Effects of Coffee Versus Hibiscus Tea Consumption During Prolonged Sitting on Blood Pressure and Heart Rate

NCT07159152 | Not Yet Recruiting

• 1 other identifier: No. E-25-9503
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

Modern lifestyles often involve long periods of sitting, which can increase the risk of heart problems, obesity, and other health issues. Diet also plays a key role in heart health. Coffee and hibiscus tea are two common beverages, but their effects during prolonged sitting are not well understood. This study will examine how drinking coffee versus hibiscus tea affects blood pressure, heart rate, and heart rate variability in men and women during extended periods of sitting. Participants (30 in total: 15 women and 15 men) will take part in a randomized crossover study, meaning each person will try both beverages at different times. Data will be collected using questionnaires, body measurements, and devices to measure heart rate, blood pressure, and heart rate variability. The goal is to better understand how these drinks influence heart health during sedentary behavior.

Conditions

Hypertension

Keywords

hibiscus drink; coffee; prolonged sitting; sedentary behavior; cardiovascular health; vascular function; cardiovascular regulation

Outcome Measures

Primary Outcomes (4)

• Systolic and diastolic blood pressure

  Systolic and diastolic blood pressure will be assessed using an oscillometric blood pressure monitor (Omron HEM 7124 CP, Omron Healthcare, Illinois, USA). Measurements will be conducted in accordance with the guidelines of the American Heart Association (AHA) and the American College of Cardiology (ACC).

  Blood pressure will be recorded at five standardized time points: prior to consumption of coffee or hibiscus tea, one hour post-consumption, and following one, two, and three hours of prolonged sitting.

• Heart Rate

  Heart rate will be measured using the Polar V800 system, which consists of a wristwatch and a Bluetooth heart rate sensor. The sensor will be positioned on the participant's chest, just below the pectoral muscles. Participants will remain seated quietly for 10 minutes while continuous heart rate data are recorded according to the manufacturer's instructions. The clearest five-minute segment of the 10-minute recording will be analyzed using Kubios HRV Premium software to assess heart rate (beat/minute)

  Heart rate measurements will be performed at multiple time points during each visit: prior to beverage consumption, one hour post-consumption, and after one, two, and three hours of prolonged sitting.

• NN Intervals

  NN Intervals will be measured using the Polar V800 system, which consists of a wristwatch and a Bluetooth heart rate sensor. The sensor will be positioned on the participant's chest, just below the pectoral muscles. Participants will remain seated quietly for 10 minutes while continuous heart rate data are recorded according to the manufacturer's instructions. The clearest five-minute segment of the 10-minute recording will be analyzed using Kubios HRV Premium software to assess NN Intervals (milliseconds)

  NN Intervals measurements will be performed at multiple time points during each visit: prior to beverage consumption, one hour post-consumption, and after one, two, and three hours of prolonged sitting.

• RMSSD

  RMSSD will be measured using the Polar V800 system, which consists of a wristwatch and a Bluetooth heart rate sensor. The sensor will be positioned on the participant's chest, just below the pectoral muscles. Participants will remain seated quietly for 10 minutes while continuous heart rate data are recorded according to the manufacturer's instructions. The clearest five-minute segment of the 10-minute recording will be analyzed using Kubios HRV Premium software to assess RMSSD (milliseconds squared)

  RMSSD measurements will be performed at multiple time points during each visit: prior to beverage consumption, one hour post-consumption, and after one, two, and three hours of prolonged sitting.

Other Outcomes (6)

• Height

  One time at baseline

• Weight

  One time at baseline

• Body Mass Index

  One time at baseline

Study Arms (2)

Coffee plus prolonged sitting protocol

EXPERIMENTAL

all participants in this group follow the coffee protocol

Dietary Supplement: Coffee

Hibiscus drink plus prolonged sitting protocol

EXPERIMENTAL

all participants in this group follow the hibiscus drink protocol

Dietary Supplement: Hibiscus drink

Interventions

Coffee DIETARY_SUPPLEMENT

Participants will consume 3 cups of Arabica coffee (Guatemalan origin), providing a total of 400 mg of caffeine. Each cup is prepared with 6% coffee grounds per 100 mL of water, brewed at 90°C for 6 minutes using an electric drip coffee maker, yielding 100.8 mg caffeine per 100 mL. Immediately following coffee consumption, participants will engage in uninterrupted sitting for 3 hours. Blood pressure, heart rate, and other study questionnaires will be measured at baseline (before coffee), 1 hour after coffee intake, and hourly during the 3-hour sitting period.

