Education as a moderator of genetic risk for higher body mass index: prospective cohort study from childhood to adulthood.

OBJECTIVES: The life-course development of body mass index (BMI) may be driven by interactions between genes and obesity-inducing social environments. We examined whether lower parental or own education accentuates the genetic risk for higher BMI over the life course, and whether diet and physical activity account for the educational differences in genetic associations with BMI. SUBJECTS/METHODS: The study comprised 2441 participants (1319 women, 3-18 years at baseline) from the prospective, population-based Cardiovascular Risk in Young Finns Study. BMI (kg/m2) trajectories were calculated from 18 to 49 years, using data from six time points spanning 31 years. A polygenic risk score for BMI was calculated as a weighted sum of risk alleles in 97 single-nucleotide polymorphisms. Education was assessed via self-reports, measured prospectively from participants in adulthood and from parents when participants were children. Diet and physical activity were self-reported in adulthood. RESULTS: Mean BMI increased from 22.6 to 26.6 kg/m2 during the follow-up. In growth curve analyses, the genetic risk score was associated with faster BMI increase over time (b=0.02, (95% CI, 0.01-0.02, P<0.001)). The association between the genetic risk score and BMI was more pronounced among those with lower educational level in adulthood (b=-0.12 (95% CI, -0.23-0.01); P=0.036)). No interaction effect was observed between the genetic risk score and parental education (b=0.05 (95% CI, -0.09-0.18; P=0.51)). Diet and physical activity explained little of the interaction effect between the genetic risk score and adulthood education. CONCLUSIONS: In this prospective study, the association of a risk score of 97 genetic variants with BMI was stronger among those with low compared with high education. This suggests lower education in adulthood accentuates the risk of higher BMI in people at genetic risk.

Job strain as a risk factor for clinical depression: systematic review and meta-analysis with additional individual participant data.

BACKGROUND: Adverse psychosocial working environments characterized by job strain (the combination of high demands and low control at work) are associated with an increased risk of depressive symptoms among employees, but evidence on clinically diagnosed depression is scarce. We examined job strain as a risk factor for clinical depression. METHOD: We identified published cohort studies from a systematic literature search in PubMed and PsycNET and obtained 14 cohort studies with unpublished individual-level data from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium. Summary estimates of the association were obtained using random-effects models. Individual-level data analyses were based on a pre-published study protocol. RESULTS: We included six published studies with a total of 27 461 individuals and 914 incident cases of clinical depression. From unpublished datasets we included 120 221 individuals and 982 first episodes of hospital-treated clinical depression. Job strain was associated with an increased risk of clinical depression in both published [relative risk (RR) = 1.77, 95% confidence interval (CI) 1.47-2.13] and unpublished datasets (RR = 1.27, 95% CI 1.04-1.55). Further individual participant analyses showed a similar association across sociodemographic subgroups and after excluding individuals with baseline somatic disease. The association was unchanged when excluding individuals with baseline depressive symptoms (RR = 1.25, 95% CI 0.94-1.65), but attenuated on adjustment for a continuous depressive symptoms score (RR = 1.03, 95% CI 0.81-1.32). CONCLUSIONS: Job strain may precipitate clinical depression among employees. Future intervention studies should test whether job strain is a modifiable risk factor for depression.

Psychosocial factors associated with work disability in men and women with diabetes: a pooled analysis of three occupational cohort studies.

AIMS: To examine the extent to which adverse psychosocial factors, such as living alone, psychological distress, job strain and low support from supervisor, increase the risk of work disability (sickness absence and disability pension) among employees with diabetes. METHODS: In this pooled analysis of individual-participant data from three occupational cohort studies (the Finnish Public Sector Study, the British Whitehall II study, and the French GAZEL study), 1088 women and 949 men with diabetes were followed up to determine the duration (number of days) and frequency (number of spells) of work disability. The mean follow-up periods were 3.2 years in the GAZEL study, 4.6 years in the Whitehall II study and 4.7 years in the Finnish Public Sector Study. Psychosocial factors and potential confounding factors were assessed at baseline using standard questionnaires. Study-specific estimates were pooled using fixed-effects meta-analysis. RESULTS: In analysis adjusted for sociodemographic factors, health behaviours and comorbidities, participants with psychological distress had longer (rate ratio 1.66; 95% CI 1.31-2.09) and more frequent absences (rate ratio 1.33; 95% CI 1.19-1.49) compared with those with no psychological distress. Job strain was associated with slightly increased absence frequency (rate ratio 1.19 95% CI 1.05-1.35), but not with absence duration. Living alone and low supervisor support were not associated with absence duration or frequency. We observed no sex differences in these associations. CONCLUSIONS: Psychological distress was associated with increased duration and frequency of work disability among employees with diabetes. Job strain was associated with increased absence frequency but not with absence duration.

