Consequences of Anorexia of Aging in Hospital Settings: An Updated Review

The anorexia of aging is a widespread problem amongst older people, particularly in the hospital setting with up to 60% affected. Despite its high prevalence anorexia often goes undiagnosed in hospital, due to a lack of standardized assessment and evidence-based management, but also lack of knowledge regarding consequences. This review summarizes current evidence for anorexia of aging specific to the hospital setting, giving an overview of correlates of appetite in hospital and consequences of anorexia. It highlights an overall scarcity of research on this important clinical problem for hospitalized cohorts. The few studies point to the importance of anorexia of aging in major health burdens for older people, namely malnutrition, sarcopenia and reduced physical performance, as well as higher mortality. Further research is needed to assess temporal sequence in pathways of causality and to develop effective interventions to combat anorexia.

Factors that influence older adults' participation in physical activity: a systematic review of qualitative studies

BACKGROUND

Despite the advantages of physical activity (PA), older adults are often insufficiently active to maximise health. Understanding factors that influence PA engagement will support well-designed interventions for older people. Our aim was to review the qualitative evidence exploring the factors affecting older adults' engagement in PA.

METHODS

We searched six electronic databases for studies of community-dwelling older adults (≥70 years) including qualitative methods. We excluded studies of a single-disease group, individuals with cognitive impairment and care home residents. Methodological rigour was assessed with the Critical Appraisal Skills Programme, and framework synthesis was applied using the Capability Opportunity Motivation-Behaviour (COM-B) model, which hypothesises that behaviour is influenced by three factors: capability, opportunity and motivation.

RESULTS

Twenty-five studies were included in the review (N = 4,978; mean 79 years) and 32 themes were identified. Older adults' capability was influenced by functional capacity (e.g. strength) and perceived risk of injury from PA (e.g. falls). Opportunity was impacted by the environment 'fit' (e.g. neighbourhood safety), the availability of social interaction and socio-cultural ageing stereotypes. PA was motivated by identifying as an 'exerciser', health gains and experiencing positive emotions (e.g. enjoyment), whereas negative sensations (e.g. pain) reduced motivation.

CONCLUSIONS

The qualitative synthesis showcased a complex web of interacting factors influencing PA between the sub-domains of COM-B, pinpointing directions for intervention, including a focus on whole systems approaches. There was a lack of research exploring PA influences in the oldest old and in low-income countries. Future research should seek to involve under-served groups, including a wider diversity of older people.

Mood and physical activity are associated with appetite in hospitalised older men and women

BACKGROUND

The anorexia of ageing is important in the development of malnutrition, frailty and sarcopenia amongst the older population and is a particular problem for hospital inpatients. This study assessed appetite-related factors in a group of hospitalised older adults, to identify potential preventive strategies.

DESIGN

Cross sectional observational study.

SETTING

Eleven wards in one large hospital in England.

SUBJECTS

Older inpatients aged ≥70 years, admitted non-electively.

METHODS

Appetite was assessed using the four-item Simplified Nutritional Appetite Questionnaire (SNAQ). Associations between SNAQ score and appetite-related factors present in the dataset were assessed in continuous analyses, including habitual physical activity, mood, medication, cognition and living circumstances.

RESULTS

200 participants, mean age of 80.7 years (SD 6.9); 40% were women. Prevalence of poor appetite was 43%. In univariate analyses, lower medication count, higher habitual physical activity and better mood were associated with higher SNAQ scores during admission. In a multivariate analysis, independent associations of higher habitual physical activity and better mood with higher SNAQ scores during hospital admission remained.

CONCLUSION

In this group of older adults, better mood and higher habitual physical activity were independently associated with better appetite during hospital admission. These are potentially modifiable factors and could be targets for future research into interventions for the anorexia of ageing in the hospitalised older population.

The Experiences of Treatment Burden in People with Parkinson's Disease and Their Caregivers: A Systematic Review of Qualitative Studies

BackgroundHigh treatment burden is associated with poor adherence, wasted resources, poor quality of life and poor health outcomes. Identifying factors that impact treatment burden in Parkinson's disease can offer insights into strategies to mitigate them.ObjectiveTo explore the experiences of treatment burden among people with Parkinson's disease (PwP) and their caregivers.MethodsA systematic review of studies published from year 2006 was conducted. Qualitative and mixed-method studies with a qualitative component that relate to usual care in Parkinson's disease were included. Quantitative studies and grey literature were excluded. Data synthesis was conducted using framework synthesis.Results1757 articles were screened, and 39 articles included. Understanding treatment burden in PwP and caregivers was not the primary aim in any of the included studies. The main issues of treatment burden in Parkinson's disease are: 1) work and challenges of taking medication; 2) healthcare provider obstacles including lack of patient-centered care, poor patient-provider relationships, lack of care coordination, inflexible organizational structures, lack of access to services and issues in care home or hospital settings; and 3) learning about health and challenges with information provision. The treatment burden led to physical and mental exhaustion of self-care and limitations on the role and social activities of PwP and caregivers.Conclusion:There are potential strategies to improve the treatment burden in Parkinson's disease at an individual level such as patient-centered approach to care, and at system level by improving access and care coordination between services. Future research is needed to determine the modifiable factors of treatment burden in Parkinson's disease.

Older individual's perceptions of appetite, its loss, influencing factors and adaptions to poor appetite. A qualitative study

Appetite loss in later life is common and associated with malnutrition; however, there is limited knowledge on older individuals' perspectives of appetite. This study aimed to explore what 'appetite' means to older adults, how they experience its change and perceived influences on this experience. Semi-structured interviews were conducted with thirteen participants, aged ≥65 years, in their own home, following a recent arm fracture. Transcripts were analysed using reflexive thematic analysis with inductive coding resulting in three themes. 1. 'Appetite as an emotional experience' encompassed positive or negative thoughts and feelings driving or undermining desire to eat. Mood, the appeal of food, cooking and effects of interaction and experiences with other people were factors in this narrative. 2. 'Appetite reflects a physical need' comprised physical bodily sensations or requirements as a driver for appetite with poor appetite resulting from early or over fullness. Declines with age, illness and less activity, were factors in this narrative. 3. 'Adaption to poor appetite aligns with perception of appetite and wider physical health' accounts for how experiential strategies, or practical strategies were used to mitigate poor appetite depending on the narrative of appetite loss, alongside perceptions of physical health and unplanned weight loss. Most individuals used one narrative in their discussions and reflections but for some, perceptions of appetite and its change were more complex. Understanding relationships between these perceptions of appetite and influential factors could facilitate development of multi-component, person-centred, strategies that are optimally meaningful and relevant to address appetite loss in later life.

Nutrition and Frailty: Opportunities for Prevention and Treatment

Frailty is a syndrome of growing importance given the global ageing population. While frailty is a multifactorial process, poor nutritional status is considered a key contributor to its pathophysiology. As nutrition is a modifiable risk factor for frailty, strategies to prevent and treat frailty should consider dietary change. Observational evidence linking nutrition with frailty appears most robust for dietary quality: for example, dietary patterns such as the Mediterranean diet appear to be protective. In addition, research on specific foods, such as a higher consumption of fruit and vegetables and lower consumption of ultra-processed foods are consistent, with healthier profiles linked to lower frailty risk. Few dietary intervention studies have been conducted to date, although a growing number of trials that combine supplementation with exercise training suggest a multi-domain approach may be more effective. This review is based on an interdisciplinary workshop, held in November 2020, and synthesises current understanding of dietary influences on frailty, focusing on opportunities for prevention and treatment. Longer term prospective studies and well-designed trials are needed to determine the causal effects of nutrition on frailty risk and progression and how dietary change can be used to prevent and/or treat frailty in the future.