Coffee plus prolonged sitting protocol

Hibiscus drink DIETARY_SUPPLEMENT

Participants will consume 3 servings of hibiscus leaves tea per day, each serving containing 1.25 g of dried hibiscus leaves, totaling 3.75 g per session. The tea will be prepared by steeping the leaves in 240 mL of boiling water (100°C) for 10 minutes. Immediately after consuming the hibiscus tea, participants will engage in uninterrupted sitting for 3 hours. Blood pressure, heart rate, and other study questionnaires will be measured at baseline (before tea), 1 hour after tea intake, and hourly during the 3-hour sitting.

Hibiscus drink plus prolonged sitting protocol

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age between 18 and 35 years.
• Normal to elevated blood pressure (systolic \<130 mmHg and diastolic \<80 mmHg) and normal resting heart rate (60-100 bpm), ensuring selection of healthy adults and minimizing confounding factors.
• Generally healthy, without chronic or acute medical conditions, to reduce external influences on study outcomes.
• Physically inactive, not meeting current physical activity guidelines, as the study targets sedentary individuals.

You may not qualify if:

• Known allergy or hypersensitivity to hibiscus or coffee, as participants will consume these beverages during the study.
• Current use of medications that could influence blood pressure, heart rate, or heart rate variability, including antihypertensive, chronotropic, or vasoactive drugs.
• Any medical condition or health issue that may interfere with safe participation or affect study measurements.

Sponsors & Collaborators

• King Saud University: lead
• Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia: collaborator

Study Sites (1)

Princess Nourah University Lifestyle Center

Riyadh, 80200, Saudi Arabia

Location

Related Publications (14)

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  PMID: 34694241 RESULT

• Ellis LR, Zulfiqar S, Holmes M, Marshall L, Dye L, Boesch C. A systematic review and meta-analysis of the effects of Hibiscus sabdariffa on blood pressure and cardiometabolic markers. Nutr Rev. 2022 May 9;80(6):1723-1737. doi: 10.1093/nutrit/nuab104.

  PMID: 34927694 RESULT

• Da-Costa-Rocha I, Bonnlaender B, Sievers H, Pischel I, Heinrich M. Hibiscus sabdariffa L. - a phytochemical and pharmacological review. Food Chem. 2014 Dec 15;165:424-43. doi: 10.1016/j.foodchem.2014.05.002. Epub 2014 May 27.

  PMID: 25038696 RESULT

• Sindi HA, Marshall LJ, Morgan MR. Comparative chemical and biochemical analysis of extracts of Hibiscus sabdariffa. Food Chem. 2014 Dec 1;164:23-9. doi: 10.1016/j.foodchem.2014.04.097. Epub 2014 May 6.

  PMID: 24996300 RESULT

• Nohara-Shitama Y, Adachi H, Enomoto M, Fukami A, Nakamura S, Kono S, Morikawa N, Sakaue A, Hamamura H, Toyomasu K, Fukumoto Y. Habitual coffee intake reduces all-cause mortality by decreasing heart rate. Heart Vessels. 2019 Nov;34(11):1823-1829. doi: 10.1007/s00380-019-01422-0. Epub 2019 May 6.

  PMID: 31062117 RESULT

• Nurminen ML, Niittynen L, Korpela R, Vapaatalo H. Coffee, caffeine and blood pressure: a critical review. Eur J Clin Nutr. 1999 Nov;53(11):831-9. doi: 10.1038/sj.ejcn.1600899.

