Adults with Down syndrome: a comprehensive approach to manage complexity

BACKGROUND

Down syndrome (DS) is characterised by premature ageing that affects selected organ systems, and persons with this condition can present patterns of co-morbidities and deficits often observed in the older population without DS. However, information on the characteristics of adult persons with DS is limited. The objective of the study is to describe characteristics of adults with DS collected with a standardised, comprehensive assessment instrument.

METHODS

Cross-sectional study. Four hundred thirty adults with DS (age range 18/75 years) from three countries (Italy, n = 95; USA, n = 175; and Canada, n = 160). A standardised assessment instrument (interRAI intellectual disability) was used to assess sample characteristics.

RESULTS

Mean age ranged from 35.2 (standard deviation 12.0) years in the US sample to 48.8 (standard deviation 9.0) years in the Canadian sample. Most participants in the Italian and US sample were living in private homes, while more than half of those in the Canadian sample were institutionalised. Prevalences of geriatric conditions, including cognitive deficits, disability in the common activities of daily living, symptoms of withdrawal or anhedonia, aggressive behaviour, communication problems, falls and hearing problems were high in the study sample. Gastrointestinal symptoms, skin and dental problems and obesity were also frequently observed.

CONCLUSIONS

Adults with DS present with a high level of complexity, which may suggest the need for an approach based on a comprehensive assessment and management that can provide adequate care. Further research is needed to understand better the effectiveness of such an approach in the DS population.

Bone mineral density in adults with Down syndrome

This study analyzed data of bone mineral density (BMD) from a large cohort of adults with Down syndrome (DS). BMD was found to decrease with age more rapidly in these subjects than in the general population, exposing adults with DS to an increased risk of osteoporosis and bone fracture.

INTRODUCTION

Down syndrome (DS) in adulthood presents with a high prevalence of osteoporosis. However, in DS, bone mineral density (BMD) can be underestimated due to short stature. Furthermore, the rate of age-related decline in BMD and its association with gender in DS has been rarely evaluated or compared with the general population. The present study is aimed at assessing the variation of BMD with age and gender in a sample of adults with DS and to compare these data with those of the general population, after adjusting for anthropometric differences.

METHODS

Adults with DS, aged 18 or older, were assessed dual-energy-X-ray-absorptiometry (DXA) at the femoral neck and at the lumbar spine. They were compared with the general population enrolled in the National Health and Nutrition Examination Survey (NHANES) 2009-2010 dataset. Bone mineral apparent density (BMAD) was calculated for each individual.

RESULTS

DXA was evaluated in 234 subjects with DS (mean age 36.93 ± 11.83 years, ranging from 20 to 69 years; 50.4% females). In the lumbar spine both mean BMD (DS 0.880 ± 0.141 vs. NHANES 1.062 ± 0.167, p < 0.001) and BMAD (DS 0.138 ± 0.020 vs. NHANES 0.152 ± 0.020, p < 0.001) were significantly lower in the DS sample than in the NAHNES cohort. The same trend was observed at the femoral neck in both BMD (DS 0.658 ± 0.128 vs. NHANES 0.835 ± 0.137, p < 0.001) and BMAD (DS 0.151 ± 0.030 vs. NHANES 0.159 ± 0.028, p<0.001). Age was associated with lower femoral neck BMAD in both samples; importantly, this association was significantly stronger in the DS sample. In the lumbar spine region, no significant association between BMAD and age could be observed in both samples.

CONCLUSIONS

Adults with DS have lower bone mineral density compared to the general population and they experience a steeper decline with age. Early screening programs are needed in DS population.

Thyroid Function and its Implications in Oxidative Stress Influencing the Pathogenesis of Osteoporosis in Adults with Down Syndrome: A Cohort Study

People with Down syndrome (DS) show lower bone mass density (BMD) and a higher prevalence of hypothyroidism compared to general population. Furthermore, DS is a well-known high oxidative stress (OS) condition because genes involved in OS map on chromosome 21. Thyroid function too is involved in OS. Since both thyroid function and OS lead to lower BMD and osteoporotic fractures, we have explored correlations among BMD, thyroid hormones, and parameters of OS in DS adults. A total of 105 DS patients (48 males; 21-71 years; mean BMI 28.88±7.12 kg/m(2)) were enrolled in a cohort study, 48 of them undergoing thyroid replacement therapy. We evaluated thyroid function, BMD, and total antioxidant capacity (TAC) in blood plasma. TAC was assayed by H2O2-metmyoglobin system, as source of radicals, and by the chromogenous ABTS, with a latency time (LAG) in the appearance of its cation ABTS+proportional to antioxidant concentration. BMD was evaluated with DEXA, using WHO criteria to classify osteoporosis. Low BMD was found in 83.78% of patients. TSH and LAG did not correlate with BMD. Nevertheless, LAG significantly correlates to Z-scores estimated at the lumbar spine (r(2)=0.558; p=0.03) in hypothyroid patients. Our data show that low TAC could be more associated with reduced BMD rather than TSH itself in DS patients and that the OS could have a role in the pathogenesis of osteoporosis regarding the hypothyroid subgroup.

Molecular identification of Borrelia valaisiana and HGE-like Ehrlichia in Ixodes ricinus ticks sampled in north-eastern Italy: first report in Veneto region

PCR amplification was applied to screen the presence of both Borrelia burgdorferi s.l. and Ehrlichia species in pools of field-collected Ixodes ricinus ticks. The specimens so far analysed (n = 55), grouped in 11 pools, were sampled in Feltre area (Veneto region, NE Italy). Five pools proved positive for B. valaisiana (45%) and one of them (9%) was also positive for Ehrlichia, that was further characterised as a HGE-like Ehrlichia. This is the first report of the two bacteria in the Veneto region. The pool positive for both pathogens was used to adjust a multiplex PCR assay, which allowed the detection and identification of both parasites in a single experiment. The advantages offered by this assay, when standardised, will substantially broaden the perspectives of ecological and epidemiological investigations on animal/human Lyme disease and ehrlichiosis, greatly facilitating disease surveillance and control programs.