Job strain and risk of obesity: systematic review and meta-analysis of cohort studies.

Job strain, the most widely used indicator of work stress, is a risk factor for obesity-related disorders such as cardiovascular disease and type 2 diabetes. However, the extent to which job strain is related to the development of obesity itself has not been systematically evaluated. We carried out a systematic review (PubMed and Embase until May 2014) and meta-analysis of cohort studies to address this issue. Eight studies that fulfilled inclusion criteria showed no overall association between job strain and the risk of weight gain (pooled odds ratio for job strain compared with no job strain 1.04, 95% confidence interval (CI) 0.99-1.09, NTotal=18 240) or becoming obese (1.00, 95% CI 0.89-1.13, NTotal=42 222). In addition, a reduction in job strain over time was not associated with lower obesity risk (1.13, 95% CI 0.90-1.41, NTotal=6507). These longitudinal findings do not support the hypothesis that job strain is an important risk factor for obesity or a promising target for obesity prevention.

Association of metabolically healthy obesity with depressive symptoms: pooled analysis of eight studies.

The hypothesis of metabolically healthy obesity posits that adverse health effects of obesity are largely avoided when obesity is accompanied by a favorable metabolic profile. We tested this hypothesis with depressive symptoms as the outcome using cross-sectional data on obesity, metabolic health and depressive symptoms. Data were extracted from eight studies and pooled for individual-participant meta-analysis with 30,337 men and women aged 15-105 years (mean age=46.1). Clinic measures included height, weight and metabolic risk factors (high blood pressure, high triglycerides, low high-density lipoprotein cholesterol, high C-reactive protein and high glycated hemoglobin). Depressive symptoms were assessed using clinical interview or standardized rating scales. The pooled sample comprised 7673 (25%) obese participants (body mass index ⩾30 kg m(-2)). Compared to all non-obese individuals, the OR for depressive symptoms was higher in metabolically unhealthy obese individuals with two or more metabolic risk factors (1.45; 95% confidence interval (CI)=1.30, 1.61) and for metabolically healthy obese with ⩽1 metabolic risk factor (1.19; 95% CI=1.03, 1.37), adjusted for sex, age and race/ethnicity. Metabolically unhealthy obesity was associated with higher depression risk (OR=1.23; 95% CI=1.05, 1.45) compared with metabolically healthy obesity. These associations were consistent across studies with no evidence for heterogeneity in estimates (all I(2)-values<4%). In conclusion, obese persons with a favorable metabolic profile have a slightly increased risk of depressive symptoms compared with non-obese, but the risk is greater when obesity is combined with an adverse metabolic profile. These findings suggest that metabolically healthy obesity is not a completely benign condition in relation to depression risk.

Is personality associated with cancer incidence and mortality? An individual-participant meta-analysis of 2156 incident cancer cases among 42,843 men and women.

BACKGROUND: The putative role of personality in cancer risk has been controversial, and the evidence remains inconclusive. METHODS: We pooled data from six prospective cohort studies (British Household Panel Survey; Health and Retirement Study; Household, Income, and Labour Dynamics in Australia; Midlife in the United Survey; Wisconsin Longitudinal Study Graduate; and Sibling samples) for an individual-participant meta-analysis to examine whether personality traits of the Five Factor Model (extraversion, neuroticism, agreeableness, conscientiousness, and openness to experience) were associated with the incidence of cancer and cancer mortality in 42,843 cancer-free men and women at baseline (mean age 52.2 years, 55.6% women). RESULTS: During an average follow-up of 5.4 years, there were 2156 incident cancer cases. In random-effects meta-analysis adjusted for age, sex, and race/ethnicity, none of the personality traits were associated with the incidence of all cancers or any of the six site-specific cancers included in the analysis (lung, colon, breast, prostate, skin, and leukaemia/lymphoma). In the three cohorts with cause-specific mortality data (421 cancer deaths among 21,835 participants), none of the personality traits were associated with cancer mortality. CONCLUSIONS: These data suggest that personality is not associated with increased risk of incident cancer or cancer-related mortality.