A systematic review of the evidence for deprescribing interventions among older people living with frailty

BACKGROUND

Older people living with frailty are often exposed to polypharmacy and potential harm from medications. Targeted deprescribing in this population represents an important component of optimizing medication. This systematic review aims to summarise the current evidence for deprescribing among older people living with frailty.

METHODS

The literature was searched using Medline, Embase, CINAHL, PsycInfo, Web of Science, and the Cochrane library up to May 2020. Interventional studies with any design or setting were included if they reported deprescribing interventions among people aged 65+ who live with frailty identified using reliable measures. The primary outcome was safety of deprescribing; whereas secondary outcomes included clinical outcomes, medication-related outcomes, feasibility, acceptability and cost-related outcomes. Narrative synthesis was used to summarise findings and study quality was assessed using Joanna Briggs Institute checklists.

RESULTS

Two thousand three hundred twenty-two articles were identified and six (two randomised controlled trials) were included with 657 participants in total (mean age range 79-87 years). Studies were heterogeneous in their designs, settings and outcomes. Deprescribing interventions were pharmacist-led (n = 3) or multidisciplinary team-led (n = 3). Frailty was identified using several measures and deprescribing was implemented using either explicit or implicit tools or both. Three studies reported safety outcomes and showed no significant changes in adverse events, hospitalisation or mortality rates. Three studies reported positive impact on clinical outcomes including depression, mental health status, function and frailty; with mixed findings on falls and cognition; and no significant impact on quality of life. All studies described medication-related outcomes and reported a reduction in potentially inappropriate medications and total number of medications per-patient. Feasibility of deprescribing was reported in four studies which showed that 72-91% of recommendations made were implemented. Two studies evaluated and reported the acceptability of their interventions and further two described cost saving.

CONCLUSION

There is a paucity of research about the impact of deprescribing in older people living with frailty. However, included studies suggest that deprescribing could be safe, feasible, well tolerated and can lead to important benefits. Research should now focus on understanding the impact of deprescribing on frailty status in high risk populations.

TRIAL REGISTRATION

The review was registered on the international prospective register of systematic reviews (PROSPERO) ID number: CRD42019153367 .

The composition of the gut microbiome differs among community dwelling older people with good and poor appetite

BACKGROUND

Anorexia of ageing is common and important in the development of sarcopenia in older individuals. Links have been proposed between the gut microbiota and sarcopenia. Disordered gut function is also recognized in anorexia of ageing, but how this may relate to resident gut microbiota is unexplored. Understanding this relationship may provide a basis for novel interventions for anorexia of ageing and sarcopenia. This study explores compositional differences of the gut microbiota between community dwelling healthy older adults with good or poor appetite, and associated differences in sarcopenia.

METHODS

We assessed appetite by the Simplified Nutritional Appetite Questionnaire (SNAQ) in members of the TwinsUK cohort aged ≥65 years. Using a pool of 776 individuals with existing microbiome data estimated from 16S rRNA sequencing data, we identified 102 cases (SNAQ score < 14) (95% female, mean age 68 years) matched to controls (SNAQ > 14) on body mass index, gender, age, diet, calorie consumption, frailty, antibiotic use, socio-economic status, and technical variables to minimize confounding microbiota associations. Species abundance and diversity, compositional differences, and paired differences in taxa abundance were compared between cases and controls. Additionally, we compared case and controls for sarcopenia as measured by muscle mass (appendicular lean mass/height² ) and strength (chair stand time in seconds).

RESULTS

Cases with poor appetite had reduced species richness and diversity of their gut microbiome (adjusted OBSERVED: beta = -0.2, P < 0.001; adjusted SHANNON: beta = -0.17, P = 0.0135), significant compositional differences (adjusted non-parametric multivariate analysis of variance, P = 0.0095), and significant differences in taxa abundance including reduction of genus Lachnospira (logFC = -1.015, q = 0.023). In all-female subgroup analysis, cases with poor appetite demonstrated reduction in muscle strength (11.03 s vs. 9.26 s, P = 0.02).

CONCLUSIONS

This study is the first to observe differences in the composition of gut microbiota between healthy community dwelling older individuals with good and poor appetite. We found female individuals with reduced muscle strength had poor appetite compared with those with normal strength. These associations require further examination to understand causality and mechanisms of interaction, to inform potential strategies targeting the gut microbiota as a novel intervention for anorexia of ageing and sarcopenia.

39 The Experiences of Treatment Burden Among People with Parkinson’s Disease and Their Caregivers: A Systematic Review

Introduction

Treatment burden is the “workload of healthcare and its impact on patient functioning and well-being”. High treatment burden may lead to non-adherence to treatment regimens, poor health outcomes, poor quality of life and wasted healthcare resources. Treatment burden among people with Parkinson’s (PwP) and their caregivers has not been previously explored.

Methods

Using five electronic databases (MEDLINE, Embase, CINAHL, Scopus and PsychInfo), we conducted a systematic review of studies published since 2006 when the first National Institute for Clinical Excellence (NICE) Clinical Guideline for Parkinson’s Disease was published. This allows an understanding of the impact of current healthcare systems on treatment burden. We included qualitative and mixed-method studies with a qualitative component that reported data from PwP and/or caregivers. Quantitative studies, qualitative data from clinical trials not related to usual care and grey literature were excluded. Two reviewers independently screened articles and extracted data. Data analysis was conducted using framework analysis.

Results

1757 articles were screened, and 39 included in this review. Understanding treatment burden among PwP and their caregivers was not the primary aim in any of the included studies. They described the experiences of those living at home and during hospital or care home admissions. Issues with medications (adherence to advice, effectiveness, side-effects and timing), obtaining appropriate levels of information and healthcare provision (lack of integrated care, care coordination and person-centred approach) were among factors that exacerbate treatment burden experienced by PwP and caregivers. Both reported the impact of Parkinson’s on their daily lives, physical and mental exhaustion of self-care and limitations on their role and social activities.

Conclusion

This review describes considerable treatment burden experienced by PwP and their caregivers and its major influences including aspects of current healthcare provision. Future research should focus on patient-centred care with service redesign to improve this treatment burden.

15 What Influences Loss of Appetite in Older People? A Qualitative Study

Introduction

Appetite loss in older people is common and associated with malnutrition, sarcopenia and frailty. Management of appetite loss may prevent these health burdens but currently no effective clinical interventions exist. This is partly due to lack of knowledge about influences on appetite perceived by older individuals. These views may provide novel avenues for intervention on appetite loss. Aim: To understand older individual’s perceptions of influences on appetite loss.

Method

Semi-structured qualitative interviews with men and women aged ≥65 years, living in their own home, were audio-recorded and transcribed. Reflexive thematic analysis, with inductive coding, generated themes with data examples.

Results

13 individuals (8/13 female, 4/13 living alone) were recruited. Accounts of influences on appetite were grouped into three themes: physical, psychological and external factors. The physical theme related to a physical state of ageing, using energy and being active, and physical symptoms, illness and treatment. The psychological theme explained the influence of mood or wellbeing, the appeal of food, and reward in the activity of cooking. External factors related to influences of other people, coping with life experiences and transitions, and perceptions of health. Influences were perceived to impact on appetite loss in distinct ways, via a physical feeling of fullness (physical theme), or creating a negative experience with food and eating (psychological and external themes). Individuals tended to have either a physical or psychological focus. Importantly, illness and its treatment impacted on both appetite loss narratives.

