Comparative survival advantage of males with Down syndrome

Effects of substituting sedentary time with physical activity on body mass index in Japanese adults with Down syndrome: A cross-sectional study

Objective

and Rationale: Obesity is a health challenge for adults with Down syndrome. Therefore, a physical activity promotion program is required to prevent or reduce obesity in adults with this condition. However, there is a lack of evidence of useful risk reduction initiatives. The objective of this study was to suggest a rationale for behaviors that should replace time of inactivity to reduce obesity in Japanese adults with Down syndrome.

Methods

The participants were adults with Down syndrome, aged 18-48 years, living in Japan. The snowball sampling method was used. To detect an effect size of 0.20 for body mass index using an F-test, 80 participants were required, generating a statistical power of 0.8 and a risk level of 0.05. Survey items included sex, age, height, weight, body mass index, and physical activity (min/d). Physical activity was categorized by intensity and further divided into ambulatory and non-ambulatory activities. The body mass index categories were compared using analysis of covariance. An isotemporal substitution model was used to confirm the interdependence of behaviors.

Results

Half of the participants were obese, with a body mass index of 25 kg/m2 or higher. The obese group had significantly fewer light physical activity, moderate-to-vigorous physical activity, and ambulatory moderate-to-vigorous physical activity times than the non-obese group. Replacing 10 min of sedentary behavior with ambulatory moderate-to-vigorous physical activity was significantly associated with a lower body mass index.

Conclusions

This study suggests a rationale for behaviors that should replace time of inactivity to reduce obesity in adults with Down syndrome. Specifically, replacing 10 min of sedentary behavior with ambulatory moderate-to-vigorous physical activity time may contribute to obesity reduction.

Senescent hearts from male Ts65Dn mice exhibit preserved function but altered size and nicotinamide adenine dinucleotide pathway signaling

Down syndrome (DS) is associated with congenital heart defects at birth, but cardiac function has not been assessed at older ages. We used the Ts65Dn mouse, a model of DS, to quantify heart structure and function with echocardiography in 18-mo male Ts65Dn and wild-type (WT) mice. Heart weight, nicotinamide adenine dinucleotide (NAD) signaling, and mitochondrial (citrate synthase) activity were investigated, as these pathways may be implicated in the cardiac pathology of DS. The left ventricle was smaller in Ts65Dn versus WT, as well as the anterior wall thickness of the left ventricle during both diastole (LVAW_d; mm) and systole (LVAW_s; mm) as assessed by echocardiography. Other functional metrics were similar between groups including left ventricular area end systole (mm2), left ventricular area end diastole (mm2), left ventricular diameter end systole (mm), left ventricular diameter end diastole (mm), isovolumetric relaxation time (ms), mitral valve atrial peak velocity (mm/s), mitral valve early peak velocity (mm/s), ratio of atrial and early peak velocities (E/A), heart rate (beats/min), ejection fraction (%), and fractional shortening (%). Nicotinamide phosphoribosyltransferase (NAMPT) protein expression, NAD concentration, and tissue weight were lower in the left ventricle of Ts65Dn versus WT mice. Sirtuin 3 (SIRT3) protein expression and citrate synthase activity were not different between groups. Although cardiac function was generally preserved in male Ts65Dn, the altered heart size and bioenergetic disturbances may contribute to differences in aging for DS.

Sex differences in cardiovascular disease and dysregulation in Down syndrome

This meta-analysis, which consisted of a scoping review and retrospective medical record review, is focused on potential sex differences in cardiovascular diseases in patients with Down syndrome. We limited our review to peer-reviewed, primary articles in the English language, in the PubMed and Web of Science databases from 1965 to 2021. Guidelines for scoping reviews were followed throughout the process. Four categorical domains were identified and searched using additional keywords: 1) congenital heart disease, 2) baseline physiology and risk factors, 3) heart disease and hypertension, and 4) stroke and cerebrovascular disease. Articles were included if they reported male and female distinct data, participants with Down syndrome, and one of our keywords. The retrospective medical record review was completed using 75 participating health care organizations to identify the incidence of congenital and cardiovascular diseases and to quantify cardiovascular risk factors in male and female patients. Female patients with Down syndrome are at higher risk of hypertension, ischemic heart disease, and cerebrovascular disease. The risk of congenital heart disease is higher in males with Down syndrome at all ages included in our analyses. Some of the male-to-female sex differences in cardiovascular disease risk in the general patient population are not present, or reversed in the Down syndrome population. This information should be considered for future investigations and ongoing patient care.NEW & NOTEWORTHY In patients with Down syndrome (DS), CHD is the leading cause of death <20 yr old and cardiovascular disease is a leading cause of death in individuals >20 yr old. Men with DS live longer than women. It is unknown if sex differences are present in cardiovascular disease and dysregulation in DS across the lifespan. We observed higher risk of hypertension, ischemic heart disease, and cerebrovascular disease in females and a higher risk of CHD in males with DS.

A preliminary study of cerebral blood flow, aging and dementia in people with Down syndrome

BACKGROUND

People with Down syndrome (DS) develop Alzheimer's disease (AD) at an earlier age of onset than those with sporadic AD. AD neuropathology is typically present in DS by 40 years of age with an onset of dementia approximately 10 years later. This early onset is due to the overexpression of amyloid precursor protein from the third copy of chromosome 21. Cerebrovascular neuropathology is thought to contribute in 40-60% of cases sporadic AD. However, the vascular contribution to dementia in people with DS has been relatively unexplored. We hypothesised that vascular perfusion is compromised in older adults with DS relative to younger individuals and is further exacerbated in those with dementia.

METHOD

Cerebral blood flow (CBF) was measured using pulsed arterial spin labelling in 35 cognitively characterised adults with DS (26-65 years). DS participants were also compared with 15 control subjects without DS or dementia (26-65 years). Linear regression evaluated the difference in CBF across groups and diagnosis along with assessing the association between CBF and cognitive measures within the DS cohort.

