Understanding how inequality in the distribution of income affects health

Research on the determinants of health has almost exclusively focused on the individual but it seems clear we cannot understand or improve patterns of population health without engaging structural determinants at the societal level. This article traces the development of research on income distribution and health to the most recent epidemiologic studies from the USA that show how income inequality is related to age- adjusted mortality within the 50 States. (r = -0.62, p = 0.0001) even after accounting for absolute levels of income. We discuss potential material, psychological, social and behavioral pathways through which income distribution might be linked to health status. Distributional aspects of the economy are important determinants of health and may well provide one of the most pertinent indicators of overall social well-being.

Low maximal oxygen uptake is associated with elevated depressive symptoms in middle-aged men

A low level of physical activity has been associated with depression, and increased physical activity has been found to have a positive effect on mood. However, the association between maximal oxygen uptake (VO(2max)) and mood has been poorly studied. In this study VO(2max) (ml/kg per min) was measured in a sample of 1,519 men aged 46-61 years during a cycle ergometer test by using respiratory gas exchange. Men with a history of psychiatric disorder or serious physical illness were excluded. Depressive symptoms were assessed using the 18-item Human Population Laboratory Depression Scale (HPL). Those who scored 5 or more in the HPL were considered to have elevated depressive symptoms. The participants were classified into quartiles according to the VO(2max). Those in the lowest quartile had a more than 3-fold (OR: 3.42; 95% CI: 1.65-7.09; p < 0.001) higher risk of having elevated depressive symptoms compared with those in the highest quartile, even after adjusting for several confounders (OR: 3.38; 95% CI: 1.60-7.14; p < 0.001). In conclusion, low VO(2max) is associated with having elevated depressive symptoms in middle-aged men.

Depression and early retirement: prospective population based study in middle aged men

BACKGROUND

Mental depression is an important health problem in many countries. It reduces productivity at work and is the fastest increasing reason for early retirement.

METHODS

This study followed up a Finnish cohort of 1726 men from 1984 to 2000. Depression was assessed at baseline by HPL depression score. Pension records were obtained from the national pension registers. Cox's regression analysis was used to estimate the associations of depression with the risk of all disability pensions combined, separately for different causes of disability, and non-illness based pension.

RESULTS

During the follow up, 839 men (48.6%) received a disability pension. A total of 142 men (16.9% of all disability pensions) retired because of mental disorder and of these, 75 (52.8%) because of depression. After adjustment for the potential confounders, men in the highest third of depression score had an increased risk of non-illness based pension (RR 1.86 95% CI 1.37 to 2.51) and disability pension attributable to mental disorders (RR 2.74, 95% CI 1.68 to 4.46), chronic somatic diseases (RR 1.68, 95% CI 1.05 to 2.71), cardiovascular diseases (RR 1.61, 95% CI 1.12 to 2.32). The mean age of retirement for men with a high and low depression score was 57.6 years (SD 3.87) and 59.1 years (SD 3.65) (p<0.001) respectively.

CONCLUSIONS

A high depression score predicted disability attributable to any cause, especially mental disorders, and non-illness based pensions. Depressed people retired on average 1.5 years younger than those without depression. Further studies are needed to elucidate the pathways of how mental depression leads people to seek retirement pension.

Homocysteine as a risk factor for CVD mortality in men with other CVD risk factors: the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study

OBJECTIVE

Based on case-control and prospective studies elevated blood total homocysteine (tHcy) has been suggested to be an independent risk factor for cardiovascular diseases (CVD). The purpose of the study was to explore the joint effect of increased serum tHcy concentration and other risk factors on the risk of CVD mortality in middle-aged men without a history of heart disease or stroke.

DESIGN

A prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study.

SETTING

Eastern Finland. Subjects. A total of 802 men aged 46-64 years, examined in 1991-93.

MAIN OUTCOME MEASURES

CVD mortality event.

RESULTS

The mean serum tHcy concentration was 10.8 micromol L(-1) (SD 3.3). During the average follow-up time of 10.8 years 50 men experienced a CVD death. The hazard rate ratio for CVD mortality was 1.80 (95% confidence interval: 1.02-3.19) in men in the highest serum tHcy third versus lower thirds after adjustment for cardiovascular risk factors. Furthermore, elevated serum tHcy concentration appeared to increase the risk of CVD death in men who smoke or who have high circulating concentrations of serum total or LDL cholesterol, apo-B apolipoprotein or plasma fibrinogen.

CONCLUSION

We conclude that homocysteine may increase the risk of CVD mortality in middle-aged men from Eastern Finland, and it may especially increase the risk when present with other risk factors for CVD.

Prospective association between obesity and depression: evidence from the Alameda County Study

OBJECTIVE

To examine the temporal relation between obesity and depression to determine if each constitutes a risk factor for the other.

DESIGN

A two-wave, 5-y-observational study with all measures at both times.

SUBJECTS

A total of 2123 subjects, 50 y of age and older, who participated in the 1994 and 1999 waves of the Alameda County Study.

MEASUREMENTS

Obesity defined as body mass index (BMI)> or =30. Depression assessed using DSM-IV symptom criteria for major depressive episodes. Covariates include indicators of age, gender, education, marital status, social support, life events, physical health problems, and functional limitations.

RESULTS

Obesity at baseline was associated with increased risk of depression 5 y later, even after controlling for depression at baseline and an array of covariates. The reverse was not true; depression did not increase the risk of future obesity.

CONCLUSION

These results, the first ever on reciprocal effects between obesity and depression, add to a growing body of evidence concerning the adverse effects of obesity on mental health. More studies are needed on the relation between obesity and mental health and implications for prevention and treatment.