Conclusions

A number of influences on appetite are described by older individuals, relating to their physical and psychological self, and social and environmental factors. These seem to impact on appetite loss in distinct ways, by precipitating either a physical feeling of fullness, or a negative experience with food and eating. Identifying factors affecting an individual’s appetite could facilitate person-centred approaches to management.

Can probiotics, prebiotics and synbiotics improve functional outcomes for older people: a systematic review

Aim

To review current evidence on whether probiotics, prebiotics and synbiotics improve functional outcomes for older people.

Findings

There is limited evidence that probiotics might improve cognition in older people with pre-existing cognitive impairment. There is little evidence for benefit of probiotics, prebiotics and synbiotics on physical function, frailty, mood, mortality or length of hospital admission among older people, although the 18 studies identified for the review were heterogeneous and these functional outcomes were largely secondary outcomes.

Message

More robust research with larger studies, consistency of interventions and clear assessment of confounding variables (such as diet, co-morbidities and medications) is needed to evaluate the effect of probiotics, prebiotics and synbiotics on functional outcomes in an older population.

Electronic supplementary material

The online version of this article (10.1007/s41999-020-00396-x) contains supplementary material, which is available to authorized users.

Purpose

Research evaluating the effect of probiotics, prebiotics and synbiotics (PPS) on laboratory markers of health (such as immunomodulatory and microbiota changes) is growing but it is unclear whether these markers translate to improved functional outcomes in the older population. This systematic review evaluates the effect of PPS on functional outcomes in older people.

Methods

We conducted a systematic review of the effect of PPS in older adults on functional outcomes (physical strength, frailty, mood and cognition, mortality and receipt of care). Four electronic databases were searched for studies published since year 2000.

Results

Eighteen studies (including 15 RCTs) were identified. One of five studies evaluating physical function reported benefit (improved grip strength). Two analyses of one prebiotic RCT assessed frailty by different methods with mixed results. Four studies evaluated mood with no benefit reported. Six studies evaluated cognition: four reported cognitive improvement in participants with pre-existing cognitive impairment receiving probiotics. Seven studies reported mortality as a secondary outcome with a trend to reduction in only one. Five studies reported length of hospital stay but only two peri-operative studies reported shorter stays.

Conclusion

There is limited evidence that probiotics may improve cognition in older people with pre-existing cognitive impairment but no clear evidence of benefit of PPS on physical function, frailty, mood, length of hospitalisation and mortality. Larger studies with more homogenous interventions, accounting for confounding factors, such as diet, co-morbidities and medications, are required. There is currently inadequate evidence to recommend PPS use to older people in general.

PROSPERO registration number

PROSPERO registration number is CRD42020173417. Date of PROSPERO registration: 01/05/20.

Electronic supplementary material

The online version of this article (10.1007/s41999-020-00396-x) contains supplementary material, which is available to authorized users.

New horizons in appetite and the anorexia of ageing

Appetite drives essential oral nutritional intake. Its regulation is complex, influenced by physiology, hedonism (the reward of eating) and learning from external cues within a person's society and culture. Appetite loss is common in the older population and not always attributable to medical conditions or treatment. Although the physiological basis of the anorexia of ageing (loss of appetite due to the ageing process) has been established, the effect of ageing on hedonism and external cues, which may be equally important, is less well understood. The anorexia of ageing is associated with reductions in dietary diversity and oral intake, and increased risk of malnutrition, sarcopenia and frailty. Early identification of poor appetite could allow timely intervention before weight loss occurs. There is no standardised tool for assessing appetite in clinical settings at present but the 4-item Simplified Nutritional Appetite Questionnaire (SNAQ) has the potential to be used in this way. This review, designed for clinicians, will discuss the regulation of appetite and the pathogenesis of the anorexia of ageing. It will describe the current evidence for interventions to manage the anorexia of ageing, which is limited, with little benefit reported from individual studies of education, physical activity and medication. There is some positive evidence for flavour enhancement, fortified food and oral nutritional supplements but mainly within single studies. Looking ahead, the aim is to develop multicomponent approaches to the treatment of the anorexia of ageing based on growing understanding of the role of physiological signalling, hedonism and external cues.

90 The Effectiveness of Volunteer-Led Physical Activity Interventions in Improving Health Outcomes for Community-Dwelling Older People: A Systematic Review

Introduction

Physical activity (PA) is important for older people to maintain functional independence and healthy ageing. PA interventions for community-dwelling older adults are often delivered by healthcare professionals, fitness instructors or trained members of a research team. Innovative approaches are needed to ensure that these interventions are practical and sustainable. This systematic review explores the effectiveness of volunteer-led PA interventions in improving health outcomes for community-dwelling older people.

Methods

Following PRISMA recommendations, five databases (MEDLINE, Embase, CINAHL, PEDro, Cochrane library) were systematically searched until May 2019, for studies using trained volunteers to deliver PA interventions for community-dwelling older people aged ≥ 65 years, reporting on participant outcomes. Meta-analysis was not conducted due to included study heterogeneity.

Results

Twelve papers (eight studies including three randomised controlled trials (RCTs)) were included in the review; five papers reported different outcomes from the same RCT. Intervention settings included community exercise groups (n=4), home (n=2) and care homes (n=2). All eight studies included strength and balance exercises and frequency of PA ranged from once daily to weekly sessions.

The three RCTs showed improvement in grip strength, nutritional and frailty status, and reduction in fear of falling, among 39 older adults (mean age 83 years) who received a physical training and nutritional intervention; improvement in grip strength and activity of daily living scores among 56 nursing home older adults (mean age 78 years) who received resistance exercise training; and a significantly higher proportion of older adults (n = 193, 9% improvement vs 0.5% in the control group) achieved the recommended target of 150 minutes of moderate vigorous PA per week using the Falls Management Exercise intervention.

Two studies compared volunteer and health professional-delivered PA interventions and reported that both interventions were equally effective in reducing fear of falls and improving quality of life. Two quasi-experimental studies reported improvement in functional outcomes including functional reach, timed up and go test, and chair stand. A large prospective cohort study (n = 1620) reported a reduction in disability among older adults who received volunteer-led exercise compared to control, with a hazard ratio of 0.73 (95% CI 0.62-0.86) for development of disability.

Conclusions

Trained volunteers can lead PA interventions among community-dwelling older adults with some evidence of improved health outcomes including nutritional, functional and frailty status.

108 Poor Appetite is Common in Hospitalised Older People and Associated with Subclinical Low Mood

Introduction

Appetite loss in older people -anorexia of ageing (AA) - is common. Recognised consequences include undernutrition, sarcopenia, frailty, and increased mortality after discharge from hospital. Identification and management of AA may prevent onset of these health burdens. Whilst appetite can be assessed, this is often not routine.

Methods

Cross-sectional data from three studies (carried out 2010-2017), with comparable data collection methods and drawn from the same population, were combined. Participants were over 70 years, admitted to acute wards within a large UK hospital. Appetite was assessed using the simple 4 item Simplified Nutritional Appetite Questionnaire (SNAQ); a score of ≤14/20 defines poor appetite. Correlates of SNAQ scores were evaluated.

Results

The dataset included 474 participants (64% female) with mean age 84 (6.5), median Barthel 78 (IQR 53-91), mini-mental state exam (MMSE) 27 (IQR 23-29) and comorbidity index 5 (IQR 4-7). The median GDS for the population was 4 (IQR 4-6). The mean SNAQ score was 13.9 (SD 2.6), and 265 (56%) participants scored ≤14 indicating poor appetite. There was no significant difference between mean SNAQ scores of men and women (P=.26), or those living alone and with others (P=.62).

