Heritability of SF-36 Among Middle-Age, Middle-Class, Male???Male Twins

The aetiological relationship between depressive symptoms and health-related quality of life: A population-based twin study in Sri Lanka

Objective

Depression often co-occurs with poor health-related quality of life (HRQL). Twin studies report genetic and individual-level environmental underpinnings in the aetiology of both depression and HRQL, but there is limited twin research exploring this association further. There is also little evidence on sex differences and non-Western populations are underrepresented. In this paper we explored the phenotypic and aetiological relationship between depressive symptoms and HRQL and possible sex differences in a low-middle-income Sri Lankan population.

Method

Data for 3,948 participants came from the Colombo Twin and Singleton Follow-up Study (CoTaSS-2). Using self-report measures of depressive symptoms and HRQL, we conducted univariate and bivariate sex-limitation twin analyses.

Results

Depressive symptoms showed moderate genetic (33%) and strong nonshared environmental influences (67%). Nonshared environment accounted for the majority of variance in all the subscales of HRQL (ranging from 68 to 93%), alongside small genetic influences (ranging from 0 to 23%) and shared environmental influences (ranging from 0 to 28%). Genetic influences were significant for emotional wellbeing (23%). Shared environmental influences were significant for four out of the eight HRQL variables (ranging from 22–28%), and they were more prominent in females than males. Depressive symptoms were significantly associated with lower HRQL scores. These correlations were mostly explained by overlapping nonshared environmental effects. For traits related to emotional functioning, we also detected substantial overlapping genetic influences with depressive symptoms.

Conclusions

Our study confirmed previous findings of a negative association between depressive symptoms and HRQL. However, some of the aetiological factors of HRQL differed from Western studies, particularly regarding the effects of shared environment. Our findings highlight the importance of cross-cultural research in understanding associations between psychological wellbeing and HRQL.

Associations Between Anxiety Symptoms and Health-Related Quality of Life: A Population-Based Twin Study in Sri Lanka

Anxiety not only concerns mental wellbeing but also negatively impacts other areas of health. Yet, there is limited research on (a) the genetic and environmental aetiology of such relationships; (b) sex differences in aetiology and (c) non-European samples. In this study, we investigated the genetic and environmental variation and covariation of anxiety symptoms and eight components of health-related quality of life (QoL), as measured by the short form health survey (SF-36), using genetic twin model fitting analysis. Data was drawn from the Colombo Twin and Singleton Study (COTASS), a population-based sample in Sri Lanka with data on twins (N = 2921) and singletons (N = 1027). Individual differences in anxiety and QoL traits showed more shared environmental (family) effects in women. Men did not show familial effects. Anxiety negatively correlated with all eight components of QoL, mostly driven by overlapping unique (individual-specific) environmental effects in both sexes and overlapping shared environmental effects in women. This is the first study in a South Asian population supporting the association between poor mental health and reduced QoL, highlighting the value of integrated healthcare services. Associations were largely environmental, on both individual and family levels, which could be informative for therapy and intervention.

Predicting Health-Related Quality of Life in Trauma-Exposed Male Veterans in Late Midlife: A 20 Year Longitudinal Study

Trauma-exposed adults with high levels of posttraumatic stress symptoms (PTSS) report poorer health-related quality of life (HRQOL), but less is known about the persistence of this relationship over time. Participants from the Vietnam Era Twin Study of Aging reported on PTSS, health, and sociodemographic characteristics at average age 38; 775 participants reported having been exposed to trauma. Later, at average ages 56 and 62, mental and physical HRQOL were assessed with the Short-Form 36. Premorbid risk for anxiety/neuroticism was evaluated with a polygenic risk score derived from a large genome-wide association study meta-analysis. In multivariate mixed models, having higher levels of PTSS, poorer self-rated health, lower income, and less education at age 38 were associated with worse physical and mental HRQOL two decades later. Chronic health problems at age 38 predicted midlife physical but not mental HRQOL. Although genetic risk for neuroticism was correlated with HRQOL and PTSS, it was no longer significant in multivariate models. Health-related quality of life (HRQOL) predicts morbidity and mortality independently of objective health measures; early interventions may help to mitigate the ongoing impact of trauma on quality of life.

