Looking Beyond the Individual: The Impact of Neighbourhood on Gestational Diabetes

1.

Gestational diabetes mellitus (GDM), characterised by insulin resistance during pregnancy, is one of the most common pregnancy complications, with its incidence increasing [1]. GDM is a well‐established risk factor for adverse pregnancy outcomes, including hypertensive disorders of pregnancy, macrosomia, operative delivery, neonatal metabolic disturbances, and long‐term cardiometabolic complications in both birthing people and their offspring [1]. While studies have demonstrated racial and ethnic disparities in the prevalence of GDM, the specific factors contributing to these health disparities remain poorly understood.

Social determinants of health are non‐medical, broader societal factors that shape health outcomes, including the conditions in which individuals are born, grow, work, live, play, and age [2]. Traditionally, investigations and interventions to improve health and health equity have focused on individual risk factors. However, a growing body of evidence highlights the critical role of neighbourhood‐level exposures—such as housing quality, violence, access to healthy food, and poverty—in contributing to adverse health outcomes [3].

In this issue of Paediatric and Perinatal Epidemiology, Parra and colleagues [4] explore the relationship between neighbourhood deprivation and the risk of developing GDM. Outside of pregnancy, neighbourhood deprivation has been associated with poorer control of diabetes, but there is limited data on the pregnant population [5]. They conducted a population‐based retrospective cohort study using data from the Arizona Prenatal Environmental and Reproductive Outcomes Study (AzPEARS), which merges birth certificate data with area‐level exposure data from the US Census. For this analysis, data from over 480,000 births were merged with the Neighbourhood Deprivation Index (NDI), a composite measure that quantifies overall neighbourhood socioeconomic status. The NDI is scored on a scale from 0 to 1, with higher scores indicating greater deprivation. A multivariable log‐binomial regression model calculated the risk of GDM across NDI quartiles, adjusting for maternal age, education, race/ethnicity, parity, rurality, and birth year. Additionally, a sensitivity analysis was conducted to account for body mass index, a known covariate, but one that may be on the causal pathway.

The authors found that the overall incidence of GDM was consistent with existing literature, at 7.8%. However, there was considerable geographical variation, with incidence as high as 12% in communities with a high proportion of patients identifying as Native American/American Indian. Residents in the most deprived quartile were younger, less educated, had a higher prevalence of obesity, had smaller infants, and were more likely to have public insurance. The authors found a dose‐dependent increase in GDM incidence with greater exposure to neighbourhood deprivation, which persisted in adjusted analyses. This finding is consistent with other literature demonstrating a dose‐dependent relationship between developing GDM and increasing exposure to neighbourhood deprivation [6].

The authors utilised a large dataset that included almost half a million births, of which 37,636 were affected by GDM. The investigators used robust statistical methods to explore the association between neighbourhood deprivation and GDM. However, the study is limited by the absence of data on pregnancy outcomes beyond the incidence of GDM. Additional information regarding the impact of neighbourhood deprivation on glycaemic control, the need for pharmacologic treatment, hypertensive disorders, mode of delivery, and other neonatal complications would have provided a more comprehensive understanding of the broader impact of neighbourhood deprivation on maternal and neonatal health outcomes.

This study found a high incidence of GDM in patients identifying as Native American/American Indian (almost 18%), which is more than double the overall incidence. This finding highlights the need for further work focusing on this population, which is vulnerable to healthcare disparities, to understand the factors contributing to this higher incidence of GDM and develop targeted interventions to address this disparity.

Neighbourhoods can influence metabolic health through multiple pathways. The neighbourhood deprivation used by Parra et al. includes multiple area‐level socioeconomic indicators. It may serve as a proxy for other neighbourhood characteristics such as access to greenspace, walkability, violent crime, and access to nutritious food and healthcare. Studies of the built environment and diabetes in non‐pregnant adults have found that higher neighbourhood walkability and more greenspace are associated with a lower prevalence of diabetes [7]. In pregnancy, lower levels of neighbourhood greenness have been associated with increased odds of developing a hypertensive disorder [8]. Greenspace improves air quality while encouraging physical and social activities, which can lead to positive health outcomes. The food environment within a neighbourhood, including access, availability, and affordability of nutritious foods, impacts metabolic health. Access to neighbourhood healthcare resources may influence the utilisation of prenatal care. Perceptions of neighbourhood safety may increase stress, decrease physical activity, and affect the ability to consume a healthy diet, all of which can have adverse metabolic consequences.

While a growing body of research has focused on understanding social determinants of health, it is equally essential for clinical practice to recognise the social factors that influence patient health. The first step toward meaningful improvements in care is recognising and acknowledging the social barriers our patients face. As part of patient‐centred care, all individuals should be screened for social determinants of health, including food insecurity, stable housing, transportation needs, exposure to violence, and health literacy, at least once during pregnancy [9]. Implementing standardised screening programmes and referral mechanisms to social services is essential to addressing these needs.

This study contributes to our understanding of the role neighbourhood‐level factors play in the risk of developing GDM. To improve pregnancy outcomes, healthcare professionals and policymakers must look beyond individual factors and address the root cause of community, neighbourhood, and societal factors that are contributing to pregnancy health inequities. Identifying and investing in high‐risk communities and neighbourhoods, as well as place‐based health interventions that support access to nutritious food, physical activity, and healthcare, and mitigate environmental stressors could help reduce the prevalence of GDM and ultimately decrease healthcare disparities.

Author Contributions

CDD was invited to write the commentary. CDD wrote the first draft of the article with input from HHB

2. Conflicts of Interest

The authors declare no conflicts of interest.