Steven K Malin

Rutgers, The State University of New Jersey | Rutgers · Kinesiology and Health

Objective This crossover study explored the impact of a single bout of exercise on insulin-stimulated responses in conduit arteries and capillaries. Methods Twelve sedentary adults (49.5 [7.8] years; maximal oxygen consumption [VO2max]: 23.7 [5.4] mL/kg/min) with obesity (BMI 34.5 [4.3] kg/m²) completed a control and exercise bout (70% VO2max to e...

Extracellular vesicles (EVs) are often elevated in obesity and may modulate disease risk. Although acute exercise reduces fasting EVs in adults with obesity, no data exist on insulin‐mediated EV responses. This study evaluated the effects of exercise on EV responses to insulin in relation to vascular function. Ten (5M/5F) sedentary adults with obes...

This consensus statement is an update of the 2010 American College of Sports Medicine position stand on exercise and type 2 diabetes. Since then, a substantial amount of research on select topics in exercise in individuals of various ages with type 2 diabetes has been published while diabetes prevalence has continued to expand worldwide. This conse...

Purpose People characterized as late chronotype have elevated type 2 diabetes and cardiovascular disease risk compared to early chronotype. It is unclear how chronotype is associated with insulin sensitivity, metabolic flexibility, or plasma TCA cycle intermediates concentration, amino acids (AA), and/or beta-oxidation. Methods The Morning-Evening...

Adults with prediabetes are at risk for Alzheimer's Disease and Related Dementia (ADRD). While exercise may lower ADRD risk, the exact mechanism is unclear. We tested the hypothesis that short‐term exercise would raise neuronal insulin signaling and pro‐BDNF in neuronal extracellular vesicles (nEVs) in prediabetes. Twenty‐one older adults (18F, 60....

Introduction The New Jersey Kids Study (NJKS) is a transdisciplinary statewide initiative to understand influences on child health, development, and disease. We conducted a mixed-methods study of project planning teams to investigate team effectiveness and relationships between team dynamics and quality of deliverables. Methods Ten theme-based wor...

Introduction: Bisphenol A (BPA) is a synthetic chemical widely used in consumer goods and is linked to Type 2 diabetes progression in observational studies. No experimental studies have examined whether BPA promotes reductions in peripheral insulin sensitivity. Objective: To determine the effects of oral BPA administration on peripheral insulin sen...

Introduction & Objective: Prediabetes raises Alzheimer’s Disease and Related Dementia (ADRD) risk. While exercise may lower ADRD risk, it is unclear if it does so by raising brain insulin sensitivity and/or brain derived neurotrophic growth factor (BDNF). We hypothesized that short-term exercise would raise brain insulin signaling and BDNF from neu...

Hypertension disproportionately affects African Americans and is a risk factor for Alzheimer's disease (AD). We investigated the relationship of blood pressure (BP) with medial temporal lobe (MTL) dynamic network flexibility (a novel AD biomarker) and cognitive generalization in older African Americans. In a cross‐sectional study, 37 normotensive (...

Background: Insulin resistance is a major etiological factor in obesity, type 2 diabetes, and cardiovascular disease (CVD). Endothelial dysfunction may precede impairments in insulin-stimulated glucose uptake, thereby making it a key feature in development of CVD. However, the mechanism by which vascular tissue becomes dysfunctional is not clear....

Tricarboxylic acid cycle intermediates (TCAi) have been proposed to act as myokines that influence energy metabolism. We determined if 2‐weeks of low‐calorie diet with interval exercise (LCD + INT) would increase TCAi more than a low‐calorie diet (LCD). Twenty‐three women were randomized to 2‐weeks of LCD ( n = 12, 48.4 ± 2.5 years, 37.8 ± 1.5 kg/m...

Context Relative hypoglycemia (RH) is linked to sympathetic responses that can alter vascular function in individuals with type 2 diabetes. However, less is known about the role of RH on hemodynamics or metabolic insulin sensitivity in prediabetes. Objective Determine if RH alters peripheral endothelial function or central hemodynamics to a greate...