RESULTS

Cerebral blood flow was significantly lower among DS participants with probable AD compared with controls (P = 0.02) and DS participants with no dementia (P = 0.01). Within the DS cohort, CBF was significantly associated with the Severe Impairment Battery (SIB) measure and the Dementia Questionnaire for People with Learning Disabilities (DLD) rating (F_3,25  = 5.13; P = 0.007). Both the SIB (β = 0.74; t = 2.71; P = 0.01) and DLD (β = -0.96; t = -3.87; P < 0.001) indicated greater impairment as global CBF decreased. Age was significantly associated with CBF among participants with DS. There was a non-linear effect of age, whereby CBF declined more rapidly after 45 years of age.

CONCLUSIONS

This preliminary study of CBF in DS indicates that cerebrovascular pathology may be a significant contributor to dementia in DS. CBF was associated with diagnosis, cognition and age. Notably, CBF decreases at a greater rate after age 45 and may represent a significant prodromal event in AD progression.

Predictors of Receipt of Clinical Preventive Services in Adolescents and Adults with Down Syndrome Accessing Medicaid

BACKGROUND

Persons with Down syndrome (DS) require preventive care that addresses their age-/gender- and syndrome-specific needs. Yet, adolescents and adults with DS do not receive these preventive care services as recommended.

OBJECTIVE/HYPOTHESIS

To identify factors that predict receipt of age-/gender- and syndrome-specific preventive healthcare among adolescents and adults with DS. We hypothesized that more healthcare encounters and greater medical complexity would increase receipt of preventive care due to more opportunities to complete these activities.

METHODS

Using Medicaid claims (2006-2010) for California, Colorado, Michigan, and Pennsylvania, we conducted a retrospective cohort study of adolescents and adults with DS (≥12 years old). We modeled receipt of both ≥1 wellness examination and ≥1 thyroid function test (TFT) in 2009-2010 as a function of receipt of those same healthcare activities in 2006-08, adjusting for demographics, key comorbidities, and medical complexity using multivariable logistic regression.

RESULTS

In this cohort of 3487 adolescents and adults with DS accessing Medicaid, 17% received both ≥1 wellness examination and ≥1 TFT in 2006-2008, 15% in 2009-2010, and only 7% during both time periods. Despite medical complexity and frequent healthcare interactions, the best predictor of future receipt of these activities was past receipt. State of residence variably impacted receipt of these preventive activities.

CONCLUSIONS

Although past receipt of wellness examination and TFT was the best predictor of future receipt of these activities, overall rates were quite low in this cohort of adolescents and adults with DS. Further work is needed to improve preventive healthcare delivery to this vulnerable population.

Etiology of intellectual disability in individuals from special education schools in the south of Brazil

Background

Intellectual Disability (ID) is characterized by significant limitations that affect intellectual functioning, adaptive behavior, and practical skills which directly interfere with interpersonal relationships and the environment. In Western countries, individuals with ID are overrepresented in the health system, often due to associated comorbidities, and its life-time cost places ID as one of the most expensive conditions of all diagnoses in the International Classification of Diseases. Most of the people affected (75%) live in low-income countries, suffer from malnutrition, lack health care, and do not have access to adequate treatment. The aim of this study was to obtain an estimate of the diagnostic status as well as the prevalence of familial ID among individuals with serious (moderate or severe) ID in a region of the State of Santa Catarina, investigating attendees of special education schools of the Florianópolis Macroregion.

Methods

This was a cross-sectional study conducted between August 2011 and August 2014, through a semi-structured screening questionnaire for the collection of relevant developmental, clinical, familial and educational data, applied in an interview to guardians of students of special education schools of the macroregion of Florianópolis.

Results

The participant special schools enrolled close to 1700 students during the study period and the questionnaire was applied to 849 (50.5%). The male to female ratio of the participants was 1.39:1. Clear etiologic explanations were relatively scarce (24%); most diagnoses referring only to the type and the degree of impairment and for the majority (61.4%) the cause was unknown. About half were sporadic cases within their families (considering three generations). For 44.2% at least one other case of an ID-related condition in the extended family was mentioned, with 293 (34.5%) representing potential familial cases.

Conclusion

Here we describe the epidemiological profile, the available diagnostics, etiology, family history and possible parental consanguinity of participants with ID of special education schools in the South of Brazil. The main results show the need for etiological diagnosis and uncover the relevance of potential hereditary cases in a population where consanguineous unions have a relatively low frequency (0,6%) and highlight the need for public health actions.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12887-020-02382-5.

Mortality Among Children with Down syndrome in Hong Kong: A Population-Based Cohort Study from Birth

OBJECTIVES

To describe the mortality patterns, comorbidities, and attendance at accident and emergency departments among children with Down syndrome in Hong Kong.

STUDY DESIGN

This is a population-based, retrospective cohort study of live births of children with Down syndrome delivered between 1995 and 2014, as identified from territory-wide hospitalization data in Hong Kong. The Kaplan-Meier product limit method was adopted to estimate the survival probabilities of children with Down syndrome by selected demographic and clinical characteristics. Cox regression analyses were conducted to examine associations of comorbidities and accident and emergency department accident and emergency departments attendances with mortality patterns.

RESULTS

There were 1010 live births of children with Down syndrome in Hong Kong within the study period and the average rate of live births with Down syndrome was 8.0 per 10 000 live births (95% CI, 6.8-9.30). The rate of live births with Down syndrome over the past 2 decades decreased from 11.8 per 10 000 live births in 1995 to 3.4 per 10 000 in 2014. Eighty-three patients with Down syndrome died during this period. The overall 6-month and 1- and 5-year survival probabilities were 95.8%, 94.4%, and 92.6%, respectively. There was a significant decrease in mortality rates over the study period, particularly among those born between 2000-2004 and 2005-2009 compared with those born between 1995 and 1999 (P < .05). Patients with Down syndrome without congenital cardiovascular anomalies and without low birth weight had lower mortality rates than those with these diagnoses.