Age, MMSE, comorbidity index, and total number of medications were not related to SNAQ score in continuous analyses but geriatric depression score (GDS-15) was (adjusted coefficient -.248; P&lt;.001); such that lower mood was associated with poorer appetite.

Conclusions

These findings highlight the importance of assessing appetite in hospitalised older people, as poor appetite is very common. Appetite can be assessed in hospital using the simple 4 item SNAQ tool. Subclinical low mood, measured by GDS-15, had the strongest association with SNAQ score whilst in hospital. Therefore, for those with poor appetite in hospital, clinicians should have a low threshold to evaluate and treat low mood.

Comprehensive geriatric assessment in primary care: a systematic review

Background

Comprehensive geriatric assessment (CGA) involves the multidimensional assessment and management of an older person. It is well described in hospital and home-based settings. A novel approach could be to perform CGA within primary healthcare, the initial community located healthcare setting for patients, improving accessibility to a co-located multidisciplinary team.

Aim

To appraise the evidence on CGA implemented within the primary care practice.

Methods

The review followed PRISMA recommendations. Eligible studies reported CGA on persons aged ≥ 65 in a primary care practice. Studies focusing on a single condition were excluded. Searches were run in five databases; reference lists and publications were screened. Two researchers independently screened for eligibility and assessed study quality. All study outcomes were reviewed.

Results

The authors screened 9003 titles, 145 abstracts and 97 full texts. Four studies were included. Limited study bias was observed. Studies were heterogeneous in design and reported outcomes. CGAs were led by a geriatrician (n = 3) or nurse practitioner (n = 1), with varied length and extent of follow-up (12–48 months). Post-intervention hospital admission rates showed mixed results, with improved adherence to medication modifications. No improvement in survival or functional outcomes was observed. Interventions were widely accepted and potentially cost-effective.

Discussion

The four studies demonstrated that CGA was acceptable and provided variable outcome benefit. Further research is needed to identify the most effective strategy for implementing CGA in primary care. Particular questions include identification of patients suitable for CGA within primary care CGA, a consensus list of outcome measures, and the role of different healthcare professionals in delivering CGA.

Electronic supplementary material

The online version of this article (10.1007/s40520-019-01183-w) contains supplementary material, which is available to authorized users.

Poor Appetite Is Associated with Six Month Mortality in Hospitalised Older Men and Women

OBJECTIVES

Appetite loss is common in hospitalised older individuals but not routinely assessed. Poor appetite in hospital has previously been identified as predictive of greater mortality in the six months following discharge in a single study of female patients. The present study aimed to assess this association in a larger sample including both hospitalised men and women.

DESIGN

Longitudinal observational study with six month follow up.

SETTING

Acute hospital wards in a single large hospital in England.

PARTICIPANTS

Older inpatients aged over 70 years.

MEASUREMENTS

Appetite was assessed using the Simplified Nutritional Appetite Questionnaire (SNAQ) during hospital stay. Deaths during six month follow-up period were recorded. Association between SNAQ score during hospital admission and death 6 months post-discharge was assessed using binary logistic regression in unadjusted and adjusted analysis.

RESULTS

296 participants (43% female, mean age 83 years (SD 6.9)) were included in this study. Prevalence of poor appetite (SNAQ score <14) was 41%. In unadjusted analysis a SNAQ score of <14 was associated with a 2.47 increase in odds of mortality at six months (OR 2.47 (95% CI 1.27,4.82)). This association remained after adjusting for number of comorbidities (Charlson index), length of stay and gender (OR 2.62 (95% CI 1.30, 5.27)). In unadjusted continuous analysis, every one point decrease in SNAQ score led to a 1.20 fold increase in odds of mortality at six months (OR 1.20 (95% CI 1.06-1.36)). This association remained in adjusted analysis (OR 1.22 (95% CI 1.07-1.39)).

CONCLUSION

Poor appetite is common in hospitalised older people. We have confirmed the association, previously reported in older women, between poor appetite during hospital stay and greater mortality at six months post-discharge but in a larger study including older men and women. Further research is needed to understand the mechanisms of poor appetite, which lead to increased mortality.

The Challenge of Managing Undernutrition in Older People with Frailty

Many older people with frailty are at risk of malnutrition and poor health, yet there is evidence that improving nutrition and weight loss can reduce frailty. This will become more important as the number of older people with frailty increases worldwide in future. Identifying those at risk is challenging due to the difficulty of reaching and screening those older people most at risk, the large number of nutritional assessment tools used, and the lack of consensus on the criteria to make a diagnosis of malnutrition. The management of older people with or at risk of malnutrition should be multi-modal and multi-disciplinary, and all care staff have an important role in delivering appropriate nutritional advice and support. This paper will highlight a number of practical approaches that clinicians can take to manage malnutrition in older people with frailty in community and acute settings, including environmental changes to enhance mealtime experience, food fortification and supplementation.

A genome-wide sib-pair scan for quantitative language traits reveals linkage to chromosomes 10 and 13

Although there is considerable evidence that individual differences in language development are highly heritable, there have been few genome-wide scans to locate genes associated with the trait. Previous analyses of language impairment have yielded replicable evidence for linkage to regions on chromosomes 16q, 19q, 13q (within lab) and at 13q (between labs). Here we report the first linkage study to screen the continuum of language ability, from normal to disordered, as found in the general population. 383 children from 147 sib-ships (214 sib-pairs) were genotyped on the Illumina(®) Linkage IVb Marker Panel using three composite language-related phenotypes and a measure of phonological memory (PM). Two regions (10q23.33; 13q33.3) yielded genome-wide significant peaks for linkage with PM. A peak suggestive of linkage was also found at 17q12 for the overall language composite. This study presents two novel genetic loci for the study of language development and disorders, but fails to replicate findings by previous groups. Possible reasons for this are discussed.

Guidelines for investigating causality of sequence variants in human disease

The discovery of rare genetic variants is accelerating, and clear guidelines for distinguishing disease-causing sequence variants from the many potentially functional variants present in any human genome are urgently needed. Without rigorous standards we risk an acceleration of false-positive reports of causality, which would impede the translation of genomic research findings into the clinical diagnostic setting and hinder biological understanding of disease. Here we discuss the key challenges of assessing sequence variants in human disease, integrating both gene-level and variant-level support for causality. We propose guidelines for summarizing confidence in variant pathogenicity and highlight several areas that require further resource development.

Challenges in interpreting the evidence for genetic predictors of ototoxicity

There has been recent controversy regarding predictors of cisplatin-induced ototoxicity in children, as highlighted in a previous issue of this journal. We have reviewed the two articles that purport to show an association between TPMT and COMT variants and ototoxicity, as well as the related patent applications dating back to 2006. We summarize statistical issues not fully addressed by the authors that appear to have confounded the results of their studies.