Genetic variation in health insurance coverage

We provide the first investigation into whether and how much genes explain having health insurance coverage or not and possible mechanisms for genetic variation. Using a twin-design that compares identical and non-identical twins from a national sample of US twins from the National Survey of Midlife Development in the United States, we find that genetic effects explain over 40% of the variation in whether a person has any health coverage versus not, and nearly 50% of the variation in whether individuals younger than 65 have private coverage versus whether they have no coverage at all. Nearly one third of the genetic variation in being uninsured versus having private coverage is explained by employment industry, self-employment status, and income, and together with education, they explain over 40% of the genetic influence. Marital status, number of children, and available measures of health status, risk preferences, and prevention effort do not appear to be important channels for genetic effects. That genes have meaningful effects on the insurance status suggests an important source of heterogeneity in insurance take up.

Associations of HSP90AA2 gene polymorphisms with disease susceptibility, glucocorticoids efficacy and health-related quality of life in Chinese systemic lupus erythematosus patients

Although the current glucocorticoids (GCs) treatment for systemic lupus erythematosus (SLE) is effective to a certain extent, the difference in therapeutic effect between patients is still a widespread problem. Some patients can have repeated attacks that greatly diminish their quality of life. This study was conducted to investigate the relationship between HSP90AA2 polymorphisms and disease susceptibility, GCs efficacy and health-related quality of life (HRQoL) in Chinese SLE patients. A case-control study was performed in 470 SLE patients and 470 normal controls. Then, 444 patients in the case group were followed up for 12 weeks to observe efficacy of GCs and improvement of HRQoL. Two single nucleotide polymorphisms (SNPs) of HSP90AA2 were selected for genotyping: rs1826330 and rs6484340. HRQoL was assessed using the SF-36 questionnaire. The minor T allele of rs1826330 and the TT haplotype formed by rs1826330 and rs6484340 showed associations with decreased SLE risk (T allele: P_BH = 0.022; TT haplotype: P_BH = 0.033). A significant association between rs6484340 and improvement of HRQoL was revealed in the follow-up study. Five subscales of SF-36 were appeared to be influenced by rs6484340: total score of SF-36 (additive model: P_BH = 0.026), physical function (additive model: P_BH = 0.026), role-physical (recessive model: P_BH = 0.041), mental health (dominant model: P_BH = 0.047), and physical component summary (additive model: P_BH = 0.026). No statistical significance was found between HSP90AA2 gene polymorphisms and GCs efficacy. These results revealed a genetic association between HSP90AA2 and SLE. Remarkably, HSP90AA2 has an impact on the improvement of HRQoL in Chinese population with SLE.

Relations between subdomains of physical activity, sedentary lifestyle, and quality of life in young adult men

To assess the relationship between physical activity (PA) in work, transport, domestic, and leisure-time domains (with sitting time included) and health-related quality of life (HRQoL) among young adult men. The long version of IPAQ and SF-36 Health Survey were used to assess PA and HRQoL, respectively, in 1425 voluntary 20- to 40-year-old Finnish male participants. Participants were divided into tertiles (MET-h/week): Lowest tertile (<38 MET-h/week), Middle tertile (38-100 MET-h/week), and Highest tertile (>100 MET-h/week). The IPAQ domain leisure-time PA predicted positively the Physical Component Summary (PCS) (β = 0.11, 95% CI: 0.06 to 0.16) and Mental Component Summary (MCS) (β = 0.11, 95% CI: 0.05 to 0.16) dimensions. Occupational PA predicted negative relationships in the PCS (β = -0.13, 95% CI: -0.19 to -0.07), and sitting time predicted negative relationships in the MCS dimension (β = -0.13, 95% CI: -0.18 to -0.07). In addition, a linear relationship was found between total PA level (including sitting time) and all of the IPAQ domains (<0.001). The Middle tertile had the highest leisure-time PA (38% of total PA), whereas the highest sitting time (28%) and lowest occupational PA (8%) were found in the Lowest tertile. The Highest tertile had the highest occupational PA (61%), while the leisure-time PA was the lowest (16%). Different PA domains appear to have positive and negative relationships to mental and physical aspects of HRQoL. Relatively high leisure-time PA indicated a better HRQoL regardless of the amount of total PA, while occupational PA and higher daily sitting time related negatively to HRQoL.

Facets of Subjective Health From Early Adulthood to Old Age

OBJECTIVE

Subjective health is a complex indicator predicting longevity independent of objective health. Few studies examine genetic and environmental mechanisms underlying different facets of subjective health across the life course.

