948 work gave rise to two distinct areas of research: information theory and mathematical coding theory. While information theory has had a strong influence on theoretical neuroscience, ideas from mathematical coding theory have received considerably less attention. Here we take a new look at combinatorial neural codes from a mathematical coding theory perspective, examining the error correction capabilities of familiar receptive field codes (RF codes). We find, perhaps surprisingly, that the high levels of redundancy present in these codes do not support accurate error correction, although the error-correcting performance of receptive field codes catches up to that of random comparison codes when a small tolerance to error is introduced. However, receptive field codes are good at reflecting distances between represented stimuli, while the random comparison codes are not. We suggest that a compromise in error-correcting capability may be a necessary price to pay for a neural code whose structure serves not only error correction, but must also reflect relationships between stimuli.

Maternal and newborn health profile in a first nations community in Canada

OBJECTIVES

We sought to characterize maternal health profiles and birth outcomes among First Nations people living in Southern Ontario.

METHODS

We performed a retrospective chart review of all 453 women from the Six Nations Reserve, Ontario, who were pregnant between 2005 and 2010. Maternal health behaviours, past medical history, physical measurements, birth outcomes, and newborn characteristics were abstracted. Key maternal and newborn characteristics were compared with those of a cohort of non-First Nations women recruited from nearby Hamilton, Ontario.

RESULTS

The average age of women in the study cohort was 25.1 ± 6.2 (mean ± SD) years, and 75.8% were multiparous. The mean pre-pregnancy BMI was 28.3 ± 6.6 kg/m(2), and the average weight gain in pregnancy was 14.9 ± 8.3 kg. Mean weight gain during pregnancy was inversely associated with pre-pregnancy BMI, and 57.1% of women gained more than the recommended weight. The prevalence of type 2 diabetes or gestational diabetes was 4.7%, hypertension was present before or during pregnancy in 5.6%, and 35% used tobacco during pregnancy. The mean gestational age at delivery was 39.5 ± 1.7 weeks and the mean crude birth weight was 3619 ± 557 g. The main determinants of newborn weight included sex of the newborn, pre-pregnancy BMI, and weight gain during pregnancy. Compared with a contemporary cohort of 622 non-First Nations mothers and newborns, First Nations mothers were, on average, younger (25.1 vs. 32.1 years; P < 0.001), had a higher mean pre-pregnancy BMI (28.3 vs. 26.8 kg/m(2); P < 0.001), and were more likely to use tobacco during pregnancy (35.0% vs. 14.4%; P < 0.001). First Nations newborns had significantly higher mean birth weight (+176 grams) and length (+2.3 cm) than non-First Nations newborns.

CONCLUSION

First Nations mothers from the Six Nations Reserve tended to have a high pre-pregnancy BMI, tended to gain more than the recommended weight during pregnancy, and commonly used tobacco during pregnancy. Programs to prevent overweight/obesity and excess weight gain during pregnancy and to minimize smoking are required among women of child-bearing age in this community.

Are children and adolescents with psychiatric illness at risk for increased future body weight? A systematic review

The aim of this paper was to review the longitudinal relationship between early-onset depression and disruptive behaviour and adult body weight. A systematic review of prospective longitudinal studies was conducted of articles in which (1) initial assessment occurred during childhood or adolescence (<18 y); and (2) the primary outcome reported as body mass index (BMI), overweight (BMI>25-<30 kg/m(2)), obesity (BMI ≥ 30 kg/m(2)), or depression; and (3) validated assessment measures for assessment of depressive symptoms or disruptive behaviour problems were employed. A total number of 16 articles were identified for review. Obese adolescent females are more likely to develop depressive illness in adulthood than their non-obese peers. Conversely, depressed adolescent females, and possibly males, are more likely to become overweight adults than non-depressed adolescents. There are insufficient data addressing future depression risk among overweight, non-obese, adolescents to evaluate the potentially interactive nature of this relationship. Studies to date are consistent in reporting that children with behaviour problems are at increased risk of future overweight, though whether this risk is conferred by conduct symptoms, ADHD symptoms, or both, is less clear. Care providers of children with disruptive behaviour problems and depressed adolescents should monitor weight gain. Among obese adolescent females, mood should be followed.

Global, multicenter, randomized, phase II trial of gemcitabine and gemcitabine plus AGS-1C4D4 in patients with previously untreated, metastatic pancreatic cancer

BACKGROUND

We evaluated AGS-1C4D4, a fully human monoclonal antibody to prostate stem cell antigen (PSCA), with gemcitabine in a randomized, phase II study of metastatic pancreatic cancer.

PATIENTS AND METHODS

Patients with Eastern Cooperative Oncology Group (ECOG) performance status 0/1 and previously untreated, metastatic pancreatic adenocarcinoma were randomly assigned 1:2 to gemcitabine (1000 mg/m(2) weekly seven times, 1 week rest, weekly three times q4weeks) or gemcitabine plus AGS-1C4D4 (48 mg/kg loading dose, then 24 mg/kg q3weeks IV). The primary end point was 6-month survival rate (SR). Archived tumor samples were collected for pre-planned analyses by PSCA expression.

RESULTS

Between April 2009 and May 2010, 196 patients were randomly assigned to gemcitabine (n = 63) or gemcitabine plus AGS-1C4D4 (n = 133). The 6-month SR was 44.4% (95% CI, 31.9-57.5) in the gemcitabine arm and 60.9% (95% CI, 52.1-69.2) in the gemcitabine plus AGS-1C4D4 arm (P = 0.03), while the median survival was 5.5 versus 7.6 months and the response rate was 13.1% versus 21.6% in the two arms, respectively. The 6-month SR was 57.1% in the gemcitabine arm versus 79.5% in the gemcitabine plus AGS-1C4D4 arm among the PSCA-positive subgroup and 31.6% versus 46.2% among the PSCA-negative subgroup.

CONCLUSIONS

This randomized, phase II study achieved its primary end point, demonstrating an improved 6-month SR with addition of AGS-1C4D4 to gemcitabine among patients with previously untreated, metastatic pancreatic adenocarcinoma. ClinicalTrials.gov identifier: NCT00902291.