Obesity and weight gain are associated with increased incidence of hyperinsulinemia in non-diabetic men

We investigated the temporal relationships between obesity, weight change and hyperinsulinemia in a population-based 4-year follow-up study of 695 middle-aged, non-diabetic, and normoinsulinemic men. Thirty-eight men developed hyperinsulinemia during the follow-up (fasting serum insulin > or = 12.0 mU/l). In logistic regression analysis adjusting for other risk factors, men with body mass index of > or = 26.7 kg/m2 (highest third) had a 6.6-fold (p = 0.001) risk of developing hyperinsulinemia, compared with men with body mass index of < 24.4 kg/m2 (lowest third). Correspondingly, men with waist-to-hip ratio of > or = 0.95 (highest third) had a 3.5-fold (p = 0.028) incidence of hyperinsulinemia compared with men with waist-to-hip ratio of < 0.90 (lowest third). Weight gain in middle age and weight gain from the age of 20 years to middle age were also associated with increased risk of hyperinsulinemia. Hyperinsulinemia at baseline was not associated with weight gain during the follow-up. This prospective population-based study emphasizes the importance of avoiding obesity and weight gain during adulthood in preventing hyperinsulinemia.

Associations between apolipoprotein E phenotype, glucose metabolism and cognitive function in men. An explorative study in a population sample

AIMS

To investigate the associations of the apolipoprotein E phenotype (apoE) and disturbed glucose metabolism with cognitive function in a random population sample.

METHODS

A cross-sectional study was conducted, in which 528 men aged 54 or 60 years were recruited randomly from a larger population-based sample of 1516 men. A subject was defined as having abnormal glucose tolerance (AGT), if he had a clinical diagnosis of diabetes, with either dietary or oral antidiabetic treatment or showed impaired glucose tolerance in an oral glucose tolerance test. The subjects were divided into three groups according to apolipoprotein E phenotypes: (a) E2/4, E3/4 or E4/4 (apoE E4); (b) E 3/3 (apoE E3); and (c) E2/2 or E2/3 (apoE E2). Memory function was examined using a word-list learning with Buschke's selective reminding method and test. Executive functions were assessed with the Trail Making Test A and B.

RESULTS

Those subjects with apoE E2 and abnormal glucose metabolism demonstrated the worst cognitive executive control compared to other groups. Simple cognitive speed did not differ between the groups.

CONCLUSIONS

The exploratory analyses revealed that subjects with apoE E2 allele and AGT had worse glycaemic control and cognitive executive control compared to other groups. Different apolipoprotein phenotypes together with impaired glucose tolerance may have different cumulative adverse effects on age-related cognitive performance. Some subgroups of subjects may be especially vulnerable to cognitive impairment.

Childhood socioeconomic position and cognitive function in adulthood

BACKGROUND

Risk of dementia and Alzheimer's disease is higher among adults with limited education, and the less educated perform poorer on cognitive function tests. This study determines whether the socioeconomic environment experienced during childhood has an impact on cognitive functioning in middle age.

METHODS

A population-based study of eastern Finnish men (n = 496) aged 58 and 64 for whom there were data on parent's socioeconomic position (SEP), their own education level, and performance on neuropsychological tests. Cognitive function was measured using the Trail Making Test, the Selective Reminding Test, the Verbal Fluency Test, the Visual Reproduction Test, and the Mini Mental State Exam.

RESULTS

We found a significant and graded association between parental SEP (combined as an index) and cognitive function both prior to and after adjustment for respondent's education. Those from more disadvantaged backgrounds exhibited the poorest performance. When the separate components of the parental SEP measure were used, father's occupation and mother's education were independently associated with the respondent's score for three and five of the tests, respectively (there was no association with father's education and mother's occupation). After adjustment for the respondent's education, father's occupation was no longer associated with respondent's test score, however, the results were essentially unchanged for mother's education.

CONCLUSIONS

Higher SEP during childhood and greater educational attainment are both associated with cognitive function in adulthood, with mothers and fathers each contributing to their offspring's formative cognitive development and later life cognitive ability (albeit in different ways). Improvements in both parental socioeconomic circumstances and the educational attainment of their offspring could possibly enhance cognitive function and decrease risk of dementia later in life.

Women's exposure to early and later life socioeconomic disadvantage and coronary heart disease risk: the Stockholm Female Coronary Risk Study

BACKGROUND

Measures of low socioeconomic position have been associated with increased risk for coronary heart disease (CHD) among women. A more complete understanding of this association is gained when socioeconomic position is conceptualized from a life course perspective where socioeconomic position is measured both in early and later life. We examined various life course socioeconomic indicators in relation to CHD risk among women.

METHODS

The Stockholm Female Coronary Risk Study is a population-based case-control study, in which 292 women with CHD aged < or =65 years and 292 age-matched controls were investigated using a wide range of socioeconomic, behavioural, psychosocial and physiological risk factors. Socioeconomic disadvantage in early life (large family size in childhood, being born last, low education), and in later life (housewife or blue-collar occupation at labour force entry, blue-collar occupation at examination, economic hardships prior to examination) was assessed.

RESULTS

Exposure to early (OR = 2.65, 95% CI : 1.12-6.54) or later (OR = 5.38, 95% CI : 2.01-11.43) life socioeconomic disadvantage was associated with increased CHD risk as compared to not being exposed. After simultaneous adjustment for marital status and traditional CHD risk factors, early and later socioeconomic disadvantage, exposure to three instances of socioeconomic disadvantage in early life was associated with an increased CHD risk of 2.48 (95% CI : 0.90-6.83) as compared to not being exposed to any disadvantage. The corresponding adjusted risk associated with exposure to later life disadvantage was 3.22 (95% CI : 1.02-10.53). Further analyses did not show statistical evidence of interaction effects between early and later life exposures (P = 0.12), although being exposed to both resulted in a 4.2-fold (95% CI : 1.4-12.1) increased CHD risk. Exposure to cumulative socioeconomic disadvantage (combining both early and later life), across all stages in the life course showed strong, graded associations with CHD risk after adjusting for traditional CHD risk factors. Stratification of cumulative disadvantage by body height showed that exposure to more than three periods of cumulative socioeconomic disadvantage had a 1.7- (95% CI : 0.9-3.2) and 1.9- (95% CI : 1.0-7.7) fold increased CHD risk for taller and shorter women, respectively. The combination of both short stature and more than two periods of cumulative socioeconomic disadvantage resulted in a 4.4-fold (95% CI : 1.7-9.3) increased CHD risk.