METHOD

Three subjective health measures were examined in 12,900 twins ( M_age = 63.38, range = 25-102) from nine studies in the Interplay of Genes and Environment across Multiple Studies Consortium: self-rated health (SRH), health compared with others (COMP), and health interfering with activities (ACT).

RESULTS

Analyses indicated age and sex differences in mean scores depending on the measure. SRH and ACT showed significant linear and non-linear moderation by age for individual differences in both genetic and environmental variance. Significant sex differences in components of variance were found for SRH and ACT, but not COMP.

DISCUSSION

Subjective health appears to be dependent on frame of reference and reflect different aspects of health. Results suggest different genetic and environmental mechanisms underlie each facet.

Serotonin Transporter and COMT Polymorphisms as Independent Predictors of Health-related Quality of Life in Patients with Panic Disorder

There is growing evidence of poor health-related quality of life (HRQOL) in patients with panic disorder (PD). However, little is known about the factors affecting HRQOL in patients with PD. The authors examined whether 5-HTTLPR tri-allelic approach and Cathechol-O-methyltransferase (COMT) Val(158)Met polymorphism can predict HRQOL in patients with PD controlling for sociodemographic factors and disorder-related symptom levels. The sample consisted of 179 patients with PD consecutively recruited from an outpatient clinic and age- and gender ratio-matched 110 healthy controls. The SF-36 was used to assess multiple domains of HRQOL. Hierarchical multiple regression analysis was performed to determine the independent effect of the 5-HTTLPR and COMT Val(158)Met on the SF-36 in panic patients. Patients with PD showed lowered HRQOL in all sub-domains of the SF-36 compared to healthy controls. The 5-HTTLPR independently and additively accounted for 2.2% of variation (6.7% of inherited variance) of perceived general health and the COMT Val(158)Met independently and additively accounted for 1.5% of variation (5.0% of inherited variance) of role limitation due to emotional problems in patient group. The present study suggests that specific genetic polymorphisms are associated with certain domains of HRQOL and provides a new insight on exploring the factors that predict HRQOL in patients with PD.

Evidence of associations between cytokine gene polymorphisms and quality of life in patients with cancer and their family caregivers

PURPOSE/OBJECTIVES

To identify latent classes of individuals with distinct quality-of-life (QOL) trajectories, to evaluate for differences in demographic characteristics between the latent classes, and to evaluate for variations in pro- and anti-inflammatory cytokine genes between the latent classes.

DESIGN

Descriptive, longitudinal study.

SETTING

Two radiation therapy departments located in a comprehensive cancer center and a community-based oncology program in northern California.

SAMPLE

168 outpatients with prostate, breast, brain, or lung cancer and 85 of their family caregivers (FCs).

METHODS

Growth mixture modeling (GMM) was employed to identify latent classes of individuals based on QOL scores measured prior to, during, and for four months following completion of radiation therapy. Single nucleotide polymorphisms (SNPs) and haplotypes in 16 candidate cytokine genes were tested between the latent classes. Logistic regression was used to evaluate the relationships among genotypic and phenotypic characteristics and QOL GMM group membership.

MAIN RESEARCH VARIABLES

QOL latent class membership and variations in cytokine genes.

FINDINGS

Two latent QOL classes were found: higher and lower. Patients and FCs who were younger, identified with an ethnic minority group, had poorer functional status, or had children living at home were more likely to belong to the lower QOL class. After controlling for significant covariates, between-group differences were found in SNPs in interleukin 1 receptor 2 (IL1R2) and nuclear factor kappa beta 2 (NFKB2). For IL1R2, carrying one or two doses of the rare C allele was associated with decreased odds of belonging to the lower QOL class. For NFKB2, carriers with two doses of the rare G allele were more likely to belong to the lower QOL class.

CONCLUSIONS

Unique genetic markers in cytokine genes may partially explain interindividual variability in QOL.

IMPLICATIONS FOR NURSING

Determination of high-risk characteristics and unique genetic markers would allow for earlier identification of patients with cancer and FCs at higher risk for poorer QOL. Knowledge of these risk factors could assist in the development of more targeted clinical or supportive care interventions for those identified.

Association between single-nucleotide polymorphisms in growth factor genes and quality of life in men with prostate cancer and the general population

PURPOSE

Improved survival for men with prostate cancer has led to increased attention to factors influencing quality of life (QOL). As protein levels of vascular endothelial growth factor (VEGF) and insulin-like growth factor 1 (IGF-1) have been reported to be associated with QOL in people with cancer, we sought to identify whether single-nucleotide polymorphisms (SNPs) of these genes were associated with QOL in men with prostate cancer.