Late chronotype (LC) is related to obesity and altered food intake throughout the day. But whether appetite perception and gut hormones differ among chronotypes is unclear. Thus, we examined if early chronotype (EC) have different appetite responses in relation to food intake than LC. Adults with obesity were categorized using the Morningness-Eveni...

Aim Chronotype reflects a circadian rhythmicity that regulates endothelial function. While the morning chronotype (MORN) usually has low cardiovascular disease risk, no study has examined insulin action on endothelial function between chronotypes. We hypothesized intermediate chronotypes (INT) would have lower vascular insulin sensitivity than morn...

Introduction People with obesity have high circulating bile acids (BA). Although aerobic fitness favors low circulating BAs, the effect of training intensity prior to clinically meaningful weight loss on BA is unclear. Test the hypothesis that 2-wks of interval (INT) versus continuous (CONT) exercise would lower plasma BAs in relation to insulin se...

Background Alzheimer’s disease (AD) is a leading cause of death in the United States and disproportionately impacts African Americans. AD has recently been characterized as “type 3 diabetes” due to evidence that hyperglycemia impairs cognitive function. Individuals with the Apolipoprotein ε4 (APOE ε4) allele may also have triple the risk of Alzheim...

Background Hypertension disproportionately affects African Americans (AA) and is an established mid‐life risk factor for Alzheimer’s disease (AD). However, previous research suggests there is inconclusive data examining late‐life hypertension and Alzheimer’s risk. Recently, a dynamic rearrangement (neural flexibility) imaging method was validated f...

Introduction African Americans are two to three times more likely to be diagnosed with Alzheimer’s disease (AD) compared to White Americans. Exercise is a lifestyle behavior associated with neuroprotection and decreased AD risk, although most African Americans, especially older adults, perform less than the recommended 150 min/week of moderate-to-v...

Cardiorespiratory fitness (CRF) is critical for cardiovascular health. Normal-weight obesity (NWO) and metabolically healthy obesity (MHO) may be at increased risk for cardiovascular disease, but a comparison of CRF and submaximal exercise dynamics against rigorously defined low- and high-risk groups is lacking. Four groups (N = 40; 10/group) based...

β-Aminoisobutyric acid (BAIBA) is secreted by skeletal muscle and promotes insulin sensitivity, fat oxidation, and anti-inflammation. While BAIBA is purportedly lower in individuals with obesity, no work has examined if prediabetes (PD) differentially impacts BAIBA concentrations in people with obesity. Methods. Adults were classified as normal glu...

Introduction Excess body weight and Alzheimer’s disease (AD) disproportionately affect older African Americans. While mid-life obesity increases risk for AD, few data exist on the relationship between late-life obesity and AD, or how obesity-based and genetic risk for AD interact. Although the APOE-ε4 allele confers a strong genetic risk for AD, it...

Exaggerated exercise blood pressure (BP) is linked to cardiovascular disease (CVD). While evening chronotypes have greater CVD risk than morning (MORN) types, it is unknown if exercise BP differs in intermediate (INT) types. Adults with obesity were classified as either MORN (n=23 (18F), MEQ=63.96±1.0, 54.74±1.4yr, 33.7±0.6kg/m2) or INT (n=23 (19F)...

Exercise improves blood glucose control among people with type 2 diabetes (T2D), and can lead to reduced need for glucose medications (1, 2). Although the optimal exercise “dose” (eg, intensity, modality, time of day, and/or duration) remains to be determined, it is appropriate to recognize that the improvements seen across people vary—with some ex...

Purpose of Review Strong evidence is evolving that physical exercise prevents hypertension and reduces blood pressure in patients with pre- and manifest HTN. Yet, identifying and confirming the effectiveness of exercise are challenging. Herein, we discuss conventional and novel biomarkers such as extracellular vesicles (EVs) which may track respons...