CONCLUSIONS

Over the past 2 decades, the early life mortality of children with Down syndrome in Hong Kong has improved significantly along with a reduction in Down syndrome live births.

Benefits and Harms of Mammography Screening for Women With Down Syndrome: a Collaborative Modeling Study

BACKGROUND

Women with Down syndrome have a lower breast cancer risk and significantly lower life expectancies than women without Down syndrome. Therefore, it is not clear whether mammography screening strategies used for women without Down syndrome would benefit women with Down syndrome in the same way.

OBJECTIVE

To determine the benefits and harms of various mammography screening strategies for women with Down syndrome using collaborative simulation modeling.

DESIGN

Two established Cancer Intervention and Surveillance Modeling Network (CISNET) simulation models estimated the benefits and harms of various screening strategies for women with Down syndrome over a lifetime horizon.

PARTICIPANTS

We modeled a hypothetical cohort of US women with Down syndrome who were born in 1970.

INTERVENTIONS

Annual, biennial, triennial, and one-time digital mammography screenings during the ages 40-74.

MAIN MEASURES

The models estimated numbers of mammograms, false-positives, benign biopsies, breast cancer deaths prevented, and life-years gained per 1000 screened women when compared with no screening.

KEY RESULTS

In average-risk women 50-74, biennial screening incurred 122 mammograms, 10 false-positive mammograms, and 1.4 benign biopsies per one life-year gained compared with no screening. In women with Down syndrome, the same screening strategy incurred 2752 mammograms, 242 false-positive mammograms, and 34 benign biopsies per one life-year gained compared with no screening. The harm/benefit ratio varied for other screening strategies, and was most favorable for one-time screening at age 50, which incurred 1629 mammograms, 144 false-positive mammograms, and 20 benign biopsies per one life-year gained compared with no screening.

CONCLUSIONS

The harm/benefit ratios for various mammography screening strategies in women with Down syndrome are not as favorable as those for average-risk women. The benefit of screening mammography for women with Down syndrome is less pronounced due to lower breast cancer risk and shorter life expectancy.

Sex differences in congenital heart disease in Down syndrome: study data from medical records and questionnaires in a region of Japan

Reports indicate lower Down syndrome (DS) survival among females than among males in Australia, contrasting with female longevity in the general population. Using data on 1310 people with DS (626 females and 684 males) in Japan from five hospitals' medical records and questionnaires completed by parents of people with DS, we investigated sex differences in congenital heart disease (CHD), which may be related to mortality. The CHD rate was significantly higher for females (354, 57%) than for males (338, 49%; p=0.010). Significantly more females (199, 32%) than males (175, 26%) underwent surgery for CHD (p=0.018).

Cerebrospinal fluid biomarkers for Alzheimer's disease in Down syndrome

Down syndrome (DS), present in nearly six million people, is associated with an extremely high risk to develop Alzheimer's disease (AD). Amyloid-β and tau pathology are omnipresent from age 40 years onward, but clinical symptoms do not appear in all DS individuals. Dementia diagnostics is complex in this population, illustrating the great need for predictive biomarkers. Although blood biomarkers have not yet proven useful, cerebrospinal fluid (CSF) biomarkers (low amyloid-β42, high t-tau, and high p-tau) effectively contribute to AD diagnoses in the general population and are increasingly used in clinical practice. Surprisingly, CSF biomarkers have been barely evaluated in DS. Breaking the taboo on CSF analyses would finally allow for the elucidation of its utility in (differential) diagnoses and staging of disease severity. A sensitive and specific biomarker profile for AD in DS would be of paramount importance to daily care, adaptive caregiving, and specific therapeutic interventions.

The Life Expectancy of People with Intellectual Disabilities in Germany

BACKGROUND

This study presents age group-specific mortality rates and the average life expectancy of people with intellectual disabilities in Germany.

METHOD

For two samples from Westphalia-Lippe and Baden-Wuerttemberg, person-related data for the years 2007-2009 were analysed. Age group-specific mortality rates were estimated by exponential regression analyses.

RESULTS

The average life expectancy of men with intellectual disabilities was 70.9 years in Westphalia-Lippe and 65.3 years in the Baden-Wuerttemberg sample. Women with intellectual disabilities reached a life expectancy of 72.8 years in the Westphalian sample and 69.9 years in Baden-Wuerttemberg. The mortality tables, the crude mortality rates and the standardized mortality rates according to the WHO standard population are reported.

CONCLUSION

Comparing the results with other international studies, the trend of increasing life expectancies of people with intellectual disabilities is confirmed. People with intellectual disabilities still have a lower average life expectancy than the general population, partly due to subgroups with low life expectancies.

Sex differences in protein expression in the mouse brain and their perturbations in a model of Down syndrome

Background

While many sex differences in structure and function of the mammalian brain have been described, the molecular correlates of these differences are not broadly known. Also unknown is how sex differences at the protein level are perturbed by mutations that lead to intellectual disability (ID). Down syndrome (DS) is the most common genetic cause of ID and is due to trisomy of human chromosome 21 (Hsa21) and the resulting increased expression of Hsa21-encoded genes. The Dp(10)1Yey mouse model (Dp10) of DS is trisomic for orthologs of 39 Hsa21 protein-coding genes that map to mouse chromosome 10 (Mmu10), including four genes with known sex differences in functional properties. How these genes contribute to the DS cognitive phenotype is not known.

Methods

Using reverse phase protein arrays, levels of ~100 proteins/protein modifications were measured in the hippocampus, cerebellum, and cortex of female and male controls and their trisomic Dp10 littermates. Proteins were chosen for their known roles in learning/memory and synaptic plasticity and include components of the MAPK, MTOR, and apoptosis pathways, immediate early genes, and subunits of ionotropic glutamate receptors. Protein levels were compared between genotypes, sexes, and brain regions using a three-level mixed effects model and the Benjamini-Hochberg correction for multiple testing.