Treatment of depression in diagnosed diabetes: common cause or detection bias?

BACKGROUND: This study examined two competing hypotheses concerning the association between diabetes and treatment for depression: (1) the detection/ascertainment bias hypothesis suggesting that those with diabetes are more likely to be diagnosed with and treated for depression because of increased medical attention and (2) a hypothesis assuming that diabetes and depression share common underlying pathophysiological pathways. METHOD: The study population included all persons aged 35-65 years in Finland with any record of type 2 diabetes in the national health and population registers from 1999 to 2002 and for whom register-based data on depression treatment (antidepressant medication use and hospitalizations for depression) were available at least 2 years before and after the diagnosis of diabetes (n = 18,217). Sociodemographic data were individually linked to the study population. Associations between diabetes diagnosis and time and indicators of depression care were assessed with population-averaged multilevel logistic models. RESULTS: Within the year following diagnosis diabetes, there was a 5% increase in antidepressant medication use but not in hospitalization for depression. The longitudinal change in antidepressant use over time was less steep after the diabetes diagnosis, and hospitalization risk decreased after the diagnosis. These associations between diabetes diagnosis and depression treatment were not modified by the participant's socio-economic position (SEP). CONCLUSIONS: These findings support the common cause hypothesis that treatment for diabetes is beneficial to the prevention of depression rather than the detection/ascertainment hypothesis that individuals with diabetes have higher rates of depression because they receive more medical attention in general.

Personality change associated with chronic diseases: pooled analysis of four prospective cohort studies.

BACKGROUND: Common chronic conditions, such as heart disease and cancer, are associated with increased psychological distress, functional limitations and shortened life expectancy, but whether these diseases alter aspects of personality remains unclear. METHOD: To examine whether the onset of heart disease, stroke, diabetes, cancer, hypertension, arthritis and respiratory disease is associated with subsequent changes in personality traits of the five-factor model, we pooled data from the Health and Retirement Study, the Midlife in the United States Survey, and the graduate and sibling samples of the Wisconsin Longitudinal Study for an individual-participant meta-analysis (total n=17,493; mean age at baseline 55.8 years). RESULTS: After adjustment for age, we observed consistent decreases in extraversion [-0.25 T-scores per one disease; 95% confidence interval (CI) -0.40 to -0.10], emotional stability (-0.40, 95% CI -0.61 to -0.19), conscientiousness (-0.44, 95% CI -0.57 to -0.30) and openness to experience (-0.25, 95% CI -0.37 to -0.13) but not in agreeableness (-0.05, 95% CI -0.19 to 0.08) after the onset of chronic diseases. The onset of each additional chronic disease accelerated the average age-related personality change by 2.5 years in decreasing extraversion, 5.5 years in decreasing conscientiousness, and 1.6 years in decreasing openness to experience, and attenuated the increasing levels of emotional stability by 1.9 years. Co-morbid conditions were associated with larger changes than single diseases, suggesting a dose-response association between morbidity and personality change. CONCLUSIONS: These results support the hypothesis that chronic diseases influence personality development in adulthood.

Ageing and the prevalence and treatment of mental health problems.