The acute effect of exercise on β-cell function during a high fat meal (HFM) in young (YA) vs. old (OA) adults is unclear. In this randomized cross-over trial, YA (n=5M/7F, 23.3±3.9y) and OA (n=8M/4F, 67.7±6.0y) underwent a 180 min HFM (12 kcal/kgbw; 57% fat, 37% CHO) after a rest or exercise (~65% HRpeak) condition ~12hr prior. After an overnight...

Introduction: β-aminoisobutyric acid (BAIBA) is a suggested cytokine secreted from skeletal muscles that regulates insulin sensitivity, pancreatic function, and fat oxidation. However, no studies to date have examined if a low-calorie diet (LCD) or LCD + with interval exercise (LCD + INT) differentially raises BAIBA. The purpose was to examine if L...

Exercise is a first-line therapy recommended for patients with type 2 diabetes (T2D). Although moderate to vigorous exercise (e.g. 150 min/wk) is often advised alongside diet and/or behavior modification, exercise is an independent treatment that can prevent, delay or reverse T2D. Habitual exercise, consisting of aerobic, resistance or their combin...

Cost-effectiveness analyses of weight loss programs for university students can inform administrator decision-making. This study quantifies and compares the costs and cost-effectiveness of implementing two digitally-delivered weight loss interventions designed for university populations. Healthy Body Healthy U (HBHU) was a randomized controlled tri...

Trimethylamine N-oxide (TMAO) is linked to cardiovascular disease (CVD) through partly altered central hemodynamics. We sought to examine if a low-calorie diet plus interval exercise (LCD+INT) intervention reduces TMAO more than a low-calorie diet (LCD) program alone in relation to hemodynamics, prior to clinically meaningful weight loss. Women wit...

Introduction: Newer therapies have increased heart failure (HF) survival rates, but these therapies are rarely curative. The consequence of increased longevity is the likelihood that patients with HF will experience higher symptom burden over time. Exercise, such as cardiac rehabilitation programs, can palliate symptom burden, but numerous barrier...

Liver-expressed antimicrobial peptide-2 (LEAP-2) is associated with caloric intake and glucose metabolism. Purpose: Assess if a low-calorie diet with interval exercise (LCD+INT) raises LEAP-2 more than LCD in relation to appetite and cardiometabolic health. Methods: Women with obesity were randomized to either 2 weeks of LCD (n = 13, ~1200 kcal/d)...

Exercise is advised to improve overall cardiovascular health and endothelial function. However, the role of nutrition on this exercise induced endothelial adaptation is not clear. Here, we hypothesize that nutrients interact with exercise to influence endothelial function and chronic disease risk.

Prediabetes raises cardiovascular disease risk, in part through elevated aortic waveforms. While insulin is a vasodilatory hormone, the gut hormone relation to aortic waveforms is less clear. We hypothesized that exercise, independent of intensity, would favor aortic waveforms in relation to gut hormones. Older adults (61.3 ± 1.5 yr; 33.2 ± 1.1 kg/...

Metabolic Syndrome (MetS) raises cardiovascular disease risk. Extracellular vesicles (EVs) have emerged as important mediators of insulin sensitivity, although few studies on vascular function exist in humans. We determined the effect of insulin on EVs in relation to vascular function. Adults with MetS (n = 51, n = 9 M, 54.8 ± 1.0 years, 36.4 ± 0.7...

Late chronotype (LC) correlates with reduced metabolic insulin sensitivity and cardiovascular disease. It is unclear if insulin action on aortic waveforms and inflammation is altered in LC versus early chronotype (EC). Adults with metabolic syndrome (n = 39, MetS) were classified as either EC (Morning-Eveningness Questionnaire [MEQ] = 63.5 ± 1.2) o...

