Panayotes Demakakos

Social isolation, loneliness, and all-cause mortality in older men and women

Both social isolation and loneliness are associated with increased mortality, but it is uncertain whether their effects are independent or whether loneliness represents the emotional pathway through which social isolation impairs health. We therefore assessed the extent to which the association between social isolation and mortality is mediated by loneliness. We assessed social isolation in terms of contact with family and friends and participation in civic organizations in 6,500 men and women aged 52 and older who took part in the English Longitudinal Study of Ageing in 2004–2005. A standard questionnaire measure of loneliness was administered also. We monitored all-cause mortality up to March 2012 (mean follow-up 7.25 y) and analyzed results using Cox proportional hazards regression. We found that mortality was higher among more socially isolated and more lonely participants. However, after adjusting statistically for demographic factors and baseline health, social isolation remained significantly associated with mortality (hazard ratio 1.26, 95% confidence interval, 1.08–1.48 for the top quintile of isolation), but loneliness did not (hazard ratio 0.92, 95% confidence interval, 0.78–1.09). The association of social isolation with mortality was unchanged when loneliness was included in the model. Both social isolation and loneliness were associated with increased mortality. However, the effect of loneliness was not independent of demographic characteristics or health problems and did not contribute to the risk associated with social isolation. Although both isolation and loneliness impair quality of life and well-being, efforts to reduce isolation are likely to be more relevant to mortality.

Socioeconomic status and health: the role of subjective social status

Studies have suggested that subjective social status (SSS) is an important predictor of health. This study examined the link between SSS and health in old age and investigated whether SSS mediated the associations between objective indicators of socioeconomic status and health. It used cross-sectional data from the second wave (2004-2005) of the English Longitudinal Study of Ageing, which were collected through personal interviews and nurse visits. The study population consisted of 3368 men and 4065 women aged 52 years or older. The outcome measures included: self-rated health, long-standing illness, depression, hypertension, diabetes, central obesity, high-density lipoprotein cholesterol, triglycerides, fibrinogen, and C-reactive protein. The main independent variable was SSS measured using a scale representing a 10-rung ladder. Wealth, education, and occupational class were employed as covariates along with age and marital status and also, in additional analyses, as the main independent variables. Gender-specific logistic and linear regression analyses were performed. In age-adjusted analyses SSS was related positively to almost all health outcomes. Many of these relationships remained significant after adjustment for covariates. In men, SSS was significantly (p<or=0.05) related to self-rated health, depression, and long-standing illness after adjustment for all covariates, while its association with fibrinogen became non-significant. In women, after adjusting for all covariates, SSS was significantly associated with self-rated health, depression, long-standing illness, diabetes, and high-density lipoprotein cholesterol, but its associations with central obesity and C-reactive protein became non-significant. Further analysis suggested that SSS mediated fully or partially the associations between education, occupational class and self-reported and clinical health measures. On the contrary, SSS did not mediate wealths associations with the outcome measures, except those with self-reported health measures. Our results suggest that SSS is an important correlate of health in old age, possibly because of its ability to epitomize life-time achievement and socioeconomic status.

Childhood Socioeconomic Position and Objectively Measured Physical Capability Levels in Adulthood: A Systematic Review and Meta-Analysis

Background Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood. Methods and Findings Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N = 17,215 for chair rise time to N = 1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations. Conclusions Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life.

Age and gender differences in physical capability levels from mid-life onwards: the harmonisation and meta-analysis of data from eight UK cohort studies.

Using data from eight UK cohorts participating in the Healthy Ageing across the Life Course (HALCyon) research programme, with ages at physical capability assessment ranging from 50 to 90+ years, we harmonised data on objective measures of physical capability (i.e. grip strength, chair rising ability, walking speed, timed get up and go, and standing balance performance) and investigated the cross-sectional age and gender differences in these measures. Levels of physical capability were generally lower in study participants of older ages, and men performed better than women (for example, results from meta-analyses (N = 14,213 (5 studies)), found that men had 12.62 kg (11.34, 13.90) higher grip strength than women after adjustment for age and body size), although for walking speed, this gender difference was attenuated after adjustment for body size. There was also evidence that the gender difference in grip strength diminished with increasing age,whereas the gender difference in walking speed widened (p<0.01 for interactions between age and gender in both cases). This study highlights not only the presence of age and gender differences in objective measures of physical capability but provides a demonstration that harmonisation of data from several large cohort studies is possible. These harmonised data are now being used within HALCyon to understand the lifetime social and biological determinants of physical capability and its changes with age.

