Measurement protocols and determinants of peak oxygen consumption in adults with Down syndrome: a systematic review.

This systematic review aimed to provide an overview of test protocols used to measure peak oxygen uptake (VO2peak) in adults with Down syndrome (DS) and to determine how generalisable the outcomes are for the entire population of adults with DS by describing the sample characteristics of these studies and their impact on VO2peak. A literature search (PROSPERO CRD42022309560) was performed (18 July 2023) using the following databases: PubMed, CINAHL, APA PsycINFO, Web of Science, Embase and SPORTDiscus. For articles to be included, they had to be peer-reviewed pubications, reporting VO2peak or VO2max for individuals with DS separately, with a sample of n ≥ 5 and a mean age ≥18 years. Systematic reviews and meta-analyses were excluded but their reference lists were searched for additional papers to include. Studies were evaluated for risk of bias following the guidelines of Kmet et al. The results were summarised with frequency statistics. Forty-three studies were included in this systematic review. Sample sizes of included adults with DS ranged from n = 4-226, with a total of n = 1498 adults with DS being included. Most studies (29/43) used the same standardised maximal exercise treadmill protocol to measure VO2peak in adults with DS, and 33 out of 43 studies used at least one objective criterion to determine a valid maximal effort. Participants were predominantly male, under 40 years old, and overweight or obese. Additionally, the diversity of study samples was lacking or not reported. The most widely used, standardised, maximal exercise test treadmill protocol is recommended for future use in research and practice, including objective criteria to determine valid maximal effort. The current study samples are not representative of the population of adults with DS in terms of sex, age and diverse backgrounds and therefore likely overestimate VO2peak of this population.

Long-term effects of environmental dynamic lighting on sleep-wake rhythm, mood and behaviour in older adults with intellectual disabilities.

BACKGROUND: Sleep-wake problems and depressive symptoms are common in people with intellectual disabilities (IDs) and are thought to be related to the unstable sleep-wake rhythm in this population. Previously, we showed that after increasing environmental light exposure, mid-sleep and sleep onset advanced, and mood improved over a period of 14 weeks after installing environmental dynamic light installations in the living room of people with IDs. We invited participants of that short-term study to take part in the current study on sleep-wake rhythm, mood and behaviour in older adults with IDs 1 year after installing environmental dynamic light installations in the common living rooms of six group homes. METHODS: A pre-post study was performed from October 2017 to February 2019. We included 45 participants (63.5 ± 8.5 years, 67% female) from six group home facilities who provided data at baseline (9, 4 and 1 weeks prior to installing light installations), short term (3, 7 and 14 weeks after installing light installations) and 1 year (54 weeks after installing light installations). Wrist activity was measured with actigraphy (GENEActiv) to derive the primary outcome of interdaily stability of sleep-wake rhythms as well as sleep estimates. Mood was measured with the Anxiety, Depression and Mood Scale. Behaviour was measured with the Aberrant Behaviour Checklist. RESULTS: One year after installing dynamic lighting, we did not find a change in interdaily stability. Total sleep time decreased (ß = -25.40 min; confidence interval: -10.99, -39.82), and sleep onset time was delayed (ß = 25.63 min; confidence interval: 11.18, 40.08). No effect on mood or behaviour was found. CONCLUSIONS: We did not find a change in sleep-wake rhythm, mood or behaviour in older persons with IDs living in care facilities 1 year after installing the light. We did find evidence for a long-term effect on sleep duration and sleep timing. The results have to be interpreted with care as the current study had a limited number of participants. The need for more research on the long-term effects of enhancing environmental light in ID settings is evident.

Sarcopenia predicts 5-year mortality in older adults with intellectual disabilities.

