Overweight/obesity and chronic health conditions in older people with intellectual disability in Ireland.

BACKGROUND: This study examines overweight/obesity and chronic health conditions (CHCs) in older people with intellectual disability (ID). METHODS: Data for this cross-sectional observational study emanated from Wave 2 of the Intellectual Disability Supplement to the Irish Longitudinal Study on Ageing, a longitudinal study assessing the health and well-being of older Irish adults with ID aged ≥40 years across all levels of ID. Participation involves an interview process and collation of objective health measures. In this study, body mass index (BMI) (n = 572), used as a measure of weight status, was examined with clustered doctor's diagnosed CHCs. Descriptive analysis was conducted where counts (n) and proportions (%) were used to summarise the variables univariately, while cross-tabulations were used for bivariate summary into counts and proportions. With overweight/obesity prevalence established and patterns described using logistical regression, Pearson's chi-squared test was used to test for significant associations. RESULTS: Overweight/obesity identified in 69% of participants occurred with greater frequency in women (72%). A higher percentage of participants aged <50 years (72.5%) were overweight/obese than those aged 50-64 (70%) and 65+ (61.4%). Level of ID and residence type were significantly associated with weight status (P < 0.001), with overweight/obesity more prevalent in mild (85.7%) than moderate (72%) or severe/profound ID (51.4%). Of those who lived independently/with family, 78.4% were overweight/obese, as were 74% living in a community group home (P < 0.001). Almost all overweight/obese participants' waist measurements were in the substantially increased risk of metabolic disease waist measurement category (92%, P < 0.001). Logistical regression used to model CHCs on BMI showed significant association between BMI and gastrointestinal tract [odds ratio (OR) = 0.57, P < 0.008, 95% confidence interval (CI) = (0.37; 0.86)], respiratory condition [OR = 8.95, P < 0.004, 95% CI = (2.57; 56.72)] and musculoskeletal disorders [OR = 0.40, P < 0.001, 95% CI = (0.25; 0.63)]. CONCLUSIONS: The findings illustrate the strong cross-sectional association between overweight/obesity and CHCs. These findings suggest a need to prioritise weight status as a health risk to people with ID as they age.

Biallelic mutations in mitochondrial tryptophanyl-tRNA synthetase cause Levodopa-responsive infantile-onset Parkinsonism.

Mitochondrial aminoacyl-tRNA synthetases (mtARSs) are essential, ubiquitously expressed enzymes that covalently attach amino acids to their corresponding tRNA molecules during translation of mitochondrial genes. Deleterious variants in the mtARS genes cause a diverse array of phenotypes, many of which involve the nervous system. Moreover, distinct mutations in mtARSs often cause different clinical manifestations. Recently, the gene encoding mitochondrial tryptophanyl tRNA synthetase (WARS2) was reported to cause 2 different neurological phenotypes, a form of autosomal recessive intellectual disability and a syndrome of severe infantile-onset leukoencephalopathy. Here, we report the case of a 17-year-old boy with compound heterozygous mutations in WARS2 (p.Trp13Gly, p.Ser228Trp) who presented with infantile-onset, Levodopa-responsive Parkinsonism at the age of 2 years. Analysis of patient-derived dermal fibroblasts revealed decreased steady-state WARS2 protein and normal OXPHOS content. Muscle mitochondrial studies suggested mitochondrial proliferation without obvious respiratory chain deficiencies at the age of 9 years. This case expands the phenotypic spectrum of WARS2 deficiency and emphasizes the importance of mitochondrial protein synthesis in the pathogenesis of Parkinsonism.

An exploration of the bone health of older adults with an intellectual disability in Ireland.

BACKGROUND: Many risk factors have been confirmed for poor bone health among the general population including age, gender and corticosteroid use. There is a paucity of investigation among people with intellectual disability; however, research points to differing risks namely anti-epileptic medication use, Down syndrome and poor behaviour lifestyle. METHODS: Data was extracted from the Intellectual Disability Supplement to the Irish Longitudinal Study on Ageing in Ireland. In total, 753 participants took part, and data was gathered on participants' health status, behavioural health, health screenings and activities of daily living. The prevalence of osteoporosis and related risk factors were specifically examined. RESULTS: Overall, 8.1% reported a doctor's diagnosis of osteoporosis with over 20% reporting history of fracture. Risk identified included older age (P < 0.0001), female gender (P < 0.0001), difficulty walking (P < 0.0001) with older age and being female the stronger predictors for osteoporosis, odds ratio = 6.53; 95% confidence interval 2.82-15.11 and odds ratio = 4.58; 95% confidence interval 2.29-9.17, respectively. There was no gender difference regarding the level of fractures; however, epilepsy and anti-epileptic medication were strong predictors. Overall, 11.1% attended for bone screening diagnostics. CONCLUSION: Despite low levels of reported doctor's diagnosis of osteoporosis risk factor prevalence was high. Considering the insidious nature of osteoporosis and the low levels of diagnostic screening, prevalence could be possibly higher.