BACKGROUND: Ageing is an important factor in the development of mental health problems and their treatment. We assessed age trajectories of common mental disorders (CMDs) and psychotherapy utilization from adolescence to old age, and examined whether these trajectories were modified by time period or birth cohort effects. METHOD: British Household Panel Survey (BHPS) with an 18-year follow-up between 1991 and 2009 (n=30 224 participants, aged 15­100 years, with an average 7.3 person-observations per person). CMDs were assessed with the 12-item version of the General Health Questionnaire (GHQ). Psychotherapy treatment utilization during the past year was self-reported by the participants. The modifying influences of time period and cohort effects were assessed in a cohort-sequential longitudinal setting. RESULTS: Following a moderate decrease after age 50, the prevalence of GHQ caseness increased steeply from age 75. This increase was more marked in the 2000s (GHQ prevalence increasing from 24% to 43%) than in the 1990s (from 22% to 34%). Psychotherapy utilization decreased after age 55, with no time period or cohort effects modifying the age trajectory. These ageing patterns were replicated in within-individual longitudinal analysis. CONCLUSIONS: Old age is associated with higher risk of CMDs, and this association has become more marked during the past two decades. Ageing is also associated with an increasing discrepancy between prevalence of mental disorders and provision of treatment, as indicated by lower use of psychotherapy in older individuals.

Longitudinal course of depressive symptoms in adulthood: linear stochastic differential equation modeling.

BACKGROUND: Although many studies have addressed the topic of stability versus change in depressive symptoms, few have further decomposed the change to continuous accumulation versus non-systematic state fluctuations or measurement errors. This further step requires a longitudinal follow-up and an appropriate stochastic model; it would, for example, evaluate the hypothesis that women accumulate more susceptibility events than men. Method A linear stochastic differential equation model was estimated for a 16-year longitudinal course of depressive symptoms in the Young Finns community sample of 3596 participants (1832 women, 1764 men). This model enabled us to decompose the variance in depression symptoms into a stable trait, cumulative effects and state/error fluctuations. RESULTS: Women showed higher mean levels and higher variance of depressive symptoms than men. In men, the stable trait accounted for the majority [61%, 90% confidence interval (CI) 48.9-69.2] of the total variance, followed by cumulative effects (23%, 90% CI 9.9-41.7) and state/error fluctuations (16%, 90% CI 5.6-23.2). In women, the cumulative sources were more important than among men and accounted for 44% (90% CI 23.6-58.9) of the variance, followed by stable individual differences (32%, 90% CI 18.5-54.2) and state fluctuations (24%, 90% CI 19.1-27.3). CONCLUSIONS: The results are consistent with previous observations that women suffer more depression than men, and have more variance in depressive symptoms. We also found that continuously accumulating effects are a significant contributor to between-individual differences in depression, especially for women. Although the accumulating effects are often confounded with non-systematic state fluctuations, the latter are unlikely to exceed 27% of the total variance of depressive symptoms.

Childhood family factors predict developmental trajectories of hostility and anger: a prospective study from childhood into middle adulthood.

BACKGROUND: Low socio-economic status (SES), and a conflictive, cold and unsupportive family environment in childhood have been associated with early adulthood hostility. However, it is unknown whether this association changes in magnitude with age from childhood to adulthood. We investigated whether childhood family factors (SES and parental child-rearing style) predicted differential development of offspring hostility and anger from early to middle adulthood. METHOD: Between 2041 and 2316 participants (age range 3-18 years at baseline) were selected from the longitudinal Young Finns study. The participants were followed for 27 years between 1980 and 2007. Childhood SES and parent's self-reported child-rearing style were measured twice: at baseline and 3 years after baseline. Hostility and anger were assessed with self-report questionnaires at 12, 17, 21 and 27 years after baseline. RESULTS: Low parental SES and hostile child-rearing style at baseline predicted higher mean levels of offspring anger and hostility. Low parental SES and one of the hostile child-rearing style components (strict disciplinary style) became more strongly associated with offspring hostility with age, suggesting an accumulating effect. CONCLUSIONS: Childhood family factors predict the development of hostility and anger over 27 years and some of these family factors have a long-term accumulating effect on the development of hostility.

The association of cognitive performance with mental health and physical functioning strengthens with age: the Whitehall II cohort study.