Rapid, climate-driven changes in outlet glaciers on the Pacific coast of East Antarctica

Observations of ocean-terminating outlet glaciers in Greenland and West Antarctica indicate that their contribution to sea level is accelerating as a result of increased velocity, thinning and retreat. Thinning has also been reported along the margin of the much larger East Antarctic ice sheet, but whether glaciers are advancing or retreating there is largely unknown, and there has been no attempt to place such changes in the context of localized mass loss or climatic or oceanic forcing. Here we present multidecadal trends in the terminus position of 175 ocean-terminating outlet glaciers along 5,400 kilometres of the margin of the East Antarctic ice sheet, and reveal widespread and synchronous changes. Despite large fluctuations between glaciers--linked to their size--three epochal patterns emerged: 63 per cent of glaciers retreated from 1974 to 1990, 72 per cent advanced from 1990 to 2000, and 58 per cent advanced from 2000 to 2010. These trends were most pronounced along the warmer western South Pacific coast, whereas glaciers along the cooler Ross Sea coast experienced no significant changes. We find that glacier change along the Pacific coast is consistent with a rapid and coherent response to air temperature and sea-ice trends, linked through the dominant mode of atmospheric variability (the Southern Annular Mode). We conclude that parts of the world's largest ice sheet may be more vulnerable to external forcing than recognized previously.

Genome wide association studies for diabetes: perspective on results and challenges

Recent results of genome wide association study (GWAS) for diabetes genes, while reaching impressive technical milestones and implicating new findings for research, have been uniformly disappointing in terms of immediate clinical utility. The relative risk associated with any of the newly reported genetic loci, or even considering all of them together, is far less than simply that which can be obtained by taking a history and a physical exam. For type 2 diabetes (T2D), GWAS have implicated novel pathways, supported previously known associations, and highlighted the importance of the beta cell and insulin secretion. Monogenic forms of diabetes, on the other hand, continue to yield interesting insights into genes controlling human beta cell function but most cases of monogenic diabetes are simply not diagnosed. Here, we briefly review recent results related to type 1, type 2 and maturity onset diabetes of youth (MODY) diabetes and suggest that future studies emphasizing quantitative traits are likely to yield even more insights.

Enrichment of cis-regulatory gene expression SNPs and methylation quantitative trait loci among bipolar disorder susceptibility variants

We conducted a systematic study of top susceptibility variants from a genome-wide association (GWA) study of bipolar disorder to gain insight into the functional consequences of genetic variation influencing disease risk. We report here the results of experiments to explore the effects of these susceptibility variants on DNA methylation and mRNA expression in human cerebellum samples. Among the top susceptibility variants, we identified an enrichment of cis regulatory loci on mRNA expression (eQTLs), and a significant excess of quantitative trait loci for DNA CpG methylation, hereafter referred to as methylation quantitative trait loci (mQTLs). Bipolar disorder susceptibility variants that cis regulate both cerebellar expression and methylation of the same gene are a very small proportion of bipolar disorder susceptibility variants. This finding suggests that mQTLs and eQTLs provide orthogonal ways of functionally annotating genetic variation within the context of studies of pathophysiology in brain. No lymphocyte mQTL enrichment was found, suggesting that mQTL enrichment was specific to the cerebellum, in contrast to eQTLs. Separately, we found that using mQTL information to restrict the number of single-nucleotide polymorphisms studied enhances our ability to detect a significant association. With this restriction a priori informed by the observed functional enrichment, we identified a significant association (rs12618769, P(bonferroni)<0.05) from two other GWA studies (TGen+GAIN; 2191 cases and 1434 controls) of bipolar disorder, which we replicated in an independent GWA study (WTCCC). Collectively, our findings highlight the importance of integrating functional annotation of genetic variants for gene expression and DNA methylation to advance the biological understanding of bipolar disorder.

Clinical translation of cell-based pharmacogenomic discovery

The use of cell-based models has emerged as a promising means to discover and validate pharmacologic phenotype-genotype relationships. The availability of large-scale genome studies in both human and model systems is now allowing us an unprecedented opportunity to understand how well cell-based models identify clinically relevant genetic variants associated with drug response and toxicity. Here we review these studies and the emerging translational information.

Genome-wide meta-analysis identifies variants associated with platinating agent susceptibility across populations

Platinating agents are used in the treatment of many cancers, yet they can induce toxicities and resistance that limit their utility. Using previously published and additional world population panels of diverse ancestry totaling 608 lymphoblastoid cell lines (LCLs), we performed meta-analyses of over 3 million SNPs for both carboplatin- and cisplatin-induced cytotoxicity. The most significant SNP in the carboplatin meta-analysis is located in an intron of NBAS (p = 5.1 × 10⁻⁷). The most significant SNP in the cisplatin meta-analysis is upstream of KRT16P2 (p = 5.8 × 10⁻⁷). We also show that cisplatin-susceptibility SNPs are enriched for carboplatin-susceptibility SNPs. Most of the variants that associate with platinum-induced cytotoxicity are polymorphic across multiple world populations; therefore, they could be tested in follow-up studies in diverse clinical populations. Seven genes previously implicated in platinating agent response, including BCL2, GSTM1, GSTT1, ERCC2, and ERCC6 were also implicated in our meta-analyses.

Genome-wide association study of type 2 diabetes in a sample from Mexico City and a meta-analysis of a Mexican-American sample from Starr County, Texas

AIMS/HYPOTHESIS

We report a genome-wide association study of type 2 diabetes in an admixed sample from Mexico City and describe the results of a meta-analysis of this study and another genome-wide scan in a Mexican-American sample from Starr County, TX, USA. The top signals observed in this meta-analysis were followed up in the Diabetes Genetics Replication and Meta-analysis Consortium (DIAGRAM) and DIAGRAM+ datasets.

METHODS

We analysed 967 cases and 343 normoglycaemic controls. The samples were genotyped with the Affymetrix Genome-wide Human SNP array 5.0. Associations of genotyped and imputed markers with type 2 diabetes were tested using a missing data likelihood score test. A fixed-effects meta-analysis including 1,804 cases and 780 normoglycaemic controls was carried out by weighting the effect estimates by their inverse variances.

RESULTS

In the meta-analysis of the two Hispanic studies, markers showing suggestive associations (p < 10(-5)) were identified in two known diabetes genes, HNF1A and KCNQ1, as well as in several additional regions. Meta-analysis of the two Hispanic studies and the recent DIAGRAM+ dataset identified genome-wide significant signals (p < 5 × 10(-8)) within or near the genes HNF1A and CDKN2A/CDKN2B, as well as suggestive associations in three additional regions, IGF2BP2, KCNQ1 and the previously unreported C14orf70.

CONCLUSIONS/INTERPRETATION

We observed numerous regions with suggestive associations with type 2 diabetes. Some of these signals correspond to regions described in previous studies. However, many of these regions could not be replicated in the DIAGRAM datasets. It is critical to carry out additional studies in Hispanic and American Indian populations, which have a high prevalence of type 2 diabetes.

Detecting 2009 pandemic influenza A (H1N1) virus infection: availability of diagnostic testing led to rapid pandemic response

Diagnostic tests for detecting emerging influenza virus strains with pandemic potential are critical for directing global influenza prevention and control activities. In 2008, the Centers for Disease Control and Prevention received US Food and Drug Administration approval for a highly sensitive influenza polymerase chain reaction (PCR) assay. Devices were deployed to public health laboratories in the United States and globally. Within 2 weeks of the first recognition of 2009 pandemic influenza H1N1, the Centers for Disease Control and Prevention developed and began distributing a new approved pandemic influenza H1N1 PCR assay, which used the previously deployed device platform to meet a >8-fold increase in specimen submissions. Rapid antigen tests were widely used by clinicians at the point of care; however, test sensitivity was low (40%-69%). Many clinical laboratories developed their own pandemic influenza H1N1 PCR assays to meet clinician demand. Future planning efforts should identify ways to improve availability of reliable testing to manage patient care and approaches for optimal use of molecular testing for detecting and controlling emerging influenza virus strains.