CONCLUSIONS

Both early and later exposure to socioeconomic disadvantage were associated with increased CHD risk in women. Later life exposure seems to be more harmful for women's cardiovascular health than early life exposure to socioeconomic disadvantage. However, being exposed to socioeconomic disadvantage in both early and later life magnified the risk for CHD in women. Cumulative exposure to socioeconomic disadvantage resulted in greater likelihood of CHD risk, even among women who were above median height. In terms of better understanding health inequalities among women, measures of socioeconomic disadvantage over the life course are both conceptually and empirically superior to using socioeconomic indicators from one point in time.

Comparative impact of hearing and vision impairment on subsequent functioning

OBJECTIVES

The purpose of this study was to compare independent impacts of two levels of self-reported hearing and vision impairment on subsequent disability, physical functioning, mental health, and social functioning.

DESIGN

A 1-year prospective cohort study.

SETTING

San Francisco Bay Area, California.

PARTICIPANTS

Two thousand four hundred forty-two community-dwelling men and women age 50 to 102 from the Alameda County Study (California).

MEASUREMENTS

Hearing and vision impairment were assessed in 1994. Outcomes, measured in 1995, included physical disability (activities of daily living, instrumental activities of daily living, physical performance, mobility, and lack of participation in activities), mental health (self-assessed, major depressive episode), and social functioning (feeling left out, feeling lonely, hard to feel close to others, inability to pay attention). All 1995 outcomes were adjusted for baseline 1994 values.

RESULTS

Both impairments had strong independent impacts on subsequent functioning. Vision impairment exerted a more wide-ranging impact on functional status, ranging from physical disability to social functioning. However, the results also highlighted the importance of hearing impairment, even when mild.

CONCLUSIONS

These impairments can be partially ameliorated through prevention, assessment, and treatment strategies. Greater attention to sensory impairments by clinicians, patients, public health advocates, and researchers is needed to enhance functioning in older adults.

Religious attendance increases survival by improving and maintaining good health behaviors, mental health, and social relationships

Several recent prospective analyses involving community-based populations have demonstrated a protective effect on survival for frequent attendance at religious services. How such involvement increases survival are unclear. To test the hypothesis that religious attendance might serve to improve and maintain good health behaviors, mental health, and social relationships, changes and consistencies in these variables were studied between 1965 and 1994 for 2,676 Alameda County Study participants, from 17 to 65 years of age in 1965, who survived to 1994. Measures included smoking, physical activity, alcohol consumption, medical checkups, depression, social interactions, and marital status. Those reporting weekly religious attendance in 1965 were more likely to both improve poor health behaviors and maintain good ones by 1994 than were those whose attendance was less or none. Weekly attendance was also associated with improving and maintaining good mental health, increased social relationships, and marital stability. Results were stronger for women in improving poor health behaviors and mental health, consistent with known gender differences in associations between religious attendance and survival. Further understanding the mechanisms involved could aid health promotion and intervention efforts.

Stress-induced blood pressure reactivity and incident stroke in middle-aged men

BACKGROUND AND PURPOSE

Exaggerated blood pressure reactivity to stress is associated with atherosclerosis and hypertension, which are known stroke risk factors, but its relation to stroke is unknown. Previous work also indicates that the association between reactivity and cardiovascular diseases may be influenced by socioeconomic status.

METHODS

The impact of blood pressure reactivity and socioeconomic status on incident stroke was examined in 2303 men (mean age, 52.8+/-5.1 years) from a population-based, longitudinal study of risk factors for ischemic heart disease in eastern FINLAND: Reactivity was calculated as the difference between blood pressure measured during the anticipatory phase of an exercise tolerance test (before exercise) and resting blood pressure, measured 1 week earlier. Mean systolic reactivity was 20 mm Hg (+/-15.9), and mean diastolic reactivity was 8.6 mm Hg (+/-8.5). Socioeconomic status was assessed as years of education. One hundred thirteen incident strokes (90 ischemic) occurred in 11.2 (+/-1.6) years of follow-up.

RESULTS

Men with exaggerated systolic reactivity (>/=20 mm Hg) had 72% greater risk of any stroke (relative hazard ratio [RH], 1.72; 95% CI, 1.17 to 2.54) and 87% greater risk of ischemic stroke (RH, 1.87; 95% CI, 1.20 to 2.89) relative to less reactive men. Moreover, men who were high reactors and poorly educated were nearly 3 times more likely to suffer a stroke than better educated, less reactive men (RH, 2.90; 95% CI, 1.66 to 5.08). Adjustment for stroke risk factors had little impact on these associations. Diastolic reactivity was unrelated to stroke risk.

CONCLUSIONS

Excessive sympathetic reactivity to stress may be etiologically important in stroke, especially ischemic strokes, and low socioeconomic status confers added risk.

Low serum lycopene concentration is associated with an excess incidence of acute coronary events and stroke: the Kuopio Ischaemic Heart Disease Risk Factor Study

A number of epidemiological studies have shown an association between beta-carotene and the risk of cardiovascular diseases, whereas only a few studies are available concerning the association of lycopene with the risk of coronary events, and no studies have been undertaken concerning lycopene and stroke. Thus, we tested the hypothesis that low serum levels of lycopene are associated with increased risk of acute coronary events and stroke in middle-aged men previously free of CHD and stroke. The subjects were 725 men aged 46-64 years examined in 1991-3 in the Kuopio Ischaemic Heart Disease Risk Factor Study. Forty-one men had either a fatal or a non-fatal acute coronary event or a stroke by December 1997. In a Cox' proportional hazard's model adjusting for examination years, age, systolic blood pressure and three nutritional factors (serum folate, beta-carotene and plasma vitamin C), men in the lowest quarter of serum lycopene levels (< or =0.07 micromol/l) had a 3.3-fold (95 % CI 1.7, 6.4, risk of acute coronary events or stroke compared with the others. Our study suggests that a low serum level of lycopene is associated with an increased risk of atherosclerotic vascular events in middle-aged men previously free of CHD and stroke.

Psychosocial Predictors of Hypertension in Men and Women

BACKGROUND

Psychosocial stressors have been shown to predict hypertension in several cohort studies; patterns of importance, sex differences, and interactions with standard risk factors have not been fully characterized.

