Browsing by Subject "cardiovascular disease"
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Item Cholesterol lowering effects of bovine serum immunoglobulin in human participants with mild hypercholesterolemia(Texas A&M University, 2006-10-30) Black, Melinda LoriHypercholesterolemia is a major risk factor for cardiovascular disease (CVD). Interestingly, the consumption of dairy products, namely milk, has been shown to lower cholesterol. The mechanism of action surrounding this observation has been attributed to the protein fraction of milk. While there have been many studies evaluating the effects of dietary protein sources on cholesterol concentrations, few studies have evaluated specific animal protein components and no human clinical studies regarding the effects of animal plasma protein fractions on cholesterol metabolism have been conducted. This study examined the effect of an oral serum bovine immunoglobulin protein fraction (bIg) derived from US Department of Agriculture approved beef (aged < 30 months) on lipid indices in hypercholesterolemic humans. Participants included men and women (aged 25 ?????? 70 years) with mild hypercholesterolemia (5.44-6.99 mmol/L) who were not receiving cholesterol-lowering medication. Treatment consisted of the randomized, double blind, parallel group, placebo-controlled administration of 5 grams (g) bIg daily for 6 weeks (W) in 52 participants (n = 26 each in treatment and control groups). Mean (???? SD) baseline treatment and placebo total cholesterol (TC) was 6.33 ???? 0.1 mmol/L and 6.16 ???? 0.1 mmol/L respectively. A repeated-measures multivariate analysis of covariance (MANCOVA) covaried for change in total energy and alcohol intake, and a Tukey posthoc examination of the data showed that the bIg-treated group demonstrated a significant reduction in TC at 3-week (W) (5.98 ???? 0.5 mmol/L; P < 0.05) and 6-week (W) (5.97 ???? 0.7 mmol/L; P > 0.05) intervals compared to baseline. The 6W concentration was significantly lower than the placebo group (P < 0.05). Additionally, study findings displayed no significant changes in the placebo group or in any other lipid indexes or markers associated with hepatorenal or cardiovascular health. Consumption of bIg appears to lower major lipid indexes associated with CVD.Item Effects of a High Oleic Acid Beef Diet on Cardiovascular Disease Risk Factors of Human Subjects(2012-10-19) Adams, Thaddeus HunterThe consumption of high-fat hamburger enriched with saturated fatty acids (SFA) and trans-fatty acids (TFA) may increase risk factors for cardiovascular disease, whereas hamburger enriched with monounsaturated fatty acids (MUFA) may have the opposite effect. Ten mildly hypercholesterolemic men consumed five, 114-g hamburger patties per week for two consecutive phases. Participants consumed low-MUFA (high SFA) hamburger (MUFA:SFA = 0.95; produced from pasture-fed cattle) for 5 wk, consumed their habitual diets for 3 wk, and then consumed high-MUFA hamburger (MUFA:SFA = 1.31; produced from grain-fed cattle) for 5 wk. These MUFA:SFA were typical of ranges observed for retail ground beef. Relative to habitual levels and levels during the high-MUFA phase, the low-MUFA hamburger: increased plasma palmitic acid, palmitoleic acid, and triacylglycerols (P < 0.01); decreased HDL cholesterol (HDL-C) and LDL particle diameter percentile distributions (P < 0.05); and had no effect on LDL-C or plasma glucose (P > 0.10). Plasma palmitoleic acid was positively correlated with triacylglycerols (r = 0.90), VLDL-C (r = 0.73), and the LDL:HDL (r = 0.45), and was negatively correlated with plasma HDL-C (r = -0.58), whereas plasma palmitic, stearic, and oleic acid were negatively correlated with LDL particle diameter (all P <= 0.05). Because plasma palmitoleic acid was derived from [delta]9 desaturation of palmitic acid in the liver, we conclude that alterations in hepatic stearoyl-CoA desaturase activity may have been responsible for the variation in HDL-C and triacylglycerols caused by the low-MUFA and high-MUFA hamburgers. Cattle with a genetic predisposition to deposit MUFA in their lean and fat tissues, such as Wagyu cattle can be used to produce beef products that are especially enriched with oleic acid and lower in SFA and TFA, and feeding practices can further enhance the composition of beef fat. This indicates that ground beef or hamburger products can be produced that are naturally enriched with oleic acid, and conversely that certain production practices can impair the nutritional quality of beef fat. Finally, we cannot discern from this study design whether the high-MUFA hamburger reversed the effects of the low-MUFA hamburger, or whether the subjects gradually adapted to the elevated intake of total fat. It is clear, however, that the high-MUFA hamburger did not exacerbate any of the effects of the low-MUFA hamburger and can be viewed as at least neutral in its effects on HDL-C and triacylglycerols.Item High-Oleic Ground Beef and Risk Factors for Cardiovascular Disease in Men and Postmenopausal Women(2012-07-16) Ghahramany, GhazalAbout half of all deaths in developed countries are caused by cardiovascular disease. It is well known that cardiovascular disease (CVD) risk can be influenced by diet, but optimal dietary content of fatty acids continues to be debated. The effect of fatty acid composition of ground beef on