Association of Food Insecurity with Changes in Diet Quality, Weight, and Glycemia Over Two Years in Adults with Prediabetes and Type 2 Diabetes on Medicaid

Little is known about longitudinal associations between food insecurity (FI) and diet, weight, and glycemia in people with prediabetes and type 2 diabetes (T2D). In a secondary analysis of Medicaid-enrolled health center patients with prediabetes or T2D in Boston, Massachusetts (N = 188), we examined associations between food security (FS) and measures of diet quality, weight, and hyperglycemia. FS (10-item USDA FS module) was ascertained at baseline, 1-year, and 2-year follow-up and categorized as persistently secure, intermittently insecure, or persistently insecure. Associations between FS category and changes in Healthy Eating Index-2020 (HEI-20), body mass index (BMI), and hemoglobin A1c (A1c) from baseline to year 2 were assessed using multivariate generalized linear models. Participants had median (p25, p75) age of 52 (42, 57); 71.8% were female and 62.8% Hispanic. Over follow-up, 32.4% were persistently food secure, 33.0% intermittently insecure, and 34.5% persistently insecure. Baseline mean (SD) HEI-20, BMI, and A1c were 55.8 (14.5), 35.9 (8.7) kg/m2, 7.1% (1.6) and did not differ by FS category. FS category was not associated with changes in HEI-20, BMI, and A1c at 2 years (all p > 0.05). Results suggest that Medicaid-enrolled adults with prediabetes or T2D, regardless of FS status, would benefit from dietary and weight management interventions.


Introduction
Food insecurity (FI) disproportionately affects people with prediabetes and diabetes (1) and is associated with poor glycemic control (2).While mechanisms explaining the relationship between FI and hyperglycemia remain unclear, diet may play a role.Poor diet quality has been associated with higher hemoglobin A1c (A1c) among adults with diabetes both cross-sectionally (3) and longitudinally (4).
Most research assessing FI and diabetes has included people with variable access to health care, including individuals with and without health insurance, and controlling for access to adequate medical care is challenging.In the current study, we sought to examine the association of 3 food security (FS) categories over 2 years (persistently secure, intermittently insecure, and persistently insecure) and 2-year changes in diet quality, weight, and glycemia in adults with prediabetes and type 2 diabetes (T2D) who had stable access to health care (i.e., enrolled in Medicaid with established care in a community health clinic).We hypothesized that those who were persistently food insecure over 2 years would have greater decrease in diet quality and higher increase in body mass index (BMI) and A1c over 2 years compared to those who were intermittently insecure or persistently secure.

Methods
This was a secondary analysis of data from LiveWell, a cohort study to evaluate the impact of a new state Medicaid program to provide food and housing support for eligible patients (5).Participants were recruited between December 2019 and December 2020 from 5 community health centers a liated with a large health system in Boston, Massachusetts.Eligible patients were 21-62 years old, had ≥ 2 health center visits in the prior 2 years, and spoke English or Spanish; 846 patients with Medicaid insurance were enrolled.This analysis included 188 participants with prediabetes or T2D at enrollment.Diagnoses were determined using the electronic health record (EHR) to identify an International Classi cation of Diseases-10 code, problem list diagnosis, use of T2D medication(s), or a laboratory value consistent with prediabetes or diabetes within 2 years prior to enrollment.When the diagnosis was unclear (i.e., EHR diagnosis of prediabetes or T2D but no prior abnormal A1c), a physician (K.D.G.) performed chart review to adjudicate the diagnosis.
Primary outcomes were changes in Healthy Eating Index-2020 (HEI-20) scores, BMI, and A1c over 2 years, calculated as the value at year 2 minus the value at baseline for each outcome.HEI-20, a valid and reliable measure of dietary quality (10) that aligns with the Dietary Guidelines for Americans 2015-2020 (11), was calculated from 2 Automated Self-Administered 24-Hour dietary recalls collected at baseline and annual follow-up using the National Cancer Institute's simple scoring algorithm (12).Scores range from 0 (least healthy) to 100 (most healthy).BMI (kg/m 2 ) was calculated using self-reported weight and height from annual surveys because EHR data was less complete due to pandemic-related virtual visits.Hemoglobin A1c was ascertained using EHR-recorded laboratory data.We used the average A1c within 24 months preceding enrollment to represent baseline A1c, and average A1c within 12 months preceding the 2-year follow-up survey to represent year 2 A1c.We chose this strategy to capture average exposure to hyperglycemia leading up to enrollment and 2-year follow-up dates.
Baseline differences in participant characteristics by FS category (persistently secure, intermittently insecure, persistently insecure) were compared using non-parametric tests.Separate multivariate generalized linear models adjusted for age, gender, and ethnicity were used to test the association of FS category with change in each outcome.Those missing FS data at any of the 3 time points were excluded (N = 37).Participants who were missing HEI-20 (N = 3), BMI (N = 73), and A1c (N = 56) at baseline or year 2 were also excluded from the relevant models.To address missing data on BMI, a sensitivity analysis was conducted using available EHR weight data to impute missing self-reported weights.All analyses were run using SAS 9.4 (Cary, NC).
Figure 1 shows unadjusted mean HEI-20, BMI, and A1c by FS category at each timepoint.Unadjusted mean A1c was higher in the persistently insecure versus persistently secure groups at baseline (7.3 vs. 7.0%) and year 2 (7.3 vs. 6.9%), but there was no evidence that the 2-year change in HEI-20, BMI, or A1c differed by FS category adjusting for age, gender, and ethnicity (all p-values > 0.05, Supplementary Table 1).Results of the sensitivity analysis using imputed BMI were similar (Supplementary Table 1).

