Epidemiologic evidence for the relation between socioeconomic status and depression, obesity, and diabetes

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Abstract

Many of the leading causes of death and disability in the United States and other countries are associated with socioeconomic position. The least well-off suffer a disproportionate share of the burden of disease, including depression, obesity, and diabetes. Research suggests that the adverse effects of economic hardship on both mental and physical health and functioning are evident at young ages and persist across the lifecourse. Moreover, these associations are seen across cultures. Data from four large epidemiologic studies on the role of psychological characteristics, social factors, and behaviors in health and disease risk are presented that highlight the striking associations between socioeconomic factors and chronic diseases. Data from these studies demonstrate that the effects of economic disadvantage are cumulative, with the greatest risk of poor mental and physical health seen among those who experienced sustained hardship over time.

Introduction

Many of the leading causes of death and disability in the United States and elsewhere are related to socioeconomic position. Indeed, it has long been recognized that individuals of lower socioeconomic status (SES) suffer a disproportionate share of the burden and consequences of numerous diseases, relative to those who are of higher SES [1], [2], [3]. In addition, there is a social gradient or dose–response relationship between SES and health status, with individuals at the highest levels of SES experiencing the best health, those at the next level having slightly worse health and so on, with the worst health seen among those at the lowest SES [4]. While this observation that health is patterned by SES is very longstanding, it is important to note that the association between SES and various health outcomes has become a topic of study in its own right over the past three decades [5].

The goal of this paper is to present epidemiological evidence for the important role that SES plays in depression, obesity, and diabetes. An association between SES and these chronic diseases is highly plausible, given what is known about the mechanisms that underlie these disorders. For example, low SES individuals may be at increased risk of depression, obesity, and diabetes because of unhealthy behaviors. Factors ranging from limited availability of affordable, nutritious foods in the local supermarkets to threatening neighborhoods to the greater stress that accompanies the economic uncertainties faced by low-SES individuals may contribute to the greater prevalence of smoking, higher alcohol consumption, poorer diets, and more sedentary lifestyles reported by lower SES groups [6]. The higher levels of stress experienced by low-SES individuals also may influence chronic disease risk via physiological mechanisms [7]. For example, acute and chronic stress activate the hypothalamo-pituitary-adrenal (HPA) axis, which triggers a cascade of neuroendocrine alterations that can play a role in depression, fat metabolism, and insulin resistance. Detailed investigation of these or other putative mechanisms is beyond the purview of this paper; however, it is important to note the plausibility of these underlying factors in studying the association between SES and depression, obesity, and diabetes.

Section snippets

SES and depression

Several studies have found that major depressive disorder and greater depressive symptomatology are more prevalent at lower levels of SES [8], [9]. Data from the Alameda County Study, which is a community-based longitudinal study of psychological and social factors and their role in health and well-being in nearly 7000 adults from Alameda County, California [10], demonstrate a graded relationship between SES, measured by education or income, and both prevalent and incident depression. As shown

SES and obesity

Obesity is a growing public health problem [16], [17] and several sources indicate that rates of obesity are higher among lower SES individuals [6], [10]. We looked at obesity (defined as a body mass index [BMI] of 30 kg/m2 or higher) rates in the Kuopio Study at the baseline exam, which occurred between 1984 and 1989, and in the Alameda County Study in 1983 (the data collection that corresponded most closely in time to the data collection in Kuopio). In the Kuopio Study, obesity rates were

SES and diabetes

Given that obesity is one of the strongest predictors of Type II diabetes, it is not surprising to learn that the prevalence of Type II diabetes also is related to several indicators of SES. Numerous studies have found an inverse relationship between Type II diabetes and education, occupation, and income that is consistent across all adult age groups [19], [20], [21], [22]. Robbins et al. [22], who used data from the Third National Health and Nutrition Examination Survey, found that the poverty

Cumulative effects of SES

In recent years, research has started to examine the cumulative effects of economic stress or disadvantage across the lifecourse and how such effects impact both physical functioning and mental health. The hypothesis underlying this work is that repeated exposure over time to the negative consequences associated with poorer socioeconomic circumstances leads to significantly worse health outcomes. Published data from the Alameda County Study and Kuopio Study support this hypothesis. Lynch et al.

Summary

Depression, obesity, and diabetes impose an enormous public health burden and, thus, it is particularly critical to identify risk factors for these disorders. It is predicted that depression will be one of the two leading causes of disability by the year 2020 [28]. Rates of obesity have increased dramatically over the past decade in the United States [29], despite our knowledge of the importance of diet and physical activity and maintaining a healthy body weight. Coincident with rising rates of

Acknowledgements

Supported by grants HL44199, AG11375, and HD35120 and by a Faculty Research Grant from the Office of the Vice President for Research at the University of Michigan. This article is based on a presentation made at a conference entitled Depression and Mental Disorders in Patients with Diabetes, Renal Disease, and Obesity/Eating Disorders, sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases, the National Institutes of Mental Health, and the Office of Behavioral and

References (33)

  • ML Bruce et al.

    Poverty and psychiatric status. Longitudinal evidence from the New Haven Epidemiologic Catchment Area study

    Arch Gen Psychiatry

    (1991)
  • SA Stansfeld et al.

    Social class and minor psychiatric disorder in British Civil Servants: a validated screening survey using the General Health Questionnaire

    Psychol Med

    (1992)
  • LF Berkman et al.

    Health and ways of living: the Alameda County Study

    (1983)
  • RE Roberts et al.

    Symptoms of depression among blacks and whites in an urban community

    J Nerv Ment Dis

    (1981)
  • GA Kaplan et al.

    Psychosocial predictors of depression. Prospective evidence from the human population laboratory studies

    Am J Epidemiol

    (1987)
  • JT Salonen

    Is there a continuing need for longitudinal epidemiologic research? The Kuopio Ischemic Heart Disease Risk Factor Study

    Ann Clin Res

    (1988)
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