BACKGROUND: Cognitive performance has been associated with mental and physical health, but it is unknown whether the strength of these associations changes with ageing and with age-related social transitions, such as retirement. We examined whether cognitive performance predicted mental and physical health from midlife to early old age. METHOD: Participants were 5414 men and 2278 women from the Whitehall II cohort study followed for 15 years between 1991 and 2006. The age range included over the follow-up was from 40 to 75 years. Mental health and physical functioning were measured six times using SF-36 subscales. Cognitive performance was assessed three times using five cognitive tests assessing verbal and numerical reasoning, verbal memory, and phonemic and semantic fluency. Socio-economic status (SES) and retirement were included as covariates. RESULTS: High cognitive performance was associated with better mental health and physical functioning. Mental health differences associated with cognitive performance widened with age from 39 to 76 years of age, whereas physical functioning differences widened only between 39 and 60 years and not after 60 years of age. SES explained part of the widening differences in mental health and physical functioning before age 60. Cognitive performance was more strongly associated with mental health in retired than non-retired participants, which contributed to the widening differences after 60 years of age. CONCLUSIONS: The strength of cognitive performance in predicting mental and physical health may increase from midlife to early old age, and these changes may be related to SES and age-related transitions, such as retirement.

ApoE phenotype is associated with inflammatory markers in middle-aged subjects.

OBJECTIVES: Apolipoprotein (apo) E phenotype has been associated with inflammation markers. The determinants of these associations and the relationship between novel inflammation marker, resistin, and apoE phenotype are studied here. METHODS AND RESULTS: Middle-aged subjects of the population- based cohort (n = 526) of the OPERA- study were studied. Intima-media thickness (IMT) was measured with carotid ultrasound. The results suggest that, apoE phenotype was a significant independent predictive factor for resistin (p < 0.01) and hsCRP (p < 0.01) levels. The association of ApoE phenotype with hsCRP was seen among the subjects with the normal renal function (p = 0.005). ApoE4 was associated (p < 0.01) with the lowest hsCRP in the lowest IMT quartile while it's relation with the highest resistin levels was evident in the highest IMT quartile. CONCLUSIONS: ApoE phenotype is an independent determinant of plasma resistin and hsCRP levels. The extent of atherosclerosis and renal function seem to modify the effects of apoE phenotype on inflammatory parameters.

Association between passive jobs and low levels of leisure-time physical activity: the Whitehall II cohort study.

BACKGROUND: There is mixed evidence on the association between psychosocial work exposures (ie, passive jobs) and physical activity, but previous studies did not take into account the effect of cumulative exposures nor did they examine different trajectories in exposure. We investigated whether exposure to passive jobs, measured three times over an average of 5 years, is associated with leisure-time physical activity (LTPA). METHODS: Data were from working men (n = 4291) and women (n = 1794) aged 35-55 years who participated in the first three phases of the Whitehall II prospective cohort. Exposure to passive jobs was measured at each phase and LTPA at phases 1 and 3. Participants were categorised according to whether or not they worked in a passive job at each phase, leading to a scale ranging from 0 (non-passive job at all three phases) to 3 (passive job at all three phases). Poisson regression with robust variance estimates were used to assess the prevalence ratios of low LTPA. RESULTS: An association was found in men between exposure to passive jobs over 5 years and low LTPA at follow-up, independently of other relevant risk factors. The prevalence ratio for low LTPA in men was 1.16 (95% CI 1.01 to 1.33) times greater for employees with three reports of passive job than for those who had never worked in passive jobs. No association was observed in women. CONCLUSION: This study provides evidence that working in passive jobs may encourage a passive lifestyle in men.

The effect of a short-term hypocaloric diet on liver gene expression and metabolic risk factors in obese women.

