Angela G. Brega

Cognitive Profile of Fragile X Premutation Carriers With and Without Fragile X-Associated Tremor/Ataxia Syndrome

Fragile X-associated tremor/ataxia syndrome (FXTAS) develops in a subset of fragile X premutation carriers and involves gait ataxia, action tremor, Parkinsonism, peripheral neuropathy, autonomic disorders, and cognitive impairment. The study was designed to define the nature of cognitive deficits affecting male premutation carriers with and without FXTAS. A sample of 109 men underwent motor, cognitive, genetic, and neurologic testing, as well as brain magnetic resonance imaging. Subjects were classified into 3 groups: (a) asymptomatic premutation carriers, (b) premutation carriers with FXTAS, and (c) normal controls. Men with FXTAS performed worse than controls on mental status, intelligence, executive cognitive functioning (ECF), working memory, remote recall of information, declarative learning and memory, information processing speed, and temporal sequencing, as well as 1 measure of visuospatial functioning. Language and verbal comprehension were spared. Asymptomatic carriers performed worse than controls on ECF and declarative learning and memory. This comprehensive examination of cognitive impairment in male premutation carriers suggests that FXTAS involves substantial executive impairment and diffuse deficits in other cognitive functions. Longitudinal research currently underway will provide insight into the progression of the disorder.

Impairment of executive cognitive functioning in males with fragile X-associated tremor/ataxia syndrome

The fragile X‐associated tremor/ataxia syndrome (FXTAS) is a recently identified phenotype associated with trinucleotide repeat expansions in the premutation range of the fragile X mental retardation 1 (FMR1) gene. In addition to progressive gait ataxia, action tremor, peripheral neuropathy, and parkinsonism, FXTAS involves impaired cognition. Our preliminary research suggests that executive cognitive functioning (ECF) is especially affected. In this study, a brief neuropsychological exam was administered to 33 men with FXTAS and 27 healthy controls. Compared with controls, individuals with FXTAS showed statistically significant impairments on measures from the Wechsler Adult Intelligence Scale, third edition (WAIS‐III; verbal IQ, performance [nonverbal] IQ, verbal comprehension, perceptual organization, and processing speed). FXTAS subjects scored significantly lower on three of four measures of ECF and on two tests of information processing speed. The results provide evidence that FXTAS involves impairment of general intellectual functioning, with marked impairment of executive cognitive abilities. The pattern of cognitive performance is somewhat similar to that observed in the frontal variant of frontotemporal dementia and several of the spinocerebellar ataxias, but differs from the deficits observed in dementia of the Alzheimer type.

The primary cognitive deficit among males with fragile X-associated tremor/ataxia syndrome (FXTAS) is a dysexecutive syndrome

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder associated with a premutation trinucleotide repeat expansion in the fragile X mental retardation 1 gene. Symptoms include gait ataxia, action tremor, and cognitive impairment. The objectives of the study were to clarify the nature of the dysexecutive syndrome observed in FXTAS and to assess the contribution of executive impairment to deficits in nonexecutive cognitive functions. Compared to controls, men with FXTAS demonstrated significant executive impairment, which was found to mediate group differences in most other cognitive abilities. Asymptomatic premutation carriers performed similarly to controls on all but two measures of executive functioning. These findings suggest that the impairment of nonexecutive cognitive skills in FXTAS is in large part secondary to executive dysfunction.

Update on Health Literacy and Diabetes

Purpose Inadequate literacy is common among patients with diabetes and may lead to adverse outcomes. The authors reviewed the relationship between literacy and health outcomes in patients with diabetes and potential interventions to improve outcomes. Methods We reviewed 79 articles covering 3 key domains: (1) evaluation of screening tools to identify inadequate literacy and numeracy, (2) the relationships of a range of diabetes-related health outcomes with literacy and numeracy, and (3) interventions to reduce literacy-related differences in health outcomes. Results Several screening tools are available to assess patients’ print literacy and numeracy skills, some specifically addressing diabetes. Literacy and numeracy are consistently associated with diabetes-related knowledge. Some studies suggest literacy and numeracy are associated with intermediate outcomes, including self-efficacy, communication, and self-care (including adherence), but the relationship between literacy and glycemic control is mixed. Few studies have assessed more distal health outcomes, including diabetes-related complications, health care utilization, safety, or quality of life, but available studies suggest low literacy may be associated with increased risk of complications, including hypoglycemia. Several interventions appear to be effective in improving diabetes-related outcomes regardless of literacy status, but it is unclear if these interventions can reduce literacy-related differences in outcomes. Conclusions Low literacy is associated with less diabetes-related knowledge and may be related to other important health outcomes. Further studies are needed to better elucidate pathways by which literacy skills affect health outcomes. Promising interventions are available to improve diabetes outcomes for patients with low literacy; more research is needed to determine their effectiveness outside of research settings.

The impact of executive cognitive functioning on rates of smoking cessation in the San Luis Valley Health and Aging Study

Cigarette smoking is one of the leading preventable causes of death. Previous research has shown that many common smoking cessation interventions are effective with older smokers; a few interventions have been tailored to this population. To our knowledge, however, no smoking cessation research or interventions targeted at older adults have addressed the influence of cognition on successful smoking cessation. We hypothesized that impairment of executive cognitive functioning (ECF), which is relatively prevalent among older adults, would negatively influence smoking cessation rates among older smokers. The relationship of ECF to smoking cessation was examined in a population-based sample of 1,338 community-dwelling older persons in Colorados San Luis Valley, 204 of whom were current smokers. As predicted, current ECF did not predict early smoking behaviour, but was a significant predictor of successful smoking cessation. Older persons suffering from executive dysfunction were less likely to have quit smoking than were their cognitively intact counterparts (OR = 1.10, 95% CI 1.04-1.17, P < 0.01). Among those with normal ECF, 73.7% had quit smoking, compared with 65.1% of participants showing any level of ECF impairment. Limiting the sample to individuals who were active smokers at or after the age of 65, when executive impairment is relatively common, produced similar results. Individuals with better executive functioning were more likely to have quit smoking (OR = 1.12, 95% CI 1.02-1.23, P = 0.02).