Results

In control mice, levels of approximately one half of the proteins differ significantly between females and males in at least one brain region; in the hippocampus alone, levels of 40 % of the proteins are significantly higher in females. Trisomy of the Mmu10 segment differentially affects female and male profiles, perturbing protein levels most in the cerebellum of female Dp10 and most in the hippocampus of male Dp10. Cortex is minimally affected by sex and genotype. Diverse pathways and processes are implicated in both sex and genotype differences.

Conclusions

The extensive sex differences in control mice in levels of proteins involved in learning/memory illustrate the molecular complexity underlying sex differences in normal neurological processes. The sex-specific abnormalities in the Dp10 suggest the possibility of sex-specific phenotypic features in DS and reinforce the need to use female as well as male mice, in particular in preclinical evaluations of drug responses.

Electronic supplementary material

The online version of this article (doi:10.1186/s13293-015-0043-9) contains supplementary material, which is available to authorized users.

Does the Well-Being of Individuals with Down Syndrome and Dementia Improve When Using Life Story Books and Rummage Boxes? A Randomized Single Case Series Experiment

BACKGROUND

This study investigated whether a personalized life story book and rummage box enhanced well-being and led to changes in behaviour for people with Down syndrome (DS) who have dementia.

MATERIALS AND METHODS

A randomized single case series design was used with five participants who had DS and a diagnosis of dementia. Participants were invited to take part in three conditions at random (i) life story book, (ii) rummage box and (iii) no-intervention condition.

RESULTS

The two reminiscence conditions were significantly associated with enhanced well-being as compared to the no-intervention condition. However, for one participant, the life story book was associated with significantly higher well-being, while for another participant, the rummage box was associated with significantly higher well-being, suggesting some participants may prefer one method over another.

CONCLUSIONS

Personalized life story books and rummage boxes are associated with higher levels of well-being for people with DS and dementia.

Variability of the aging process in dementia-free adults with Down syndrome

The aim of this cross-sectional study was to analyze the typical aging process in adults with Down syndrome, focusing on its variability. The sample comprised 120 adults with Down syndrome who were free of dementia. Ages ranged from 20 to 69 years. Each participant was assessed on cognitive functioning and social adaptation, and was checked for the presence of psychopathological disorders. Results revealed an age-related deterioration in both cognitive and social adaptation skills, the extent of this decline depending on the dimension under scrutiny, and interindividual variability in aging profiles.

People with intellectual disability: what do we know about adulthood and life expectancy?

Increases in the life expectancy of people with Intellectual Disability have followed similar trends to those found in the general population. With the exception of people with severe and multiple disabilities or Down syndrome, the life expectancy of this group now closely approximates with that of the general population. Middle and old age, which until 30 years ago were not recognized in this population, are now important parts of the life course of these individuals. Older adults with Intellectual Disabilities form a small, but significant and growing proportion of older people in the community. How these persons grow older and how symptoms and complications of the underlying cause of the Intellectual Disability will influence their life expectancy is of the utmost importance.

Dementia and mild cognitive impairment in adults with intellectual disability: issues of diagnosis

Individuals with intellectual disability (ID) are now living longer with the majority of individuals reaching middle and even "old age." As a consequence of this extended longevity they are vulnerable to the same age-associated health problems as elderly adults in the general population without ID. This includes dementia, a general term referring to a variety of diseases and conditions causing substantial loss of cognitive ability and functional declines; adults with Down syndrome are at especially high risk. A great deal of recent effort has focused on the very earliest detectable indicators of decline (and even prodromal stages of dementia-causing diseases). A condition called mild cognitive impairment (MCI) has been conceptually defined as a decline in functioning that is more severe than expected with typical brain aging but not severe enough to meet criteria for a diagnosis of dementia. Consensus criteria for both dementia and MCI have been developed for typically developing adults but are of limited applicability for adults with ID, given their pre-existing cognitive impairments. Early diagnosis will continue to be of growing importance, both to support symptomatic treatment and to prevent irreversible neuropathology when interventions are developed to slow or halt the progression of underlying disease. While the intellectual and developmental disabilities field has for some time recognized the need to develop best-practices for the diagnosis of MCI and dementia, there remains a pressing need for empirically based assessment methods and classification criteria.

Hospitalizations and mortality in the United States for adults with Down syndrome and congenital heart disease

Congenital heart disease (CHD) is common in patients with Down syndrome (DS), and these patients are living longer lives. The aim of this study was to describe the epidemiology of hospitalizations in adults with DS and CHD in the United States. Hospitalizations from 1998 to 2009 for adults aged 18 to 64 years with and without DS with CHD diagnoses associated with DS (atrioventricular canal defect, ventricular septal defect, tetralogy of Fallot, and patent ductus arteriosus) were analyzed using the Nationwide Inpatient Sample. Outcomes of interest were (1) in-hospital mortality, (2) common co-morbidities, (3) cardiac procedures, (4) hospital charges, and (5) length of stay. Multivariate modeling adjusted for age, gender, CHD diagnosis, and co-morbidities. There were 78,793 ± 2,653 CHD admissions, 9,088 ± 351 (11.5%) of which were associated with diagnoses of DS. The proportion of admissions associated with DS (DS/CHD) decreased from 15.2 ± 1.3% to 8.5 ± 0.9%. DS was associated with higher in-hospital mortality (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.4 to 2.4), especially in women (OR 2.4, 95% CI 1.7 to 3.4). DS/CHD admissions were more commonly associated with hypothyroidism (OR 7.7, 95% CI 6.6 to 9.0), dementia (OR 82.0, 95% CI 32 to 213), heart failure (OR 2.2, 95% CI 1.9 to 2.5), pulmonary hypertension (OR 2.5, 95% CI 2.2 to 2.9), and cyanosis or secondary polycythemia (OR 4.6, 95% CI 3.8 to 5.6). Conversely, DS/CHD hospitalizations were less likely to include cardiac procedures or surgery (OR 0.3, 95% CI 0.2 to 0.4) and were associated with lower charges ($23,789 ± $1,177 vs $39,464 ± $1,371, p <0.0001) compared to non-DS/CHD admissions. In conclusion, DS/CHD hospitalizations represent a decreasing proportion of admissions for adults with CHD typical of DS; patients with DS/CHD are more likely to die during hospitalization but less likely to undergo a cardiac procedure.

