Native Americans, Stress, and Type 2 Diabetes: Exploring the Roots of the Epidemic

Type 2 diabetes mellitus is reaching epidemic proportions in many populations despite significant efforts and awareness in both the medical and lay communities. This article explores the proposition that the current diabetes etiological model of genetic predisposition and poor lifestyle choices is incomplete. It is suggested that the model be expanded to include both the underlying reasons for unhealthy behaviors as well as the direct physiologic effects of stress and trauma through the HPA axis and autonomic nervous system. This expanded model is looked at in the particular context of the population often most at risk for diabetes: Native Americans. Native Americans (American Indians and Alaska Natives) have known many plagues since the Spanish first arrived in the mid-1500s. Smallpox, measles, typhus, typhoid, tuberculosis, cholera, scarlet fever and other diseases devastated Native populations. Today there is a new plague, type 2 diabetes, which affects all races but is disproportionately high in disadvantaged and minority populations. Native Americans as a whole have up to three times the rate of diabetes of non-Hispanic whites, but certain Indian groups have far higher rates still. The highest rates of type 2 diabetes in the world are in the Pima Indians of Arizona. However, diabetes is not the only plague in Indian Country. Dr. Michael H. Trujillo, Director of the Indian Health Service (IHS), states, “The disparity of health status for American Indians and Alaska Natives has many underlying causes: Social and cultural disruption of traditional native societies, lack of education and economic opportunities and high levels of unemployment and poverty all put Indian people at higher risk. The consequence is disproportionately high levels of disease and health problems among Indian people.” 2(p 2) Could the plagues of diabetes and poverty be related? Is it unreasonable to think that the collective and individual experiences of a people have a direct impact on their physical health? The current model of diabetes holds that the disease is caused by a combination of genetic predisposition (“thrifty gene” in Native Americans) and unhealthy lifestyle choices (i.e. being sedentary and eating a high fat/calorie diet). Diabetes practice today reflects this model in its emphasis on educating patients on healthier lifestyles and using medications when these are not sufficient. It is evident this model is not complete, however, as it has yielded few programs producing consistent risk factor reduction for significant numbers of people. Indeed, as Wing et al noted in one such study, “Although initially successful, the interventions studied (diet and exercise) here were not effective in producing long-term changes in behavior, weight, or physiological parameters. ...further research is needed to determine how best to increase the percentage of subjects achieving at least a modest weight loss.” 350) While obesity has become epidemic in the U.S. and across Indian Country, it is not because of a lack of awareness or effort: Serdula et al looked at Behavioral Risk Factor Surveillance System (BRFSS) data and found that 78% of women and 63.9% of men were actively attempting to either lose or maintain their weight . If people are generally aware of the major lifestyle changes needed to prevent or control diabetes, why has there been so little success in lifestyle modification? Or, in other words, why is education necessary, but definitely not sufficient, for true long-term health? As we try to find ways to translate the success of the Diabetes Prevention Program (NIDDK, Press Release August 2001) into programs for large numbers of people, answering these questions will be critical. Rozanski et al reviewed the literature on another facet of the Insulin Resistance Syndrome, cardiovascular disease, and concluded, “Recent studies provide clear and convincing evidence that psychosocial factors contribute significantly to the pathogenesis and expression of coronary artery disease (CAD). This evidence is composed largely of data relating CAD risk to 5 specific domains: (1) depression, (2) anxiety, (3) personality factors and character traits, (4) social isolation, and (5) chronic life stress. Pathophysiological mechanisms underlying the relationship between these entities and CAD can be divided into behavioral mechanisms, whereby psychosocial conditions contribute to a higher frequency of adverse behaviors, such as poor diet and smoking, and direct pathophysiological mechanisms, such as neuroendocrine and platelet activation.” 5(p 2192) Perhaps we similarly need to expand the current diabetes model to include both, (1) the underlying reasons for “unhealthy” behavior choices as well as, (2) the direct effects of stress, poverty, low self-esteem, social isolation, and personal and community-wide trauma on diabetes risk—all of which cluster in lower socioeconomic status (SES) and minority groups, like Native Americans. The following sections will explore each of these two areas. (1) Health-related behaviors (e.g. overeating, smoking, sedentary lifestyle/excessive TV, alcohol abuse) are not primarily cognitively based; they are feeling based, stress-relieving responses. A team from the CDC studied “Adverse Childhood Experiences” (defined as: emotional, physical, or sexual abuse; a battered mother; parental separation or divorce; growing up with a substance-abusing, mentally ill or incarcerated household member) and the risk for smoking (a known risk factor for diabetes) in over 9000 adults. Not only was the risk of smoking strongly associated with adverse childhood experiences, it was “dose dependent” with increasing likelihood of being a smoker with the more categories of abuse one experienced. The researchers went so far as to recommend that, “Current smokers who consciously or unconsciously use nicotine as a pharmacological tool to alleviate the long-term emotional and psycho-biological wounds of adverse childhood experiences may need special assistance to help them quit. Such assistance includes recognition of the use of nicotine to modulate problems with affect, treatment of the residua of these adverse childhood experiences, and the use of nicotine replacement therapy or antidepressant therapy.” 6(pp1657-8) Similarly, data from the Kuopio Ischaemic Heart Disease Risk Factor Study were used to look at the association between unhealthy lifestyle choices and SES. Lynch et al comment that, “Results show that many adult behaviours and psychosocial dispositions detrimental to health are consistently related to poor childhood conditions, low levels of education, and blue-collar employment. ...Understanding that adult health behaviour and psychosocial orientations are associated with socioeconomic conditions throughout the lifecourse implies that efforts to reduce socioeconomic inequalities in health must recognize that economic policy is public health policy. ” 7(p 809) Bessel van der Kolk addressed the mechanisms by which adverse childhood experiences affect behavior: “Secure attachments with caregivers play a critical role in helping children develop a capacity to modulate physiological arousal. Loss of ability to regulate the intensity of feelings and impulses is possibly the most far-reaching effect of trauma and neglect. It has been shown that most abused and neglected children develop disorganized attachment patterns. The inability to modulate emotions gives rise to a range of behaviors that are best understood as attempts at selfregulation. These include aggression against others, self-destructive behavior, eating disorders, and substance abuse. The capacity to regulate internal states affects both self-definition and one’s attitude toward one’s surroundings.” 8(p 145) Looking at eating behavior, Pine found, “All obese and high-anxiety-condition subjects consumed more food than did nonobese and low-anxiety-condition obese subjects, respectively. The overall consumption of food was greater with American Indians than with White Americans...An alternative stress-reaction theory is proposed to more fully account for American Indian eating behavior. Obese and nonobese American Indians overeat in response to stress.” 9(p 774) Or, as Redford Williams states, “Growing up in such conditions could teach the child of parents with lower SES that the world is a hostile, depressing, and alienating place, and the child could also learn that smoking and consumption of larger amounts of alcohol and food help reduce the resulting distress.” 10(p 1746) Poverty plays another role in risk behaviors in that food insecure women are more likely to be obese than women who have a constant food supply. Further, the types of foods which are both available and affordable in impoverished area are often the highly processed, high fat and simple carbohydrate foods most likely to contribute to obesity and diabetes risk. In light of studies such as these, simply educating people on the adverse health consequences of their behaviors seems almost absurd when it is realized that these behaviors are actually strategies to help them cope with multiple life stressors. If diabetes risk behaviors like overeating and smoking are actually stress-relievers, then stopping them without healing the underlying stress issues only further increases the stress--which may help explain the high long-term failure rates of conventional behavior