A probabilistic computation framework to estimate the dawn phenomenon in type 2 diabetes using continuous glucose monitoring.

In type 2 diabetes (T2D), the dawn phenomenon is an overnight glucose rise recognized to contribute to overall glycemia and is a potential target for therapeutic intervention. Existing CGM-based approaches do not account for sensor error, which can mask the true extent of the dawn phenomenon. To address this challenge, we developed a probabilistic framework that incorporates sensor error to assign a probability to the occurrence of dawn phenomenon. In contrast, the current approaches label glucose fluctuations as dawn phenomena as a binary yes/no. We compared the proposed probabilistic model with a standard binary model on CGM data from 173 participants (71% female, 87% Hispanic/Latino, 54 ± 12 years, with either a diagnosis of T2D for six months or with an elevated risk of T2D) stratified by HbA1c levels into normal but at risk for T2D, with pre-T2D, or with non-insulin-treated T2D. The probabilistic model revealed a higher dawn phenomenon frequency in T2D [49% (95% CI 37-63%)] compared to pre-T2D [36% (95% CI 31-48%), p = 0.01] and at-risk participants [34% (95% CI 27-39%), p < 0.0001]. While these trends were also found using the binary approach, the probabilistic model identified significantly greater dawn phenomenon frequency than the traditional binary model across all three HbA1c sub-groups (p < 0.0001), indicating its potential to detect the dawn phenomenon earlier across diabetes risk categories.

Temporal changes in bio-behavioral and glycemic outcomes following a produce prescription program among predominantly Hispanic/Latino adults with or at risk of type 2 diabetes.

In the United States (U.S.), consumption of fresh vegetables and fruits is below recommended levels. Enhancing access to nutritious food through food prescriptions has been recognized as a promising approach to combat diet-related illnesses. However, the effectiveness of this strategy at a large scale remains untested, particularly in marginalized communities where food insecurity rates and the prevalence of health conditions such as type 2 diabetes (T2D) are higher compared to the background population. This study evaluated the impact of a produce prescription program for predominantly Hispanic/Latino adults living with or at risk of T2D. A total of 303 participants enrolled in a 3-month observational cohort received 21 medically prescribed portions/week of fresh produce. A subgroup of 189 participants used continuous glucose monitoring (CGM) to assess the relationship between CGM profile changes and HbA1c level changes. For 247 participants completing the study (76% female, 84% Hispanic/Latino, 32% with T2D, age 56·6 ± 11·9 years), there was a reduction in weight (-1·1 [-1·6 to -0·6] lbs., p < 0.001), waist circumference (-0·4 [-1·0 to 0·6] cm, p = 0·007) and systolic blood pressure (SBP) for participants with baseline SBP >120 mmHg (-4·2 [-6·8 to -1·8] mmHg, p = 0·001). For participants with an HbA1c ≥ 7·0% at baseline, HbA1c fell significantly (-0·5 [-0·9 to -0·1] %, p = 0·01). There were also improvements in food security (p < 0·0001), self-reported ratings of sleep, mood, pain (all p < 0·001), and measures of depression (p < 0·0001), anxiety (p = 0·045), and stress (p = 0·002) (DASS-21). There was significant correlation (r = 0·8, p = 0·001) between HbA1c change and the change in average glucose for participants with worsening HbA1c, but not for participants with an improvement in HbA1c. In conclusion, medical prescription of fresh produce is associated with significant improvements in cardio-metabolic and psycho-social risk factors for Hispanic/Latino adults with or at risk of T2D.

Patterns of Timing and Intensity of Physical Activity and HbA1c Levels in Hispanic/Latino Adults With or at Risk of Type 2 Diabetes.

