Mark Pereira

University of Minnesota Twin Cities | UMN · Division of Epidemiology and Community Health

Background Non‐alcoholic fatty liver disease (NAFLD) is recognized as a prevalent determinant of cardiometabolic diseases. The association between NAFLD and obesity warrants further research on how NAFLD modifies associations between body mass index (BMI) and Waist circumference (WC) with cardiometabolic risk (CMR). Objective This study assessed w...

Introduction: Neighborhood green (e.g., parks) and blue (e.g., lakes) spaces have been associated with reduced stress and cardiometabolic risk (CMR), but research is limited in socially vulnerable urban communities affected by structural racism and redlining. This study explored the spatial correlation between green and blue spaces and cortisol lev...

Introduction: Cardiovascular diseases (CVDs) account for ~33% of all deaths globally. Aerobic exercise (AE) is a well-established modifiable risk factor for lowering the risk of CVD mortality, but the global prevalence of meeting the World Health Organization’s (WHO’s) recommendation for weekly AE in adults is only ~25%. Given the rapidly growing b...

This chapter provides an overview of sedentary behaviour correlates, theories, and interventions in youth communities (schools), adult communities (worksites), and neighbourhoods. Within each community, we identify and discuss (a) observational and experimental studies examining the correlates of sedentary behaviour; (b) demographic, psychosocial,...

Habitual physical activity (PA) impacts the plasma proteome and reduces the risk of developing type 2 diabetes (T2D). Using a large-scale proteome-wide approach in Atherosclerosis Risk in Communities study participants, we aimed to identify plasma proteins associated with PA and determine which of these may be causally related to lower T2D risk. PA...

Importance Physical activity (PA) is recommended for preventing and treating nonalcoholic fatty liver disease (NAFLD). Yet, how long-term patterns of intensity-based physical activity, including moderate-intensity PA (MPA) and vigorous-intensity PA (VPA), might affect the prevalence of NAFLD in middle age remains unclear. Objective To identify dis...

Background: The prevalence of non-alcoholic fatty liver disease (NAFLD) in U.S. adults is over 30%, yet the role of lifestyle factors in the etiology of NAFLD remains understudied. We examined the associations of physical activity, by intensity and type, and television viewing with prevalent NAFLD. Methods: Cross-sectional analysis of a population-...

Background: This study examined the associations between BMI trajectories and emerging cardiometabolic risk (CMR) in children living in low-income and racially and ethnically diverse households in the United States. Methods: Data were drawn from NET-Works randomized intervention trial and NET-Works 2 prospective follow-up study (N = 338). BMI was m...

Background Efforts to limit the spread of COVID-19 have included public space closures, mask usage, and quarantining. Studies regarding the impact of these measures on the psychosocial and behavioral health outcomes of the workforce have focused frequently on healthcare employees. To expand the literature base, we deployed a one-year longitudinal s...

Intervention strategies to break up sitting have mostly focused on the modality (i.e., comparing different intensities and/or type of activities) and less on how frequency and duration of breaks affect health outcomes. This study compared the efficacy of different strategies to break up sitting time [i.e., high frequency, low duration standing brea...

Introduction: Non-alcoholic fatty liver disease (NAFLD) is often unrecognized and untreated despite its high prevalence (~25% of adults) and implications for cardiometabolic diseases. We examined the potential for NAFLD to modify the associations between BMI and waist circumference (WC) with changes in cardiometabolic risk. Hypothesis: The associat...

Introduction: The prevalence of nonalcoholic fatty liver disease (NAFLD) in US adults is over 25%, yet the etiology of lifestyle factors in the development of NAFLD remains understudied. We examined the independent and joint associations among aerobic physical activity (PA) intensity (moderate, vigorous) and PA type (aerobic, muscle strengthening),...

Introduction: Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease in the US. Weight loss and lifestyle modifications, including increases in physical activity (PA), are the primary therapeutic recommendations for managing NAFLD. However, little is known about longitudinal physical activity patterns an...

Introduction/purpose: Although many US adults report trying to lose weight, little research has examined weight loss goals as a motivator for reducing workplace sitting and increasing physical activity. This exploratory analysis examined weight goals and the association with changes in workplace sitting, physical activity, and weight. Methods: E...

Background: Higher levels of intra-abdominal adipose tissue (IAAT) comprising visceral adipose tissue (VAT), intermuscular adipose tissue (IMAT), and liver fat are posited drivers of obesity-related chronic disease risk. Fast food is hypothesized to contribute to IAAT patterns. Objectives: We quantified levels of abdominal subcutaneous adipose t...