Mechanisms underlying the relationship between health literacy and glycemic control in American Indians and Alaska Natives.

OBJECTIVE Research suggests that health literacy (HL) is associated with clinical outcomes. Few studies, however, have examined the mechanisms accounting for this relationship. To understand why HL is related to outcomes, we tested a theoretical framework proposing that diabetes-related knowledge and behavior mediate (explain) the relationship between HL and glycemic control (i.e., A1c). METHODS Analyses used baseline data from the Special Diabetes Program for Indians Healthy Heart Project (N=2594), an intervention to reduce cardiovascular risk among American Indians/Alaska Natives (AI/ANs) with diabetes. Three nested structural equation models tested the theoretical framework. RESULTS Model 1 demonstrated that participants with stronger HL skills had better glycemic control. Model 2 tested whether diabetes-related behaviors accounted for this relationship. Self-monitoring of blood glucose significantly mediated the HL-A1c relationship. Model 3 examined the role of diabetes knowledge, showing that it mediated the relationship between HL and dietary behavior. When knowledge was included, behavior was no longer a significant mediator, suggesting that knowledge was the main driver of the relationship between HL with A1c. CONCLUSION Interventions to improve knowledge may be particularly important in enhancing outcomes among AI/ANs with diabetes. PRACTICE IMPLICATIONS Strategies known to enhance patient comprehension may enable low-literate patients to develop needed diabetes knowledge.

Practice Variations in Home Health Care

ABSTRACT Wide variation in Medicare home care utilization became apparent in the 1990s. This study examined the impact of patient, provider, agency, and market factors on five measures of home care practice. Data were collected at 44 agencies in eight states. The final analysis sample included 732 home care episodes for which longitudinal patient data were available. Results indicated that patient factors, such as complexity and functional status, were important predictors of the care a patient received. Agency and market characteristics also strongly influenced care practices. Characteristics of the care providers, on the other hand, exerted only minimal influence.

A Cluster-Randomized, Community-Based, Tribally Delivered Oral Health Promotion Trial in Navajo Head Start Children

The authors tested the effectiveness of a community-based, tribally delivered oral health promotion (OHP) intervention (INT) at reducing caries increment in Navajo children attending Head Start. In a 3-y cluster-randomized trial, we developed an OHP INT with Navajo input that was delivered by trained Navajo lay health workers to children attending 52 Navajo Head Start classrooms (26 INT, 26 usual care [UC]). The INT was designed as a highly personalized set of oral health–focused interactions (5 for children and 4 for parents), along with 4 fluoride varnish applications delivered in Head Start during academic years of 2011 to 2012 and 2012 to 2013. The authors evaluated INT impact on decayed, missing, and filled tooth surfaces (dmfs) increment compared with UC. Other outcomes included caries prevalence and caregiver oral health–related knowledge and behaviors. Modified intention-to-treat and per-protocol analyses were conducted. The authors enrolled 1,016 caregiver-child dyads. Baseline mean dmfs/caries prevalence equaled 19.9/86.5% for the INT group and 22.8/90.1% for the UC group, respectively. INT adherence was 53% (i.e., ≥3 child OHP events, ≥1 caregiver OHP events, and ≥3 fluoride varnish). After 3 y, dmfs increased in both groups (+12.9 INT vs. +10.8 UC; P = 0.216), as did caries prevalence (86.5% to 96.6% INT vs. 90.1% to 98.2% UC; P = 0.808) in a modified intention-to-treat analysis of 897 caregiver-child dyads receiving 1 y of INT. Caregiver oral health knowledge scores improved in both groups (75.1% to 81.2% INT vs. 73.6% to 79.5% UC; P = 0.369). Caregiver oral health behavior scores improved more rapidly in the INT group versus the UC group (P = 0.006). The dmfs increment was smaller among adherent INT children (+8.9) than among UC children (+10.8; P = 0.028) in a per-protocol analysis. In conclusion, the severity of dental disease in Navajo Head Start children is extreme and difficult to improve. The authors argue that successful approaches to prevention may require even more highly personalized approaches shaped by cultural perspectives and attentive to the social determinants of oral health (ClinicalTrials.gov NCT01116739).

Racial and Ethnic Disparities in the Outcomes of Elderly Home Care Recipients

ABSTRACT The purpose of this study was to examine racial/ethnic disparities in functional outcomes of elderly home health care recipients. Analyses were conducted using Outcome and Assessment Information Set (OASIS) data for a nationally representative sample of home health care episodes for patients aged 65 and older. Risk-adjusted regression analyses examined the association between race/ethnicity and functional outcomes. Fourteen outcome measures reflected improvement in specific functional areas (e.g., ambulation) and two reflected overall functional change. Non-Hispanic Whites (“Whites”) experienced substantially better functional outcomes than did home health care recipients of other racial/ethnic backgrounds. The disparity in outcomes was most pronounced between Whites and African Americans.

Functional status of men with the fragile X premutation, with and without the tremor/ataxia syndrome (FXTAS)

Fragile X‐associated tremor/ataxia syndrome (FXTAS), which occurs in some premutation carriers of the fragile X mental retardation 1 (FMR1) gene, is a neurodegenerative disorder characterized by action tremor, gait ataxia, and impaired executive cognitive functioning.