METHODS

Multiple linear regression of two data sets (including approximately 750 men newly diagnosed with prostate cancer and 550 men from the general population) was used to investigate SNPs of VEGF and IGF-1 (10 SNPs in total) for associations with QOL (measured by the SF-36v2 health survey).

RESULTS

Men with prostate cancer who carried the minor 'T' allele for IGF-1 SNP rs35767 had higher mean Role-Physical scale scores (≥0.3 SD) compared to non-carriers (p < 0.05). While this association was not identified in men from the general population, one IGF-1 SNP rs7965399 was associated with higher mean Bodily Pain scale scores in men from the general population that was not found in men with prostate cancer. Men from the general population who carried the rare 'C' allele had higher mean Bodily Pain scale scores (≥0.3 SD) than non-carriers (p < 0.05).

CONCLUSIONS

Through identifying SNPs that are associated with QOL in men with prostate cancer and men from the general population, this study adds to the mapping of complex interrelationships that influence QOL and suggests a role for IGF-I in physical QOL outcomes. Future research may identify biomarkers associated with increased risk of poor QOL that could assist in the provision of pre-emptive support for those identified at risk.

Prevention, Use of Health Services, and Genes: Implications of Genetics for Policy Formation

We evaluate the hypothesis that genetic factors influence the use of health services and prevention behaviors in a national sample of adult twins in the United States. The analysis compares the correlation of these outcomes between identical twins, who share all their genes, to the correlation between nonidentical twins, who share, on average, only one-half of their genes. Because the environmental similarities of twins are assumed to be the same for identical and nonidentical twin pairs, researchers can partition the variance in behavioral outcomes that are due to genetic and environmental factors. Using established methods in this field, we find evidence of significant genetic influences on preferences toward prevention, overall prevention effort, routine checkups, and prescription drug use. Use of curative services does not appear to be influenced by genes. Our findings offer several implications for policymakers and researchers and suggest that genetics could be informative for health services and policy research.

Genetic variations underlying self-reported physical functioning: a review

PURPOSE

Genetic associations with self-reported physical functioning (SPF) are less well-studied than genetic associations with performance-measured physical functioning (PPF). We review the literature on the associations of genetic variations on SPF. We provide an overview of SPF assessment, genetic contributions to SPF including heritability, effects of genetic variations and mutations, and effects of interventions on the gene-SPF relationship. We also aim to provide directions for future research.

METHODS

A computerized literature search using PubMed, Web of Science, and PsychInfo was conducted to select relevant literature published up to November 2013. Inclusion criteria were the use of an SPF questionnaire, original articles in English on human subjects, published in peer-reviewed journals and reporting significant associations between SPF and the genome.

RESULTS

Nineteen articles were included. SPF was commonly assessed with the Short Form-36 questionnaire involving mainly convenience samples of either older persons or chronically ill. Heritability estimates were 10-30 %. Candidate genes associated with SPF could be ascribed to biological pathways associated with neurodegeneration, physiological systems regulation, or cell regulation. The APOE gene associated with neurodegeneration was most studied (n = 3). Three papers included both SPF and PPF assessments. No genome-wide association study on SPF has been conducted.

CONCLUSIONS

Associations between SPF and the genome have been investigated in selected populations in a limited number of publications. Future research should consider increasing sample variation and incorporate both SPF and PPF assessments. Also, longitudinal studies should be conducted in order to elicit stronger conclusions regarding the genetic associations with SPF.

Health-related quality of life in alcohol dependence: a systematic literature review with a specific focus on the role of depression and other psychopathology

BACKGROUND

Health-related quality of life (HRQOL) is considered a valid measure of treatment effectiveness in addictions. However, alcohol research has lagged behind other biomedical fields in using HRQOL outcomes as primary or secondary endpoints. Previous work has suggested that psychiatric co-morbidity may mediate the relationship between alcohol dependence and HRQOL.

AIM

The goal was to summarize the literature on HRQOL and its domains in the context of alcohol dependence. A specific focus was on the impact of depression and other psychopathology on these areas of life.