Background Stand and Move at Work was a 12-month, multicomponent, peer-led (intervention delivery personnel) worksite intervention to reduce sedentary time. Although successful, the magnitude of reduced sedentary time varied by intervention worksite. The purpose of this study was to use a qualitative comparative analysis approach to examine potenti...

Objective: Few studies have reported the cost and cost-effectiveness of workplace interventions to reduce sedentary time. The purpose of this study was to complete an economic evaluation of a multilevel intervention to reduce sitting time and increase light-intensity physical activity (LPA) among employees. Methods: We conducted a retrospective...

Introduction: Substantial cross-sectional evidence exists supporting an association between high body mass index (BMI) during childhood and increased cardiometabolic risk factors. However, less is known about longitudinal associations of child BMI trajectories with biomarkers of cardiometabolic risk. The objective of this study was to (1) identify...

Objective: To examine the effect on continuously monitored blood glucose (CGM) among participants with impaired fasting glucose (IFG) who used a height-adjustable desk while working. Methods: The study was a repeated measures pilot study in overweight or obese women who had IFG (blood glucose [BG] >100 mg/dL) and a sedentary job. Blood glucose w...

Background Sedentary time is associated with chronic disease and premature mortality. We tested a multilevel workplace intervention with and without sit-stand workstations to reduce sedentary time and lower cardiometabolic risk. Methods Stand and Move at Work was a group (cluster) randomized trial conducted between January 2016 and December 2017 a...

Meta-analyses of genome-wide association studies (GWAS) have identified more than 240 loci that are associated with type 2 diabetes (T2D)1,2; however, most of these loci have been identified in analyses of individuals with European ancestry. Here, to examine T2D risk in East Asian individuals, we carried out a meta-analysis of GWAS data from 77,418...

Objective To investigate the possible associations between the food environment and dietary intake in the Mexican population. Design Four databases (PubMed, PsychInfo, Web of Science and SCIelo) were used to retrieve relevant articles using an open timeframe. Articles were reviewed if they contained a systematic measure (i.e. food checklist) of th...

Multicomponent interventions that use sit-stand workstations (SSW) to reduce workplace sitting time have been largely successful. However, the long-term maintenance (i.e., >12 months) of this behavior change is relatively unknown. We aimed to evaluate the 24-month maintenance of reductions in workplace sitting time, along with the effects of introd...

Introduction: We estimated cross-sectional associations between accelerometer-estimated light (LPA), moderate (MPA), and vigorous (VPA) intensity physical activity (PA) and heart rate variability (HRV), and tested mediation of these associations by glycemic control indices, blood lipids, and blood pressure. Hypothesis: PA is positively and independ...

Long-term effects of workplace sedentary behavior interventions on cardiometabolic risk are poorly understood. Stand and Move at Work was a multi-site group randomized trial in 24 worksites (N=630, 74% female, 45±11 years of age) of office-based employees in Phoenix, AZ and Minneapolis/St. Paul, MN. Worksites in the STAND+ study arm received 12 mon...

Purpose: We evaluated the associations between accelerometer-estimated physical activity (PA) intensity and heart rate variability (HRV) and examined mediation of these associations by glycemic control indices and other cardiovascular disease (CVD) risk factors. Methods: Data were from 1,668 participants (X[Combining Overline]age=45.9±3.5 years,...

Background: This study tested for differences in personal, social, and environmental correlates of moderate to vigorous physical activity (MVPA) across ethnicity/race in male and female adolescents. Methods: Self-reported MVPA and 47 potential correlates of MVPA were measured in an ethnically/racially diverse cross-sectional sample of adolescent...

Although the health benefits of exercise and exposure to nature are well established, most evidence of their interaction comes from acute observations of single sessions of activity. However, documenting improved health outcomes requires ongoing interventions, measurement of multiple outcomes, and longitudinal analyses. We conducted a pilot study t...

College students demonstrate poor physical activity (PA) and dietary behaviors. We evaluated the feasibility of a combined smartwatch and theoretically based, social media-delivered health education intervention versus a comparison on improving college students’ health behaviors/outcomes. Thirty-eight students (28 female; Xage = 21.5 ± 3.4 years) p...

This study investigated the acute effects of repeated walking sessions within green and suburban environments on participants’ psychological (anxiety and mood) and cognitive (directed-attention) outcomes. Twenty-three middle-aged adults (19 female) participated in a non-randomized crossover study comprised of once-weekly 50-min moderate-intensity w...