Leisure time physical activity, risk of depressive symptoms, and inflammatory mediators: The English Longitudinal Study of Ageing

OBJECTIVES To examine if inflammatory markers (CRP, fibrinogen) might partly explain the association between physical activity (PA) and risk of depression. DESIGN/SETTING The English Longitudinal Study of Ageing, a prospective study of community dwelling older adults. PARTICIPANTS 4323 men and women (aged 63.4+/-9.7 yrs) free from depression at baseline. MEASURES Self reported leisure time PA levels and depressive symptoms (a score of > or = 4 using the 8-item CES-D scale) were assessed at baseline and 4 yrs follow up. The inflammatory markers, CRP and fibrinogen, were assessed at a 2 yrs intermediate time point between baseline and follow up. RESULTS At follow up 8% of the sample reported depressive symptomatology. In comparison with participants reporting none or light PA, the odds of depressive symptomatology for those reporting moderate or vigorous PA were 0.71 (95% CI, 0.54-0.95) and 0.58 (0.41-0.81), respectively, after adjustments for baseline CES-D score, age, gender, social-occupational class, smoking, alcohol, and chronic illness. Each standard unit increase in log CRP was associated with higher odds of depressive symptomatology at follow up (1.32, 1.13-1.55) and CRP was inversely associated with physical activity. The association between PA and depressive symptomatology was not, however, substantially modified by further adjustment for CRP (odds for none vs. vigorous PA=0.60, 0.43-0.84). CONCLUSIONS These data suggest that low grade systemic inflammation, as indexed by CRP, is a risk marker for depressive symptomatology, although this mechanism explains only a modest (approximately 5%) amount of the association between PA and risk of depression.

Social Gradients in Oral Health in Older Adults: Findings From the English Longitudinal Survey of Aging

OBJECTIVES We examined prospective associations between socioeconomic position (SEP) markers and oral health outcomes in a national sample of older adults in England. METHODS Data were from the English Longitudinal Survey of Aging, a national cohort study of community-dwelling people aged 50 years and older. SEP markers (education, occupation, household income, household wealth, subjective social status, and childhood SEP) and sociodemographic confounders (age, gender, and marital status) were from wave 1. We collected 3 self-reported oral health outcomes at wave 3: having natural teeth (dentate vs edentate), self-rated oral health, and oral impacts on daily life. Using multivariate logistic regression models, we estimated associations between each SEP indicator and each oral health outcome, adjusted for confounders. RESULTS Irrespective of SEP marker, there were inverse graded associations between SEP and edentulousness, with proportionately more edentate participants at each lower SEP level. Lower SEP was also associated with worse self-rated oral health and oral impacts among dentate, but not among edentate, participants. CONCLUSIONS There are consistent and clear social gradients in the oral health of older adults in England, with disparities evident throughout the SEP hierarchy.

Depressive symptoms and risk of type 2 diabetes in a national sample of middle-aged and older adults. The English Longitudinal Study of Aging.

OBJECTIVE To examine the association between baseline elevated depressive symptoms and incident type 2 diabetes in a national sample of people aged ≥50 years. RESEARCH DESIGN AND METHODS The sample consisted of 6,111 individuals free from self-reported doctor-diagnosed diabetes at baseline in 2002–2003. The eight-item Center for Epidemiological Studies–Depression (CES-D) scale was the measurement of depressive symptoms. Cox proportional hazards regression models were used to assess whether baseline elevated (≥4) depressive symptoms were associated with a higher risk of type 2 diabetes over 45.8 months of follow-up. RESULTS The hazard ratio (HR) for diabetes was 1.62 (95% CI 1.15–2.29) in a model adjusted for age, sex, marital status, education, total net household wealth, cardiovascular and psychiatric and other noncardiovascular comorbidities, BMI, and health behaviors for participants with elevated CES-D symptoms compared with those without. Complementary analysis performed for a subsample (n = 5,090) showed that additional adjustment of this model for use of antidepressants did not explain the association (HR 1.58, 95% CI 1.09–2.29). CONCLUSIONS Elevated depressive symptoms were associated with a higher risk of developing type 2 diabetes after accounting for sociodemographic, lifestyle, and clinical factors in a national sample of people aged ≥50 years.

Persistent depressive symptomatology and inflammation: to what extent do health behaviours and weight control mediate this relationship?