MATERIALS AND METHODS

A database search of MEDLINE and PsychINFO was performed within the scope of PARADISE (Psychosocial fActors Relevant to brAin DISorders in Europe); a European Commission funded coordination action. Using pre-defined eligibility criteria, 42 studies were identified. A systematic approach to data collection was employed.

RESULTS AND CONCLUSIONS

Alcohol dependence was shown to affect overall HRQOL and its domains, including general health, physical and mental health, general and social functioning, activities of daily living, pain and sleep. The evidence demonstrating that alcohol dependence is a primary cause of impairments in overall HRQOL, general health, mental and physical health and social functioning was fairly strong. Treatment interventions helped improve HRQOL and its aforementioned domains. The reduction or cessation of alcohol use facilitated these improvements; however, it was not reported to be predictive of improvement in all instances where improvement was reported. Depression was associated with further decreases in HRQOL. Personality disorders contributed to the severity of social functioning impairment.

Genetic predictors of risk and resilience in psychiatric disorders: a cross-disorder genome-wide association study of functional impairment in major depressive disorder, bipolar disorder, and schizophrenia

Functional impairment is one of the most enduring, intractable consequences of psychiatric disorders and is both familial and heritable. Previous studies have suggested that variation in functional impairment can be independent of symptom severity. Here we report the first genome-wide association study (GWAS) of functional impairment in the context of major mental illness. Participants of European-American descent (N = 2,246) were included from three large treatment studies of bipolar disorder (STEP-BD) (N = 765), major depressive disorder (STAR*D) (N = 1091), and schizophrenia (CATIE) (N = 390). At study entry, participants completed the SF-12, a widely used measure of health-related quality of life. We performed a GWAS and pathway analysis of the mental and physical components of health-related quality of life across diagnosis (∼1.6 million single nucleotide polymorphisms), adjusting for psychiatric symptom severity. Psychiatric symptom severity was a significant predictor of functional impairment, but it accounted for less than one-third of the variance across disorders. After controlling for diagnostic category and symptom severity, the strongest evidence of genetic association was between variants in ADAMTS16 and physical functioning (P = 5.87 × 10(-8) ). Pathway analysis did not indicate significant enrichment after correction for gene clustering and multiple testing. This study illustrates a phenotypic framework for examining genetic contributions to functional impairment across psychiatric disorders.

Association of healthy aging with parental longevity

Various measures incorporated in geriatric assessment have found their way into frailty indices (FIs), which have been used as indicators of survival/mortality and longevity. Our goal is to understand the genetic basis of healthy aging to enhance its evidence base and utility. We constructed a FI as a quantitative measure of healthy aging and examined its characteristics and potential for genetic analyses. Two groups were selected from two separate studies. One group (OLLP for offspring of long-lived parents) consisted of unrelated participants at least one of whose parents was age 90 or older, and the other group of unrelated participants (OSLP for offspring of short-lived parents), both of whose parents died before age 76. FI34 scores were computed from 34 common health variables and compared between the two groups. The FI34 was better correlated than chronological age with mortality. The mean FI34 value of the OSLP was 31 % higher than that of the OLLP (P = 0.0034). The FI34 increased exponentially, at an instantaneous rate that accelerated 2.0 % annually in the OLLP (P = 0.024) and 2.7 % in the OSLP (P < < 0.0001) consequently yielding a 63 % larger accumulation in the latter group (P = 0.0002). The results suggest that accumulation of health deficiencies over the life course is not the same in the two groups, likely due to inheritance related to parental longevity. Consistent with this, sib pairs were significantly correlated regarding FI34 scores, and heritability of the FI34 was estimated to be 0.39. Finally, hierarchical clustering suggests that the OLLP and OSLP differ in their aging patterns. Variation in the FI34 is, in part, due to genetic variation; thus, the FI34 can be a phenotypic measure suitable for genetic analyses of healthy aging.

Relationship of back and neck pain with quality of life in the Croatian general population

OBJECTIVE

The purpose of this study was to determine the prevalence of back pain and neck pain and their relationship with the quality of life in the Croatian general population.

METHODS

This was a cross-sectional study using home-based face-to-face interviews of 1030 participants (51.6% females) 15 years or older. Back and neck pain frequencies were assessed using single items and quality of life using the Short Form Survey and Satisfaction with Life Scale. Analysis of covariance was conducted, where back pain or neck pain frequency was used as the categorical predictor; physical component summary or mental component summary, as the dependent variable; and age, body mass index, and physical activity level, as covariates.