Prediction of CYP3A4 enzyme activity using haplotype tag SNPs in African Americans

The CYP3A locus encodes hepatic enzymes that metabolize many clinically used drugs. However, there is marked interindividual variability in enzyme expression and clearance of drugs metabolized by these enzymes. We utilized comparative genomics and computational prediction of transcriptional factor binding sites to evaluate regions within CYP3A that were most likely to contribute to this variation. We then used a haplotype tagging single-nucleotide polymorphisms (htSNPs) approach to evaluate the entire locus with the fewest number of maximally informative SNPs. We investigated the association between these htSNPs and in vivo CYP3A enzyme activity using a single-point IV midazolam clearance assay. We found associations between the midazolam phenotype and age, diagnosis of hypertension and one htSNP (141689) located upstream of CYP3A4. 141689 lies near the xenobiotic responsive enhancer module (XREM) regulatory region of CYP3A4. Cell-based studies show increased transcriptional activation with the minor allele at 141689, in agreement with the in vivo association study findings. This study marks the first systematic evaluation of coding and noncoding variation that may contribute to CYP3A phenotypic variability.

A German genome-wide linkage scan for type 2 diabetes supports the existence of a metabolic syndrome locus on chromosome 1p36.13 and a type 2 diabetes locus on chromosome 16p12.2

AIMS/HYPOTHESIS

The aim was to identify type 2 diabetes susceptibility regions in 250 German families.

SUBJECTS AND METHODS

We conducted a genome-wide linkage scan using 439 short tandem repeat polymorphisms at an average resolution of 7.76 +/- 3.80 cM (Marshfield). In an affected-only-design (affected sib pairs), we performed nonparametric multipoint linkage analyses. Conditional analyses were applied where linkage signals were found in the baseline analyses.

RESULTS

We identified two loci with nominal evidence for linkage on chromosomes 1p36.13 and 16p12.2 (D1S3669, 37.05 cM, logarithmic odds ratio [LOD] = 1.49, p = 0.004; D16S403, 43.89 cM, LOD = 1.85, p = 0.002). D16S403 crossed the empirically obtained threshold of genome-wide suggestive significance of LOD = 1.51. Positive findings in those regions have been reported by the following other linkage studies on: (1) symptomatic/clinical gall bladder disease with type 2 diabetes in Mexican Americans from the San Antonio Family Diabetes/Gallbladder Study (LOD = 3.7, D1S1597-D1S407, 29.93-33.75 cM); (2) body size-adiposity in another Mexican American population (D1S1597, LOD = 2.53, 29.93 cM); (3) lipid abnormalities (LOD = 3.1, D1S2826-D1S513, 41.92-60.01 cM); and (4) hypertension in Australian sib pairs (LOD = 3.1, D1S2834-D1S2728, 31.02-33.75 cM); as well as (5) a meta-analysis of four European type 2 diabetes-related genome scans (LOD = 1.09, D16S412, 42.81 cM). In linkage analyses conditional on evidence for linkage at D16S403 we identified a LOD increase (Delta LOD) of 1.55 (p = 0.0075) at D17S2180. Similar conditioning on D17S2180 revealed evidence for interaction with D1S3669 (Delta LOD = 1.67, p = 0.0055), D16S403 (Delta LOD = 1.48, p = 0.0091) and another locus on chromosome 1 where several genome scans have reported evidence for linkage ( approximately 200 cM, Delta LOD = 1.60, p = 0.0066).

CONCLUSIONS/INTERPRETATION

Our results and the findings of other studies are consistent with the presence of a locus for a complex metabolic syndrome on chromosome 1p36.13.

Combined analysis of three whole genome linkage scans for Ankylosing Spondylitis

OBJECTIVE

Ankylosing spondylitis (AS) is a debilitating chronic inflammatory condition with a high degree of familiality (lambda(s) = 82) and heritability (>90%) that primarily affects spinal and sacroiliac joints. Whole genome scans for linkage to AS phenotypes have been conducted, although results have been inconsistent between studies and all have had modest sample sizes. One potential solution to these issues is to combine data from multiple studies in a retrospective meta-analysis.

METHODS

The International Genetics of Ankylosing Spondylitis Consortium combined data from three whole genome linkage scans for AS (n = 3744 subjects) to determine chromosomal markers that show evidence of linkage with disease. Linkage markers typed in different centres were integrated into a consensus map to facilitate effective data pooling. We performed a weighted meta-analysis to combine the linkage results, and compared them with the three individual scans and a combined pooled scan.

RESULTS

In addition to the expected region surrounding the HLA-B27 gene on chromosome 6, we determined that several marker regions showed significant evidence of linkage with disease status. Regions on chromosome 10q and 16q achieved 'suggestive' evidence of linkage, and regions on chromosomes 1q, 3q, 5q, 6q, 9q, 17q and 19q showed at least nominal linkage in two or more scans and in the weighted meta-analysis. Regions previously associated with AS on chromosome 2q (the IL-1 gene cluster) and 22q (CYP2D6) exhibited nominal linkage in the meta-analysis, providing further statistical support for their involvement in susceptibility to AS.

CONCLUSION

These findings provide a useful guide for future studies aiming to identify the genes involved in this highly heritable condition.

Common polymorphisms of calpain-10 are associated with abdominal obesity in subjects at high risk of type 2 diabetes

AIMS/HYPOTHESIS

The mechanisms by which the calpain-10 gene (CAPN10) affects the risk of type 2 diabetes are unclear. Therefore, we investigated the effects of four polymorphisms in CAPN10 (single nucleotide polymorphism [SNP]-43, SNP-44, Insertion/Deletion [Indel]-19 and SNP-63) on insulin secretion, insulin action and abdominal fat distribution in offspring of patients with type 2 diabetes.

SUBJECTS AND METHODS

Insulin secretion was determined by an IVGTT, insulin action by the hyperinsulinaemic-euglycaemic clamp and abdominal fat distribution by computed tomography in 158 non-diabetic offspring (age 34.9+/-6.3 years [mean+/-SD], BMI 26.2+/-4.9 kg/m(2)) of type 2 diabetic patients.

RESULTS

SNP-43 (p=0.009 over the three genotypes, adjusted for age, sex, BMI and family relationship) and haplotypes carrying the A allele of SNP-43 were associated with intra-abdominal fat area. The A allele of SNP-43 was associated with intra-abdominal fat area in men (p=0.014) but not in women. SNP-44, InDel-19 and SNP-63 were not associated with intra-abdominal fat area or insulin action. Furthermore, we demonstrated in a separate sample of middle-aged men (n=234) who had a history of type 2 diabetes in first-degree relatives that the A allele of SNP-43 was associated with a large waist circumference, and high insulin levels in an OGTT.

CONCLUSIONS/INTERPRETATION

SNP-43 of CAPN10 may contribute to the risk of diabetes by regulating abdominal obesity in subjects with high risk of type 2 diabetes.