We examined if persistent depressive symptoms are associated with markers of inflammation (C-Reactive Protein-CRP) and coagulation (fibrinogen), and if this association can be partly explained by weight control and behavioural risk factors (smoking, alcohol, physical activity). The study sample included 3609 men and women (aged 60.5+/-9.2 years) from The English Longitudinal Study of Ageing, a prospective study of community dwelling older adults. Depressive symptoms (using the 8-item CES-D scale), health behaviours (smoking, alcohol, physical activity), body weight, and central adiposity were assessed at baseline and 2 years follow up. CRP and fibrinogen were assessed at follow up. At baseline 12.7% of the sample reported elevated depressive symptomatology, which persisted in 6.1% of participants at follow up. Baseline CES-D score was associated with CRP (beta=.035, SE=.0066) and fibrinogen (beta=.023, SE=.0060) measured 2 years later. Using simple mediation analysis we observed both a direct association of depressive symptoms on CRP (beta=.013, SE=.0066) and indirect mediating effects through behavioural risk factors (beta for total indirect effect beta=.022, SE=.0023). For fibrinogen there were no direct effects of depression, and the association was entirely explained through indirect mediating effects of health behaviours. The presence of recurrent elevated depressive symptomatology at both time points was more strongly associated with CRP and fibrinogen. In summary, the association between depressive symptoms and low grade inflammation can be partly explained by behavioural risk factors. The presence of persistent depression appears to be associated with the greatest risk of elevated inflammation.

Body Mass Index, Muscle Strength and Physical Performance in Older Adults from Eight Cohort Studies: The HALCyon Programme

Objective To investigate the associations of body mass index (BMI) and grip strength with objective measures of physical performance (chair rise time, walking speed and balance) including an assessment of sex differences and non-linearity. Methods Cross-sectional data from eight UK cohort studies (total N = 16 444) participating in the Healthy Ageing across the Life Course (HALCyon) research programme, ranging in age from 50 to 90+ years at the time of physical capability assessment, were used. Regression models were fitted within each study and meta-analysis methods used to pool regression coefficients across studies and to assess the extent of heterogeneity between studies. Results Higher BMI was associated with poorer performance on chair rise (N = 10 773), walking speed (N = 9 761) and standing balance (N = 13 921) tests. Higher BMI was associated with stronger grip strength in men only. Stronger grip strength was associated with better performance on all tests with a tendency for the associations to be stronger in women than men; for example, walking speed was higher by 0.43 cm/s (0.14, 0.71) more per kg in women than men. Both BMI and grip strength remained independently related with performance after mutual adjustment, but there was no evidence of effect modification. Both BMI and grip strength exhibited non-linear relations with performance; those in the lowest fifth of grip strength and highest fifth of BMI having particularly poor performance. Findings were similar when waist circumference was examined in place of BMI. Conclusion Older men and women with weak muscle strength and high BMI have considerably poorer performance than others and associations were observed even in the youngest cohort (age 53). Although causality cannot be inferred from observational cross-sectional studies, our findings suggest the likely benefit of early assessment and interventions to reduce fat mass and improve muscle strength in the prevention of future functional limitations.

Wealth and mortality at older ages: a prospective cohort study

Background Despite the importance of socioeconomic position for survival, total wealth, which is a measure of accumulation of assets over the life course, has been underinvestigated as a predictor of mortality. We investigated the association between total wealth and mortality at older ages. Methods We estimated Cox proportional hazards models using a sample of 10 305 community-dwelling individuals aged ≥50 years from the English Longitudinal Study of Ageing. Results 2401 deaths were observed over a mean follow-up of 9.4 years. Among participants aged 50–64 years, the fully adjusted HRs for mortality were 1.21 (95% CI 0.92 to 1.59) and 1.77 (1.35 to 2.33) for those in the intermediate and lowest wealth tertiles, respectively, compared with those in the highest wealth tertile. The respective HRs were 2.54 (1.27 to 5.09) and 3.73 (1.86 to 7.45) for cardiovascular mortality and 1.36 (0.76 to 2.42) and 2.53 (1.45 to 4.41) for other non-cancer mortality. Wealth was not associated with cancer mortality in the fully adjusted model. Similar but less strong associations were observed among participants aged ≥65 years. The use of repeated measurements of wealth and covariates brought about only minor changes, except for the association between wealth and cardiovascular mortality, which became less strong in the younger participants. Wealth explained the associations between paternal occupation at age 14 years, education, occupational class, and income and mortality. Conclusions There are persisting wealth inequalities in mortality at older ages, which only partially are explained by established risk factors. Wealth appears to be more strongly associated with mortality than other socioeconomic position measures.