Iva Čukić

Childhood intelligence in relation to major causes of death in 68 year follow-up: prospective population study.

Objectives To examine the association between intelligence measured in childhood and leading causes of death in men and women over the life course. Design Prospective cohort study based on a whole population of participants born in Scotland in 1936 and linked to mortality data across 68 years of follow-up. Setting Scotland. Participants 33 536 men and 32 229 women who were participants in the Scottish Mental Survey of 1947 (SMS1947) and who could be linked to cause of death data up to December 2015. Main outcome measures Cause specific mortality, including from coronary heart disease, stroke, specific cancer types, respiratory disease, digestive disease, external causes, and dementia. Results Childhood intelligence was inversely associated with all major causes of death. The age and sex adjusted hazard ratios (and 95% confidence intervals) per 1 SD (about 15 points) advantage in intelligence test score were strongest for respiratory disease (0.72, 0.70 to 0.74), coronary heart disease (0.75, 0.73 to 0.77), and stroke (0.76, 0.73 to 0.79). Other notable associations (all P<0.001) were observed for deaths from injury (0.81, 0.75 to 0.86), smoking related cancers (0.82, 0.80 to 0.84), digestive disease (0.82, 0.79 to 0.86), and dementia (0.84, 0.78 to 0.90). Weak associations were apparent for suicide (0.87, 0.74 to 1.02) and deaths from cancer not related to smoking (0.96, 0.93 to 1.00), and their confidence intervals included unity. There was a suggestion that childhood intelligence was somewhat more strongly related to coronary heart disease, smoking related cancers, respiratory disease, and dementia in women than men (P value for interactions <0.001, 0.02, <0.001, and 0.02, respectively).Childhood intelligence was related to selected cancer presentations, including lung (0.75, 0.72 to 0.77), stomach (0.77, 0.69 to 0.85), bladder (0.81, 0.71 to 0.91), oesophageal (0.85, 0.78 to 0.94), liver (0.85, 0.74 to 0.97), colorectal (0.89, 0.83 to 0.95), and haematopoietic (0.91, 0.83 to 0.98). Sensitivity analyses on a representative subsample of the cohort observed only small attenuation of the estimated effect of intelligence (by 10-26%) after adjustment for potential confounders, including three indicators of childhood socioeconomic status. In a replication sample from Scotland, in a similar birth year cohort and follow-up period, smoking and adult socioeconomic status partially attenuated (by 16-58%) the association of intelligence with outcome rates. Conclusions In a whole national population year of birth cohort followed over the life course from age 11 to age 79, higher scores on a well validated childhood intelligence test were associated with lower risk of mortality ascribed to coronary heart disease and stroke, cancers related to smoking (particularly lung and stomach), respiratory diseases, digestive diseases, injury, and dementia.

Childhood Body Weight in Relation to Morbidity From Cardiovascular Disease and Cancer in Older Adulthood: 67-Year Follow-up of Participants in the 1947 Scottish Mental Survey

Although it has been well documented that elevated body weight in middle- and older-aged populations is associated with multiple morbidities, the influence of childhood body weight on health endpoints other than coronary heart disease is not well understood. Accordingly, using a subsample of 4,620 participants (2,288 women) from the Scottish Mental Survey of 1947, we examined the association between body mass index measured at 11 years of age and future risk of 9 independent health endpoints as ascertained from national hospital admissions and cancer registers until 2014 (up to age 77 years). Although there was some evidence of a relationship between elevated childhood body mass index and higher rates of peripheral vascular disease (per each 1-standard deviation increase in body mass index, hazard ratio = 1.21, 95% confidence interval: 1.07, 1.37) and smoking-related cancers (per each 1-standard deviation increase in body mass index, hazard ratio = 1.09, 95% confidence interval: 1.01, 1.17), there was no apparent association with coronary heart disease, stroke (including ischemic stroke), heart failure, or carcinomas of the colorectum, stomach, lung, prostate, or breast. In conclusion, a relationship between childhood body weight and later morbidity was largely lacking in the present study.

Childhood IQ and survival to 79: Follow-up of 94% of the Scottish Mental Survey 1947

Objective To extend previous literature that suggests higher IQ in youth is associated with living longer. Previous studies have been unable to assess reliably whether the effect differs across sexes and ages of death, and whether the effect is graded across different levels of IQ. Methods We test IQ-survival associations in 94% of the near-entire population born in Scotland in 1936 who took an IQ test at age 11 (n = 70,805) and were traced in a 68-year follow-up. Results Higher IQ at age 11 years was associated with a lower risk of death (HR = 0.80, 95% CI = 0.79, 0.81). The decline in risk across categories of IQ scores was graded across the full range with the effect slightly stronger in women (HR = 0.79, 95% CI = 0.77, 0.80) than in men (HR = 0.82, 95% CI = 0.81, 0.84). Higher IQ had a significantly stronger association with death before and including age 65 (HR = 0.76, 95% CI = 0.74, 0.77) than in those participants who died at an older age (HR = 0.79, 95% CI = 0.78, 0.80). Conclusions Higher childhood IQ is associated with lower risk of all-cause mortality in both men and women. This is the only near-entire population study to date that examines the association between childhood IQ and mortality across most of the human life course.