Survival analysis of Down syndrome cohort in a tertiary health care center in India

OBJECTIVE

To identify the major causes of death in Down Syndrome (DS), the ages at which mortality rates are the highest and recognize factors associated with it.

METHODS

The prospective cohort-based study was carried out in a tertiary health care center. Children with DS (n = 543) counseled at the Center of Medical Genetics, Sir Ganga Ram Hospital from 2005 through 2009 were followed up in year 2010. Survival curves and Cox's proportional hazards regression analysis were used to determine the effect of different variables on survival.

RESULTS

Total mortality was 13 %, of which 80.3 % was in children less than 2 y of age. Presence of congenital heart disease (CHD) increased the risk of mortality by 5.7 folds (p = 0.001). A definitive survival benefit after cardiac intervention was noted, although it differed with the type of CHD. Sex, maternal age at time of birth and karyotypes did not show a significant correlation with survival.

CONCLUSIONS

The higher DS infant mortality observed in the present study could be attributed to financial constraints of the families and misconceptions amongst health professionals. It is recommended that a nation-wide DS registry be created to study the morbidity and mortality in Down syndrome from birth. The findings of this study will help clinicians in making management decisions and enable better counseling.

Trends in survival among children with Down syndrome in 10 regions of the United States

OBJECTIVE

This study examined changes in survival among children with Down syndrome (DS) by race/ethnicity in 10 regions of the United States. A retrospective cohort study was conducted on 16,506 infants with DS delivered during 1983-2003 and identified by 10 US birth defects monitoring programs. Kaplan-Meier survival probabilities were estimated by select demographic and clinical characteristics. Adjusted hazard ratios (aHR) were estimated for maternal and infant characteristics by using Cox proportional hazard models.

RESULTS

The overall 1-month and 1-, 5-, and 20-year survival probabilities were 98%, 93%, 91%, and 88%, respectively. Over the study period, neonatal survival did not improve appreciably, but survival at all other ages improved modestly. Infants of very low birth weight had 24 times the risk of dying in the neonatal period compared with infants of normal birth weight (aHR 23.8; 95% confidence interval [CI] 18.4-30.7). Presence of a heart defect increased the risk of death in the postneonatal period nearly fivefold (aHR 4.6; 95% CI 3.9-5.4) and continued to be one of the most significant predictors of mortality through to age 20. The postneonatal aHR among non-Hispanic blacks was 1.4 (95% CI 1.2-1.8) compared with non-Hispanic whites and remained elevated by age 10 (2.0; 95% CI 1.0-4.0).

CONCLUSIONS

The survival of children born with DS has improved and racial disparities in infant survival have narrowed. However, compared with non-Hispanic white children, non-Hispanic black children have lower survival beyond infancy. Congenital heart defects are a significant risk factor for mortality through age twenty.

Aging and intellectual disability: insights from mouse models of Down syndrome

Down syndrome (DS) is one of many causes of intellectual disability (ID), others including but not limited to, fetal alcohol syndrome, Fragile X syndrome, Rett syndrome, Williams syndrome, hypoxia, and infection. Down syndrome is characterized by a number of neurobiological problems resulting in learning and memory deficits and early onset Alzheimer's disease. The cognitive impairment in people with DS is virtually universal but varies considerably with respect to expressivity and severity. Significant advances in medical treatment and social inclusion have increased longevity in people with DS resulting in an increased aging population, thus highlighting the significance of early onset of dementia and the importance of identifying pharmacotherapies to treat DS-associated health complications in adults. Given its prevalence and established mouse models, this review will focus on ID in the DS population; specifically, the superimposed effect of aging on the complications already manifest in DS adults and the cognitive insights gained from studies on mouse models of DS.

Survival among people with Down syndrome: a nationwide population-based study in Denmark

PURPOSE

Several studies have shown substantially longer survival among persons with Down syndrome in recent decades. We examined survival patterns among Danish persons with Down syndrome by karyotype.

METHODS

A national cohort of 3,530 persons with Down syndrome identified from the Danish Cytogenetic Register and a reference cohort of persons without Down syndrome randomly selected from the general population were followed from 1 April 1968 to 15 January 2009 by linkages to the Register of Causes of Death and the Civil Registration System.

RESULTS

Overall, persons with Down syndrome had higher mortality than the reference cohort but to a lesser degree for persons with mosaic trisomy 21 than for persons with standard trisomy 21 or with Robertsonian translocations (hazard ratio 4.98 (95% confidence interval 3.51-7.08), 8.94 (8.32-9.60), and 10.23 (7.50-13.97), respectively). Among persons with Down syndrome born after April 1968, more recent birth cohorts had lower mortality rates than older birth cohorts, which was largely due to declining mortality among persons with Down syndrome who also had congenital heart defects.

CONCLUSION

Recent birth cohorts of persons with Down syndrome experienced declining mortality, likely due to treatment for congenital heart defects, and persons with mosaic trisomy 21 had better survival than persons with other Down syndrome karyotypes.

Predictors of survival in children born with Down syndrome: a registry-based study

OBJECTIVE

To examine the influence of fetal and maternal characteristics on the survival of children born with Down syndrome.

METHODS

We used prospectively collected population-based data on Down syndrome extracted from the UK Northern Congenital Abnormality Survey (NorCAS), January 1, 1985-December 31, 2003, matched to hospital and national mortality records to January 29, 2008, to determine survival status of liveborn children. Survival to 20 years was estimated by using Kaplan-Meier methods. Cox proportional hazards regression was used to examine factors that predict survival.