Characterization of an influenza A H5N2 reassortant as a candidate for live-attenuated and inactivated vaccines against highly pathogenic H5N1 viruses with pandemic potential

We generated a high-growth 7:1 reassortant (Len17/H5) that contained the hemagglutinin (HA) gene from non-pathogenic A/Duck/Potsdam/1402-6/86 (H5N2) virus and other genes from the cold-adapted (ca) attenuated A/Leningrad/134/17/57 (H2H2) strain. Len17/H5 demonstrated an attenuated phenotype in mice and did not infect chickens. Mice administered Len17/H5 either as a live-attenuated intranasal vaccine or as an inactivated intramuscular vaccine were substantially protected from lethal challenge with highly pathogenic A/Hong Kong/483/97 (H5N1) virus and were protected from pulmonary infection with antigenically distinct A/Hong Kong/213/2003 (H5N1) virus. The cross-protective effect correlated with the levels of virus-specific mucosal IgA and/or serum IgG antibodies. Our results suggest a new strategy of using classical genetic reassortment between a high-growth ca H2N2 strain and antigenically related non-pathogenic avian viruses to prepare live-attenuated and inactivated vaccines for influenza pandemic.

The linkage and association of the gene encoding upstream stimulatory factor 1 with type 2 diabetes and metabolic syndrome in the Chinese population

AIMS/HYPOTHESIS

The transcription factor upstream stimulatory factor 1 (USF1) regulates the expression of genes involved in glucose and lipid metabolism and has been associated with familial combined hyperlipidaemia. USF1 is located on chromosome 1q22-23, a region with evidence for linkage to type 2 diabetes and various traits of the metabolic syndrome in Chinese and other populations. The aim of this study was to investigate the linkage and association of USF1 with type 2 diabetes and the metabolic syndrome in Chinese individuals.

MATERIALS AND METHODS

We genotyped three haplotype-tagging single nucleotide polymorphisms (SNPs) (rs3737787, rs2516841 and rs2516839) at USF1 in three samples of the Hong Kong Chinese population, including members of 179 families from the Hong Kong Family Diabetes Study, 1,383 hospital cases with type 2 diabetes and/or the metabolic syndrome and 454 normal control subjects.

RESULTS

We found significant association of individual polymorphisms and haplotypes with type 2 diabetes and/or metabolic syndrome-related traits in the family samples using either family-based or unrelated normal control subjects. However, these variants could not explain much of the evidence for linkage in this region. Moreover, they were not associated with type 2 diabetes and/or the metabolic syndrome in the hospital cases.

CONCLUSIONS/INTERPRETATION

The results are consistent with the hypothesis that variation at USF1 contributes to the risk of type 2 diabetes and the metabolic syndrome in families with strong evidence for linkage in the chromosome 1q region. However, they provide little support for USF1 as the susceptibility locus that generates the observed evidence for linkage at 1q21-25 for type 2 diabetes and/or the metabolic syndrome, and USF1 does not appear to have a major contribution to these phenotypes in the general Chinese population.

Segregation analyses of stuttering

Although stuttering is known to be a familial disorder, no clear evidence regarding precise mode of transmission has arisen from previous research. In this report segregation analysis is applied to data on 386 stuttering probands and their first-degree relatives in an effort to discriminate among possible genetic models for the transmission of stuttering. Two different segregation analysis programs, PAP and POINTER, gave comparable results with respect to both hypothesis testing and parameter estimation. Specifically, the transmission of stuttering observed in these families cannot be adequately explained by a Mendelian major locus. The hypothesis of no polygenic component in the transmission of stuttering can, however, be rejected. Existence in these data of potential heterogeneity and possible violations of assumptions concerning ascertainment are considered in interpreting the results.

Genetic analysis workshop II: Results of segregation analyses using POINTER and linkage analyses using LIPED

Genetic Analysis Workshop II Problems 2 and 3 were analyzed using the segregation analysis program, POINTER and the linkage analysis program LIPED. Results of the segregation analyses were acceptable with respect to both parameter estimation and hypothesis testing. Results of the linkage analyses were also good. Although it was noted that the linkage and population association data were sometimes compatible with more than one hypothesis, the correct relationships among the trait and marker loci were generally among those found compatible with the data.

Generation and characterization of a cold-adapted influenza A H9N2 reassortant as a live pandemic influenza virus vaccine candidate

H9N2 subtype influenza A viruses have been identified in avian species worldwide and were isolated from humans in 1999, raising concerns about their pandemic potential and prompting the development of candidate vaccines to protect humans against this subtype of influenza A virus. Reassortant H1N1 and H3N2 human influenza A viruses with the internal genes of the influenza A/Ann Arbor/6/60 (H2N2) (AA) cold-adapted (ca) virus have proven to be attenuated and safe as live virus vaccines in humans. Using classical genetic reassortment, we generated a reassortant virus (G9/AA ca) that contains the hemagglutinin and neuraminidase genes from influenza A/chicken/Hong Kong/G9/97 (H9N2) (G9) and six internal gene segments from the AA ca virus. When administered intranasally, the reassortant virus was immunogenic and protected mice from subsequent challenge with wild-type H9N2 viruses, although it was restricted in replication in the respiratory tract of mice. The G9/AA ca virus bears properties that are desirable in a vaccine for humans and is available for clinical evaluation and use, should the need arise.

Findings in an independent sample support an association between bipolar affective disorder and the G72/G30 locus on chromosome 13q33

Markers near the nested genes G72 and G30 on chromosome 13q33 have been implicated in the etiology of schizophrenia and, recently, bipolar affective disorder (BPAD). Hattori et al (2003) reported that single-nucleotide polymorphisms (SNPs) near the G72/G30 locus were associated with BPAD in a sample of 22 pedigrees, and that SNP haplotypes were associated in a second, larger sample of triads. The present study attempts to replicate this finding in an independent case-control sample. Six SNPs near the G72/G30 locus, including the most strongly associated markers in the previous study, were tested in 139 cases and 113 ethnically matched controls. Significant association was detected between BPAD and two adjacent SNPs (smallest P=0.007; global P=0.024). Haplotype analysis produced additional support for association (smallest P=0.004; global P=0.004). Analysis of 31 unlinked microsatellite markers detected no population stratification in the cases or controls studied. Although the associated alleles and haplotypes differ from those previously reported, these new results provide further evidence, in an independent sample, for an association between BPAD and genetic variation in the vicinity of the genes G72 and G30.

Generation and characterization of an H9N2 cold-adapted reassortant as a vaccine candidate

H9N2 subtype avian influenza viruses have been identified in avian species worldwide, and infections in pigs were confirmed in Hong Kong in 1998. Subsequently, H9N2 viruses were isolated from two children in Hong Kong in 1999, and five human infections were reported from China, raising the possibility that H9N2 viruses pose a potential pandemic threat for humans. These events prompted us to develop a vaccine candidate to protect humans against this subtype of influenza A viruses. Reassortant H1N1 and H3N2 human influenza A viruses with the six internal gene segments of A/Ann Arbor/6/60 (H2N2)(AA) cold-adapted (ca) virus have been tested extensively in humans and have proved to be attenuated and safe as live virus vaccines. Using classical genetic reassortment, we generated a reassortant that contains the hemagglutinin and neuraminidase genes from A/chicken/Hong Kong/G9/97 (H9N2) and six internal gene segments from the AAca virus. The G9/AAca reassortant virus exhibits the ca phenotype and the temperature-sensitive phenotypes of the AAca virus and was attenuated in mice. The reassortant virus was immunogenic and protected mice from wild-type H9N2 virus challenge. The G9/AAca virus bears the in vitro and in vivo phenotypes specified by the AAca virus and will be evaluated as a potential vaccine candidate in humans.

