Three Lessons About Diabetes and the Social Determinants of Health

The three articles published in conjunction with the American Diabetes Association Diabetes Care Symposium, Social Determinants of Health: Impact on Diabetes Development and Care, are important works of evidence synthesis that relate social context, including social (1), political (2), and commercial (3) determinants of health, to type 2 diabetes risk and outcomes. Each summarizes an important area of investigation and will be a go-to reference in their respective areas for many years to come.

The article by Hill-Briggs and Fitzpatrick (4), “Overview of Social Determinants of Health in the Development of Diabetes,” vividly describes both socioeconomic gradients and racist oppression as fundamental causes of diabetes. These factors function to produce the same result through various mechanisms, making clear that addressing fundamental, rather than superficial, causes is critical to improving diabetes outcomes.

The article by Levi et al. (5), “Food Insecurity and Diabetes: Overview of Intersections and Potential Dual Solutions,” focuses on food insecurity—a key health-related social need with clear links to diabetes incidence, diabetes control, and diabetes complications. They describe mechanisms of the connection and how specific food and nutrition programs can help improve health.

Finally, the article by Mujahid et al. (6), “The Impact of Neighborhoods on Diabetes Risk and Outcomes: Centering Health Equity,” points to the important role of the neighborhood environment in producing health outcomes. Moreover, they provide clear theoretical arguments for the importance of historical context in shaping present-day neighborhoods and support those arguments with empirical findings that demonstrate how much historical context matters.

Given both the depth and breadth of coverage each article provides, we do not seek to summarize them in this commentary. Instead, our goal is to highlight three big-picture lessons we took from reading the articles.

The first lesson is the importance of thinking about levels of analysis (7). One can think of relatively macro-level factors—in this context, levels of analysis that are larger than individuals, like national or state policy, or the neighborhood environment. Many social determinants of health, the conditions in which people are born, grow, work, and live (1), are macro-level factors in this sense. At another level are health-related social needs, like food insecurity, housing instability, or transportation barriers. These are household- or individual-level constructs that result from particular arrangements of social determinants of health. The configurations of social determinants of health that exist in a society are what cause, for example, both the overall prevalence of a health-related social need, like food insecurity, and its distribution in that society. For instance, the distribution of food insecurity falls along lines of social stratification patterned by distributive institutions (social structures that distribute material resources, like the labor market or income support policies) that intersect with forms of oppression, including racism and sexism (8). These individual-level factors are embodied in a way that affects intraindividual biological processes—leading to insulin resistance, loss of β-cell function, impaired glucose homeostasis, and, too often, end-organ damage mediated through macrovascular and microvascular pathways (7). Multilevel thinking is important for understanding the nuances of how the social conditions in which one has lived ultimately result in cellular changes that affect health. As one example, Hill-Briggs and Fitzpatrick (4) show how macro-level factors shape individual-level socioeconomic status, which in turn influences intraindividual biological processes.

Although different levels are often conceptualized as nesting neatly within each other, reality can be more complicated. In particular, both cross-level interactions and level skipping are important (7). For example, although individuals are often depicted as being nested with neighborhoods that are nested within states, state-level policy, such as regulations that make SNAP (the Supplemental Nutrition Assistance Program) or WIC (the Special Supplemental Nutrition Program for Women, Infants, and Children) enrollment more difficult, can affect individual-level health directly without needing to “pass through” neighborhood effects (although they can have neighborhood effects as well) (9,10).

The second lesson is the importance of considering social structure as the context in which behaviors are adopted (11). Diabetes prevention and management strategies often focus on promoting and maintaining healthy behaviors such as dietary adherence, physical activity, medication management, and self-monitoring of blood glucose (12). There are good reasons for this—all of these behaviors can improve health. However, without paying attention to social structures, it is hard to understand the reasons why health-promoting behaviors differ across populations. The way people are positioned within the social structure strongly affects the power and resources available to them (11,13). This in turn constrains and incentivizes individuals to engage in particular behaviors. Without paying attention to social structure, questions of health behaviors can be cast as issues of individual choice, which frequently leads to stigma and does little to explain differences in health across populations (14). To help us avoid this problem, Levi et al. (5) make plain how structural factors that help determine food security status influence dietary patterns.

Questions that are central to health equity scholarship cannot be answered without reference to social structure. For example, the etiological question of why the current social context, which harms the health of many while benefiting the health of few, is the way it is cannot be investigated without a structural focus, and the same is true of the interventional question of how we can transform social conditions to improve everyone’s health (15–17).

Another important reason to incorporate structural analysis into questions of health equity is that it can help to avoid downstream drift, i.e., the tendency to justify interventions on the basis of structural factors but then to intervene at the level of individual behaviors (15). For example, if dilapidated housing and lack of public investment were identified as causes of unsafe conditions that affected diabetes risk through decreasing opportunities for physical activity, intervening with videoconference home exercise classes, rather than neighborhood remediation, would represent downstream drift.

The third lesson is about the importance of taking a life course approach to understanding diabetes epidemiology. For instance, Mujahid et al. (6) emphasize the multiple ways that neighborhood exposures can affect diabetes outcomes over time. Critical periods, path dependence, and cumulative effects are all important concepts in understanding how social conditions come to be embodied (18,19). Although the overt phenotype of type 2 diabetes is becoming more common in children (20), perhaps even more concerning is the proportion of children who are experiencing social conditions that greatly increase their risk for developing type 2 diabetes, and its complications, later in life. For example, risk factors for developing type 2 diabetes, such as overweight and obesity, can be established in the earliest months of a child’s life (21). These issues are often related to food insecurity and other social needs (22,23). Using a life course approach helps investigators think about how early life interventions can reduce type 2 diabetes risk long before it becomes clinically apparent (24), especially for children from communities at increased risk for type 2 diabetes (25).

Beyond clinical interventions, research that examines the life course effects of policies like unconditional cash transfers (26), universal school meals, national childcare and family leave benefits, and regulations that address commercial determinants of health (3) is a pressing need.

Understanding how social conditions affect diabetes outcomes is, of course, important for diabetes treatment, and the symposium articles all achieve that goal. However, these articles are also important more broadly, as type 2 diabetes is an exemplar of how social conditions affect health outcomes of all kinds. The articles in this collection each bear a close reading and are well worth referencing by those who study health equity and the social determinants of health, but their value is not purely academic. Instead, they help show us what policies to seek—policies that can help equalize the unequal distributions of power and resources that drive the unequal distribution of poor health.