Personality and diabetes mellitus incidence in a national sample

OBJECTIVE To test whether personality traits were prospectively associated with type 2 diabetes incidence. METHODS The sample (n=6798) was derived from the National Health and Nutrition Examination Survey Epidemiological Follow-up Study cohort. We fit four logistic regression models to test whether neuroticism, extraversion, openness to experience, or the Type A behavior pattern predicted type 2 diabetes incidence. Model 1 included sex, age, and race/ethnicity. Model 2 added personality traits, Model 3 added depressive symptoms, and Model 4 added body mass index (BMI), hypertension, and cigarette smoking status as predictors. RESULTS In Model 1 age was associated with increased risk of diabetes (2% per year); being black as opposed to white was associated with a three-fold increase in risk. In Model 2 age and being black were still significant and extraversion was associated with decreased risk (17% per standard deviation [SD]). In Model 3 age, being black, and extraversion were still significant. In addition, neuroticism was associated with decreased risk (26% per SD) and depressive symptoms were associated with increased risk (28% per SD). In Model 4 age, being black, neuroticism, and depressive symptoms were still significant. BMI was associated with increased risk (14% per SD) and extraversion was no longer significant. CONCLUSIONS Higher neuroticism was associated with reduced type 2 diabetes risk even after controlling for race/ethnicity, age, depressive symptoms, and BMI. Extraversion and Type A behavior were not significant after including covariates.

When Is Higher Neuroticism Protective Against Death? Findings From UK Biobank

We examined the association between neuroticism and mortality in a sample of 321,456 people from UK Biobank and explored the influence of self-rated health on this relationship. After adjustment for age and sex, a 1-SD increment in neuroticism was associated with a 6% increase in all-cause mortality (hazard ratio = 1.06, 95% confidence interval = [1.03, 1.09]). After adjustment for other covariates, and, in particular, self-rated health, higher neuroticism was associated with an 8% reduction in all-cause mortality (hazard ratio = 0.92, 95% confidence interval = [0.89, 0.95]), as well as with reductions in mortality from cancer, cardiovascular disease, and respiratory disease, but not external causes. Further analyses revealed that higher neuroticism was associated with lower mortality only in those people with fair or poor self-rated health, and that higher scores on a facet of neuroticism related to worry and vulnerability were associated with lower mortality. Research into associations between personality facets and mortality may elucidate mechanisms underlying neuroticism’s covert protection against death.

Exploring communities of inquiry in Massive Open Online Courses

Abstract This study presents an evaluation of the Community of Inquiry (CoI) survey instrument developed by Arbaugh et al. (2008) within the context of Massive Open Online Courses (MOOCs). The study reports the results of a reliability analysis and exploratory factor analysis of the CoI survey instrument using the data of 1487 students from five MOOC courses. The findings confirmed the reliability and validity of the CoI survey instrument for the assessment of the key dimensions of the CoI model: teaching presence, social presence, and cognitive presence. Although the CoI survey instrument captured the same latent constructs within the MOOC context as in the Garrisons three-factor model (Garrison et al., 1999), analyses suggested a six-factor model with additional three factors as a better fit to the data. These additional factors were 1) course organization and design (a sub-component of teaching presence), 2) group affectivity (a sub-component of social presence), and 3) resolution phase of inquiry learning (a sub-component of cognitive presence). The emergence of these additional factors revealed that the discrepancies between the dynamics of the traditional online courses and MOOCs affect the student perceptions of the three CoI presences. Based on the results of our analysis, we provide an update to the famous CoI model which captures the distinctive characteristics of the CoI model within the MOOC setting. The results of the study and their implications are further discussed.

Relationships between socioeconomic position and objectively measured sedentary behaviour in older adults in three prospective cohorts

Objectives To investigate whether sedentary behaviour in older adults is associated with a systematic and comprehensive range of socioeconomic position (SEP) measures across the life course. SEP measures included prospective measures of social class, income, educational qualifications and parental social class and contemporaneous measures of area deprivation. Setting Glasgow and the surrounding (West of Scotland) combined with Edinburgh and the surrounding area (the Lothians). Participants Community-dwelling adults aged around 79, 83, and 64 years from, respectively, the Lothian Birth Cohort 1936 (LBC1936) (n=271) and the 1930s (n=119) and 1950s (n=310) cohorts of the West of Scotland Twenty-07 study. Primary outcome measure Sedentary behaviour was measured objectively using an activPAL activity monitor worn continuously for 7 days and used to calculate percentage of waking time spent sedentary. Results Among retired participants, for most cohort and SEP combinations, greater social disadvantage was associated with increased sedentary time. For example, in the Twenty-07 1930s cohort, those most deprived on the Carstairs measure spent 6.5% (95% CI 0.3 to 12.7) more of their waking time sedentary than the least deprived. However, for employed people, the relationship between SEP and sedentary behaviour was much weaker. For example, in terms of social class differences, among the retired, the most disadvantaged spent 5.7% more waking time sedentary (95% CI 2.6% to 87%), whereas among the employed, there was effectively no difference (−0.5%; 95% CI −9.0 to 8.0). Conclusions Diverse SEP measures were associated with increased sedentary behaviour among retired people. There was little evidence for a relationship between SEP measures and sedentary behaviour among employed older adults. Prior to retirement, the constraints of the workplace may be masking effects that are only apparent at weekends.