selected cardiovascular disease risk indicators was evaluated with two primary goals. The first goal was to document effects of ground beef fatty acid composition on plasma lipoprotein concentrations, whereas the second goal was to determine the effects of ground beef fatty acid composition on gene expression in peripheral blood mononuclear cells (PBMC). In both studies the results were compared between men and women. Twelve men and women over age of 45 out of initially 15 completed a two-way crossover design. Subjects consumed five, 114-g ground beef patties per week for 5-wk periods separated by a 3-wk washout period. Patties contained on average 20% fat and monounsaturated fatty acid (MUFA): saturated fatty acid (SFA) of 0.8 and 1.1 for low- MUFA (conventional) ground beef high-MUFA (premium) ground beef patties, respectively. Blood was collected from each subject before and at the end of each diet period. Overall, the ground beef interventions decreased total plasma cholesterol, triacylglycerol, and very low density lipoprotein (VLDL) cholesterol. Plasma concentrations of high density lipoprotein (HDL) cholesterol and low density lipoprotein (LDL) cholesterol decreased and increased, respectively with premium ground beef consumption. The change in HDL cholesterol was significant in women but not in men suggesting that premium ground beef consumption had a greater impact on women than in men. For the second goal PBMC were isolated and the expression of selected genes was quantified by real-time PCR. ATP-binding cassette A1, ATP-binding cassette G1, and low-density lipoprotein receptor relative expression was increased with premium ground beef consumption. A significant increase was seen in stearoyl-Coenzyme-A desaturase 1 expression after premium ground beef treatment. With the exception of stearoyl-Coenzyme-A desaturase 1, all these genes were down-regulated with conventional ground beef consumption. Both sterol regulatory element binding transcription factor 1 and mediator complex subunit 1 were down-regulated after each beef patty treatment, but the effect was significant after consuming conventional ground beef. This suggests that genes involved in cholesterol metabolism were down-regulated with conventional ground beef consumption; whereas genes related to lipogenesis were up-regulated with premium ground beef consumption. From these data we concluded that different ground beef dietary interventions have different impacts on the PBMC gene expression that is related to cholesterol metabolism, inflammation and liver X receptor pathways.Item Relationships between psychosocial factors and adherence to diet and exercise in adults with type 2 diabetes: A test of a theoretical model(2007-05-21) Elizabeth Gressle Tovar; Michele Clark, RN, PhD; Susan Weller, PhD; Regina Lederman, RN, PhD; Hoang Nguyen, PhD; Carrie Jo Braden, RN, PhDIntroduction: Cardiovascular disease (CVD) is the leading cause of premature death among people with diabetes. Diet and exercise adherence are\r\nimportant diabetes self management behaviors that can reduce CVD risk; unfortunately, adherence rates are low among diabetics. Improved understanding of psychosocial factors related to diet and exercise adherence among adults with\r\ntype 2 diabetes can improve strategies to reduce CVD morbidity and mortality in this population.\r\n Purpose: 1) Evaluate psychometrics of the Health Beliefs related to Cardiovascular Disease scale (HBCVD) which measures perceived susceptibility to and severity of heart attack or stroke and perceived benefits of and barriers to\r\ndiet and exercise; 2) Explore relationships between selected bio-psychosocial factors and diet and exercise adherence; and 3) Evaluate the ability of a theoretical model integrating the Health Belief Model (HBM) and Stages of Change Model (SOC) to explain diet and exercise adherence.\r\n Methods: The study design was a descriptive correlational cross section using a convenience sample of 212 adults with type 2 diabetes who completed a series of questionnaires measuring study variables. Outcome variables measured were diet and exercise adherence scores. Predictor/independent variables included knowledge related to CVD risk, cues to action, health beliefs, stage of change, social support, depression, comorbidity, diabetes duration, and\r\nsocioeconomic status. Relationships among model variables were explored using analysis of variance and simple and multiple regression techniques.\r\n Results: The HBCVD demonstrated evidence of validity and reliability, although an improved barriers subscale is recommended. The theoretical model was not supported, although significant paths between model variables were identified. The best model to predict diet included diet stage, susceptibility, self efficacy, social support, and age. The best model to predict exercise included\r\nexercise stage, self efficacy, and social support. Models including HBM and SOC provided greater explanatory power for diet and exercise adherence than either model alone. Susceptibility, barriers, and self efficacy varied significantly across\r\nstages of change. Significant group differences were found among model variables. Participants with depressive symptoms and the least education had lower diet and exercise adherence scores. Younger age and unemployment were also associated with lower diet adherence.\r\n