RESULTS

A total of 1115 Down syndrome pregnancies were notified to NorCAS during the 19 years, a total prevalence of 16.8 (95% CI, 15.8-17.8) per 10,000 live births and stillbirths. Of these, 5.4% resulted in a spontaneous fetal loss (late miscarriage ≥ 20 weeks and stillbirth), 31.7% in a termination of pregnancy, and 63.0% in a live birth. Survival status was known for 95.3% of live births; 16.6% resulted in a death. Year of birth (P < .001), gestational age at delivery (P < .001), standardized birth weight (P < .001), karyotype (P < .01), and presence of additional structural anomalies (P < .001) were significant predictors of survival. Infant gender, plurality, maternal age, and maternal deprivation were not significant predictors of survival.

CONCLUSIONS

These robust estimates of predictors of survival are important for the prenatal counseling of parents whose pregnancy is affected by Down syndrome and for health care planning for the future care needs of these children.

Clinical Predictors of Mortality in Adults with Intellectual Disabilities with and without Down Syndrome

Background. Mood, baseline functioning, and cognitive abilities as well as psychotropic medications may contribute to mortality in adults with and without Down Syndrome (DS). Methods. Population-based (nonclinical), community-dwelling adults with intellectual disabilities (IDs) were recruited between 1995 and 2000, assessed individually for 1–4 times, and then followed by yearly phone calls. Results. 360 participants (116 with DS and 244 without DS) were followed for an average of 12.9 years (range 0–16.1 years as of July 2011). 108 people died during the course of the followup, 65 males (31.9% of all male participants) and 43 females (27.6% of all female participants). Cox proportional hazards modeling showed that baseline practical skills, seizures, anticonvulsant use, depressive symptoms, and cognitive decline over the first six years all significantly contributed to mortality, as did a diagnosis of DS, male gender, and higher age at study entry. Analysis stratified by DS showed interesting differences in mortality predictors. Conclusion. Although adults with DS have had considerable improvements in life expectancy over time, they are still disadvantaged compared to adults with ID without DS. Recognition of potentially modifiable factors such as depression may decrease this risk.

Total hip arthroplasty to treat congenital musculoskeletal abnormalities in the juvenile Down Syndrome hip: review of literature with case

Down Syndrome can result in musculoskeletal abnormalities of the hip at an early age. Avascular necrosis of the femoral head can occur as a result of slipped capital femoral epiphysis causing the patient a great deal of pain, limiting the ability to ambulate. Despite the benefits that this patient group can receive from the surgery, surgeons may be apprehensive to operate. It is our experience that these patients benefit greatly from arthroplasty without complication. In this report, we present a total hip replacement to treat avascular necrosis in an adolescent and address the concerns that surgeons may have in treating this patient population.

Demographic characteristics, health conditions, and residential service use in adults with Down syndrome in 25 U.S. states

This study describes service users with Down syndrome (N = 1,199) and a comparative sample with intellectual and developmental disabilities but not Down syndrome (N = 11,182), drawn from National Core Indicator surveys of adult service users in 25 U.S. states. Individuals with Down syndrome were younger than were individuals without Down syndrome. Men with Down syndrome were older than women with Down syndrome, whereas the reverse was true of the individuals without Down syndrome. Most (68%) people with Down syndrome had mild or moderate intellectual disability. The prevalence of vision impairment, hearing impairment, and physical disability increased with age. Adults with Down syndrome were more likely to have Alzheimer's dementia, have a hearing impairment, or be overweight, but they were less likely to have a physical disability than those without Down syndrome. Adults with Down syndrome were less likely to live in institutions or their own home, but they more likely to live in a family member's home. The results of a logistic regression showed that participants were more likely to be reported to be overweight if they had Down syndrome, were female, and were physically inactive, but they were less likely to be reported to be overweight if they were older, had more severe intellectual disability, had cerebral palsy, or were not independently mobile.

Health policy and the community safety net for individuals with intellectual disability

This article explores social policy developments in the arena of intellectual and developmental disabilities. It begins by summarizing the challenges facing persons with intellectual disabilities and their caregivers in 1945. Families depended on a patchwork of over-crowded and under-funded large state institutions. Children with intellectual disabilities were marginalized from education and public services. Shame and stigma, along with the lack of community-based services, led many parents to institutionalize a child. The federal government provided almost no specific assistance for disabled individuals or to their families. Postwar America provided fertile ground for parents to act collectively through the emergence of the National Association of Retarded Children (NARC). Partly as a consequence of such organizing, the 1950s marked a surprising turning-point, in which the federal government expanded income support to disabled persons through measures such as Social Security's "Disabled Adult Child" program and, by the early 1970s, the advent of Supplemental Security Income (SSI). It also reviews the growth of Medicaid as the dominant payer of medical and social services at the boundaries between personal medical services, case management, education, and other social services. The article ends by summarizing current challenges in intellectual disability policy. It notes that the size, complexity, and expense of I/DD services poses inherent challenges, particularly to state and local governments in the current recession. Adjusting for inflation, 23 states actually reduced real spending on I/DD services between 2008 and 2009. Controlling for local conditions, politically conservative states enacted deeper cuts and spent a smaller fraction of state income on intellectual disability services than other states.

Cognitive deficits and associated neurological complications in individuals with Down's syndrome

Improvements in medical interventions for people with Down's syndrome have led to a substantial increase in their longevity. Diagnosis and treatment of neurological complications are important in maintaining optimal cognitive functioning. The cognitive phenotype in Down's syndrome is characterised by impairments in morphosyntax, verbal short-term memory, and explicit long-term memory. However, visuospatial short-term memory, associative learning, and implicit long-term memory functions are preserved. Seizures are associated with cognitive decline and seem to cause additional decline in cognitive functioning, particularly in people with Down's syndrome and comorbid disorders such as autism. Vision and hearing disorders as well as hypothyroidism can negatively impact cognitive functioning in people with Down's syndrome. Dementia that resembles Alzheimer's disease is common in adults with Down's syndrome. Early-onset dementia in adults with Down's syndrome does not seem to be associated with atherosclerotic complications.