Exercise has systemic health benefits in people, in part, through improving whole-body insulin sensitivity. The brain is an insulin sensitive organ that is often underdiscussed relative to skeletal muscle, liver, and adipose tissue. While brain insulin action may have only subtle impacts on peripheral regulation of systemic glucose homeostasis, it...

The purpose of the present study was to determine fasting and high-fat meal (HFM)-induced post-prandial systemic inflammation and airway inflammation (exhaled nitric oxide (eNO)) in older adults (OAs) compared to younger adults (YAs) before and after acute exercise. Twelve YAs (23.3 ± 3.9 y n = 5 M/7 F) and 12 OAs (67.7 ± 6 y, n = 8 M/4 F) complete...

New findings: What is the central question of this study? Chronotype reflects differences in circadian-mediated metabolic and hormonal profiles. But, does resting and/or exercise fuel use differ in early versus late chronotype as it relates to insulin sensitivity? What are the main finding and its importance? Early chronotypes with metabolic syndr...

Elevated extracellular vesicles (EVs) are associated with glucose dysmetabolism. However, the effects of insulin on EVs and subsequent relationships with insulin sensitivity, substrate oxidation, and inflammation are unknown. We tested the hypothesis that insulin would lower EVs and relate to insulin action. Fifty-one sedentary adults (54.8 ± 1.0 y...

Objectives To examine the effect of ad-libitum low-glycemic index (GI; high fiber) versus high-GI diet on energy intake, diet quality (Healthy Eating Index 2015 (HEI-2015)), self-reported feelings of hunger and fullness, liking of the foods, and physical activity (PA) in preschoolers. Methods Twenty-five healthy preschoolers (aged 48 ± 7.3 mo, 47%...

Background: Although Reduced Nicotine Cigarettes (RNC) are suggested to improve smoking cessation and cardiometabolic health in relation to cancer risk, the effectiveness of exercise training with RNC on smoking cessation and cardiometabolic health is unknown. Methods: Female smokers (N = 27) were randomized to: (1) usual nicotine cigarettes (i.e.,...

Introduction: Nocturnal systolic blood pressure (SBP) dipping is independently related to cardiovascular disease risk, but it is unclear if vascular insulin sensitivity associates with SBP dipping in patients with metabolic syndrome (MetS). Methods: Eighteen adults with MetS (ATP III criteria 3.3 ± 0.6; 53.2 ± 6.5 years; body mass index 35.8 ± 4...

The objective of this study was to test if a low-calorie diet plus interval exercise (LCD+INT) reduced oxidized and non-oxidized phospholipids in relation to improved weight-related quality of life (QoL) to a greater extent than an energy-deficit matched LCD in obese females. Subjects (age: 47.2±2.6 years, body mass index: 37.5±1.3 kg/m²) were rand...

We evaluated the effect of preoperative standard medical care (SC) vs. unsupervised aerobic exercise combined with SC (EX + SC) on cardiometabolic health and quality of life (QoL) 30 days after bariatric surgery. Bariatric patients (n = 14, age: 42.3 ± 2.5 years, body mass index: 45.1 ± 2.5 kg/m2 ) were match-paired to presurgical SC (n = 7) or EX...

Background There are limited data from randomized control trials to support or refute the contention that whole-grains may enhance protein metabolism in humans. The objectives were threefold: 1) to examine the clinical effects of a whole-grain diet on whole-body protein turnover; 2) the cellular effects of whole-grains on protein synthesis in skele...

A single high-fat, high-carbohydrate meal (HFHC) results in elevated postprandial glucose (GLU), triglycerides (TRG) and metabolic load index (MLI; TRG (mg/dL) + GLU (mg/dL)) that contributes to chronic disease risk. While disease risk is higher in older adults (OA) compared to younger adults (YA), the acute effects of exercise on these outcomes in...

Elevated extracellular vesicles (EVs) are associated with glucose dysmetabolism. However, the direct effects of insulin on EVs and subsequent relationship with insulin sensitivity and substrate oxidation is unknown in adults with metabolic syndrome (MetS). Fifty sedentary adults (54.5 ± 1.0 yr; VO2peak: 22.3 ± 0.6 ml/kg/min) with MetS (36.3 ± 0.7 k...

