Cardiovascular Responses Differ Between Different Orders of Upper- and Lower-Body Resistance Exercise

Upper-body resistance exercise (RE) induces different cardiovascular responses compared to lower-body RE. However, combination of upper- and lower-body RE with different orders on cardiovascular responses are unclear. PURPOSE: To evaluate the effects of different orders of upper-and lower-body RE on cardiovascular responses in active men. METHODS: Thirteen active men (22±2 years old) participated in the study. Heart rate (HR), systolic and diastolic blood pressure (BP), cardiac output (CO), stroke volume (SV), and total peripheral resistance (TPR) were assessed at rest, 15-20 (R1), and 25-30 (R2) minutes after performing upper- and lower-body RE (UL) or lower- and upper-body RE (LU) for 3 sets of 10 repetitions at 75% 1-repetition maximum with 90-second and 2-minute rests between sets and exercises, respectively. The upper-body RE consisted of pulldown and chest press while lower-body RE consisted of knee extension and knee flexion. A repeated measures ANOVA was used to evaluate the conditions (UL, LU) across time (rest, R1, R2) on cardiovascular responses. RESULTS: There were time-by-condition interactions (p\u3c0.05) for CO and SV such that CO was significantly elevated at R1 and R2 after UL and LU compared to rest while UL had higher CO compared to LU at R1 (UL: rest: 5.68±0.99 L/min; R1: 9.09±1.44 L/min; R2: 7.65±1.87 L/min; and LU: rest: 5.55±0.78 L/min; R1: 8.14±1.65 L/min; R2: 7.23±1.76 L/min). SV was significantly increased after UL at R1 compared to rest and LU (UL: rest: 85.2±16.5 ml/beat; R1: 90.9±14.3 ml/beat; R2: 81.8±18.8 ml/beat; and LU: rest: 84.7±12.7 ml/beat; R1: 83.0±13.9 ml/beat; R2: 78.6±16.2 ml/beat). TPR was significantly (p\u3c0.001) reduced at R1 and R2 compared to rest after UL and LU with greater reduction after UL compared to LU (UL: rest: 0.96±0.27 mmHg•min/L; R1: 0.53±0.16 mmHg•min/L; R2: 0.68±0.22 mmHg•min/L; and LU: rest: 1.03±0.33 mmHg•min/L; R1: 00.67±0.26 mmHg•min/L; R2: 0.77±0.26 mmHg•min/L). HR was significantly (p\u3c0.001) increased at R1 and R2 after UL and LU compared to rest. Systolic BP was significantly (p=0.026) decreased after LU at R1 compared to rest and R2. However, there was no change for diastolic BP. CONCLUSION: These data suggest that UL significantly increases cardiac output and stroke volume than LU which means different orders of RE change cardiovascular responses

Postprandial And Fasting Lipopolysaccharide Levels In Healthy Hispanic Residents Of Southeast Texas With Positive Family History Of Type 2 Diabetes

PURPOSE: Healthy people with a family history (FH+) of type 2 diabetes (T2D) display impaired metabolic and microvascular function prior to glucose intolerance, and are at greater risk for developing T2D. While mechanisms to explain this disparity are lacking, it is possible that intestinal permeability plays a role, as it is also linked with insulin resistance, glucose intolerance, and chronic inflammation. Lipopolysaccharides (LPS) act as an outer membrane component of gram-negative bacteria in intestines and play a role in inflammation and chronic disease when in circulation, thus serving as a surrogate measure of intestinal permeability. However, the link between FH+ health disparities and intestinal permeability has not been studied. Thus, the purpose of this study was to quantify circulating plasma LPS in healthy FH+ and FH-. METHODS: In this cross-sectional study, FH- (n=14) and FH+ (n=18) participants matched for age (24.4 ± 1.6 and 25.0 ± 2.3 respectively) and BMI (25.0 ± 1.1 and 25.0 ± 1.1 years respectively) had blood drawn while fasting, and 60-min after consuming a mixed composition meal to quantify changes in plasma LPS, and had body composition determined via iDXA. Other anthropogenic data were collected. RESULTS: Fasting LPS was lower in FH- than FH+ (p \u3c 0.5, 42.3ng/ml ± 5.3 and 48.1ng/ml ± 6.8 respectively) with postprandial LPS increasing more in FH- than FH+ (p\u3c0.05, +10.3ng/ml ± 3.1 and + 1.4ng/ml ± 3.1 respectively). No group differences (p\u3e0.5) were noted in blood pressure (115/69 and 116/69mmHG) LDL-c (4.3mmol/L and 4.4mmol/L), HDL-c (2.2mmol/L and 2.3mmol/L), body fat (29% and 28%), or android fat (30.4% and 30.7%) between FH- and FH+ groups respectively. CONCLUSION: Disparities noted for increase T2D risk in FH+ have been linked to microvascular and metabolic function, with mechanisms for these remaining elusive. However, differences in circulating LPS suggest varying intestinal permeability in these groups, which may help explain the varying risk for T2D. Further work to characterize intestinal microbiota may advance our understanding of health disparities in this and other high-risk populations