Total hip arthroplasty in patients with Down's syndrome

Patients with Down's syndrome (DS) have an increased incidence of coxarthrosis which may become symptomatic with prolonged life expectancy. We present seven consecutive patients (nine hips) with DS who had primary total hip arthroplasty (THA). Average clinical and radiological follow-up was 9.9 ± 6.4 years (range 2-22.25). Harris hip scores (HHS) improved significantly (p < 0.01) from 41.1 (range 18.5-65) to 80.2 (range 67.5-91) at latest follow-up. Two patients required revision arthroplasty for stem loosening at 16 (osteolysis) and six years (trauma) following THA, respectively. Six of the THAs required a constrained liner. No dislocations or deep infections were encountered. We contend that THA is a reliable surgical intervention in patients with DS and may be performed in symptomatic patients.

Are the cognitive functions of children with Down syndrome related to their participation?

AIM

There is a lack of investigation into the functional developmental profile of children with Down syndrome. On the basis of current international health paradigms, the purpose of this study was to assess the developmental profile of these children.

METHOD

Sixty children (33 males, 27 females) with Down syndrome (age range 6-16y; mean age 9y 3mo, SD 28.8mo), who had received standard, holistic, early intervention, were assessed. Of these, 42 (70%) had congenital anomalies, 12 had severe congenital heart defects. Participants were assessed on measures of cognitive function (Beery-Buktenica Developmental Test of Visual-Motor Integration; Stanford-Binet Intelligence Scale) and participation (Vineland Adaptive Behaviour Scales).

RESULTS

No difference was found on any measure on the basis of severity of congenital anomaly. Results showed improvements in age-related body function and correlations between specific body functions and participation. No decline in IQ was found with age, and significant correlations between IQ and all other measures were noted. Although sex differences were found in the body functions of short-term memory and motor function, no difference in measures of activity performance and participation was found.

INTERPRETATION

Our findings emphasize the need for paediatric Down syndrome intervention to encourage improved body functions while emphasizing the acquisition of functional skills that enable enhanced participation in age-appropriate activities.

Health conditions associated with aging and end of life of adults with Down syndrome

Expectations for the life course of individuals with Down syndrome (DS) have changed, with life expectancy estimates increasing from 12 in 1949 to nearly 60 years of age today (Bittles & Glasson, 2004; Penrose, 1949). Along with this longer life expectancy comes a larger population of adults with DS who display premature age-related changes in their health. There is thus a need to provide specialized health care to this aging population of adults with DS who are at high risk for some conditions and at lower risk for others. This review focuses on the rates and contributing factors to medical conditions that are common in adults with DS or that show changes with age. The review of medical conditions includes the increased risk for skin and hair changes, early onset menopause, visual and hearing impairments, adult onset seizure disorder, thyroid dysfunction, diabetes, obesity, sleep apnea and musculoskeletal problems. The different pattern of conditions associated with the mortality of adults with DS is also reviewed.

Successful aging in a 70-year-old man with down syndrome: a case study

The authors present a case study of a 70-year-old man with Down syndrome ("Mr. C.") who they followed for 16 years and who does not exhibit declines in cognitive or functional capacities indicative of dementia, despite having well-documented, complete trisomy 21. The authors describe the age-associated changes that occurred over 16 years as well as provide detailed information regarding Mr. C.'s health and genetic status. To further emphasize Mr. C.'s successful aging, the authors compared his longitudinal performance profile with that of 2 peers of comparable level of intellectual functioning: 1 similar-aged man with clinical Alzheimer's disease and a younger man who was healthy. The authors present potential explanations for the phenotypic variability observed in individuals with Down syndrome.

Alzheimer's disease in Down syndrome: neurobiology and risk

Down syndrome (DS) is characterized by increased mortality rates, both during early and later stages of life, and age-specific mortality risk remains higher in adults with DS compared with the overall population of people with mental retardation and with typically developing populations. Causes of increased mortality rates early in life are primarily due to the increased incidence of congenital heart disease and leukemia, while causes of higher mortality rates later in life may be due to a number of factors, two of which are an increased risk for Alzheimer's disease (AD) and an apparent tendency toward premature aging. In this article, we describe the increase in lifespan for people with DS that has occurred over the past 100 years, as well as advances in the understanding of the occurrence of AD in adults with DS. Aspects of the neurobiology of AD, including the role of amyloid, oxidative stress, Cu/ZN dismutase (SOD-1), as well as advances in neuroimaging are presented. The function of risk factors in the observed heterogeneity in the expression of AD dementia in adults with DS, as well as the need for sensitive and specific biomarkers of the clinical and pathological progressing of AD in adults with DS is considered.

Factors predicting mortality in midlife adults with and without Down syndrome living with family

BACKGROUND

Little is known about the mortality of individuals with Down syndrome who have lived at home with their families throughout their lives. The current study evaluates the predictors, causes and patterns of mortality among co-residing individuals in midlife with Down syndrome as compared with co-residing individuals with ID owing to other causes.

METHOD

This paper examines mortality in 169 individuals with and 292 individuals without Down syndrome from 1988 to 2007. Dates and causes of death were obtained from maternal report, the Social Security Death Index and the National Death Index. Risk factors predicting mortality, including demographic variables, transition variables, and initial and change measures of health, functional abilities and behaviour problems, were obtained from maternal report.

RESULTS

Having Down syndrome is a risk factor of mortality, net of other risk factors including older age, poorer functional abilities, worsening behaviour problems, residential relocation and parental death. The causes of death among individuals with and without Down syndrome who are in midlife and co-residing with their families are similar, and are most commonly due to cardiovascular or respiratory problems.

CONCLUSIONS

The findings indicate that midlife adults with Down syndrome who co-reside with their families generally exhibit similar causes of mortality as do midlife adults with intellectual disability owing to other causes, but show an elevated risk of mortality in midlife net of other variables, such as age and changes in functional abilities and behaviour problems.

