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.

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.

Comprehensive cardiopulmonary profile of individuals with Down syndrome.

BACKGROUND: Individuals with Down syndrome (DS) have low levels of cardiorespiratory fitness and previous studies have shown that these low levels of fitness have a physiological cause. During exercise, the cardiovascular, ventilatory and muscular systems are simultaneously active. While individual parameters of these systems have been investigated in DS before, the interaction between these parameters and systems have not been discussed in detail. Doing so may provide important insight regarding the aetiology of low cardiorespiratory fitness and which parameters of the cardiovascular, pulmonary and muscular systems are altered in individuals with DS compared with their peers without DS. METHODS: Cardiopulmonary exercise tests were performed in healthy adults with and without DS. Parameters related to the cardiovascular, ventilatory and muscular systems were collected until VO2peak . In total, 51 participants were included in analysis, of which 21 had DS. RESULTS: Individuals with DS showed lower peak values for all collected outcomes (P ≤ 0.001) compared with those without DS, except for ventilatory threshold as a percentage of maximal oxygen uptake and VE /VCO2 slope, which were similar. CONCLUSIONS: Our results show that individuals with DS present impairments across the cardiovascular, ventilatory and muscular aspects of the cardiopulmonary system.

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.

Implementation of a program to support direct support professionals to promote a healthy lifestyle for people with moderate to profound intellectual disabilities.

BACKGROUND: There is a lack of theory-based interventions for direct support professionals (DSPs) to support a healthy lifestyle for people with moderate to profound intellectual disabilities (ID) despite their major role in this. This study aims to evaluate the preparation, implementation, and preliminary outcomes of a theory-based training and education program for DSPs to learn how to support these individuals. METHODS: The program consisting of e-learning, three in-person sessions, and three assignments was implemented. The implementation process was evaluated with a mixed method design with the following components: preparation phase, implementation phase, and the outcomes. These components were measured with project notes, questionnaires, interviews, reflections, assignments, food diaries, Actigraph/Actiwatch, and an inventory of daily activities. RESULTS: Regarding the preparation phase, enough potential participants met the inclusion criteria and the time to recruit the participants was 9 months. The program was implemented in four (residential) facilities and involved individuals with moderate to profound ID (n = 24) and DSPs (n = 32). The e-learning was completed by 81% of the DSPs, 72-88% attended the in-person sessions, and 34-47% completed the assignments. Overall, the fidelity of the program was good. DSPs would recommend the program, although they were either negative or positive about the time investment. Mutual agreement on expectations were important for the acceptability and suitability of the program. For the outcomes, the goals of the program were achieved, and the attitudes of DSPs towards a healthy lifestyle were improved after 3 months of the program (nutrition: p = < 0.01; physical activity: p = 0.04). A statistically significant improvement was found for food intake of people with ID (p = 0.047); for physical activity, no statistically significant differences were determined. CONCLUSIONS: The theory-based program consisting of a training and education section for DSPs to support a healthy lifestyle for people with moderate to profound ID was feasible to implement and, despite some barriers regarding time capacity and mutual expectations, it delivered positive changes in both persons with moderate to profound ID and DSPs. Thus, the program is a promising intervention to support DSPs.

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.

Anthropometry does not fully explain low fitness among adults with Down syndrome.