METHODS

Among 2357 adults in a population sample of Alameda County, California, free of hypertension in 1974, 637 reported in 1994 having ever used antihypertensive medication (27.9% of the men and 26.3% of the women). The effects of baseline psychosocial, behavioral, and sociodemographic factors on the incidence of treated hypertension were examined using multiple logistic regression.

RESULTS

Low education, African American race, low occupational prestige, worry about job stability, feeling less than very good at one's job, social alienation, and depressive symptoms each had significant (P<.05) age-adjusted associations with incident hypertension. Associations were weakened by adjustment for body mass index, alcohol consumption, smoking status, and leisure time physical activity, especially the associations of anomy and depression, which persisted in women but not in men. In multivariate models, job insecurity (odds ratio, 1.6), unemployment (odds ratio, 2.7), and low self-reported job performance (odds ratio, 2.1) remained independent predictors of hypertension in men, whereas low-status work (odds ratio, 1.3) was an independent predictor of hypertension in women.

CONCLUSIONS

In the general population, low occupational status and performance and the threat or reality of unemployment increase the likelihood of developing hypertension, especially among men, independent of demographic and behavioral risk factors. Psychological distress and social alienation may also increase hypertension incidence, especially in women, chiefly through an association with health risk behaviors.

Abdominal obesity is associated with accelerated progression of carotid atherosclerosis in men

Abdominal obesity increases the risk of clinical atherosclerotic diseases, but whether it accelerates the progression of preclinical atherosclerosis is unknown. We studied whether waist-to-hip ratio (WHR) and waist circumference are associated with 4-year increase in indicators of common carotid atherosclerosis, assessed by B-mode ultrasonography, in 774 Finnish men aged 42-60 years without atherosclerotic diseases. Men with WHR of <0.91, 0.91-0.96 and >0.96 (thirds) had increase in maximal intima-media thickness (IMT) of 0.230, 0.255 and 0.281 mm/4 years (P=0.007 for linear trend; P=0.025 for difference) and plaque height of 0.241, 0.254 and 0.291 mm/4 years (P=0.005, P=0.013) adjusting for age, body mass index and technical covariates. Men with waist circumference of <85, 85-93 and >93 cm (thirds) had increase in maximal IMT of 0.227, 0.251 and 0.290 mm/4 years (P=0.011, P=0.035) and plaque height of 0.229, 0.263 and 0.296 mm/4 years (P=0.003, P=0.013). These associations were stronger in men with high (> or =3.8 mmol/l) than lower serum LDL cholesterol (P<0.05 for interaction). This is the first documentation that abdominal obesity is associated with accelerated progression of atherosclerosis, and supports the view that it is an important cardiovascular risk factor. This study emphasizes the role of avoiding abdominal obesity to prevent atherosclerotic diseases.

Cardiorespiratory fitness and the progression of carotid atherosclerosis in middle-aged men

BACKGROUND

Good cardiorespiratory fitness has been associated with reduced risk for clinical events of atherosclerotic vascular diseases, but whether it is related to slower progression of early atherosclerosis is unclear.

OBJECTIVE

To study the association between cardiorespiratory fitness and the progression of early carotid atherosclerosis.

DESIGN

4-year follow-up study.

SETTING

Eastem Finland.

PARTICIPANTS

Population-based sample of 854 men 42 to 60 years of age.

MEASUREMENTS

Maximal oxygen uptake (VO2max [mL/kg per minute]) was measured directly by using respiratory gas exchange in a cycle ergometer exercise test. Carotid atherosclerosis was assessed by using B-mode ultrasonography.

RESULTS

After adjustments for age, technical covariates, and cigarette smoking, VO2max had strong, inverse, and graded associations with 4-year increases in maximal intima-media thickness (IMT) (standardized regression coefficient beta = -0.120; P = 0.002), plaque height (beta = -0.140; P < 0.001), surface roughness (beta = -0.147; P < 0.001), and mean IMT (beta = -0.080; P = 0.035). These associations weakened but remained statistically significant after additional adjustment for systolic blood pressure, serum levels of apolipoprotein B, diabetes, and plasma fibrinogen levels. The increases in maximal IMT, surface roughness, and mean IMT (23%, 31%, and 100%, respectively) were larger among men in the lowest quartile of VO2max (<26.1 mL/kg per minute) than among those in the highest quartile (>36.2 mL/kg per minute).

CONCLUSIONS

Good cardiorespiratory fitness is associated with slower progression of early atherosclerosis in middle-aged men. These findings are important because they emphasize that middle-aged men can be evaluated for cardiorespiratory fitness to estimate their future risk for atherosclerotic vascular diseases. Additional research is warranted to investigate a possible causal relationship between cardiorespiratory fitness and atherosclerosis.

Anticipatory blood pressure responses to exercise are associated with left ventricular mass in Finnish men: Kuopio Ischemic Heart Disease Risk Factor Study

BACKGROUND

Exaggerated cardiovascular reactivity to psychological demands may contribute to the development of left ventricular (LV) hypertrophy. We examined the cross-sectional association between anticipatory blood pressure (BP) responses to bicycle exercise and LV mass in the Kuopio Ischemic Heart Disease Risk Factor Study, a population-based epidemiological sample.

METHODS AND RESULTS

Among 876 men from 4 age cohorts (ages 42, 48, 58, and 64 years), we collected echocardiographic assessments of LV mass along with measures of BP response taken before bicycle ergometry testing. Anticipatory BP responses were positively associated with LV mass, with significant associations only among younger (age <50 years) subjects with elevated resting pressures (3-way interactions for anticipatory BP x age x resting pressure for systolic and diastolic BP, all P:<0.05; for younger subjects with elevated systolic BP, P:<0. 01; and for younger subjects with elevated diastolic BP, P:<0.001). Among these subgroups, exaggerated anticipatory BP responses (top quartile) were associated with an incremental increase in LV mass of 10% or greater, corrected for body surface area. Results remained significant after adjusting for age, education, salt consumption, and resting BP, and the pattern of findings was maintained among men with no previous history of cardiovascular disease.

CONCLUSIONS

The tendency to show exaggerated pressor responses to psychological demands may be a significant independent correlate of LV mass, especially among young men with high resting pressures. This is the first study to examine such associations in a middle-aged population sample.