Meta-analyses of genome-wide association studies (GWAS) have identified >240 loci associated with type 2 diabetes (T2D), however most loci have been identified in analyses of European-ancestry individuals. To examine T2D risk in East Asian individuals, we meta-analyzed GWAS data in 77,418 cases and 356,122 controls. In the main analysis, we identif...

Background: This analysis helps clarify the individual and joint effects of moderate to vigorous physical activity (MVPA) in concert with significant life events (eg, divorce, marriage, job change or loss, pregnancy, etc) on weight following a behavioral weight loss intervention. Methods: Data from the Tracking Study weight loss trial were utili...

Introduction: Heart rate variability (HRV) assesses the sympathetic and parasympathetic innervation of the heart. Lower HRV indicates greater sympathetic tone and is associated with adverse cardiovascular outcomes. During exercise, factors like activity intensity influence HRV. Yet, an environment’s inherent anxiety-/stress-promoting characteristic...

Purpose: We evaluated the validity and sensitivity to change of a workplace questionnaire to assess sedentary behavior (SB) during and outside work. Methods: Participants wore an activPAL and completed an SB questionnaire at two time points (baseline and 3-month follow-up). Ecological momentary assessments were used to assess workplace location...

Background Prolonged sedentary time is associated with adverse health outcomes, after controlling for the role of moderate-to-vigorous physical activity. We previously reported on a four-week randomized trial using a sit-stand desk (SSD) intervention that decreased sedentary time at work without changing activity level during non-work hours. Purpo...

Background Isotemporal substitution examines the effect on health outcomes of replacing sedentary time with light‐intensity physical activity or moderate‐to‐vigorous intensity physical activity; however, existing studies are limited by cross‐sectional study designs. Methods and Results Participants were 1922 adults from the CARDIA (Coronary Artery...

Objectives: The fit of measured variables into a social-ecological model of correlates of physical activity is rarely tested. In this study, we examined the factor structure of correlates of moderate/vigorous physical activity (MVPA) within a hypothesized social-ecological model. Methods: We measured 46 possible personal, social and environmental c...

Introduction: Desk-based office workers are at occupational risk for poor health outcomes from excessive time spent sitting. Sit-stand workstations are used to mitigate sitting, but lack of workstation usage has been observed. Point-of-choice (PoC) prompts offer a complementary strategy for office workers to break up their sitting time. Study purpo...

The primary objective of this study was to describe parents' preference for how physicians should approach diet and weight-related advice for their child. Semi-structured interviews were conducted with parents (n = 40) of preschoolers, transcribed verbatim, and double-coded using an inductive thematic analysis approach. Parents identified recommend...

Introduction: Reviewing gaps in self-monitoring during weight loss interventions may help identify individuals demonstrating signs of disengagement in behaviors, including moderate to vigorous physical activity (MVPA), associated with weight loss maintenance. This study examined the associations of different aspects of self-monitoring during a weig...

Purpose: To review enrollment strategies, participation barriers, and program reach of a large, 2-year workplace intervention targeting sedentary behavior. Approach: Cross-sectional, retrospective review. Setting: Twenty-four worksites balanced across academic, industry, and government sectors in Minneapolis/Saint Paul (Minnesota) and Phoenix...

Background: Stroke disproportionately affects people in low-income and middle-income countries. Although improvements in stroke care and outcomes have been reported in high-income countries, little is known about practice and outcomes in low and middle-income countries. We aimed to compare patterns of care available and their association with pati...

Purpose: To test the effectiveness of an intervention to increase motivation for physical activity in racially diverse third- through fifth-grade students. Design: Natural experiment. Setting: Elementary schools in Minneapolis, Minnesota. Participants: Two hundred ninety-one students in 18 Minne-Loppet Ski Program classes and 210 students in...

Introduction: Diet beverages are calorie free beverages sweetened with non-nutritive sweeteners. People with diabetes are the highest per-capita consumers of diet beverages, tending to consume them as a replacement for dietary sources of sugar, especially in place of sugar sweetened beverages. This behavior is endorsed by dietetic and scientific or...

Objective To assess the accuracy of nutrient intake calculations from leading nutrition tracking applications (apps). Design Nutrient intake estimates from thirty 24 h dietary recalls collected using Nutrition Data System for Research (NDSR) were compared with intake calculations from these recalls entered by the researcher into five free nutritio...

