UC San Diego

Rationale. Diabetes prevalence has risen rapidly in the United States and Mexico in recent years. Along the U.S.-Mexico border, diabetes is 2-3 times more prevalent than elsewhere in either country. This region is home to a high concentration of migrant and deported individuals at risk for diabetes and other chronic diseases due to low socioeconomic status, housing and food insecurity, stress, and limited access to healthcare. Formal investigation of diabetes in migrants and deportees is scant, and little is known about the unique risk profiles of this population.

Objective. Utilizing a socio-ecological, community-informed approach guided by Intervention Mapping, this study aimed to 1) Assess prevalence of diabetes and prediabetes in a high-risk border population in Tijuana, Mexico; 2) Examine the relationships of psychological adversity [depression, anxiety, adverse childhood experiences (ACES)] with diabetes prevalence, and explore indirect effects of social support in this relationship; 3) Examine the relationship of neighborhood adversity (e.g., lack of access to healthy foods, violence/crime) with diabetes prevalence, and explore indirect effects of physical activity and dietary intake in this relationship; and 4) Assess the association of diabetes knowledge/cultural beliefs with diabetes prevalence, and test whether there are indirect effects through physical activity and dietary intake. Exploratory models repeated Aims 2 - 4 with two additional dependent variables, in separate models: glucose regulation (hemoglobin A1c) and a 3-level diabetes status variable (normal glucose regulation, prediabetes, diabetes) examined continuously.

Design. This cross-sectional study recruited adults from the Health Frontiers in Tijuana medical clinic, which serves large numbers of low-income migrants and deportees near the U.S-Mexico border. Glucose regulation and diabetes status were assessed by point-of-care hemoglobin A1c (HbA1c) immunoassay. Psychosocial, neighborhood, and knowledge variables were assessed using a verbally administered self-report questionnaire. Prevalence of diabetes and prediabetes and other sample characteristics were assessed using SPSS Statistics. Multivariable logistic regression conducted in MPlus was used to examine relationships of psychological adversity, neighborhood adversity and diabetes knowledge/cultural beliefs with diabetes diagnosis. Multivariable linear regression was utilized in exploratory models.

Results. Participants were N = 220 adults aged 19-83 years (M age = 47.2, SD = 11.9). The majority was male (74.5%), of Mexican nationality (89.1%), and not married or partnered (52.7%). Over 30% had elementary school education or less. Over 70% reported history of migration to the U.S.; 58.6% reported history of at least one deportation from the U.S. to Mexico. Participants reported high levels of clinically significant depression and anxiety symptoms (33.2% and 30.5%, respectively), and 49% reported ≥4 ACEs. Prevalence of diabetes was 17.3% and prevalence of prediabetes was 29.1%. Controlling for age, sex, education, and income, psychological adversity variables were not significantly associated with diabetes prevalence. Neighborhood adversity and diabetes knowledge/cultural beliefs were likewise not associated with diabetes prevalence. Indirect effects were found from depression symptoms and ACEs, through social support, to glucose regulation. Indirect effects were also found from neighborhood adversity to diabetes prevalence and glucose regulation through dietary intake, but in an unexpected direction.

Conclusion. This is the first study to our knowledge to examine prevalence and correlates of diabetes in a large number of deported Mexican migrants, an underserved and hard-to-reach population. Results revealed a high burden of physical and psychological risk, suggesting the need for integrated approaches to physical and mental health in future prevention and intervention programs. The hypothesized correlates of diabetes may not be the most impactful determinants of health in this sample due to profound socioeconomic disadvantage, housing and food insecurity, and forced deportation. Social support may play a role in the relationship of psychological adversity and glucose regulation. In low-resource populations on the U.S.-Mexico border, future studies should explore a wider range of potential determinants of diabetes and examine mediators of relationships of psychological and neighborhood adversity with diabetes status longitudinally.