BACKGROUND: People with intellectual disabilities (ID) have a lower life expectancy than their peers without ID. A contributing factor to the lower life expectancy and early mortality could be sarcopenia: low muscle mass and low muscle function. In the general population, sarcopenia strongly predicts early mortality, but this association is unknown in people with ID. Therefore, this study aims to explore the association between sarcopenia and 5-year mortality in older adults with ID. METHODS: In the Healthy Ageing and Intellectual Disabilities (HA-ID) study, the prevalence of sarcopenia was measured at baseline among 884 older adults (≥50 years) with ID. All-cause mortality was measured over a 5-year follow-up period. Univariable and multivariable Cox proportional hazard models were applied to determine the association between sarcopenia (no sarcopenia, pre-sarcopenia, sarcopenia, severe sarcopenia) and early mortality, adjusted for age, sex, level of ID, presence of Down syndrome, and co-morbidity (chronic obstructive pulmonary disease, diabetes type 2 and metabolic syndrome). RESULTS: The unadjusted hazard ratio (HR) for sarcopenia was 2.28 [95% confidence interval (CI) 1.48-3.42], P < 0.001), and 2.40 (95% CI 1.40-4.10, P = 0.001) for severe sarcopenia. When adjusted for age, sex, level of ID, and Down syndrome, sarcopenia (HR = 1.72, 95% CI 1.08-2.75, P = 0.022) and severe sarcopenia (HR = 1.86, 95% CI 1.07-3.23, P = 0.028) were significantly associated with early mortality. When additionally adjusted for co-morbidity, the adjusted HR decreased to 1.62 (95% CI 1.02-2.59, P = 0.043) and 1.81 (95% CI 1.04-3.15, P = 0.035) for sarcopenia and severe sarcopenia, respectively. CONCLUSION: Sarcopenia is an independent risk factor for early mortality in older adults with ID over a 5-year follow-up period. Our results stress the need to delay the incidence and development of sarcopenia in older adults with ID.

Associations between physical fitness and cardiovascular disease in older adults with intellectual disabilities: Results of the Healthy Ageing and Intellectual Disability study.

BACKGROUND: Reduced physical fitness is a cardiovascular disease (CVD) risk factor in the general population. However, generalising these results to older adults with intellectual disabilities (ID) may be inappropriate given their pre-existing low physical fitness levels and high prevalence of co-morbidities. Therefore, the aim of this study is to investigate the difference in physical fitness between older adults with ID with and without CVD. METHOD: Baseline data of a cohort of older adults with borderline to profound ID (HA-ID study) were used (n = 684; 61.6 ± 8.2 years; 51.3% male). CVD status (coronary artery disease, heart failure, stroke) was obtained from medical files. Cardiorespiratory fitness (10-m incremental shuttle walking test), comfortable and fast gait speed (over 5 m distance) and grip strength (hand dynamometer) were measured. Multivariable linear regression models were used to investigate the association between these physical fitness components and the presence of CVD, adjusted for participant characteristics. RESULTS: Of the 684 participants 78 (11.4%) had CVD. Participants with CVD scored lower on cardiorespiratory fitness (-81.4 m, P = 0.002), comfortable gait speed (-0.3 km/h, P = 0.04) and fast gait speed (-1.1 km/h, P = 0.04). No significant differences were found for grip strength (-0.2 kg, P = 0.89). CONCLUSIONS: Older adults with CVD had significantly lower physical fitness levels than those without CVD, except for grip strength. Longitudinal research is needed to investigate causality.

Light up: an intervention study of the effect of environmental dynamic lighting on sleep-wake rhythm, mood and behaviour in older adults with intellectual disabilities.