Insulin resistance is a key etiological factor in promoting not only type 2 diabetes mellitus but also cardiovascular disease (CVD). Exercise is a first-line therapy for combating chronic disease by improving insulin action through, in part, reducing hepatic glucose production and lipolysis as well as increasing skeletal muscle glucose uptake and v...

Introduction Patients with type 2 diabetes experience resolution of hyperglycemia within days after Roux-en-Y gastric bypass (RYGB) surgery. This is attributed, in part, to enhanced secretion of hindgut factors following exclusion of the gastric remnant and proximal intestine during surgery. However, evidence of the mechanisms of remission remain l...

Adults with metabolic syndrome (MetS) have increased fasting arterial stiffness and altered central hemodynamics that contribute, partly, to increased cardiovascular disease (CVD) risk. Although insulin affects aortic wave reflections in healthy adults, the effects in individuals with MetS are unclear. We hypothesized that insulin stimulation would...

Endothelium, acting as a barrier, protects tissues against factors that provoke insulin resistance and type 2 diabetes and itself responds to the insult of insulin resistance inducers with altered function. Endothelial insulin resistance and vascular dysfunction occur early in the evolution of insulin resistance-related disease, can co-exist with a...

Weight loss outcomes among young adults in technology-based programs have been equivocal. The purpose of this study was to deliver digital weight loss treatments to young adults and examine the 6, 12, and 18 month effects on weight loss. Young adults with overweight/obesity (N = 459; 23.3 ± 4.4 years) were recruited from two university sites and ra...

Context: Sport-related concussion (SRC) is characterized by a pathological neurometabolic cascade that results in an increased intracranial energy demand with decreased energy supply. Little is known about the whole-body energy-related effects of SRC. Objective: To examine factors associated with whole-body resting metabolic rate (RMR), total en...

Objective Examine if adding aerobic exercise to standard medical care (EX+SC) prior to bariatric surgery improves metabolic health in relation to surgical outcomes. Methods Fourteen bariatric patients (age: 42.3±2.5y, BMI: 45.1±2.5 kg/m²) met inclusion criteria and were match-paired to pre-operative SC (n = 7) or EX+SC (n = 7; walking 30min/d, 5d/...

Introduction Palliative care can improve heart failure (HF) symptoms, however many HF patients lack access. Likewise, standard exercise programs can improve symptoms in HF patients, however participation rates are low due to poor access and patient-specific barriers, such as high symptom burden. Further, measurement of physical function at home is...

Purpose: Arterial stiffness is considered a predictor of cardiovascular disease (CVD). Females have higher values of arterial stiffness than males, suggesting a greater risk of heart-related complications. While a low-calorie diet (LCD) reduces fasting arterial stiffness, in part through weight loss, it is unknown if interval exercise (INT) adds t...

Objective Examine the effect of aerobic exercise (EX) combined with standard medical care (SC) (EX + SC) compared to SC alone on cardiometabolic health and quality of life in relation to surgical outcomes. Methods Patients receiving bariatric surgery were match-paired to 30 days of pre-operative SC (n = 7, 1 male, 39.0 ± 5.3 years, body mass index...

Metformin and exercise independently improve glycemic control. Metformin traditionally is considered to reduce hepatic glucose production, while exercise training is thought to stimulate skeletal muscle glucose disposal. Collectively, combining treatments would lead to the anticipation for additive glucose regulatory effects. Herein, we discuss rec...

Purpose Resting metabolic rate (RMR) changes as a result of moderate and severe traumatic brain injury in humans. However, the effect of sport concussion (SC) on RMR and subsequent food intake is unknown. The purpose of this study was to examine how SC affected energy expenditure, caloric intake (CI), and energy balance (EBal) in student-athletes....