Background: Interventions to raise population physical activity generally show modest effects; one possible reason is that trends and determinants of moderate to vigorous physical activity (MVPA) differ between population subgroups. This study examined differences in trends and determinants of reported MVPA by ethnicity/race and sex in a 15-year l...

This chapter provides a succinct overview of sedentary behaviour correlates, theories, and interventions in youth communities (schools), adult communities (worksites), and neighbourhoods. Within each community, we identify and discuss (a) observational and experimental studies examining the correlates of sedentary behaviour; (b) demographic, psycho...

Background: Glycated hemoglobin (HbA1c) is used to diagnose type 2 diabetes (T2D) and assess glycemic control in patients with diabetes. Previous genome-wide association studies (GWAS) have identified 18 HbA1c-associated genetic variants. These variants proved to be classifiable by their likely biological action as erythrocytic (also associated wi...

Cohort information, genotyping, quality control (QC), glycated hemoglobin (HbA1c), analysis and covariates. (XLSX)

Genome-wide significant SNPs identified in the genetic discovery analysis. (XLSX)

Proportion of additional variance explained over age and sex in measured glycated hemoglobin (HbA1c) by erythryocytic genetic variants and by all genome-wide significant genetic variants by ethnicity. (XLSX)

Mean difference in glycated hemoglobin (HbA1c) between the top and bottom 5 percentile of genetic score-total (GS-Total) by ancestry. (XLSX)

Additional analyses on the association of rs1050828, G6PD variant G202A, with glycated hemoglobin (HbA1c). (XLSX)

Association of lead glycated hemoglobin (HbA1c) variants with glycemic and erythrocytic traits from publicly available association results. (XLSX)

Attenuation of glycated hemoglobin variant (HbA1c) effect size in association models conditioned on fasting glucose (FG), 2hr glucose (2hrGlu), hemoglobin level (Hb), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) for the lead HbA1c-associated variants. (XLSX)

Baseline characteristics among those who developed incident type 2 diabetes (T2D) during follow-up and among those who did not, by cohort and ethnicity. (XLSX)

Net reclassification index of type 2 diabetes (T2D) status by measured glycated hemoglobin (HbA1c) ≥ 6.5% compared to fasting glucose (FG) ≥ 7 mmol/L with and without accounting for erythrocytic genetic variants by ancestry. (XLSX)

Association of genetic score-glycemic (GS-G) and genetic score erythrocytic (GS-E) with incident type 2 diabetes (T2D) over a decade-long follow-up period by cohort and ancestry. (XLSX)

Mean difference in glycated hemoglobin (HbA1c) between the top and bottom 5 percentile of genetic score-erythrocytic (GS-E) by ancestry. (XLSX)

Diagram describing the flow of our study. (PDF)

Overview of the classification of genetic variants as glycemic, erythrocytic, or unclassified. (PDF)

Estimated number of African Americans with type 2 diabetes (T2D) in the US whose diagnosis would be missed due to the glycose-6-phosphate dehydrogenase (G6PD) variant if screened with glycated hemoglobin (HbA1c). (XLSX)

Overview of participants included in the genetic discovery analysis. (PDF)

Forest plot of association between erythrocytic genetic score with incident type 2 diabetes (T2D) over a decade-long follow-up period adjusted for glycated hemoglobin (HbA1c) as a continuous variable by ancestry. (PDF)

Authors’ funding information. (DOCX)

BACKGROUND: Glycated hemoglobin (HbA1c) is used to diagnose type 2 diabetes (T2D) and assess glycemic control in patients with diabetes. Previous genome-wide association studies (GWAS) have identified 18 HbA1c-associated genetic variants. These variants proved to be classifiable by their likely biological action as erythrocytic (also associated wit...

Abstract Background To identify social ecological correlates of objectively measured workplace sedentary behavior. Methods Participants from 24 worksites - across academic, industrial, and government sectors - wore an activPAL-micro accelerometer for 7-days (Jan-Nov 2016). Work time was segmented using daily logs. Sedentary behavior outcomes includ...

Evidence suggests that time spent in sedentary behaviors is associated with a greater risk of adverse cardiometabolic outcomes. We investigated the cross-sectional associations of six unique sedentary tasks (television, computer, paperwork, reading, phone, and car) with cardiometabolic risk factors, and compared replacing one type of sedentary beha...

Purpose: This study describes the association between frequency of bicycling for active transportation and modifiable cardiometabolic risk factors in the Minneapolis-Saint Paul (MSP) metropolitan area. Design: We conducted an online survey from a convenience sample of likely bicycle commuters. Setting: Participants were e-mailed invitations in...