BACKGROUND: Evidence-based interventions to improve the sleep-wake rhythm, mood and behaviour in older adults with intellectual disabilities (ID) are limited. Increasing light exposure has been shown to be effective in improving the sleep-wake rhythm, mood, and behaviour in other populations. The current study investigates the effect of installing environmental dynamic lighting in common living rooms of care facilities on sleep-wake rhythm, mood, and behaviour in older adults with ID. METHODS: A non-randomised, non-concurrent, multiple baseline study was performed from October 2017 to May 2018. Fifty-four participants [mean (SD) age of 63.42 (8.6) years, 65% female] in six care facilities were included. All participants had three baseline measurements (Weeks 1, 5 and 9). Dynamic lighting was installed in Week 10, after which three intervention measurements took place (Weeks 12, 17 and 24). Sleep characteristics and the sleep-wake rhythm were assessed using actigraphy (GENEActiv). Mood was measured with the Anxiety, Depression and Mood Scale (ADAMS) and behaviour with the Aberrant Behaviour Checklist (ABC). RESULTS: Mixed-effect regression analysis showed a worsening of the primary outcome interdaily stability (P = 0.001). This could be attributed to one care facility, whereas interdaily stability did not change in the other care facilities (P = 0.74). Dynamic lighting led to earlier mid-sleep (P = 0.003) and sleep onset (P < .0001) and improved mood as indicated by lower scores on the ADAMS depression (-0.64 SD, P < 0.001) and social avoidance (-0.47 SD, P = 0.004) subscales. The prevalence of screening above cut-off for depression decreased from 23 to 9.8% (OR = .16, P = 0.003). For behaviour, a decrease was seen in hyperactivity (-0.43 SD, P < 0.001), lethargy (-0.35 SD, P = 0.008) and irritability (-0.33 SD, P < .001) as measured with the ABC. No adverse effects were reported. CONCLUSION: Installing dynamic lighting in common living areas for older adults with ID improved the mood and behaviour of the residents up to 14 weeks after placement. Integrated dynamic lighting is a promising, undemanding and potentially effective addition to improve mood and behaviour in care organisations for people with ID, but does not seem to do so by improving sleep or sleep-wake rhythms.

The responsiveness of muscle strength tests in adults with intellectual disabilities.

BACKGROUND: Muscle strength is both a strong predictor for future negative health outcomes and a prerequisite for physical fitness and daily functioning of adults with ID. Therefore, it is important to be able to monitor the muscle strength of adults with ID over time. The aim of this study is to assess the responsiveness of five field tests that measure muscle strength and endurance (grip strength, hand-held dynamometry of leg extension and arm flexion, 10RM-test of the seated squat and the biceps curl, 30-s chair stand and the 5-times Chair stand) in adults with ID after a 24-week resistance-exercise training (RT) programme. METHOD: The responsiveness of the five muscle strength and endurance tests was assessed by correlating the change scores of the five tests with the slope of the training progression of specific exercises within the RT-programme, namely, the step up, seated squat, biceps curl and triceps curl. RESULTS: The 10RM-test of the seated squat was significantly correlated with the step up (R = 0.53, P = 0.02) and the seated squat (R = 0.70 P = 0.00). None of change scores on the other tests was significantly correlated with the training progression of the exercises. CONCLUSION: The 10RM test of the seated squat could potentially be used to evaluate the effects of an RT-programme in adults with ID. Responsiveness of the grip strength, hand held dynamometry, 10RM-test of the biceps curl, 30-s chair stand and the 5-times chair stand could not yet be confirmed.

Development and validation of a shortened and practical frailty index for people with intellectual disabilities.

BACKGROUND: There is no widely used instrument to detect frailty in people with intellectual disabilities (IDs). We aimed to develop and validate a shorter and more practical version of a published frailty index for people with IDs. METHOD: This study was part of the longitudinal 'Healthy Ageing and Intellectual Disability' study. We included 982 people with IDs aged 50 years and over. The previously developed and validated ID-Frailty Index consisting of 51 deficits was used as the basis for the shortened version, the ID-FI Short Form. Content of the ID-FI Short Form was based on statistics and clinical and practical feasibility. We evaluated the precision and validity of the ID-FI Short Form using the internal consistency, the correlation between the ID-FI Short Form and the original ID-Frailty Index, the agreement in dividing participants in the categories non-frail, pre-frail and frail, and the association with survival. RESULTS: Seventeen deficits from the original ID-Frailty Index were selected for inclusion in the ID-FI Short Form. All deficits of the ID-FI Short Form are clinically and practically feasible to assess for caregivers and therapists supporting people with ID. We showed acceptable internal consistency with Cronbach's alpha of 0.75. The Pearson correlation between the ID-Frailty Index and the ID-FI Short Form was excellent (r = 0.94, P < 0.001). We observed a good agreement between the full and short forms in dividing the participants in the frailty categories, with a kappa statistic of 0.63. The ID-FI Short Form was associated with survival; with every 1/100 increase on the ID-FI Short Form, the mortality probability increased by 7% (hazard ratio 1.07, P < 0.001). CONCLUSION: The first validation of the ID-FI Short Form shows it to be a promising, practical tool to assess the frailty status of people with ID.