Do personality traits moderate the manifestation of type 2 diabetes genetic risk

Objective. To test whether personality traits moderate type 2 diabetes (T2D) genetic risk. Methods. Using a large community-dwelling sample (n = 837, Mage = 69.59 ± 0.85 years, 49% males) we fitted a series of linear regression models predicting glycated haemoglobin (HbA1c) from T2D polygenic risk — aggregation of small individual effects of a large number of single nucleotide polymorphisms (SNPs) — and five personality traits. We tested the main effects of personality traits and their interactions with T2D polygenic risk score, controlling for age and sex. The models in the final set were adjusted for cognitive ability, highest educational qualification, and occupational class. Results. Lower levels of openness were associated with heightened levels of HbA1c (β = − 0.014, p = .032). There was a significant interaction between T2D polygenic risk score and agreeableness: lower agreeableness was related to a stronger association between T2D polygenic risk and HbA1c (β = − 0.08, p = .021). In the model adjusted for cognitive ability, the main effect of openness was not significant (β = − 0.08, p = .057). The interaction between agreeableness and T2D polygenic risk was still present after controlling for cognitive ability and socioeconomic status indicators, and the interaction between conscientiousness and polygenic risk score was also significant: lower conscientiousness was associated with a stronger association between T2D polygenic risk and HbA1c levels (β = 0.09, p = .04). Conclusions. Personality may be associated with markers of diabetes, and may moderate the expression of its genetic risk.

Intelligence and all-cause mortality in the 6-Day Sample of the Scottish Mental Survey 1947 and their siblings: testing the contribution of family background

Abstract Background Higher early-life intelligence is associated with a reduced risk of mortality in adulthood, though this association is apparently hardly attenuated when accounting for early-life socio-economic status (SES). However, the use of proxy measures of SES means that residual confounding may underestimate this attenuation. In the present study, the potential confounding effect of early-life SES was instead accounted for by examining the intelligence–mortality association within families. Methods The association between early-life intelligence and mortality in adulthood was assessed in 727 members of the 6-Day Sample of the Scottish Mental Survey 1947 and, for the first time, 1580 of their younger siblings. These individuals were born between 1936 and 1958, and were followed up into later life, with deaths recorded up to 2015. Cox regression was used to estimate the relative risk of mortality associated with higher IQ scores after adjusting for shared family factors. Results A standard-deviation advantage in IQ score was associated with a significantly reduced mortality risk [hazard ratio = 0.76, p < 0.001, 95% confidence interval (CI) (0.68–0.84)]. This reduction in hazard was only slightly attenuated by adjusting for sex and shared family factors [hazard ratio = 0.79, p = 0.002, 95% CI (0.68–0.92)]. Conclusions Although somewhat conservative, adjusting for all variance shared by a family avoids any potential residual confounding of the intelligence–mortality association arising from the use of proxy measures of early-life SES. The present study demonstrates that the longevity associated with higher early-life intelligence cannot be explained by early-life SES or within-family factors.

The influence of neighbourhoods and the social environment on sedentary behaviour in older adults in three prospective cohorts

Sedentary behaviour is an emerging risk factor for poor health. This study aimed to identify ecological determinants of sedentary behaviour, for which evidence is currently scarce. The study participants were community dwelling adults from, respectively, the Lothian Birth Cohort 1936 (n = 271, mean age 79) and the 1930s (n = 119, mean age 83) and 1950s (n = 310, mean age 64) cohorts of the West of Scotland Twenty-07 study. The outcome measure, percentage of waking time spent sedentary (sedentary time), was measured using an activPAL activity monitor worn continuously for seven days. Potential determinants included objective and subjective neighbourhood measures such as natural space, crime, social cohesion and fear of crime. Other determinants included measures of social participation such as social support, social group membership and providing care. Results from multivariable regression analyses indicated that providing care was associated with reduced sedentary time in retired participants in all cohorts. Fear of crime and perceived absence of services were associated with increased sedentary time for retired 1950s cohort members. Higher crime rates were associated with increased sedentary time in all cohorts but this was not significant after adjustment for socio-demographic characteristics. Most other neighbourhood and social participation measures showed no association with sedentary time.