BACKGROUND: Cardiorespiratory fitness, expressed as peak oxygen uptake during exercise (VO2 peak), is an important predictor of cardiovascular health and is related to anthropometry in the general population. Individuals with Down syndrome (DS) have reduced cardiorespiratory fitness and often exhibit different anthropometrics compared with the general population. Interestingly, the relation between anthropometry and cardiorespiratory fitness found in the general population is not apparent in individuals with DS. However, accurate measures with dual energy X-ray absorptiometry (DEXA) scan have not been used to investigate this relationship in this population. The purpose of this paper was to investigate the relationship between accurate measures of anthropometry and cardiorespiratory fitness in adults with DS compared with an age-matched and sex-matched control group. METHODS: Anthropometrics (height, weight, waist and hip circumference, body composition via DEXA) and cardiorespiratory fitness (VO2 peak, measured during a graded maximal exercise test) were assessed in adults with (n = 9; 25 ± 3 years; 6 male patients) and without DS (n = 10, 24 ± 4 years; 5 male patients). RESULTS: Participants with DS were shorter (P < 0.01) than without DS and had a higher body mass index (P < 0.01), waist circumference (WC) (P = 0.026) and waist/height ratio (WHtR) (P < 0.01), but similar weight, body surface area (BSA), waist/hip ratio and body composition (P > 0.05). Participants with DS had significantly lower relative VO2 peak and VO2 peak corrected for total lean mass (TLM), but similar absolute VO2 peak, compared with without DS. In participants with DS, only WC and WHtR were associated with VO2 peak, whereas in participants without DS, height, weight, BSA, TLM, leg lean mass and body fat percentage were associated with VO2 peak. CONCLUSIONS: These results suggest that the relation between anthropometry and cardiorespiratory fitness found in the general population is not the same in adults with DS and that anthropometrics do not fully explain cardiorespiratory fitness in adults with DS. Further research into potential alternative explanations is required.

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.

Towards healthy settings for people with intellectual disabilities.

People with intellectual disabilities (ID) depend on their environment for support to live healthily. The characteristics of healthy settings for people with ID are unknown. This study aims to conceptualize healthy settings for people with ID by conducting an international and multidisciplinary concept mapping study. As theoretical framework the settings approach, an ecological model with a whole system focus toward health promotion, was used. The integrative mixed-methods approach of this study involved concept mapping with researchers specialized in healthcare for people with ID and researchers specialized in healthy settings. The 41 participants generated statements that were later sorted and rated. Findings encompass 13 clusters relating to the social environment, the physical environment and societal preconditions. Specific factors of healthy settings for people with ID include: (i) universal design of the physical environment, (ii) the role of care professionals in the social environment to empower people with ID, (iii) possibilities for care providers to contribute to a health-promoting setting and (iv) preconditions that allow people to engage in society. These factors can be used in strategies to apply the approach in practice and give directions to put in place policies on developing enabling environments and decreasing health inequities.

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.

Peripheral arterial disease in older people with intellectual disability in The Netherlands using the ankle-brachial index: results of the HA-ID study.

Older people with an intellectual disability (ID) have been shown to have similar to increased cardiovascular risks as compared to the general population. Peripheral arterial disease (PAD), atherosclerosis distal from the aortic bifurcation, is associated with increased cardiovascular morbidity and mortality. The prevalence of PAD has not been investigated in this population. Therefore, the aim of the present study was to determine the prevalence of PAD in older people with ID in The Netherlands, the rate of prior diagnoses, and correlations with participant characteristics, and to compare the prevalence with PAD in the general Dutch population. 771 people aged 50 years and over participated in ankle-brachial index (ABI) measurement as part of a multi-centre cross-sectional study (HA-ID study). PAD was defined as an ABI<0.9. After excluding those, who met the exclusion criteria, 629 participants remained. PAD was present in 20.7% of the participants and 97% had not been diagnosed before. People with higher age, smokers and people who lived in central settings, walked with support and were more dependent in activities of daily living were more at risk of PAD. Prevalence of PAD is higher than in the general population (17.4% of 562 eligible participants with ID, as compared to 8.1% of 917 Dutch participants of the PANDORA study, a pan-European study into the prevalence of PAD) through all age groups. Because the high prevalence of PAD implies a serious health risk for older people with ID, we recommend that ankle-brachial index measurement is to be routinely performed as part of the cardiovascular risk management in this group.

Cardiovascular risk factors (diabetes, hypertension, hypercholesterolemia and metabolic syndrome) in older people with intellectual disability: results of the HA-ID study.