  PMID: 10556993 RESULT

• Alfawaz HA, Khan N, Yakout SM, Khattak MNK, Alsaikhan AA, Almousa AA, Alsuwailem TA, Almjlad TM, Alamri NA, Alshammari SG, Al-Daghri NM. Prevalence, Predictors, and Awareness of Coffee Consumption and Its Trend among Saudi Female Students. Int J Environ Res Public Health. 2020 Sep 25;17(19):7020. doi: 10.3390/ijerph17197020.

  PMID: 32992846 RESULT

• Rao NZ, Fuller M, Grim MD. Physiochemical Characteristics of Hot and Cold Brew Coffee Chemistry: The Effects of Roast Level and Brewing Temperature on Compound Extraction. Foods. 2020 Jul 9;9(7):902. doi: 10.3390/foods9070902.

  PMID: 32659894 RESULT

• Hecimovic I, Belscak-Cvitanovic A, Horzic D, Komes D. Comparative study of polyphenols and caffeine in different coffee varieties affected by the degree of roasting. Food Chem. 2011 Dec 1;129(3):991-1000. doi: 10.1016/j.foodchem.2011.05.059. Epub 2011 May 15.

  PMID: 25212328 RESULT

• Paterson C, Fryer S, Zieff G, Stone K, Credeur DP, Barone Gibbs B, Padilla J, Parker JK, Stoner L. The Effects of Acute Exposure to Prolonged Sitting, With and Without Interruption, on Vascular Function Among Adults: A Meta-analysis. Sports Med. 2020 Nov;50(11):1929-1942. doi: 10.1007/s40279-020-01325-5.

  PMID: 32757163 RESULT

• Taylor FC, Pinto AJ, Maniar N, Dunstan DW, Green DJ. The Acute Effects of Prolonged Uninterrupted Sitting on Vascular Function: A Systematic Review and Meta-analysis. Med Sci Sports Exerc. 2022 Jan 1;54(1):67-76. doi: 10.1249/MSS.0000000000002763.

  PMID: 34334722 RESULT

• Vranish JR, Young BE, Kaur J, Patik JC, Padilla J, Fadel PJ. Influence of sex on microvascular and macrovascular responses to prolonged sitting. Am J Physiol Heart Circ Physiol. 2017 Apr 1;312(4):H800-H805. doi: 10.1152/ajpheart.00823.2016. Epub 2017 Jan 27.

  PMID: 28130340 RESULT

• Dempsey PC, Larsen RN, Dunstan DW, Owen N, Kingwell BA. Sitting Less and Moving More: Implications for Hypertension. Hypertension. 2018 Nov;72(5):1037-1046. doi: 10.1161/HYPERTENSIONAHA.118.11190. No abstract available.

  PMID: 30354827 RESULT

• Adams NT, Paterson C, Poles J, Higgins S, Stoner L. The Effect of Sitting Duration on Peripheral Blood Pressure Responses to Prolonged Sitting, With and Without Interruption: A Systematic Review and Meta-Analysis. Sports Med. 2024 Jan;54(1):169-183. doi: 10.1007/s40279-023-01915-z. Epub 2023 Sep 8.

  PMID: 37682412 RESULT

MeSH Terms

Conditions

Hypertension; Sedentary Behavior

Interventions

Coffee

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases; Behavior

Intervention Hierarchy (Ancestors)

Plant Preparations; Biological Products; Complex Mixtures; Beverages; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Study Officials

• Hadeel M Almalki, BSc

  Princess Nourah Bint Abdulrahman University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Abdullah B Alansare, PhD

CONTACT

+966555061381; aalansare@ksu.edu.sa

Mohanad S AlJubairi, MSc

CONTACT

+966553899006; MSAljabiri@pnu.edu.sa

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor of Exercise Physiology

Model Details: A randomized crossover design

Study Record Dates

• First Submitted: August 23, 2025
• First Posted: September 8, 2025
• Study Start: September 1, 2025
• Primary Completion: February 1, 2026
• Study Completion: March 1, 2026
• Last Updated: September 8, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

SA (1)