Discussion
In this sample of Medicaid recipients with prediabetes and T2D, nearly two-thirds reported FI at least once during the 2-year study period.Those who had persistent FI were more likely to have other health-related social needs, including housing instability and nancial stress, compared to those who were intermittently food insecure or persistently food secure.Contrary to our hypothesis, we did not nd differences in change in diet quality, BMI, or A1c by the degree of persistence of FI.
Longitudinal studies examining the association between FI and glycemic control in adults with prediabetes and T2DM are limited.While some studies have demonstrated worse glycemic control in those with FI, there is limited evidence that this disparity widens over time.A study of participants from 4 clinics a liated with an academic medical center found that FI was associated with higher A1c at baseline (7.6 vs. 7.0%), a difference that remained constant over a mean follow-up of 37 months (13).
Another study found that among adults with T2D receiving care at a federally quali ed health center with access to the same comprehensive diabetes management program, those with FI vs. FS had higher A1c at baseline (9.11 vs. 8.56%) and through 2 years of follow-up ( 14), but they unexpectedly found that those with FI had a signi cantly greater improvement in A1c over 2 years.In a larger study of almost 3 000 Medicare patients at an integrated health delivery system, those with FI had higher A1c at baseline (7.4 vs. 7.1%), a difference that remained constant at 1-year follow-up in an unadjusted analyses but was no longer signi cant after adjusting for sociodemographic and clinical characteristics (15).
In contrast to prior studies, we did not nd evidence that FI was associated with higher A1c at baseline.A possible explanation is that access to Medicaid coverage and care from a community health center may have mitigated some of the adverse effects of FI on diabetes management through access to medications and clinical visits.This was supported by similarities in diabetes medication use and number of A1c measurements across FS categories in our study.Furthermore, federal relief funding during the COVID-19 pandemic, including expanded Medicaid and Supplemental Nutrition Assistance Program (SNAP) bene ts (16), may have also reduced some of the negative effects of FI on health and diet during our study period.While our ndings do not show an association between persistent FI and worsening A1c over 2 years, further research is needed to explore whether differences exist in a larger population or over a longer period than assessed by our study and others.
A strength of this study is the longitudinal analysis that included multiple assessments of FS status over time to account for the dynamic nature of FS, which may uctuate depending on many factors including income, SNAP cycle, or time of year (17).Study limitations include the small sample size, which may have limited power to detect differences in outcomes.The sample was restricted to adults with Medicaid receiving care in a single health system in Massachusetts, which limits generalizability.Participants were recruited during the early months of the COVID-19 pandemic, which may have impacted health-related social needs, health behaviors, and healthcare utilization (18, 19).Finally, A1c was collected at various frequencies and time points, and BMI calculations relied on self-reported weight.
In sum, among Medicaid-insured adults with prediabetes and T2D followed over 2 years, glycemia was stable, diet quality remained low, and BMI remained high, regardless of FS category.These ndings reinforce the urgent need for interventions to improve dietary intake and weight in all Medicaid patients with prediabetes and T2D.Figures MR, Zhang G, Leung C, Song PXK, Heisler M, Choe HM, et al.Impacts of the COVID-19 pandemic on unmet social needs, self-care, and outcomes among people with diabetes and poor glycemic control.Prim Care Diabetes.2022;16(1):57-64.

Table Table 1
is available in the Supplementary Files section.