Hypertension, diabetes, hypercholesterolemia and the metabolic syndrome are important risk factors for cardiovascular disease (CVD). In older people with intellectual disability (ID), CVD is a substantial morbidity risk. The aims of the present study, which was part of the Healthy Ageing in Intellectual Disability (HA-ID) study, were (1) to determine the prevalence of CVD risk factors in older people with ID and to compare this with the prevalence in the same-aged general population, (2) to determine how many risk factors had not been previously diagnosed, and (3) to identify correlates of CVD risk factors (gender, age, level of ID, Down syndrome, independent living, activities of daily living, mobility, instrumental activities of daily living, physical activity, use of atypical antipsychotics, central obesity), using logistic regression analyses. In this cross-sectional study, 980 people with borderline to profound ID participated. Hypertension (53%), diabetes (14%) and metabolic syndrome (45%) were present similarly as in the general Dutch population. Hypercholesterolemia was present less often (23%). Fifty percent of the people with hypertension had not been previously diagnosed with this condition. Percentages for diabetes, hypercholesterolemia, and the metabolic syndrome were 45, 46 and 94 respectively. People who were more at risk for CVD risk factors were women, older people, people with obesity, people who lived more independently and people who were able to do groceries or prepare a meal independently. Policy on prevention, detection and treatment of CVD risk factors is urgently needed.

Overweight and obesity in older people with intellectual disability.

Overweight and obesity are major health problems associated with increased cardiovascular disease risk, which is not sufficiently studied in people with intellectual disability yet. The present study was part of the Healthy Ageing in Intellectual Disability (HA-ID) study. The aim of this study was to establish (1) the prevalence of overweight, obesity and body fat percentage in older people with intellectual disability (ID) through measurement of Body Mass Index (BMI), waist circumference, waist-to-hip ratio (WHR) and skin fold thickness, and compare this with prevalence of overweight and obesity in the general population, and (2) the association of overweight and obesity with participant and treatment characteristics (gender, age, level of ID, Down syndrome, autism, independent living, smoking, (instrumental) activities of daily living ((I)ADL), physical activity and use of atypical antipsychotic medication) using regression analyses. In this cross-sectional study 945 persons, aged 50 and over with borderline to profound ID, living in central settings, in community settings and independently were included. Overweight and obesity were highly prevalent, with more obesity (26%) than in the general Dutch older population (10%) as measured by BMI, and 46-48% obesity as measured by waist circumference and WHR respectively. Women, people with Down syndrome, higher age, less severe ID, autism, people who are able to eat independently, preparing meals and doing groceries independently, people with physical inactivity and use of atypical antipsychotics were significantly more at risk of being overweight or obese. This merits specific actions by policy makers and clinical practice to improve health outcomes.

Exploring the use of actigraphy to investigate sleep problems in older people with intellectual disability.

BACKGROUND: The aim of this study was to explore the use of actigraphy to investigate sleep problems in a convenience sample of clients of Dutch intellectual disability (ID) care providers. Based on data obtained in a large multi-centre study on healthy ageing in people with ID, research questions were: 'To what degree are actigraphic measurements successful in this population?' and 'What is the influence of different sensitivity settings of the Actiwatch Sleep Analysis software on the distribution of sleep variables in this group?' METHODS: Data were collected in a cross-sectional descriptive study design. We included 563 participants, aged 50 years or older, with borderline to profound ID. Sleep-wake data were measured continuously during 14 days and nights using the Actiwatch AW7. A complete measurement of at least 7 days and nights, including at least one weekend day, was considered successful. Objective variables of sleep were analysed using different sensitivity settings of the Actiwatch AW7 Sleep Analysis software. RESULTS: In 200 participants (35.5%), a successful measurement was obtained. Unsuccessful measurements were caused primarily by problems with wearing the device and incomplete information on bed time and get up time. Of 382 participants who started wearing the Actiwatch, 354 (92.3%) wore it for at least 7 days. Application of different sensitivity settings of the Sleep Analysis software resulted in clear differences of all sleep parameters. CONCLUSIONS: Further research is needed into the validity of objective sleep parameters, as measured with the Actiwatch, for screening and epidemiological research in older people with ID. It needs to be investigated which sensitivity setting of the Actiwatch gives most valid results in this specific group, whereas reference data on sleep parameters and cut-off values are to be obtained.