Despite the clear benefits of increased physical activity (PA) on glycemic control, little is known about the importance of the timing of exercise among people with diabetes. Our objective was to compare the time of day of PA with concurrent HbA1c levels and body mass index (BMI) among Hispanic/Latino adults with or at risk of type 2 diabetes (T2D).Monitored activity data obtained from Hispanic/Latino adults were summarized as number of steps per day, moderate-to-vigorous-intensity physical activity (MVPA), and energy expenditure (kcals/day). We next examined the association between PA measures and participants' HbA1c. K-means clustering analysis was applied to identify daily PA patterns by time of day and intensity. Thus, three dominant clusters were identified: low-intensity PA, and early and late PA by time of day.The step counts were correlated with HbA1c in the late-active group (P = .01). Furthermore, independently in younger adults (age ≤ 50 years) and in overweight adults (25 ≤ BMI < 30 kg/m2), there was an association between HbA1c and step counts (P < .01 and P < .005, respectively) as well as HbA1c and MVPA (P < .05 and P < .035, respectively).In conclusion, for Hispanic/Latino adults with or at risk of T2D, there appears to be clustering of PA by intensity and time of day which, in turn, may influence achieved HbA1c and BMI. Our findings demonstrate that the amount of activity is more efficacious on HbA1c in participants who are more active later during the day and separately in overweight and younger individuals.This finding may help design more personalized PA recommendations in this population.ClinicalTrials.gov Identifiers: NCT03830840 and NCT03736468.

The northeast glucose drift: Stratification of post-breakfast dysglycemia among predominantly Hispanic/Latino adults at-risk or with type 2 diabetes.

Background: There is minimal experience in continuous glucose monitoring (CGM) among underserved racial/ethnic minority populations with or at risk of type 2 diabetes (T2D), and therefore a lack of CGM-driven insight for these individuals. We analyzed breakfast-related CGM profiles of free-living, predominantly Hispanic/Latino individuals at-risk of T2D, with pre-T2D, or with non-insulin treated T2D. Methods: Starting February 2019, 119 participants in Santa Barbara, CA, USA, (93 female, 87% Hispanic/Latino [predominantly Mexican-American], age 54·4 [±12·1] years), stratified by HbA1c levels into (i) at-risk of T2D, (ii) with pre-T2D, and (iii) with non-insulin treated T2D, wore blinded CGMs for two weeks. We compared valid CGM profiles from 106 of these participants representing glucose response to breakfast using four parameters. Findings: A "northeast drift" was observed in breakfast glucose responses comparing at-risk to pre-T2D to T2D participants. T2D participants had a significantly higher pre-breakfast glucose level, glucose rise, glucose incremental area under the curve (all p < 0·0001), and time to glucose peak (p < 0·05) compared to pre-T2D and at-risk participants. After adjusting for demographic and clinical covariates, pre-breakfast glucose and time to peak (p < 0·0001) were significantly associated with HbA1c. The model predicted HbA1c within (0·55 ± 0·67)% of true laboratory HbA1c values. Interpretation: For predominantly Hispanic/Latino adults, the average two-week breakfast glucose response shows a progression of dysglycemia from at-risk of T2D to pre-T2D to T2D. CGM-based breakfast metrics have the potential to predict HbA1c levels and monitor diabetes progression. Funding: US Department of Agriculture (Grant #2018-33800-28404), a seed grant from the industry board fees of the NSF Engineering Research Center for Precise Advanced Technologies and Health Systems for Underserved Populations (PATHS-UP) (Award #1648451), and the Elsevier foundation.

Ethnicity, age, and education influence perceptions of vegetable healthiness and macronutrient content.

Objective: To assess perceptions of nutritional content and health value of popular vegetables. Design: Cross-sectional online survey. Participants: A total of 760 adults participated in the study. Main Outcome Measures: Likert scale ratings of healthy, calories, carbohydrates, protein, and fiber, for (i) avocado, (ii) romaine lettuce, (iii) white potato, (iv) white onion, and (v) red tomato. Analysis: ANOVAs for continuous variables and Chi-square for categorical variables. Outcomes for nutritional content were compared using separate one-way ANOVAs with ethnicity (Hispanic/Latino vs. non-Hispanic); education (college degree/no college degree); age (18-34, 35-50, 51-70, 70 + ); and diabetes status (with or without diabetes) as the grouping variables. Results: Significant ethnicity effects were found for avocado, lettuce, potato, onion, and tomato. Education level effects were found for avocado, lettuce, potato, and tomato. Age level effects were found for avocado, lettuce, potato, and tomato. Conclusions and Implications: Participant perceptions of the macronutrient content of common vegetables and fruits largely coincided with the US Department of Agriculture values. However, stratifying by ethnicity, age, and education revealed significant differences in both macronutrient perceptions and perceived healthiness. There were no consistent, significant results for interactions of ethnicity by education, nor ethnicity by age. These results suggest that dietary interventions may need to be adjusted based on participant sociodemographic characteristics linked to the perceptions of nutritional value and healthiness.

