Impact of Lean Pork on Endothelial Function in Perimenopause

Pennington Biomedical Research Center30 enrolled

Overview

The goal of this study is to examine the impact of a diet high in fresh lean pork, compared to a plant-based diet, on cardiovascular function and vasomotor symptoms in perimenopausal women with overweight and obesity. The main questions it aims to answer are: 1. How does a diet high in pork, compared to a plant-based diet, affects blood lipids, endothelial function, and blood pressure? 2. How does a diet high in pork, compared to a plant-based diet, affects blood nitrate, cardiometabolic biomarkers, inflammatory biomarkers, and vasomotor symptoms? Researchers will compare the diet high in pork to a plant-based diet to see if pork helps improve cardiovascular and mesopause symptoms. Participants will: * Consume both of the diets, each for 4 weeks, with a washout period between 2 and 6 weeks in between the diets trials * Visit the clinic 5 times with weekly meal pick ups during the diet trials * Undergo testing procedures including: weight and body composition, blood pressure and pulse, endothelial function using ultrasound of upper arm, microvascular blood flow, blood draws, physical activity measurements, and questionnaires.

Investigators expect about 30 women will be enrolled in this study. The expected time in this study will be between 11 and 15 weeks. Participants will consume both of the following diets, each for 4 weeks, with a washout period between 2 and 6 weeks in between the diets when participants will consume their usual diet. The diets will be consumed in random order. Participants will not be able to choose the order. Participants will receive 7 days of meals and snacks for 4 weeks for each diet. * PORK Diet: A diet following the Dietary Guidelines for Americans with at least 80% of meat consumption being pork per week including tenderloin, loin chops, sirloin roast, flank, rump roast, and small amounts of Canadian bacon and pork sausage. * PLANT Diet: A Lacto-Ovo Vegetarian diet following the Dietary Guidelines for Americans with no more than 21 oz. per week of animal protein including eggs and cheese.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

Interventions

Pork DietBEHAVIORAL

The diet will follow the Dietary Guidelines for Americans with 80% of the meat consumption per week being pork. Other animal protein (e.g., turkey, chicken, beef) will be minimized in the dietary plans (≤ 20%) so lean and processed pork are the primary protein source consumed. Within each day, \~80% of the daily pork intake will be fresh, unprocessed lean cuts (e.g., tenderloin, loin chops, sirloin roast, flank, and rump roast) and \~20% will be cured sources (e.g., Canadian bacon, pork sausage).

Plant DietBEHAVIORAL

The diet will be a Lacto-Ovo Vegetarian Diet following the Dietary Guidelines for Americans with no more than 21 oz per week of animal protein (e.g., eggs, cheese).

Eligibility

Sex: FEMALEMin age: 40 YearsMax age: 55 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Are female * Are between 40 and 55 years of age * Have a BMI (a number calculated from participant height and weight) between 28 and45 kg/m2 * Are experiencing irregular menstrual cycles but have not gone longer than 12 consecutive months without a period * Are experiencing severe vasomotor (menopause) symptoms * Are doing less than 3 hours per week of structured exercise * Have systolic blood pressure between 120 and 140 mmHg and/or diastolic blood pressure between 80 and 90 mmHg * Have "sugary" hemoglobin called hemoglobin A1c less than or equal to 6.5% * Are willing and able to refrain from using oral mouth wash for the duration of the study because the alcohol in mouth wash inhibits nitrate synthesis * Are willing and able to comply with both the study diets * Are willing to collect blood for future research * Can read, speak, and understand English Exclusion Criteria: * Hysterectomy (partial or full) or oophorectomy * Using hormone replacement therapy use and/or hormonal contraception use 6 months prior to study start * Has systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥ 90 mmHg) * Triglycerides ≥350 mg/dL, low-density lipoprotein cholesterol (LDL-C) ≥190 mg/dL, and/or taking a lipid-lowering medication -Diagnosed cardiovascular disease, diabetes (type 1 or 2), or endocrine- related disease (e.g. thyroid, PCOS), unstable gastrointestinal disease, kidney, liver, and/or pancreatic disease * Diagnosed cancer (except skin cancer) in the last 5 years * Taking \>1 blood pressure medication and/or taking 1 blood pressure medication for \<3 months * Taking phosphodiesterase-5 inhibitors, anti-coagulants, corticosteroids, metformin, or insulin. * Weight change ≥6.6 pounds in the past 3 months, actively trying to lose weight, or unwilling to remain weight stable throughout the study * Current smoking or vaping, Binge and/or heavy drinker * Food allergies or other reasons preventing consumption of study foods with both study diets

Outcomes

Primary Outcomes

Change in Macrovascular Function

Macrovascular function will be measured by endothelial function. Investigators will use brachial artery flow mediated dilation (FMD) using ultrasound. Ultrasound images will be captured (Cardiovascular Suit 4, QUIPU, Pisa, Italy) at three time points 1) end-diastole for each cardiac cycle at baseline (\~30 s), 2) during occlusion (\~5 min), and 3) after occlusion (\~5 min). The shear rate will be calculated for each cardiac cycle as 8 × mean blood velocity/ diameter, and the shear rate area under the curve from cuff release to peak diameter will be quantified as an index of the stimulus for FMD. The FMD values will be expressed as relative (%) changes from baseline to peak diameter and FMD/SRAUC will be corrected for shear rate (FMD/shear rate \[SR\] area under the curve \[AUC\]) in order to account for shear stress inter-individual variability.