Genome-wide approaches for identifying interacting susceptibility regions for asthma

A genome-wide correlation analysis and cluster analysis were utilized to determine chromosomal regions that had similar nonparametric linkage scores across families in order to locate interacting susceptibility loci for asthma. Conditional analysis was performed to detect any increase in lod score over baseline. Eight of the strongest 5% of the correlations in the German and CSGA asthma data sets occurred in both data sets. The strongest positive correlations found in both data sets were between the 200 cM region on chromosome 2 with chromosome 12 at 90-120 cM (r = 0.26) and also with chromosome 6 at 40-70 cM (r = 0.24). While the cluster analysis did not find any regions that clustered across data sets, this method did detect clustering in regions that have been previously linked to asthma.

Computational issues in mapping variation affecting susceptibility to complex disorders: the chicken and the egg

Linkage mapping strategies for complex disorders have evolved under a variety of constraints. Some of these constraints reflect the nature of complex disorders and are manifest in limitations on the kinds of data that can be collected, while others were (at least historically) strictly computational. This paper focuses on how computational issues have impacted the design of studies on complex disorders and, conversely, how our study designs have influenced the computational issues that have been addressed. We now have unprecedented computational resources, but also face unprecedented computational and methodological challenges as we move from the linkage mapping of genes influencing susceptibility to complex disorders toward the identification of the actual variation affecting susceptibility to these disorders. The near-term computational and methodological issues we must address will be profoundly influenced by the study designs of the recent past. But future study designs, as well as our investments in computational and methodological research, ought to be developed considering the computational and informatics resources we now have at hand.

Challenges in identifying genetic variation affecting susceptibility to type 2 diabetes: examples from studies of the calpain-10 gene

Type 2 diabetes is a classic example of a complex disorder. It is strongly familial, but clearly arises as a consequence of the actions and interactions of many genetic and non-genetic factors. Type 2 diabetes is a common disorder, affecting 16 million Americans. It has a major impact on public health expenditures with more than 1 in 10 health care dollars spent on treating diabetes and its complications. Although a variety of therapies can be useful in treatment of type 2 diabetes, we remain sufficiently ignorant of the genetic risk factors to believe that identifying them will lead to better understanding of the primary physiology of the disorder, as well as to more specific and effective therapies. Moreover, identification of genetic risk factors may improve our ability to characterize more specific non-genetic risk factors for this disease that could be the targets for cost-effective prevention strategies. This manuscript reviews the challenges we face in moving from the linkage mapping of susceptibility genes for type 2 diabetes toward the identification of the genetic variation that actually affects risk to this disorder. I illustrate many of the challenges in designing, conducting and interpreting these studies by reviewing recent research conducted on the calpain-10 gene, implicated in positional cloning studies as a candidate gene for type 2 diabetes.

Calpains play a role in insulin secretion and action

Studies of the genetic basis of type 2 diabetes suggest that variation in the calpain-10 gene affects susceptibility to this common disorder, raising the possibility that calpain-sensitive pathways may play a role in regulating insulin secretion and/or action. Calpains are ubiquitously expressed cysteine proteases that are thought to regulate a variety of normal cellular functions. Here, we report that short-term (4-h) exposure to the cell-permeable calpain inhibitors calpain inhibitor II and E-64-d increases the insulin secretory response to glucose in mouse pancreatic islets. This dose-dependent effect is observed at glucose concentrations above 8 mmol/l. This effect was also seen with other calpain inhibitors with different mechanisms of action but not with cathepsin inhibitors or other protease inhibitors. Enhancement of insulin secretion with short-term exposure to calpain inhibitors is not mediated by increased responses in intracellular Ca2+ or increased glucose metabolism in islets but by accelerated exocytosis of insulin granules. In muscle strips and adipocytes, exposure to both calpain inhibitor II and E-64-d reduced insulin-mediated glucose transport. Incorporation of glucose into glycogen in muscle also was reduced. These results are consistent with a role for calpains in the regulation of insulin secretion and insulin action.

Heritability of insulin secretion and insulin action in women with polycystic ovary syndrome and their first degree relatives

Polycystic ovary syndrome (PCOS), one of the most common endocrine disorders of reproductive age women, is associated with an increased risk of type 2 diabetes mellitus. Defects in both insulin action and insulin secretion contribute to this predisposition to diabetes, but the extent to which these defects are heritable among PCOS families has not been examined. In the present study we used the frequently sampled iv glucose tolerance test to quantitate insulin secretion (AIRg), insulin action (Si), and their product (AIRg x Si) among women with PCOS (n = 33) and their nondiabetic first degree relatives (n = 48). We then quantitated the heritability of these measures from familial correlations estimated within a genetic model. Familial (spousal, rhoMF; parent-offspring, rhoPO; and sibling, rhoSS) correlations were derived for log-transformed body mass index (BMI) as well as for AIRg, Si, and AIRg x Si, the latter three of which were adjusted for BMI. There was no evidence of significant heritability for either lnBMI or lnSi in these families. In contrast, the sibling correlation (rhoSS = 0.74) for lnAIRg was highly significant (chi(2) = 7.65; 1 df; P = 0.006). In addition, the parameter quantitating insulin secretion in relation to insulin sensitivity [i.e. ln(AIRg x Si)] was significant among siblings (rho(SS) = 0.74; chi(2) = 4.32; 1 df; P = 0.04). In summary, the results of the present study indicate that there is an heritable component to beta-cell dysfunction in families of women with PCOS. We conclude that heritability of beta-cell dysfunction is likely to be a significant factor in the predisposition to diabetes in PCOS.

Prevention and control of influenza. Recommendations of the Advisory Committee on Immunization Practices (ACIP)

This report updates the 2000 recommendations by the Advisory Committee on Immunization Practices (ACIP) on the use of influenza vaccine and antiviral agents (MMWR 2000;49[No. RR-3]:1-38). The 2001 recommendations include new or updated information regarding a) the cost-effectiveness of influenza vaccination; b) the influenza vaccine supply; c) neuraminidase-inhibitor antiviral drugs; d) the 2001-2002 trivalent vaccine virus strains, which are A/Moscow/10/99 (H3N2)-like, A/New Caledonia/20/99 (H1N1)-like, and B/Sichuan/379/99-like strains; and e) extension of the optimal time period for vaccination through November. A link to this report and other information regarding influenza can be accessed at the website for the Influenza Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, CDC at <http://www.cdc.gov/ncidod/diseases/flu/fluvirus.htm>.

Genome-wide linkage analyses of total serum IgE using variance components analysis in asthmatic families

Variance components models were used to analyze total IgE levels in families ascertained though the Collaborative Study of the Genetics of Asthma (CSGA) using a genome-wide array of polymorphic markers. While IgE levels are known to be associated with clinical asthma and recognized to be under strong genetic control (here the heritability was estimated at 44-60% in the three racial groups), specific genes influencing this trait are still largely unknown. Multipoint analysis of 323 markers yielded little indication of specific regions containing a trait locus controlling total serum IgE levels (adjusted for age and gender). Although a number of regions showed LOD statistics above 1.5 in Caucasian families (chromosome 4) and in African-American families (chromosomes 2 and 4), none yielded consistent evidence in all three racial groups. Analysis of total IgE adjusted for gender, age and Allergy Index (a quantitative score of skin test sensitivity to 14 common aeroallergens) was conducted on these data. In this analysis, a much stronger signal for a trait locus controlling adjusted log[total IgE] was seen on the telomeric end of chromosome 18, but only in Caucasian families. This region accounted for most of the genetic variation in log[total IgE], and may represent a quantitative trait locus for IgE levels independent of atopic response. Oligogenic analysis accounting simultaneously for the contribution of this locus on chromosome 18 and other chromosomal regions showing some evidence of linkage in these Caucasian families (on chromosomes 2, 4 and 20) failed to yield significant evidence for interaction.