Dysglycemia in adults at risk for or living with non-insulin treated type 2 diabetes: Insights from continuous glucose monitoring.

BACKGROUND: Continuous glucose monitoring (CGM) has demonstrable benefits for people living with diabetes, but the supporting evidence is almost exclusively from White individuals with type 1 diabetes. Here, we have quantified CGM profiles in Hispanic/Latino adults with or at-risk of non-insulin treated type 2 diabetes (T2D). METHODS: 100 participants (79 female, 86% Hispanic/Latino [predominantly Mexican], age 54·6 [±12·0] years) stratified into (i) at risk of T2D, (ii) with pre-diabetes (pre-T2D), and (iii) with non-insulin treated T2D, wore blinded CGMs for 2 weeks. Beyond standardized CGM measures (average glucose, glucose variability, time in 70-140 mg/dL and 70-180 mg/dL ranges), we also examined additional CGM measures based on the time of day. FINDINGS: Standardized CGM measures were significantly different for participants with T2D compared to at-risk and pre-T2D participants (p<0·0001). In addition, pre-T2D participants spent more time between 140 and 180 mg/dL during the day than at-risk participants (p<0·01). T2D participants spent more time between 140 and 180 mg/dL both during the day and overnight compared to at-risk and pre-T2D participants (both p<0·0001). Time in 70-140 mg/dL range during the day was significantly correlated with HbA1c (r=-0·72, p<0·0001), after adjusting for age, sex, BMI, and waist circumference (p<0·0001). INTERPRETATION: Standardized CGM measures show a progression of dysglycemia from at-risk of T2D, to pre-T2D, and to T2D. Stratifying CGM readings by time of day and the range 140-180 mg/dL provides additional metrics to differentiate between the groups. FUNDING: US Department of Agriculture (Grant #2018-33800-28404) and NSF PATHS-UP ERC (Award #1648451).

Insurance Status and Biological and Psychosocial Determinants of Cardiometabolic Risk Among Mexican-Origin U.S. Hispanic/Latino Adults with Type 2 Diabetes.

Purpose: Hispanics/Latinos in the United States bear higher burden of type 2 diabetes (T2D) and associated complications compared with the general population. Health insurance coverage is also lower in this population. We examined the association of health insurance with biological and psychosocial determinants of cardiometabolic risk among U.S. Mexican-origin Hispanic/Latino adults with T2D. Methods: Participants were self-reported Hispanic/Latino adults with T2D diagnosis. Trained bilingual community health workers collected cross-sectional information on biological and psychosocial factors using clinical examinations, laboratory tests, validated questionnaires, and wearable activity monitors. Results: One hundred and seven Hispanic/Latino adults (54±12 years, 65% female, 36% prescribed insulin, 60% uninsured) with T2D were enrolled. While 93% had low language-based acculturation, 88% had high health literacy in Spanish. Forty percent were food insecure and 47% expressed at least one social need. Overall, 35% had an HbA1c <7.0% (indicating good control) and 31% had an HbA1c >9.0%. Sixty-three percent had blood pressure within target (<130/80 mmHg), and overall participants were moderately physically active. However, 53% were obese (body mass index ≥30 kg/m2) and 76% had a waist measurement defined as high risk (>88 cm for women and >102 cm for men). Participants without health insurance were younger (51.9±10.4 vs. 58.8±10.5 years mean±standard deviation, p=0.0008) but had higher HbA1c (8.4±2.2% vs. 7.6±1.6, p=0.031) and fasting glucose (184.9±86.5 vs. 148.6±61.2 mg/dl, p=0.008) levels. Conclusions: Health insurance status appears to influence achieved glycemic control for U.S. Hispanic/Latino adults with T2D. However, various psychosocial factors potentially influencing cardiometabolic risk independently of health insurance status may also be implicated in the inequitable burden of T2D. ClinicalTrials.gov Identifier: NCT03736486.

