Influence of Diet on Sleep and Cardiovascular Risk
Phase: NA
Conditions: Sleep
Sponsor: Columbia University

NCT04990973 
 
Brief Title: Evaluation of Diet and Sleep in Vascular Health: A Pilot Study 
 
Official Title: Influence of Diet on Sleep and Cardiovascular Risk 
 
Unique Protocol ID: AAAT7042 
 
Date: 03/26/2024 
 
 

Protocol 
 
The goal of this study is to test the impact of diet on sleep and cardiovascular disease 
risk factors. 
 
Poor sleep quality is highly prevalent in adults in the U.S. and worldwide. Recent work 
suggests that dietary intakes may influence sleep. This pilot mechanistic study will tests 
whether consuming a diet aligning with recommendations for a Mediterranean dietary 
pattern, relative to a typical American diet, improves sleep quality in U.S. adults. 
Furthermore, we gather preliminary data on whether this diet pattern improves 
cardiovascular disease risk profile. Given the established relationship between sleep 
and cardiovascular health. 
 
This pilot study is a randomized, crossover, dietary intervention study with 2 phases: 
Mediterranean Diet or Average American Diet. Each diet is provided to participants in 
amounts necessary to maintain baseline body weight given stable activity levels, a 
requirement of the study; estimated energy needs are computed using the Mifflin St. 
Jeor equation. During the study, participants are provided 3 isocaloric meals and one 
snack daily for 4 weeks in each condition. Condition order is randomized by the 
Biostatistician, and phases are separated by at least 4 week washout. The experimental 
“Mediterranean Diet” is composed of approximately 40% energy from fat, 20% from 
protein, and 40% from carbohydrates. The control/comparison diet “Average American 
Diet” provides 35-37% of energy from fat, 15% from protein, and 48-50% from 
carbohydrates. Diets differ in fiber content: 40 g/2000 kcal/d for the Mediterranean Diet 
vs 10 g/2000 kcal/d for the Average American Diet. Participants are not blinded to the 
intervention. 
 
Prior to enrollment in the study, participants are screened for assessment of health 
history and current sleep behaviors. Individuals meeting initial eligibility criteria: aged 
18-65 y, BMI of 20-34.9 kg/m2, sleep complaints, will complete the informed consent 
process. Those providing consent will continue with screening. Prospective participants 
are not included if they currently smoke (or quit less than 3 years prior), are diagnosed 
with a cardiometabolic disease or neurologic disorder, have a psychological or sleep 
disorder, have gained or lost significant weight in the past 3 months, have allergies to 
foods included in the study, or are deemed unable to comply with study procedures 
(either self-expressed or determined by the investigator). Participants also complete a 
sleep screening; those reporting sleep complaints on the Pittsburgh Sleep Quality Index 
who also have average total sleep time ≥6 h/night based on 2 weeks of daily wrist 
actigraphy and willing to undergo the interventions post-screening are accrued into the 
study.  
 
Participants are randomized to the diet for phase 1 at their first baseline visit. At the 
baseline visit of each phase, measures are collected prior to beginning the 
corresponding study diet. Following the baseline visit, food is provided by the 
Bionutrition Unit of the Irving Institute for Clinical and Translational Science at CUIMC 
according to diet allocation. The participants return to the study site every 3-4 days to 

collect their study foods over the course of the 4 weeks during each phase. Throughout 
each phase, sleep is measured daily using wrist actigraphy along with a sleep diary. 
Fasting blood, overnight urine and fecal samples, and venous endothelial cells are 
collected at baseline and endpoint of each phase. Participants are instructed to collect 
all urine from voids occurring after bedtime until the first, next-morning void on the night 
prior to the first and last study visit of each phase. Tryptophan metabolites and 6-
sulfatoxymelatonin are measured from blood and urine samples, respectively. 
Anthropometric measurements, blood pressure, and heart rate are obtained weekly 
during each phase. One night of in-home polysomnography is performed in the last 
week of each phase using a 9-channel portable device (Z-Machine Synergy System, 
General Sleep Corporation, Cleveland, OH). 
 
Statistical Analysis Plan 
 
Outcome data collected from the study will be assessed for normality using the Shapiro-
Wilk test and histograms. Descriptive characteristics for the full sample, and stratified by 
sex, will be assessed for baseline demographic and sleep data. For continuous 
variables, means, standard deviations, and ranges will be assessed. For categorical 
variables, number of participants and corresponding percent of total participants, will be 
determined. Given the pilot nature of the study and within-person design, analyses of 
condition effects will be conducted only among those with complete data from both 
conditions. To assess condition effects, we will use linear mixed models with repeated 
measures or paired t-tests (for outcomes measured at one time point). Outcomes will be 
post-baseline values, and each outcome will be tested separately. Participant will be a 
random effect in the model. Study phase and participant sex will be fixed effects. 
Models will be adjusted for baseline values of the corresponding outcome measure.