BACKGROUND AND AIMS: Most gene expression studies examining the effect of obesity and weight loss have been performed using adipose tissue. However, the liver also plays a central role in maintaining energy balance. We wanted to study the effects of a hypocaloric diet on overall hepatic gene expression and metabolic risk factors. METHODS AND RESULTS: The study subjects were middle-aged, obese women. The diet intervention subjects (n=12) were on a hypocaloric, low-fat diet for 8 weeks with a daily energy intake of 5.0 MJ (1200 kcal), while the control subjects (n=19) maintained their weight. Liver biopsies were taken at the end of the diet period during a gallbladder operation. Hepatic gene expression was analyzed using microarrays by comparing the gene expression profiles from four subjects per group. A global decrease in gene expression was observed with 142 down-regulated genes and only one up-regulated gene in the diet intervention group. The diet resulted in a mean weight loss of 5% of body weight. Triglyceride and fasting insulin concentrations decreased significantly after the diet. CONCLUSIONS: The global decrease in hepatic gene expression was unexpected but the results are interesting, since they included several genes not previously linked to weight reduction. However, since the comparison was made only after the weight reduction, other factors in addition to weight loss may also have been involved in the differences in gene expression between the groups. The decrease in triglyceride and fasting plasma insulin concentrations is in accordance with results from previous weight-loss studies.

The varying burden of depressive symptoms across adulthood: Results from six NHANES cohorts.

BACKGROUND: Depressive symptoms differ from each other in the degree of functional impairment they cause. The incidence of depression varies across the adult lifespan. We examined whether age moderates the impairment caused by depressive symptoms. METHODS: The study sample (n = 21,056) was adults drawn from six multistage probability samples from the National Health and Nutrition Examination Survey series (NHANES, years 2005-2016) conducted in the United States using cross-sectional, representative cohorts. Depressive symptoms were assessed with the nine-item Patient Health Questionnaire (PHQ-9). We used regression models to predict high functional impairment, while controlling for sociodemographic variables and physical disorders. RESULTS: Age moderated the association between depressive symptoms and functional impairment: middle-aged adults perceived moderate and severe symptoms as more impairing than did others. Older adults reported slightly higher impairment due to mild symptoms. The individual symptoms of low mood, feelings of worthlessness and guilt, and concentration difficulties were more strongly related to high impairment in mid-adulthood as compared to early and late adulthood. LIMITATIONS: Cross-sectional data allows only between-person comparisons. The PHQ-9 is brief and joins compound symptoms into single items. There was no information available concerning comorbid mental disorders. Co-occurring physical disorders were self-reported. CONCLUSIONS: Symptoms of depression may imply varying levels of impairment at different ages. The results suggest a need for age adjustments when estimating the functional impact of depression in the general population. Additionally, they show a need for more accurate assessments of depression-related impairment at older ages. Evidence-based programs may generally benefit from symptom- and age-specific findings.

Symptom severity and disability in psychiatric disorders: The U.S. Collaborative Psychiatric Epidemiology Survey.

BACKGROUND: While most psychiatric diagnoses are based on simple counts of symptoms, some symptoms may be sign of a more severe mental syndrome than others. This calls for validated estimates of the relative severity specific symptoms imply within a disorder. We focused on four diagnostic disorders: Manic Episode (ME), Major Depressive Episode (MDE), Post-traumatic Stress Disorder (PTSD) and Generalized Anxiety Disorder (GAD). Symptom-specific severity parameters were estimated, and validated by examining their association with levels of self-reported disability in daily activities over and above the number of symptoms. METHODS: Data from the cohort study of the U.S. Collaborative Psychiatric Epidemiology Surveys (CPES) was used, which comprises the National Comorbidity Survey Replication, National Survey of American Life, and the National Latino and Asian American Study. The four analytic datasets included respondents who endorsed disorder-specific pre-screening symptoms according to the World Mental Health Survey Initiative's version of the Composite International Diagnostic Interview. Disability was measured using the WHO Disability Assessment Schedule. Item Response Theory and Tobit models were implemented. RESULTS: For ME, PTSD, and GAD (not MDE) symptom severity based on psychometric Item Response Theory predicted disability outcomes after adjusting for symptom count. For PTSD, symptom count was not associated with disability. LIMITATIONS: The analytic sample for each psychiatric disorder was based on a pre-selection stemming from index criteria (e.g. sadness or pleasure loss for MDE), which implies that our results are only generalizable to those individuals at risk rather than for the entire population. Additionally, we acknowledge that the use of unidimensional models is only one of the several options to model psychopathological constructs. CONCLUSIONS: The same number of symptoms may be related to different levels of disability, depending on the specific symptoms from which the person suffers. Diagnostic procedures and treatment decisions may benefit from such additional information without extra costs.