RESULTS

The prevalence of back pain was 66.3% (95% confidence interval [CI], 62.3%-70.3%) and 62.9% (95% CI, 58.7%-67.2%) in females and males, respectively. The prevalence of neck pain was 58.0% (95% CI, 53.8%-62.2%) for females and 53.6 (95% CI, 49.2%-58.0%) for males. Differences between men and women were not significant (P>.05). Adjusted mean values for physical component summary and mental component summary were substantially lower in participants who reported back or neck pain often/almost always compared with those without pain. Differences ranged from 8.11 to 11.86 points (95% CI, 5.54-13.99) and from 9.61 to 10.99 points (95% CI, 7.35-13.45) in females and males, respectively.

CONCLUSIONS

The findings of this study showed that back and neck pain are highly prevalent and negatively related to quality of life in the Croatian general population. These data might raise the awareness of local government health authorities and lead to improvements in health care service for people with back and neck pain.

Heritability of health-related quality of life: SF-12 summary scores in a population-based nationwide twin cohort

AIM

The present study aims to estimate the relative importance of genetic and environmental factors for health-related quality of life (HRQL) measured by the 12-item Short-Form Health Survey (SF-12).

METHODS

The study was based on two Danish twin cohorts (46,417 twin individuals) originating from the nationwide, population-based Danish Twin Registry. The twins were approached by a mailed-out questionnaire in 2002. The questionnaire included the SF-12, information on demographic factors, and questions on a variety of specific diseases. Heritability of the SF-12 includes the physical component summary (PCS) and the mental component summary (MCS); and etiologically important variance components were estimated using multivariate biometric models. The respondents were stratified into six groups, based on age and sex.

RESULTS

A total of 33,794 (73%) individual twins responded to the survey. The SF-12 was completed by 29,619 individuals, which included 9,120 complete twin pairs. Overall, the best-fitting model explaining the variance of HRQL was the ACE model. The estimated heritability of the SF-12 was between 11% and 35%, whereas between 65% and 89% could be explained by unique environmental or stochastic factors in the different sex and age groups. The highest heritability was seen among older twins. In addition, the genetic correlation between MCS and PCS scores was low (0.07 and 0.23 for males and females, respectively) among younger and high (0.26 and 0.45 for males and females, respectively) in the oldest age group. Both the largest genetic influence on HRQL and the largest genetic overlap between the scores were seen in the oldest age group, which consisted of twins older than 55. The unique environmental correlation between MCS and PCS were generally negative.

CONCLUSION

The heritability of HRQL differs between different age groups. In general, most of the variance in the SF-12 summary components was determined by unique environmental factors.

Scientific imperatives, clinical implications, and theoretical underpinnings for the investigation of the relationship between genetic variables and patient-reported quality-of-life outcomes

Objectives

There is emerging evidence for a genetic basis of patient-reported quality-of-life (QOL) outcomes that can ultimately be incorporated into clinical research and practice. Objectives are (1) to provide arguments for the timeliness of investigating the genetic basis of QOL given the scientific advances in genetics and patient-reported QOL research; (2) to describe the clinical implications of such investigations; (3) to present a theoretical foundation for investigating the genetic underpinnings of QOL; and (4) to describe a series of papers resulting from the GENEQOL Consortium that was established to move this work forward.

Methods

Discussion of scientific advances based on relevant literature.

Results

In genetics, technological advances allow for increases in speed and efficiency and decreases in costs in exploring the genetic underpinnings of disease processes, drug metabolism, treatment response, and survival. In patient-based research, advances yield empirically based and stringent approaches to measurement that are scientifically robust. Insights into the genetic basis of QOL will ultimately allow early identification of patients susceptible to QOL deficits and to target care. The Wilson and Cleary model for patient-reported outcomes was refined by incorporating the genetic underpinnings of QOL.

Conclusions

This series of papers provides a path for QOL and genetics researchers to work together to move this field forward and to unravel the intricate interplay of the genetic underpinnings of patient-reported QOL outcomes. The ultimate result will be a greater understanding of the process relating disease, patient, and doctor that will have the potential to lead to improved survival, QOL, and health services delivery.

Do Measured and Unmeasured Family Factors Bias the Association Between Education and Self-Assessed Health?