Influence of Diet on Metabolic Physiology in People with and without a Family History of Type 2 Diabetes

Type 2 diabetes (T2D) prevalence in the Rio Grande Valley is ~27% versus the 9% national average. Simply having a family history (FH+) of type 2 diabetes (T2D) increases T2D prevalence by ~40 over those with no family history (FH-). We have shown that FH+ display early markers of cardiometabolic impairment vs FH-, such as blunted microvascular reactivity, and impaired metabolic flexibility. What is not yet known is the degree to which environment vs genetics may contribute to these impairments. PURPOSE: This pilot study seeks to examine normal dietary patterns between FH groups to identify potential patterns in macro- and micro-nutrient consumption that may help explain differences in metabolic function. METHODS: Thirty-three healthy individuals, including 10 FH+ and 23 FH- (26 ± 7; 24 ± 5 yrs respectively) participated in this study. Anthropometrics were assessed at rest. One-way ANOVA was used to determine group differences. Three-day food questionnaires were given to subjects prior to testing. Amino acid, Vitamin B3 & B6, water, and caffeine levels were measured. RESULTS: Compared to FH-, FH+ had higher (p\u3c0.05) consumption of caffeine (151.54 ± 44.0mg vs 34.83 ± 11.63mg), water (1264.76 ± 713.30g vs 770.08 ± 504.16g), Vitamin B3 (30.35 ± 22.35mg vs 19.99 ± 12.92mg), B6 (2.43 ± 1.45mg), Histidine (2.56 ± 2.18g), Lysine (6.60 ± 5.84 vs 3.72 ± 2.72g), and Methionine (2.18 ± 1.77 vs 1.33 ± 0.94 compared to FH-, with no differences noted in total energy intake between groups. CONCLUSION: Differing nutritional intake noted between FH groups is a potential confounding factor in the development of T2D in FH+ of the RGV and warrants further study

Different Orders of Combined Upper- and Lower-Body Resistance Exercise on Pulse Wave Reflection

Acute upper-body resistance exercise (RE) has been shown to induce greater impacts on pulse wave reflection (PWR) compared to lower-body RE. However, different orders of combined upper- and lower-body RE on PWR is unknown. PURPOSE: To evaluate the effects of different orders of combined upper-and lower-body RE on PWR in active men. METHODS: Sixteen men (22±2 yrs) volunteered for the study. PWR was assessed at rest, 10 (R1), and 20 (R2) minutes after either upper- and lower-body RE (UL) or lower- and upper-body RE (LU) at 75% 1-repetition maximum for 3 sets of 10 repetitions, 1.5- and 2-minute rests between sets and exercises, respectively, was allotted. The upper- and lower-body RE consisted of latissimus dorsi pulldown and incline chest press, and knee extension and knee flexion, respectively. A 2x3 repeated measures ANOVA was used to evaluate the conditions across time on PWR. RESULTS: There was no difference (p=0.42) on exercise volume between UL and LU. There were significant condition-by-time interactions (pCONCLUSION: These data suggest that different orders of combined upper- and lower-body RE induce different responses on pulse wave reflection. In addition, LU significantly elevated PWR than UL which might place greater workload to the heart in active men. Starting at upper-body RE then finishing at lower-body RE may be a more cardio-protective workout regime

Microvascular Blood Flow Changes in RGV Hispanics in Response to a Mixed Meal Challenge

Type 2 diabetes rates in the Rio Grande Valley (RGV) are 3x higher than the national average, with etiologies being multifactorial. Impaired postprandial skeletal muscle microvascular blood flow (MBF) is one of the earliest T2D pathophysiologies noted in Caucasians. However, MBF responses are unknown in the Hispanic population of the RGV. PURPOSE: Our goal in this study was to determine whether normoglycemic Hispanic individuals in the RGV exhibit impaired skeletal muscle MBF responses compared with healthy Caucasian individuals from a previous study. METHODS: 15 Hispanic individuals from the RGV with no family history of T2D (FH-), and 13 with a family history of T2D (FH+) were recruited to determine skeletal muscle MBF responses to a mixed-meal challenge (MMC). MBF was measured via contrast-enhanced ultrasound while fasting, and again one hour after consuming the MMC. RESULTS: We previously reported that in Caucasian individuals, MBF increases postprandially in both FH+ (pCONCLUSION: Apparently healthy Hispanic individuals of the RGV display impaired skeletal muscle MBF responses compared with healthy Caucasian individuals. Further, there were no differences in skeletal muscle MBF responses between FH groups in Hispanic individuals of the RGV. Further research is needed to determine why this population displays early microvascular impairments