Shedding light on light exposure in elderly with intellectual disabilities.

BACKGROUND: Light exposure affects mood and sleep regulation. Sleep problems and mood complaints are common in elderly with intellectual disabilities (ID) living in care facilities. Insufficient light exposure is hypothesised to contribute to the high prevalence of these problems. The current study is the first to describe the personal light exposure pattern during the waking day in elderly with ID. METHODS: The study sample consists of 82 elderly with ID (aged 62.3 ± 9.4 years) living in 16 residential homes of three care organisations in the Netherlands. Personal light exposure was measured continuously for 7-10 days using a HOBO data logger light sensor, measuring illuminance at chest height. Participants wore a wrist-worn accelerometer (Actiwatch or Geneactiv) to indicate the bedtimes to determine the waking day. RESULTS: The variation in illuminance is small during the waking day. Elderly with ID spend most of their waking day (mean duration = 14:32:43 h) in dim light (1-500 lux) environment and spend a median of 32 min in light > 1000 lux. Within participants, the threshold associated with better sleep (>50 min of light > 1000 lux) was reached for 34% of the days, and the threshold associated with less depressive symptoms (>30 min of light > 1000 lux) was reached in 46% of the days. Exposure > 1000 lux was lower during weekends than during weekdays. CONCLUSION: Elderly with ID spend most of their waking day in low light levels and did not meet the proposed values associated with better sleep and mood. Given the importance of adequate light exposure for regulation of sleep and mood, and the prevalence of sleep and mood problems in elderly with ID, the current study suggests that the lit environment for this already frail population should be given more attention.

The association between medication use and gait in adults with intellectual disabilities.

BACKGROUND: Adults with intellectual disabilities (ID) often have polypharmacy and often use antipsychotics. Both polypharmacy and antipsychotics have a negative effect on gait in the general population, but this has not been studied in adults with ID. These negative effects may add to pre-existing gait disturbances in adults with ID and increase the risk for adverse health outcomes in this population. Therefore, the aim of this study is to investigate the difference in gait parameters between adults with ID with and without polypharmacy and between adults with ID using and not using antipsychotics. METHOD: The gait parameters of 31 participants were collected with the GAITRite walkway, a pressure sensitive walkway measuring spatial and temporal gait parameters, in addition to information about personal characteristics, prescribed medication and presence of polypharmacy. RESULTS: After adjustment for sex and body mass index, participants with polypharmacy had a significantly shorter step length [polypharmacy B (SE) = -0.079 (0.034), P = 0.03], shorter stride length [polypharmacy B (SE) = -0.157 (0.069), P = 0.03] and longer double support time [polypharmacy B (SE) = 0.0004 (0.0001), P = 0.047]. Participants using antipsychotics had a significantly longer double support time [antipsychotic use B (SE) = 0.0003 (0.0002), P = 0.019]. CONCLUSION: This study showed for the first time that both polypharmacy and using antipsychotics are associated with gait in adults with ID. The differences seem to resemble a more cautious gait. Further investigation with larger study samples, additional medication types and dosages are needed to acquire more insight in this important topic.

The relationship between motor abilities and quality of life in children with severe multiple disabilities.

