Essential Arterial HypertensionCIRCA-HTNCT07770958
Circadian Disruption And Cardiovascular Risk In Young Adults With Hypertension
An observational study of Essential Arterial Hypertension and Circadian Disruption, run by Medical University of Sofia at 1 site in Bulgaria.
Trial summary
This prospective observational study will investigate whether circadian disruption is associated with higher blood pressure and a less favorable cardiovascular profile in young adults aged 18 to 45 years with essential arterial hypertension. Read more about this study
- Who is it for?
- Ages 18 to 45 years
- Conditions the study is for
- Essential Arterial Hypertension, Circadian Disruption
- How many people
- 200 participants
- Where
- 1 siteBulgaria
- Study dates
- 1 Sep 2023to 1 May 2027
- How long will I take part?
- 14 Days
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 45 years
- All sexes
- No healthy volunteers
- Adult
Study population: The study population will consist of adults aged 18 to 45 years with established essential arterial hypertension who meet all predefined eligibility criteria. Participants will be recruited from the clinical population of the participating study center. The study population will include both male and female participants. Individuals with shift work or night-duty work, secondary hypertension, previously diagnosed circadian rhythm sleep-wake disorders, clinically significant sleep-related breathing disorders, diabetes mellitus, significant cardiovascular disease other than uncomplicated essential hypertension, clinically significant renal or endocrine disease, or other conditions likely to substantially affect circadian rhythm or blood pressure measurements will be excluded.
Who may be able to join
- Adults aged 18 to 45 years.
- Established diagnosis of essential arterial hypertension.
- Stable antihypertensive treatment for at least 4 weeks before enrollment, when pharmacological treatment is prescribed.
- Ability and willingness to undergo 14 consecutive days of wrist actigraphy using the CamNtech MotionWatch 8.
- Ability and willingness to undergo 24-hour ambulatory blood pressure monitoring.
- Ability to provide written informed consent.
Who cannot join
- Shift work or night-duty work.
- Known secondary hypertension.
- Previously diagnosed circadian rhythm sleep-wake disorder.
- Known obstructive sleep apnea or other clinically significant sleep-related breathing disorder.
- Known clinically significant cardiovascular disease other than uncomplicated essential arterial hypertension.
- Diabetes mellitus.
Show all 13Show fewer
- Chronic kidney disease with clinically significant renal impairment.
- Active thyroid disease or other clinically significant endocrine disorder that may affect blood pressure or circadian rhythm.
- Current treatment with medications known to substantially alter sleep-wake rhythm or circadian timing.
- Regular use of hypnotic or sedative medication that could substantially affect actigraphic sleep assessment.
- Pregnancy.
- Inability to comply with study procedures or insufficient actigraphy/ABPM recording quality.
- Any acute illness or unstable medical condition that, in the investigator's opinion, could substantially influence the study outcomes.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Prospective Observational Study Of Circadian Disruption And Cardiovascular Risk In Young Adults With Arterial Hypertension
This prospective observational study will investigate whether circadian disruption is associated with higher blood pressure and a less favorable cardiovascular profile in young adults aged 18 to 45 years with essential arterial hypertension. Participants will undergo 14 days of wrist actigraphy using the CamNtech MotionWatch 8, 24-hour ambulatory blood pressure monitoring, cardiovascular assessment, laboratory testing, and validated questionnaires assessing perceived stress and insomnia symptoms. Circadian disruption will be classified using a predefined five-component research index based on actigraphy measures. Participants with three or more abnormal circadian indicators will be classified as Circadian Disruption Index-positive and compared with participants with zero to two abnormal indicators. The primary outcome is mean 24-hour systolic blood pressure. Secondary outcomes include nocturnal blood pressure patterns, cardiac structure and function, heart-rate variability, stress, insomnia symptoms, and individual circadian measures. The Circadian Disruption Index is a study-specific research classification and is not intended to diagnose a circadian rhythm sleep-wake disorder.