Self-reported and objectively measured physical activity levels among Hispanic/Latino adults with type 2 diabetes.

OBJECTIVE: In the USA, minority populations face a disproportionate burden from type 2 diabetes (T2D), in whom physical activity (PA) is recommended. The aim of this study was to determine levels of PA among a community of free-living Hispanic/Latino adults with T2D using a research accelerometer, a consumer device and a pictogram self-assessment questionnaire. RESEARCH DESIGN AND METHODS: This was a cross-sectional, observational study. Participants (57 women and 31 men, body mass index (kg/m2) 32.2±7.9 and 29.9±4.5, waist circumference 97.1±30.1 and 93.7±33.0 cm and hemoglobin A1c 8.0±2.0 and 8.1%±1.8%, respectively) wore an ActiGraph (AG) on the hip and a Fitbit (FB) on the wrist for 1 week to estimate daily steps and energy expenditure (EE). Participants reported type and intensity of PA using English-language or Spanish-language pictograms and a 10-point Likert scale (1='not active' to 10='very, very active'). RESULTS: Steps per day were not normally distributed; AG median steps/weekday (Monday-Friday) was 6990 (range 1091-25 884) compared with 9329 (288-31 669) using FB (p≤0.01). Both devices recorded significantly more steps on weekdays versus weekends (p≤0.05). EE was also higher during the week. AG and FB were highly correlated to each other (p<0.01). Men were more active than women and maintained their PA throughout the week, whereas women decreased theirs on weekends. Spanish-language pictograms were preferred and self-reported PA matched objective assessments by both devices. Participants perceived themselves to be active (7.1±2.0) due to work. CONCLUSIONS: Both objectively measured and self-reported levels of PA in Hispanic/Latino adults with T2D challenge the assumption that lack of PA may be commonplace for this group. AG and FB are different in their measurement of PA but are significantly correlated. New strategies, including use of pictograms, for interventions need to be considered if further increases or changes in PA are to be used as T2D therapy. TRIAL REGISTRATION NUMBER: NCT03736486.

Understanding the impact of five major determinants of health (genetics, biology, behavior, psychology, society/environment) on type 2 diabetes in U.S. Hispanic/Latino families: Mil Familias - a cohort study.

BACKGROUND: In the United States (U.S.), the prevalence of both diagnosed and undiagnosed type 2 diabetes (T2D) is nearly twice as high among Mexican-origin Hispanic/Latino adults compared to non-Hispanic Whites. Rates of diabetes-related complications, e.g., acute stroke and end-stage renal disease, are also higher among Hispanic/Latino adults compared to their non-Hispanic/Latino White counterparts. Beyond genetic and biological factors, it is now recognized that sociocultural influences are also important factors in determining risk for T2D and the associated complications. These influences include ethnicity, acculturation, residence, education, and economic status. The primary objective of this study is to determine the influence of the 5 major determinants of human health (genetics, biology, behavior, psychology, society/environment) on the burden of T2D for Latino families. To achieve this objective, Mil Familias (www.milfamilias.sansum.org/) is establishing an observational cohort of 1000 Latino families, with at least one family member living with T2D. METHODS: Specially trained, bilingual Latino/a community health workers (Especialistas) recruit participant families and conduct research activities. Each individual family member will contribute data annually on over 100 different variables relating to their genetics, biology, psychology, behavior, and society/environment, creating a Latino-focused biobank ("Living Information Bank"). This observational cohort study is cross-sectional and longitudinal. Participants are divided into 4 groups: adults age ≥ 18 years with and without T2D, and children age ≥ 7 and < 18 years with and without T2D. Study activities take place through encounters between families and their Especialista. Encounters include screening/enrollment, informed consent, health promotion assessment, laboratory tests, questionnaires, physical activity monitoring, and reflection. DISCUSSION: By creating and providing the framework for the Cohort Establishment study, we intend to inform new approaches regarding equity and excellence in diabetes research and care. We will examine the complex set of factors that contribute to the burden of diabetes in Latino families and assess if cardio-metabolic disease risks go beyond the traditional biological and genetic factors. Breaking the code on the interplay of cardio-metabolic risk factors may help not only this fast growing segment of the U.S. population, but also other high-risk populations. TRIAL REGISTRATION: Study retrospectively registered at ClinicalTrials.gov (NCT03830840), 2/5/2019 (enrollment began 2/1/2019).