The association between educational attainment and self-assessed health is well established but the mechanisms that explain this association are not fully understood yet. It is likely that part of the association is spurious because (genetic and non-genetic) characteristics of a person's family of origin simultaneously affect one's educational attainment and one's adult health. In order to obtain an unbiased estimate of the association between education and health, we have to control for all relevant family factors. In practice, however, it is impossible to measure all relevant family factors. Sibling models are particularly appropriate in this case, because they control for the total impact of family factors, even if not all relevant aspects can be measured. I use data on siblings from a US study (MIDUS) and Dutch study (NKPS) to assess the total family impact on self-assessed health and, more importantly, to assess whether there is a family bias in the association between educational attainment and self-assessed health. The results suggest that there is a substantial family effect; about 20% of the variation in self-assessed health between siblings can be ascribed to (measured and unmeasured) family factors. Measured family factors, such as parental education and father's occupation, could account only for a small part of the family effect. Furthermore, the results imply that it is unlikely that there is substantial bias due to family effects in the association between education and self-assessed health. This strengthens the conclusions from prior studies on the association between education and self-assessed health.

Disregarding clinical trial-based patient-reported outcomes is unwarranted: Five advances to substantiate the scientific stringency of quality-of-life measurement

BACKGROUND

The clinical impact of trial-based quality of life (QL) outcomes is frequently underestimated due, in part, to prejudice and lack of knowledge by the medical community. The objectives of this paper are to show that QL assessments build upon an empirically based and stringent approach to measurement and QL outcomes should not be viewed nor handled differently than any other parameter in medical research.

MATERIAL AND METHODS

Literature overview.

RESULTS

The objectives are substantiated with empirical evidence showing that: (1) existing QL measures are as reliable as most other clinical outcomes; (2) available guidelines improve the quality of trial-based QL data; (3) QL data have strong prognostic value for survival; (4) clinical significance of QL data can be established; and (5) accounting for response-shift effects in QL data over time is feasible. Finally, the investigation of the genetic disposition of QL is described as an emerging area of research.

DISCUSSION

It is a waste of effort and money and also unethical when collected trial-based QL data are not used to their full power. QL and other patient-reported outcomes deserve to be included in more trials, with full disclosure of all results, and standardized interpretation. Only the combined use of patient-reported and clinical outcomes will enable the examination of the extent to which cancer patients live a qualitatively good life as long as possible.

The establishment of the GENEQOL consortium to investigate the genetic disposition of patient-reported quality-of-life outcomes

To our knowledge, no comprehensive, interdisciplinary initiatives have been taken to examine the role of genetic variants on patient-reported quality-of-life outcomes. The overall objective of this paper is to describe the establishment of an international and interdisciplinary consortium, the GENEQOL Consortium, which intends to investigate the genetic disposition of patient-reported quality-of-life outcomes. We have identified five primary patient-reported quality-of-life outcomes as initial targets: negative psychological affect, positive psychological affect, self-rated physical health, pain, and fatigue. The first tangible objective of the GENEQOL Consortium is to develop a list of potential biological pathways, genes and genetic variants involved in these quality-of-life outcomes, by reviewing current genetic knowledge. The second objective is to design a research agenda to investigate and validate those genes and genetic variants of patient-reported quality-of-life outcomes, by creating large datasets. During its first meeting, the Consortium has discussed draft summary documents addressing these questions for each patient-reported quality-of-life outcome. A summary of the primary pathways and robust findings of the genetic variants involved is presented here. The research agenda outlines possible research objectives and approaches to examine these and new quality-of-life domains. Intriguing questions arising from this endeavor are discussed. Insight into the genetic versus environmental components of patient-reported quality-of-life outcomes will ultimately allow us to explore new pathways for improving patient care. If we can identify patients who are susceptible to poor quality of life, we will be able to better target specific clinical interventions to enhance their quality of life and treatment outcomes.

Alcohol consumption and health among elders

PURPOSE

This article estimates the effects of alcohol consumption on self-reported overall health status, injuries, heart problems, emergency room use, and hospitalizations among persons older than the age of 65.

DESIGN AND METHODS

We analyzed data from the first wave of the National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative study. We used multivariate regression and instrumental variables methods to study the associations between alcohol consumption (current drinking, binge drinking, and average number of drinks consumed) and several indicators of health status and health care utilization.

RESULTS

Alcohol consumption by women was associated with better self-perceived health status, improved cardiovascular health, and lower rates of hospitalizations. We detected no significant negative or positive associations for older men.