Read the detailed description
This study is designed to investigate the relationship between circadian organization, sleep-wake patterns, and cardiovascular characteristics in young adults with established essential arterial hypertension. The study is based on the hypothesis that circadian disruption may be associated with an adverse cardiovascular phenotype, particularly alterations in the 24-hour blood pressure profile and early markers of cardiovascular remodeling.
Circadian organization will be assessed using prolonged ambulatory wrist actigraphy. A predefined research index will integrate five complementary indicators of circadian rhythmicity and sleep-wake regularity. The index is intended to provide an operational and reproducible classification of the degree of circadian disruption within the study population rather than to establish a clinical diagnosis of a circadian rhythm sleep-wake disorder.
Cardiovascular assessment will include ambulatory blood pressure monitoring, echocardiographic assessment of cardiac structure and function, heart-rate variability, and selected metabolic and inflammatory biomarkers. Psychological and sleep-related factors will also be assessed in order to explore the potential contribution of perceived stress and insomnia symptoms to the relationship between circadian organization and cardiovascular characteristics.
The primary analytical approach will compare participants classified as having a positive Circadian Disruption Index with those classified as negative. Multivariable statistical models will subsequently be used to determine whether the observed association between circadian disruption and cardiovascular parameters persists after adjustment for relevant demographic, anthropometric, hypertension-related, treatment-related, and sleep-related factors.
An additional exploratory objective is to evaluate whether a combination of cardiovascular, metabolic, behavioral, and psychological characteristics can identify participants with a higher probability of circadian disruption. This exploratory analysis may contribute to the development of a preliminary cardiovascular-circadian risk metric that could subsequently be evaluated and validated in independent cohorts.
The study is observational and does not assign participants to a therapeutic intervention. The research classification of circadian disruption should not be interpreted as a diagnosis of a circadian rhythm sleep-wake disorder, and the findings will be interpreted in the context of the overall clinical characteristics of the participants.
- Keywords
- Arterial hypertension, Essential hypertension, Circadian disruption, Circadian rhythm, Sleep-wake rhythm, Actigraphy, Ambulatory blood pressure monitoring, 24-hour blood pressure, Cardiovascular risk Young adults
- Medical subject headings
- Hypertension, Essential Hypertension
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| CDI-Positive | Participants with three or more abnormal criteria among the five predefined components of the Circadian Disruption Index. | |
| CDI-Negative | Participants with zero to two abnormal criteria among the five predefined components of the Circadian Disruption Index. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean 24-Hour Systolic Blood Pressure
Mean systolic blood pressure over a valid 24-hour ambulatory blood pressure monitoring period performed during the 14-day actigraphy recording period.
Measured: During the 14-day actigraphy period
Secondary outcomes (17)
Mean 24-Hour Diastolic Blood Pressure
Mean diastolic blood pressure over a valid 24-hour ambulatory blood pressure monitoring period.
Measured: During the 14-day actigraphy period
Mean Nocturnal Systolic Blood Pressure
Mean systolic blood pressure during the predefined nocturnal period measured by 24-hour ambulatory blood pressure monitoring.
Measured: During the 14-day actigraphy period
Mean Nocturnal Diastolic Blood Pressure
Mean diastolic blood pressure during the predefined nocturnal period measured by 24-hour ambulatory blood pressure monitoring.
Measured: During the 14-day actigraphy period
Nocturnal Systolic Blood Pressure Dipping
Percentage reduction in mean nocturnal systolic blood pressure compared with mean daytime systolic blood pressure.
Measured: During the 14-day actigraphy period
Non-Dipping and Reverse-Dipping Blood Pressure Pattern
Proportion of participants demonstrating a non-dipping or reverse-dipping nocturnal systolic blood pressure pattern based on 24-hour ambulatory blood pressure monitoring.
Measured: During the 14-day actigraphy period
Left Ventricular Mass Index
Left ventricular mass indexed to body surface area, assessed by transthoracic echocardiography.
Measured: At baseline assessment
Left Atrial Volume Index
Left atrial volume indexed to body surface area, assessed by transthoracic echocardiography.