P1 Height in Hispanics With and Without Family History of Type 2 Diabetes

Coronary heart disease (CHD) is the world’s leading cause of death, with type 2 diabetes (T2D) increasing that risk ~3-fold. T2D incidence in Hispanics of the Rio Grande Valley (RGV) is \u3e27% vs 9% noted nationwide. Further, having a family history of T2D (FH+) increases risk by ~40%. PURPOSE: To determine if specific aspects of macrovascular function may precede overt hypertension and T2D in FH+ people in the RGV. METHODS: Thirty-three healthy individuals, including 10 FH+ and 23 FH- (26 ± 7; 24 ± 5 yrs respectively), participated in this study. Hemodynamics and large artery function were assessed at rest. One-way ANOVA was used to determine group differences. Pearson correlation was used to determine relationships between significant variables. RESULTS: P1 Height, a measure of forward vascular pressure generated by ventricular contraction, was higher (pCONCLUSIONS: P1 Height is elevated in FH+ individuals and is related to some variables of positive health status, such as triglycerides and lower body fat. More studies are warranted to determine if P1 height is cardioprotective, or a pathophysiological precedent to hypertension

Metabolic Flexibility in Healthy Hispanics in the Rio Grande Valley with and without a Family History of Type 2 Diabetes

ABSTRACT Type 2 Diabetes (T2D) has several comorbidities such as cardiovascular disease, elevated lipid profile, microvascular complications, and impaired metabolic flexibility (MF: the ability to switch substrate use upon stimulation). Further, healthy Caucasians with a family history of T2D (FH+) have impaired MF similar to T2D, suggesting impaired MF could be an early-detection tool to identify at-risk populations. Hispanics of the Rio Grande Valley have ~3x the T2D rates as the US average, and have ~79% of the people in this region are either overweight or obese. However, patterns of MF in this population have not been addressed. Purpose: The purpose of this study was to quantify metabolic flexibility in this population, and determine if differences in MF are noted between FH+ and those with no history of T2D (FH-). Methods: To determine changes in metabolic flexibility we utilized a hooded metabolic cart to quantify substrate oxidation in FH+ and FH- participants while 1) fasted at rest, and 2) for 60-min after consumption of mixed composition meal challenge (MMC). Participants were matched according to BMI, age, weight and height (25.23 ±3.4, 74.1 ±14.9, 167.3 ±8.5 respectively). Blood draws and expired gas were taken before and after each state at intervals 0, 15, 30, 60, 90 and 120 min. Results: No differences were noted in RMR between FH+ and FH- groups (1588.90 ± 97.57 and 1540.87 ± 81.12, mean ± SD respectively, p=0.7), fasting RER (0.76 ± 0.04 and 0.80 ± 0.03 mean ± SD respectively, p=0.44), or max RER (0.85 ± 0.05 and 0.95 ± 0.04 mean ± SD respectively, p=0.1). However, MF in FH+ was lower than in FH- (0.24 ± 0.23 and 0.41 ± 0.20 mean ± SD respectively, p=0.03). Conclusion: In Hispanics of the RGV, healthy FH+ individuals display impaired MF when compared with matched FH- counterparts. Additional testing is warranted to compare ethnicities to determine differences between Caucasians and Hispanics, as well as additional variables that may affect MF

Hemodynamics and Arterial Stiffness in Response to Oral Glucose Loading in Individuals with Type II Diabetes and Controlled Hypertension

Introduction: Type 2 diabetes (T2D), the fastest growing pandemic, is typically accompanied by vascular complications. A central hallmark of both T2D and vascular disease is insulin resistance which causes impaired glucose transport and vasoconstriction concomitantly. Those with cardiometabolic disease display greater variation in central hemodynamics and arterial elasticity, both potent predictors of cardiovascular morbidity and mortality, which may be exacerbated by concomitant hyperglycemia and hyperinsulinemia during glucose testing. Thus, elucidating central and arterial responses to glucose testing in those with T2D may identify acute vascular pathophysiologies triggered by oral glucose loading. Aim: This study compared hemodynamics and arterial stiffness to an oral glucose challenge (OGC: 50g glucose) between individuals with and without T2D. 21 healthy (48 ± 10 years) and 20 participants with clinically diagnosed T2D and controlled hypertension (52 ± 8 years) were tested. Methods: Hemodynamics and arterial compliance were assessed at baseline, and 10, 20, 30, 40, 50, and 60 min post-OGC. Results: Heart rate increased between 20 and 60 post-OGC in both groups (p \u3c 0.05). Central systolic blood pressure (SBP) decreased in the T2D group between 10 and 50 min post-OGC while central diastolic blood pressure (DBP) decreased in both groups from 20 to 60 post-OGC. Central SBP decreased in T2D between 10 and 50 min post-OGC and central DBP decreased in both groups between 20 and 60 min post-OGC. Brachial SBP decreased between 10 and 50 min in healthy participants, whereas both groups displayed decreases in brachial DBP between 20 and 60 min post-OGC. Arterial stiffness was unaffected. Conclusions: An OGC alters central and peripheral blood pressure in healthy and T2D participants similarly with no changes in arterial stiffness