IMPLICATIONS

These findings suggest that light to moderate alcohol use by older women may have beneficial health effects. Experimental trials, however, are needed to more rigorously assess the potential benefits of alcohol use by elders due to the inherent biases of observational studies.

Reflections on changeability versus stability of health-related quality of life: distinguishing between its environmental and genetic components

The field of health-related quality of life (HRQOL) could benefit from a broadening of perspectives to include recent advancements in research on adaptation, positive psychology, and genetics. These advances shed new light on the extent to which HRQOL is changeable or fixed. The objective of this paper is to integrate these insights and to discuss their implications for HRQOL research. We describe the Hedonic Treadmill theory, which asserts that positive events only temporarily affect happiness since people quickly return to hedonic neutrality. New empirical evidence suggests important revisions of this theory, providing a more optimistic picture of the possibility for change. Advances in positive psychology show that relatively simple interventions have the power to induce a sustainable increase in levels of happiness. Finally, a small but growing number of studies have found independent genetic influences in well-being, life satisfaction, perceived health, and even HRQOL. Given the increasing empirical evidence that HRQOL can be sustainably enhanced and is in part genetically determined, it may be useful to consider HRQOL as a concept that has state (environmental) and trait (genetic) components. This distinction will allow us to explore new pathways of improving theory, methods, and clinical practice. The overarching novel questions concern the extent to which HRQOL components are environmentally or genetically determined, and which factors lead to lasting improvement. This distinction begs for new research approaches, such as time-sampling techniques and interdisciplinary research investigating the genetic variants of HRQOL. Distinguishing between those aspects that are amenable to change from those that are relatively fixed and stable will help better target specific support interventions.

Quality of life in unaffected twins discordant for affective disorder

BACKGROUND

The disability and hardship associated with affective disorder is shared by the family members of affective patients and might affect the family member's quality of life.

METHOD

In a cross-sectional, high-risk, case-control study, monozygotic (MZ) and dizygotic (DZ) twins with (High-Risk twins) and without (the control group/Low-Risk twins) a co-twin history of affective disorder were identified through nationwide registers. The aim of the present study was to investigate the hypothesis that a genetic liability to affective disorder is associated with a lower perception of quality of life.

RESULTS

Univariate analyses showed that quality of life in all domains was impaired for the 121 High-Risk twins compared to the 84 Low-Risk twins. In multiple regression analyses, the differences remained significant after adjustment for sex, age, marital status and years of education. Adjusted for the effect of subclinical anxiety and depressive symptoms, the differences were significant on the domain environment and total WHOQoL-BREF and marginally significant on the domain physical health and overall quality of life.

LIMITATIONS

It is not possible from the cross-sectional analyses to distinguish between subsyndromal state and trait scores.

CONCLUSIONS

Perceived health related quality of life might share common familial vulnerability with affective disorders. Having a co-twin with affective disorder seem to have a negative influence on quality of life of the healthy co-twin and this influence might be due to the genetic liability to affective disorder. These findings need to be replicated in future family studies.

A common variant of the p16(INK4a) genetic region is associated with physical function in older people

p16(INK4a) is active in cell senescence, ageing and tumor suppression. Deletion of the small p16(INK4a)/ARF/p15(INK4b) region occurs in many cancers. We screened 25 common polymorphisms across the region and three related genes for associations with physical functioning in older people. In an initial sample of 938 (aged 65-80 years) from the EPIC study (Norfolk, UK), the rs2811712 SNP minor allele (located between the shared p16(INK4a)/ARF locus and p15(INK4b)) was associated with reduced physical impairment. This association remained after testing an additional 1319 EPIC-Norfolk samples (p-value=0.013, total n=2257), and on independent replication in the InCHIANTI study (n=709, p=0.015), and at one-sided significance in Iowa-EPESE (n=419, p=0.079). Overall (n=3372), the prevalence of severely limited physical function was 15.0% in common homozygotes and 7.0% in rare homozygotes (per minor allele odds ratio=1.48, 95% CI: 1.17-1.88, p=0.001, adjusted for age, sex and study). This estimate was similar excluding screening set 1 (OR=1.45, 95% CI: 1.09-1.92, p=0.010, n=2434). These findings require further replication, but provide the first direct evidence that the p16(INK4a)/ARF/p15(INK4b) genetic region and the senescence machinery are active in physical ageing in heterogeneous human populations. The mechanism involved may be via greater cellular restorative activity and reduced stem cell senescence.