Pretransplant cachexia and morbid obesity are predictors of increased mortality after heart transplantation.

BACKGROUND: Extremes in body weight are a relative contraindication to cardiac transplantation. METHODS: We retrospectively reviewed 474 consecutive adult patients (377 male, 97 female, mean age 50.3+/-12.2 years), who received 444 primary and 30 heart retransplants between January of 1992 and January of 1999. Of these, 68 cachectic (body mass index [BMI]<20 kg/m2), 113 overweight (BMI=>27-30 kg/m2), and 55 morbidly obese (BMI>30 kg/m2) patients were compared with 238 normal-weight recipients (BMI=20-27 kg/m2). We evaluated the influence of pretransplant BMI on morbidity and mortality after cardiac transplantation. Kaplan-Meier survival distribution and Cox proportional hazards model were used for statistical analyses. RESULTS: Morbidly obese as well as cachectic recipients demonstrated nearly twice the 5-year mortality of normal-weight or overweight recipients (53% vs. 27%, respectively, P=0.001). An increase in mortality was seen at 30 days for morbidly obese and cachectic recipients (12.7% and 17.7%, respectively) versus a 30-day mortality rate of 7.6% in normal-weight recipients. Morbidly obese recipients experienced a shorter time to high-grade acute rejection (P=0.004) as well as an increased annual high-grade rejection frequency when compared with normal-weight recipients (P=0.001). By multivariable analysis, the incidence of transplant-related coronary artery disease (TCAD) was not increased in morbidly obese patients but cachectic patients had a significantly lower incidence of TCAD (P=0.05). Cachectic patients receiving oversized donor hearts had a significantly higher postoperative mortality (P=0.02). CONCLUSIONS: The risks of cardiac transplantation are increased in both morbidly obese and cachectic patients compared with normal-weight recipients. However, the results of cardiac transplantation in overweight patients is comparable to that in normal-weight patients. Recipient size should be kept in mind while selecting patients and the use of oversized donors in cachectic recipients should be avoided.

New techniques for predicting solar proton fluences for radiation effects applications.

At geosynchronous altitudes, solar proton events can be a significant source of radiation exposure for devices such as optical imagers, memories and solar cells. These events appear to occur randomly with respect to time and magnitude during the active period of each solar cycle. New probabilistic descriptions, including extreme value theory, are given in forms applicable to assessing mission risks for both single events and the cumulative fluence of multiple events. The analyses yield simpler forms than previous models, include more recent data, and can easily be incorporated into existing computer programs.

Energy deposition and ionization fluctuations induced by ions in small sites--an analytical approach.

A concise, analytical approach is developed for calculating energy deposition and ionization fluctuations in volumes within ion-irradiated media which have dimensions as small as 1 nm. The method accounts for both direct ion interactions with the site and interactions of secondary electrons which are produced by ions in the surrounding medium. Particular attention is given to the way the contributions of the two types of events are combined. Since energy deposition fluctuations are simply related to the fundamental quantities ZD and yD employed in microdosimetry theory, this new approach provides a convenient means to obtain these parameters. Results obtained with the analytical method show good agreement with Monte Carlo charged-particle track-structure calculations of yD for 0.5 to 20 MeV protons incident on spherical sites of water vapor with diameters ranging from 1 nm to 10 microns. In contrast to Monte Carlo techniques, the analytical method does not depend on knowing the intricacies of single ion and electron interactions with the target and can therefore be adapted to calculations with heavier incident ions and different target materials, including those of the condensed state.

Extreme Value Theory Applications to Space Radiation Damage Assessment in Satellite Microelectronics.

Calculations of the first and second moments of displacement damage energy distributions from clastic collisions and from nuclear reactions, at proton energies ranging from 10 MeV to 300 MeV, are incorporated into a model describing the probability of damage as a function of the proton fluence and the size of the sensitive micro-volume in Si. Comparisons between the predicted and measured leakage currents in Si imaging arrays illustrate how the Poisson distribution of higher energy nuclear reaction recoils affects the pixel-to-pixel variance in the damage across the array for proton exposures equivalent to mission duration of a few years within the earth's trapped proton belts. Extreme value statistics (EVS) quantify the largest expected damage extremes following a given proton fluence, and an analysis derived from the first-principle damage calculations shows excellent agreement with the measured extremes. EVS is also used to demonstrate the presence of high dark current pixels, or "spikes," which occur from different mechanisms. Different sources of spikes were seen in two different imager designs.