Are the obese at greater risk for depression?

Two waves of data from a community-based study (Alameda County Study, 1994-1995) were used to investigate the association between obesity and depression. Depression was measured with 12 items covering Diagnostic and Statistical Manual of Mental Disorders: DSM-IV diagnostic criteria for major depressive episode. Following US Public Health Service criteria, obese subjects were defined as those with body mass index scores at the 85th percentile or higher. Covariates were age, sex, education, marital status, social isolation and social support, chronic medical conditions, functional impairment, life events, and financial strain. Results were mixed. In cross-sectional analyses, greater odds for depression in 1994 were observed for the obese, with and without adjustment for covariates. When obesity and depression were examined prospectively, controlling for other variables, obesity in 1994 predicted depression in 1995 (odds ratio (OR) = 1.73, 95% confidence interval (CI): 1.04, 2.87). When the data were analyzed with obesity defined as a body mass index of > or = 30, cross-sectional results were the same. However, the prospective multivariate analyses were not significant (OR = 1.43, 95% CI: 0.85, 2.43). Although these data do not resolve the role of obesity as a risk factor for depression, overall the results suggest an association between obesity and depression. The authors found no support for the "jolly fat" hypothesis (obesity reduces risk of depression). However, there has been sufficient disparity of results thus far to justify continued research.

Standing at work and progression of carotid atherosclerosis

OBJECTIVES

The association between the amount of standing at work and the progression of carotid intima media thickness (IMT) was studied among 584 active working men participating in the Kuopio Ischemic Heart Disease Risk Factor Study.

METHODS

Ultrasound measurements of atherosclerotic changes in the carotid arteries were performed at the beginning of the study and after 4 years. Analyses of changes in IMT included adjustments for risk factors and stratification by base-line levels of atherosclerosis and prevalent ischemic heart disease (IHD).

RESULTS

Significant relationships were found between the amount of standing at work and atherosclerotic progression. After adjustment for the heaviness of the work, psychosocial job factors, income, and biological and behavioral risk factors, the mean change in maximum IMT for those standing not at all, a little, a lot, and very much was 0.24, 0.25, 0.28, and 0.33 mm, respectively. For men with IHD the respective changes were 0.08, 0.15, 0.37, and 0.75 mm -- a 9-fold difference between the no-exposure and high-exposure group. For the men with carotid stenosis, the respective difference was 3-fold.

CONCLUSIONS

These findings provide the first empirical support in a population study for the role of hemodynamic factors in the progression of atherosclerosis induced by long-term standing. Men with carotid stenosis or IHD appear especially vulnerable to the adverse effects associated with standing at work. Reducing the duration of standing at work should be considered both in the occupational rehabilitation of such patients and in the primary prevention of atherosclerosis.

Negative consequences of hearing impairment in old age: a longitudinal analysis

To determine whether functional and psychosocial outcomes associated with hearing impairment are a direct result or stem from prevalent comorbidity, we analyzed the impact of two levels of reported hearing impairment on health and psychosocial functioning one year later with adjustments for baseline chronic conditions. Physical functioning, mental health, and social functioning decreased in a dose-response pattern for those with progressive levels of hearing impairment compared with those reporting no impairment. Our results demonstrate an independent impact of hearing impairment on functional outcomes, reveal increasing problems with higher levels of impairment, and support the importance of preventing and treating this highly prevalent condition.

Low serum folate concentrations are associated with an excess incidence of acute coronary events: the Kuopio Ischaemic Heart Disease Risk Factor Study

OBJECTIVE

To test the hypothesis that low serum folate concentrations are associated with an increased risk of acute coronary events in men free of prior coronary heart disease.

SETTING

Research Institute of Public Health, University of Kuopio, Kuopio, Finland.

DESIGN

Prospective study in a cohort of 734 men aged 46-64 y examined in 1991-1993 as part of the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) and followed for 5 y and 3 months.

INTERVENTION

Acute coronary events during the follow-up period were obtained by national hospital discharge registry. Baseline serum folate concentrations were measured by radioimmunoassay.

RESULTS

During the follow-up, six (2.5%) men with higher serum folate concentrations (highest third>11.3 nmol/1) and 28 (5.7%) men with lower serum folate (two lowest thirds) developed an acute coronary event (P=0.008). In a Cox model adjusting for age, examination years, and plasma lycopene concentration, in men with higher serum folate concentrations the relative risk for an acute coronary event was 0.31 (95% CI 0.11-0.90, P=0.031) when compared with men with lower serum folates.

CONCLUSION

This prospective cohort study in middle-aged men from eastern Finland indicates that moderate-to-high levels of serum folate are associated with a greatly reduced incidence of acute coronary events.

Relation between income inequality and mortality in Canada and in the United States: cross sectional assessment using census data and vital statistics

OBJECTIVE

To compare the relation between mortality and income inequality in Canada with that in the United States.

DESIGN

The degree of income inequality, defined as the percentage of total household income received by the less well off 50% of households, was calculated and these measures were examined in relation to all cause mortality, grouped by and adjusted for age.

SETTING

The 10 Canadian provinces, the 50 US states, and 53 Canadian and 282 US metropolitan areas.

RESULTS

Canadian provinces and metropolitan areas generally had both lower income inequality and lower mortality than US states and metropolitan areas. In age grouped regression models that combined Canadian and US metropolitan areas, income inequality was a significant explanatory variable for all age groupings except for elderly people. The effect was largest for working age populations, in which a hypothetical 1% increase in the share of income to the poorer half of households would reduce mortality by 21 deaths per 100 000. Within Canada, however, income inequality was not significantly associated with mortality.

CONCLUSIONS

Canada seems to counter the increasingly noted association at the societal level between income inequality and mortality. The lack of a significant association between income inequality and mortality in Canada may indicate that the effects of income inequality on health are not automatic and may be blunted by the different ways in which social and economic resources are distributed in Canada and in the United States.