Farming for life: impact of medical prescriptions for fresh vegetables on cardiometabolic health for adults with or at risk of type 2 diabetes in a predominantly Mexican-American population.

INTRODUCTION: Poor diet is the leading cause of poor health in USA, with fresh vegetable consumption below recommended levels. We aimed to assess the impact of medical prescriptions for fresh (defined as picked within 72 hours) vegetables, at no cost to participants on cardiometabolic outcomes among adults (predominantly Mexican-American women) with or at risk of type 2 diabetes (T2D). METHODS: Between February 2019 and March 2020, 159 participants (122 female, 75% of Mexican heritage, 31% with non-insulin treated T2D, age 52.5 (13.2) years) were recruited using community outreach materials in English and Spanish, and received prescriptions for 21 servings/week of fresh vegetable for 10 weeks. Pre-post comparisons were made of weight; waist circumference; blood pressure; Hemoglobin A1c (HbA1c, a measure of long-term blood glucose control); self-reported sleep, mood and pain; vegetable, tortilla and soda consumption. After obtaining devices for this study, 66 of 72 participants asked, agreed to wear blinded continuous glucose monitors (CGM). RESULTS: Paired data were available for 131 participants. Over 3 months, waist circumference fell (-0.77 (95% CI -1.42 to 0.12) cm, p=0.022), as did systolic blood pressure (SBP) (-2.42 (95% CI -4.56 to 0.28) mm Hg, p=0.037), which was greater among individuals with baseline SBP >130 mm Hg (-7.5 (95% CI -12.4 to 2.6) mm Hg, p=0.005). Weight reduced by -0.4 (-0.7 to -0.04) kg, p=0.029 among women. For participants with baseline HbA1c >7.0%, HbA1c fell by -0.35 (-0.8 to -0.1), p=0.009. For participants with paired CGM data (n=40), time in range 70-180 mg/dL improved (from 97.4% to 98.9%, p<0.01). Food insecurity (p<0.001), tortilla (p<0.0001) and soda (p=0.013) consumption significantly decreased. Self-reported sleep, mood and pain level scores also improved (all p<0.01). CONCLUSIONS: Medical prescriptions for fresh vegetables were associated with clinically relevant improvements in cardiovascular risk factors and quality of life variables (sleep, mood and pain level) in adults (predominantly Mexican-American and female) with or at risk of T2D. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT03940300.

Perspectives on Long-Distance Air Travel with Type 1 Diabetes.

We sought to determine the real-life experiences of individuals traveling long distance (across five or more time-zones) with type 1 diabetes (T1D). Five hundred three members of the T1D Exchange online community ( www.myglu.org ) completed a 45-question survey about their travel experiences flying long distance. The cohort was stratified by duration of T1D and whether or not participants used continuous subcutaneous insulin infusion (CSII) therapy and/or a continuous glucose monitor (CGM). In the last 5 years, 71% of participants had flown long distance. When asked about their perceived "fear of flying," CSII users (with and without a CGM) reported their primary anxiety was "losing supplies," while non-CSII users described concerns over "unstable blood glucose (highs and lows)" (P < 0.05). In addition, 74% of participants reported more hypoglycemia and/or hyperglycemia while traveling overseas and 9% had avoided international travel altogether because of problems related to diabetes management. Furthermore, 22% of participants had run out of insulin at some point during a trip and 37% reported inadequate attention in current sources of information to the unpredictability of self-management needs while traveling. Especially problematic for individuals traveling with T1D are a lack of resources adequately addressing (1) protocols for emergencies while abroad, (2) how to navigate airport security, and (3) managing basal insulin rates when crossing time zones. A strong need exists for easily accessible, free resources for traveling with T1D that is tailored to both device use and duration of the disease.