Survival in infants with Down syndrome, Metropolitan Atlanta, 1979-1998

OBJECTIVE

Factors influencing survival among persons with Down syndrome (DS) are not well understood. We sought to evaluate survival of infants with DS and potential prognostic factors.

STUDY DESIGN

Infants with DS who were born alive during 1979 to 1998 were identified using the Metropolitan Atlanta Congenital Defects Program (MACDP), a population-based surveillance system. To document vital status, we used data from hospital records, the National Death Index (NDI), and Georgia vital records. We estimated survival probability using the Kaplan-Meier product limit method and hazard ratios using a Cox proportional hazards model.

RESULTS

Survival probability to 1 year was 92.9% (95% CI: 90.9-94.9) and to 10 years was 88.6% (95% CI: 85.0-92.2). Univariate analysis demonstrated that black maternal race, low birth weight, preterm birth, lower paternal education, presence of heart defects, and presence of other major congenital anomalies were important prognostic factors. After multivariate analysis, maternal race, presence of heart defects, low birth weight, and an interaction between maternal race and presence of heart defects were significantly associated with mortality risk.

CONCLUSIONS

A racial disparity is apparent in survival for children with Down syndrome. Further study is needed to elucidate possible reasons for the racial disparity.

Altered autonomic cardiac regulation in individuals with Down syndrome

We tested the hypothesis that individuals with Down syndrome, but without congenital heart disease, exhibit altered autonomic cardiac regulation. Ten subjects with Down syndrome (DS) and ten gender-and age-matched healthy control subjects were studied at rest and during active orthostatism, which induces reciprocal changes in sympathetic and parasympathetic traffic to the heart. Autoregressive power spectral analysis was used to investigate R-R interval variability. Baroreflex modulation of sinus node was assessed by the spontaneous baroreflex sequences method. No significant differences between DS and control subjects were observed in arterial blood pressure at rest or in response to standing. Also, R-R interval did not differ at rest. R-R interval decreased significantly less during standing in DS vs. control subjects. Low-frequency (LFNU) and high-frequency (HFNU) (both expressed in normalized units) components of R-R interval variability did not differ between DS and control subjects at rest. During standing, significant increase in LFNU and decrease in HFNU were observed in control subjects but not in DS subjects. Baroreflex sensitivity (BRS) did not differ between DS and control subjects at rest and underwent significant decrease on going from supine to upright in both groups. However, BRS was greater in DS vs. control subjects during standing. These data indicate that subjects with DS exhibit reduced HR response to orthostatic stress associated with blunted sympathetic activation and vagal withdrawal and with a lesser reduction in BRS in response to active orthostatism. These findings suggest overall impairment in autonomic cardiac regulation in DS and may help to explain the chronotropic incompetence typically reported during exercise in subjects with DS without congenital heart disease.

Risk of death for children with down syndrome and sepsis

OBJECTIVE

To determine differences in case fatality rates between children with and without Down syndrome.

STUDY DESIGN

We used the Pediatric Health Information System (PHIS) database, which includes demographic and diagnostic data from freestanding children's hospitals. Using Poisson regression, we determined the risk of mortality from sepsis for children with Down syndrome, after controlling for potential confounding factors.

RESULTS

A total of 35,645 patients met our inclusion criteria, of which 3936 (11%) died during hospitalization. Altogether, 620 of the included patients also had a diagnosis of Down syndrome; 106 (17%) of these died during hospitalization. Children with Down syndrome had significantly elevated risk of mortality (mortality rate ratio = 1.30; 95% confidence interval = 1.06 to 1.59) after adjusting for potential confounding factors including demographics, pathogens, and concomitant conditions.

CONCLUSIONS

Children with Down syndrome and sepsis have elevated risk of mortality. These findings have implications for treatment decisions, communications about prognosis, and future research.

The effects of reactive oxygen species on amphibian aging

To clarify the role of reactive oxygen species (ROS) in the aging process of amphibians, antioxidant enzyme activity and indexes of ROS damage were investigated biochemically using the livers of 3- and 10-year-old Rana nigromaculata frog males and females. Findings revealed no significant difference in survival rate between males and females. Antioxidant enzyme activity displayed an age-related decline. Superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) activity in 10-year-old liver decreased 40-80% from 3-year-old liver levels. In contrast, urate oxidase activity in the 10-year-old liver increased more than 200% from 3-year-old liver levels. At the same time levels of ROS damage, including the concentration of inorganic peroxide and thiobarbituric acid reactive substances (TBARS), greatly increased with age. Liver catalase from 10-year-old frogs proved to be more susceptible to aminotriazole and urea, losing approximately 80% of its original activity after 30 min of treatment. It seems likely that liver catalase in older frogs has diverged from liver catalase in younger frogs through oxidative modification. These findings suggest that a decrease in the activity of antioxidant enzymes over time results in increased levels of ROS damage in the livers of older frogs.

Breast cancer and the uptake of mammography screening services by women with intellectual disabilities

BACKGROUND

It is estimated that approximately 50% of women in Australia with intellectual disability will live to 70 years of age and as a result many will fall within the age group at highest risk for breast cancer (50-69 years).

METHODS

Subjects were identified through the Western Australia Disability Services database. To determine the number of women diagnosed with breast cancer during the period 1982-2000, individual records (n = 2,370) were linked to the Western Australia Cancer Registry and the Mammography Screening Registry.

RESULTS

The incidence of breast cancer among women with intellectual disability was 64.0 per 100,000 person-years, by comparison with 146.7 per 100,000 person-years in the general population. The uptake of breast cancer screening was examined in a subgroup of 380 women, 34.7% of whom had used mammographic screening, as opposed to 54.6% screening uptake in the general population. Failure to use screening services was highest in women who were unmarried, and was positively associated with severity of intellectual disability, presence of physical disabilities, and urban residence.

CONCLUSIONS

The lower incidence of breast cancer in women with intellectual disability may in part be attributable to decreased life expectancy, but it also appears to reflect significant under utilization of the readily available screening services.