Mercury accumulation and accelerated progression of carotid atherosclerosis: a population-based prospective 4-year follow-up study in men in eastern Finland

Basic research and our previous studies have suggested that mercury exposure enhances lipid peroxidation and the risk of myocardial infarction, but there are no studies concerning the association between mercury accumulation and atherosclerosis. We therefore investigated whether high hair mercury content is associated with accelerated progression of carotid atherosclerosis, determined by ultrasonographic assessment of common carotid intima-media thickness (IMT), in a prospective study among 1014 men aged 42-60 years. In a linear regression model adjusting for other atherosclerotic risk factors, high hair mercury content was one of the strongest predictors of the 4-year increase in the mean IMT (P2.81 microg/g (fifths) had an IMT increase of 0.105, 0.102, 0.113, 0.107 and 0.140 mm/4 years, respectively (P=0.041 for heterogeneity between groups). The IMT increase was 0.034 mm/4 years (31.9%) greater in the highest fifth than in the other fifths (P<0.05 for the difference). These findings suggest that mercury accumulation in the human body is associated with accelerated progression of carotid atherosclerosis.

Hypertension incidence is predicted by high levels of hopelessness in Finnish men

Recent studies have reported that hopelessness is an important factor in cardiovascular morbidity and mortality, including ischemic heart disease, acute myocardial infarction, and atherosclerotic progression. This study examined the relationship between hopelessness and incident hypertension in a population-based sample of 616 initially normotensive, middle-aged men from eastern Finland, an area with high rates of cardiovascular disease. Participants completed a medical examination and a series of psychological questionnaires at baseline and at the 4-year follow-up. Hopelessness was measured by 2 items assessing negative expectancy about the future and one's goals. A logistic regression model with adjustments for age, body mass index, baseline resting blood pressure, physical activity, smoking, alcohol consumption, education, parental history of hypertension, and self-reported depressive symptoms revealed that men reporting high levels of hopelessness at baseline were 3 times more likely to become hypertensive (systolic blood pressure > or =165 mm Hg and/or a diastolic blood pressure > or =95 mm Hg or confirmed use of antihypertensive medication) in the intervening 4 years than men who were not hopeless (odds ratio, 3.22; 95% confidence interval, 1. 56, 6.67). Men reporting moderate levels of hopelessness were not at a significantly increased risk of hypertension (odds ratio, 1.27; 95% confidence interval, 0.79, 2.07). This is the first study to identify a significant relationship between hopelessness and incident hypertension. Research is needed to explore the neuroendocrine and central nervous system mechanisms underlying this association.

Sleep complaints and depression in an aging cohort: A prospective perspective

OBJECTIVE

Most research on the association between sleep disturbances and depression has looked at cross-sectional data. The authors used two waves of data from a panel study of community residents aged 50 years or more to investigate this issue prospectively.

METHOD

Data on symptoms of major depressive episodes and sleep problems were examined for a subgroup of the 1994 and 1995 surveys of the Alameda County (California) Study (N=2,370). The authors examined the effects of age, gender, education, marital status, social isolation, functional impairment, financial strain, and alcohol use. Depression was measured with 12 items that covered the DSM-IV diagnostic criteria for major depressive episodes, including insomnia and hypersomnia.

RESULTS

The prevalences were 23. 1% for insomnia and 6.7% for hypersomnia in 1994. Sleep was a significant correlate of depression, as were being female, older age, social isolation, low education, financial strain, and functional impairment. When sleep problems and depression were examined prospectively, with controls for the effects of the other variables, sleep problems in 1994 predicted depression in 1995. However, other symptoms of major depressive episodes-anhedonia, feelings of worthlessness, psychomotor agitation/retardation, mood disturbance, thoughts of death-were much stronger predictors of future major depression.

CONCLUSIONS

Sleep disturbance and other symptoms that are diagnostic for major depression are strongly associated with the risk of future depression. Sleep disturbance appears to be a less important predictor of depression. More epidemiologic research is needed on the relative contributions of the range of depressive symptoms to the risk of clinical depression.

Pattern of alcohol drinking and progression of atherosclerosis

Most studies that examine the role of alcohol consumption in atherosclerosis and cardiovascular disease have overlooked the possible effect of drinking pattern. We investigated the association between the habit of heavy acute intake of beer and spirits (binging) and the 4-year progression of carotid atherosclerosis in a population-based sample of middle-aged Finnish men. Data from the Kuopio Ischemic Heart Disease Risk Factor Study (KIHD) were used to estimate changes in maximum and mean intima-media thickness (IMT) and the maximum plaque height in 764 KIHD participants who reported using beer and in 871 participants who used spirits. After adjustment for age, baseline carotid atherosclerosis, and average weekly alcohol consumption level, we observed the highest atherosclerosis progression in men who usually consumed a whole bottle of vodka or more in 1 session. For beer binging (>6 beers at a time), the magnitude of IMT progression was even higher, although this association was only marginally significant (P<0.1) because of smaller numbers. The associations were largely unaffected by adjustments for blood pressure, lipids, smoking, BMI, and medication. The magnitude of the difference was generally higher in a subgroup that was free of IHD at baseline. We conclude that the pattern of drinking associates with the progression of carotid atherosclerosis independently of the total level of alcohol consumption and risk factors.

Socioeconomic considerations in the primordial prevention of cardiovascular disease

Economic policy is an important determinant of population health; it is part of health policy. True primordial prevention of cardiovascular disease (CVD) may require regulation of the domestic and international market forces which produce and distribute CVD risk factors and their determinants. Because the market does not bear the cost of the legacy of poor health that it generates, primordial prevention of CVD may need to concern itself with societal mechanisms for holding these market forces accountable. Indeed, this approach is now an important part of the public health lexicon for preventing smoking. No program of primordial prevention of smoking could possibly ignore the national and international economic interests of the tobacco industry. We need to start thinking about primordial prevention of CVD risk factors such as low physical activity, high-fat diet, and psychosocial stress in the same way.