BACKGROUND: This study aimed to determine the relationship between motor abilities and quality of life in children with severe multiple disabilities. METHODS: In this cross-sectional study, motor abilities of 29 children (mean age 9.8 years; 45% girls) with severe multiple disabilities [IQ < 25; Gross Motor Function Motor Classification System level V] were measured with the MOtor eVAluation in Kids with Intellectual and Complex disabilities (Movakic) questionnaire (completed by the child's physical therapist). Quality of life was measured with the Quality of Life-Profound Multiple Disabilities (QoL-PMD) questionnaire (completed by the child's parents). RESULTS: A significantly moderate to high correlation was found between the total scores on the Movakic and the QoL-PMD (r = 0.40, P = 0.03), indicating that higher scores in motor abilities are associated with a higher level of quality of life. Furthermore, significantly moderate to high correlations were found between the total score on the Movakic and the dimension Physical Well-Being, Development and Activities of the Qol-PMD. In multiple linear regression models, all significant bivariate relationships between the Movakic total scores and QoL-PMD dimensions remained significant after controlling for the Gross Motor Function Motor Classification System level. CONCLUSIONS: In these children with severe multiple disabilities, motor abilities (as measured by Movakic) are moderately related to quality of life (as measured by the QoL-PMD).

The association between gait and physical fitness in adults with intellectual disabilities.

BACKGROUND: Gait deviations are often seen in adults with intellectual disabilities (ID). Their low physical fitness levels may be associated with these deviations. Understanding the impact of fitness on gait in this population is important for developing interventions to improve gait. In a cross-sectional study, we assessed the association between multiple physical fitness components and spatiotemporal gait parameters in adults with ID. METHOD: Gait characteristics of 31 adults (42.77 ± 16.70 years) with ID without Down syndrome were assessed with the GAITRite at comfortable (CS) and fast speed (FS), along with fitness assessments (body composition, muscular endurance, strength, balance, Short Physical Performance Battery). RESULTS: At CS, adults with ID with higher BMI and/or waist circumference spent more time in double support. At FS, those with better muscular endurance took steps faster, those with better balance took bigger steps and strides and those with better Short Physical Performance Battery scores took bigger steps and strides at higher velocity. CONCLUSIONS: Body composition was mostly associated with gait at CS, while the other physical fitness components were mostly associated with gait at FS. Better fitness may therefore be more important in more challenging conditions. These insights are useful for developing interventions to improve gait in adults with ID.

A 3-year follow-up study on cardiovascular disease and mortality in older people with intellectual disabilities.

BACKGROUND: With increasing longevity and a similar or increased prevalence of cardiovascular disease risk factors (as compared to the general population), people with intellectual disabilities (IDs) are at risk of developing cardiovascular disease. However, prospective studies on incidence and influencing factors of cardiovascular disease and mortality are lacking. METHODS: A three year follow-up study was undertaken to study the incidence and symptoms at presentation of myocardial accident, stroke and heart failure in older people with ID. Furthermore, the predictive value of cardiovascular disease risk factors on myocardial accident, stroke and heart failure and on all-cause mortality were studied. The baseline group consisted of the 1050 participants, aged 50 years and over, in the Dutch Healthy Ageing and Intellectual Disability (HA-ID) study. Baseline measurements were conducted between November 2008 and July 2010. Three years after baseline, medical files of 790 participants were studied. RESULTS: Cardiovascular disease (myocardial infarction, stroke and heart failure) occurred in 5.9% of the population during 3 year follow-up, and 32% of them died due to the condition. Incidence of myocardial infarction is 2.8 per 1000 personyears, for stroke 3.2 per 1000 personyears and for heart failure 12.5 per 1000 personyears. Incidence of these conditions is probably underestimated, due to atypical symptom presentation. The use of atypical antipsychotics and a history of heart failure were predictive for myocardial infarction. Heart failure was predicted by abdominal obesity, chronic kidney disease and a history of heart failure. A total of cardiovascular disease (myocardial infarction, stroke or heart failure) was predicted by abdominal obesity, a history of stroke and a history of heart failure. A low body-mass index, peripheral arterial disease, chronic kidney disease and inflammation were predictive for 3-year all-cause mortality. CONCLUSION: Incidence of cardiovascular disease in older people with ID is similar to that in the general population. A pro-active assessment and treatment of the presented cardiovascular disease risk factors may reduce cardiovascular disease and mortality in older people with ID.