Blood pressure and the progression of carotid atherosclerosis in middle-aged men

Elevated blood pressure has consistently been associated with increased prevalence of preclinical atherosclerosis and with increased risk of clinical atherosclerotic cardiovascular disease (CVD). However, there is no prospective evidence of the association between blood pressure and the progression of preclinical atherosclerosis. We therefore investigated the relationships of systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure to the 4-year increase in the measures of early carotid atherosclerosis, the mean and maximal common carotid intima-media thickness (IMT), assessed by B-mode ultrasonography, in 1026 men aged 42 to 60 years. Men with the SBP of <120, 120 to 126, 127 to 134, 135 to 143, and >143 mm Hg (fifths) had an increase in the mean IMT of 0.074, 0.090, 0.110, 0.136, and 0.158 mm per 4 years (P<0.001 for difference between groups, P<0.001 for linear trend) and in the maximal IMT of 0.212, 0.221, 0.279, 0.286, and 0.315 mm per 4 years, (P<0.001, P<0.001), respectively, adjusting for other atherosclerotic risk factors, including DBP. Also, pulse pressure, when adjusted for other risk factors including mean arterial pressure, was directly associated with the IMT increase. DBP was not independently related to the IMT increase. This is the first documentation to show that mildly elevated SBP and pulse pressure accelerate the progression of preclinical atherosclerosis. This study provides further evidence for the finding that systolic hypertension is a more important risk factor for atherosclerosis and consequent CVD than diastolic hypertension. Therefore, more attention should be paid to the level of SBP in the evaluation of CVD risk and in the treatment of hypertension.

Understanding changing risk factor associations with increasing age in adults

With an increasingly older population, there is considerable interest in understanding the potential for risk factor interventions in order to prevent, postpone, or slow down the common diseases seen in older persons. However, it is often reported that the strength of association between risk factors and common disease outcomes decreases with increasing age. Actually, many different age-related patterns are observed. Understanding these patterns requires knowledge of issues related to the pathophysiology of aging, including age-related physiologic and metabolic alterations, detection and diagnosis of disease in the elderly, measurement of risk factors, sample selection, comorbidity, competing risks, selective survival, ceiling effects, and methods of analysis in aging populations.

Neighborhood social environment and risk of death: multilevel evidence from the Alameda County Study

Recent reports suggest the importance of associations between residential area characteristics and health status, but most research uses only census data to measure these characteristics. The current research examined the effect of overall neighborhood social environment on 11-year risk of death. On the basis of data, the authors developed a three-component neighborhood social environment scale: 1) commercial stores; 2) population socioeconomic status; and 3) environment/housing. Data from the 1983 wave of the Alameda County Study (n = 1,129) and deaths over 11 years were analyzed with two-level logistic regression models. Age- and sex-adjusted risk of death was higher for residents in low social environment neighborhoods (odds ratio = 1.58, 95% confidence interval 1.15-2.18). Mortality risks were significantly higher in neighborhoods with a low social environment, even after account was taken of individual income level, education, race/ethnicity, perceived health status, smoking status, body mass index, and alcohol consumption. When each component of the neighborhood social environment characteristics score was examined separately, each was found to be associated with higher risk for mortality, independent of individual risk factors. These findings demonstrate the role of area characteristics as a health risk factor and point to the need for more focused attention to the meaning and measurement of neighborhood quality.

Prospective data on sleep complaints and associated risk factors in an older cohort

OBJECTIVE

The purpose of this study is to provide data on the prevalence of insomnia and hypersomnia among older persons, the stability of these sleep complaints over time, and factors associated with disturbed sleep, in particular age.

METHOD

Data on symptoms of insomnia and hypersomnia were examined for the 1994 to 1995 cohort of the Alameda County Study. In addition to age, the effects of gender, education, marital status, chronic medical conditions, functional impairment, life events, financial strain, and mood disturbance were examined using multiple logistic analyses.

RESULTS

Prevalence in 1994 was 23.4% for insomnia and 6.8% for hypersomnia. There was moderate concordance between sleep complaints in 1994 and 1995 (kappa=.43). There was a tendency for insomnia and hypersomnia to increase with age in 1995, but not in 1994. Only gender, mood disturbance, and chronic health problems predicted insomnia. Life events, mood disturbance, and chronic conditions predicted hypersomnia. Age, net of the effects of other factors, was not associated with risk of either insomnia or hypersomnia.

CONCLUSIONS

The results contribute to the expanding body of evidence concerning the important roles of psychological and somatic dysfunction in sleep disturbance. Age in and of itself is not a risk factor for insomnia or hypersomnia. That is, after adjustment for an array of putative risk factors for sleep problems, it seems the association between sleep difficulties and age is primarily due to depressed mood and physical health problems.

Anger expression and incident stroke: prospective evidence from the Kuopio ischemic heart disease study

BACKGROUND AND PURPOSE

High levels of anger are associated with an increased risk of coronary heart disease and hypertension, but little is known about the role of anger in stroke risk.

METHODS

Anger expression style and risk of incident stroke were examined in 2074 men (mean age, 53.0+/-5.2 years) from a population-based, longitudinal study of risk factors for ischemic heart disease and related outcomes in eastern Finland. Self-reported style of anger expression was assessed by questionnaire at baseline. Linkage to the FINMONICA stroke and national hospital discharge registers identified 64 first strokes (50 ischemic) through 1996. Average follow-up time was 8.3+/-0.9 (mean+/-SD) years.

RESULTS

Men who reported the highest level of expressed anger were at twice the risk of stroke (relative hazard, 2.03; 95% CI, 1.05 to 3.94) of men who reported the lowest level of anger, after adjustments for age, resting blood pressure, smoking, alcohol consumption, body mass index, low-density and high-density lipoprotein cholesterol, fibrinogen, socioeconomic status, history of diabetes, and use of antihypertensive medications. Additional analysis showed that these associations were evident only in men with a history of ischemic heart disease (n=481), among whom high levels of outwardly expressed anger (high anger-out) predicted >6-fold increased risk of stroke after risk factor adjustment (relative hazard, 6.87; 95% CI, 1.50 to 31.4). Suppressed anger (anger-in) and controlled anger (anger-control) were not consistently related to stroke risk.

CONCLUSIONS

This is the first population-based study to show a significant relationship between high levels of expressed anger and incident stroke. Additional research is necessary to explore the mechanisms that underlie this association.

Poverty area residence and changes in depression and perceived health status: evidence from the Alameda County Study

BACKGROUND

Previous evidence from the Alameda County Study indicated that residential area has an independent effect on risk for mortality, adjusting for a variety of important individual characteristics. The current research examined the effect of poverty area residence on risk for developing depressive symptoms and decline in perceived health status in a sample of 1737.

METHODS

Data were from a longitudinal population-based cohort. Multiple logistic regression analyses were used.

RESULTS

Age- and sex-adjusted risk for incident high levels of depressive symptoms in 1974 was higher for poverty area residents (odds ratio [OR] 2.14; confidence interval [CI]: 1.49-3.06). Those reporting excellent/good health in 1965 were at higher risk for having fair/poor health in 1974 if they lived in a poverty area (age- and sex-adjusted OR 3.30; CI: 2.32-4.71). Independent of individual income, education, smoking status, body mass index, and alcohol consumption, poverty area residence remained associated with change in outcome variables.

CONCLUSION

These results further support the hypothesis that characteristics of place affect health conditions and health status.

Poverty area residence and changes in physical activity level: evidence from the Alameda County Study

OBJECTIVES

Evidence from the Alameda County Study indicated that residential area has an independent effect on mortality risk. The current research examined the effect of poverty area residence on change in physical activity (n = 1737).

METHODS

Data were from a longitudinal population-based cohort. Multiple linear regression analyses were used.

RESULTS

Age- and sex-adjusted change scores between 1965 and 1974 for physical activity were 0.67 units lower for people living in poverty areas (P = .0001). Independent of individual income, education, smoking status, body mass index, and alcohol consumption, poverty area residence remained associated with physical activity change.

CONCLUSION

These results further support the hypothesis that place affects health behaviors.

Anger expression and incident hypertension

OBJECTIVE

It has long been thought that anger is important in the development of essential hypertension. However, tests of this hypothesis have yielded conflicting findings. This study prospectively examined the relationship between anger expression style and incident hypertension in a population sample of middle-aged men.

METHODS

Participants were 537 initially normotensive men from eastern Finland, who completed a medical examination and series of psychological questionnaires at baseline and at 4-year follow-up. Anger expression was assessed by Spielberger's Anger-out and Anger-in scales.

RESULTS

At follow-up, 104 men (19.4%) were hypertensive (blood pressure > or = 165 mm Hg systolic and/or 95 mm Hg diastolic). Age-adjusted logistic regression analyses revealed that each 1-point increase in Anger-out was associated with a 12% increase in risk of hypertension after 4 years of follow-up (p < .002), which corresponded to a two-fold increased risk of hypertension among men with scores in the top tertile of the Anger-out scale, relative to those with scores in the bottom tertile (odds ratio = 2.00, 95% confidence interval 1.20-3.38). Each 1-point increase on the Anger-in scale also was related to a 12% increased risk of hypertension (p < .01). Adjustments for body mass index, smoking, alcohol consumption, physical activity, a positive parental history of hypertension, and baseline resting diastolic blood pressure had little impact on the findings.

CONCLUSIONS

These data provide strong epidemiological evidence for a positive relationship between anger expression style and subsequent hypertension, independent of known risk factors. Findings support the hypothesis that extreme expression of anger in either direction has adverse cardiovascular consequences.

Weight gain and the risk of developing insulin resistance syndrome

OBJECTIVE

Obesity and weight gain have been associated independently with hypertension, hyperinsulinemia, and dyslipidemia; however, prior research has not looked at the relation between weight gain from early adulthood to middle age and the development of this cluster of risk factors, known as insulin resistance syndrome.

RESEARCH DESIGN AND METHODS

The association between weight gain over 30 years (defined as the difference between measured weight in middle age and participant recall of their weight at age 20) and the odds of developing insulin resistance syndrome at middle age was examined in a population-based sample of 2,272 eastern Finnish men.

RESULTS

Each 5% increase in weight over the reported weight at age 20 was associated with nearly a 20% greater risk of insulin resistance syndrome by middle age, after adjustment for age and height. Moreover, there was a strong graded association between categories of weight gain and risk of insulin resistance syndrome. Men with weight increases of 10-19%, 20-29%, or > or =30% since age 20 were 3.0, 4.7, or 10.6 times more likely to have insulin resistance syndrome, respectively, by middle age, compared with men within 10% of their weight at age 20. Adjustments for age, height, physical activity, smoking, education, and parental history of diabetes did not alter these findings.

CONCLUSIONS

The odds of having developed the hemodynamic and metabolic abnormalities that characterize insulin resistance syndrome by middle adulthood were increasingly higher the greater the weight gain over the preceding 30 years. This study adds to the literature identifying deleterious effects of weight gain from young to middle adulthood.

Ischemic heart disease and stroke mortality in African-American, Hispanic, and non-Hispanic white men and women, 1985 to 1991

We compare recent trends in ischemic heart disease (IHD) and stroke mortality in California among the 6 major sex-racial or -ethnic groups. Rates of age-specific and -adjusted mortality were calculated for persons aged 35 and older during the years 1985 to 1991. Log-linear regression modeling was performed to estimate the average annual percentage change in mortality. During 1985 through 1991, the mortality for IHD and stroke was generally highest for African Americans, intermediate for non-Hispanic whites, and lowest for Hispanics. Age-adjusted mortality for IHD declined significantly in all sex-racial or -ethnic groups except African-American women, and stroke rates declined significantly in all groups except African-American and Hispanic men. African Americans had excess IHD mortality relative to non-Hispanic whites until late in life, after which mortality of non-Hispanic whites was higher. Similarly, African Americans and Hispanics had excess stroke mortality relative to non-Hispanic whites early in life, whereas stroke mortality in non-Hispanic whites was higher at older ages. The lower IHD and stroke mortality among Hispanics was paradoxical, given the generally adverse risk profile and socioeconomic status observed among Hispanics. An alarmingly high prevalence of self-reported cardiovascular disease risk factors in 1994 to 1996, particularly hypertension, leisure-time sedentary lifestyle, and obesity, is a serious public health concern, with implications for future trends in cardiovascular disease mortality. Of particular concern was the growing disparities in stroke and IHD mortality among younger-aged African Americans relative to Hispanics and non-Hispanic whites.