Measured: At baseline assessment
E/e' Ratio
Ratio of early transmitral flow velocity to early diastolic mitral annular velocity as an echocardiographic measure of left ventricular diastolic function.
Measured: At baseline assessment
Global Longitudinal Strain
Left ventricular global longitudinal strain assessed by transthoracic echocardiography.
Measured: At baseline assessment
Heart Rate Variability
Heart rate variability assessed using standard time-domain parameters, including SDNN and RMSSD.
Measured: During the 14-day actigraphy period
Perceived Stress
Perceived psychological stress was assessed using the 10-item Perceived Stress Scale (PSS-10). Each item is rated on a 5-point scale from 0 (never) to 4 (very often), yielding a total score of 0-40. Higher scores indicate greater perceived stress.
Measured: At baseline assessment
Insomnia Severity
Severity of insomnia symptoms was assessed using the Insomnia Severity Index (ISI), a 7-item questionnaire assessing difficulties with sleep onset, sleep maintenance, early morning awakening, satisfaction with sleep, interference with daily functioning, noticeability of sleep problems, and distress caused by sleep difficulties. Each item is scored from 0 to 4, yielding a total score of 0-28, with higher scores indicating greater insomnia severity. Scores of 0-7 indicate no clinically significant insomnia, 8-14 subthreshold insomnia, 15-21 moderate clinical insomnia, and 22-28 severe clinical insomnia.
Measured: At baseline assessment
Interdaily Stability
Interdaily Stability (IS) derived from actigraphy to quantify the consistency of the 24-hour activity-rest pattern across monitoring days.
Measured: During the 14-day actigraphy period
Intradaily Variability
Intradaily Variability (IV) derived from actigraphy to quantify fragmentation of the activity-rest rhythm within individual days.
Measured: During the 14-day actigraphy period
Relative Amplitude
Relative Amplitude (RA) derived from actigraphy as a measure of the contrast between the most active and least active periods of the 24-hour cycle.
Measured: During the 14-day actigraphy period
Sleep-Onset Time Variability
Variability in sleep-onset time across the 14-day actigraphy monitoring period, expressed as the standard deviation of sleep-onset time.
Measured: During the 14-day actigraphy period
Wake-Time Variability
Variability in wake time across the 14-day actigraphy monitoring period, expressed as the standard deviation of wake time.
Measured: During the 14-day actigraphy period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Aug 2026
- Study start1 Sep 2023
- Primary completion31 Dec 2026 (estimated)
- Study completion1 May 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Essential Arterial HypertensionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 200 participants (estimated)
- Target duration
- 14 Days
Sponsor and investigators
- Lead sponsor
- Medical University of Sofia
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Petar Rosenov Kalaydzhiev, Medical University of Sofia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07770958
- Sponsor's protocol ID
- CIRCA-HT STUDY
- Other IDs
- BG-RRP-2.004-0004-C01
- Acronym
- CIRCA-HT
- Status last verified
- Aug 2026
- First submitted
- 12 Aug 2026
- Last updated
- 19 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared with other researchers because the study involves clinical and health-related data collected from a single-center cohort. Data will be used for the analyses specified in the study protocol and will be reported in aggregate form to protect participant confidentiality and privacy.
Study at a glance
From the registry record, last updated by the sponsor on 19 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prospective Observational Study Of Circadian Disruption And Cardiovascular Risk In Young Adults With Arterial Hypertension
- ClinicalTrials.gov ID
- NCT07770958
- Acronym / sponsor ID
- CIRCA-HT / CIRCA-HT STUDY
- Keywords
- Arterial hypertension, Essential hypertension, Circadian disruption, Circadian rhythm, Sleep-wake rhythm, Actigraphy, Ambulatory blood pressure monitoring, 24-hour blood pressure
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Medical University of SofiaUniversity, hospital or other
- Study start
- 1 Sep 2023 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 1 May 2027 (estimated)
- First posted
- 18 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This prospective observational study will investigate whether circadian disruption is associated with higher blood pressure and a less favorable cardiovascular profile in young adults aged 18 to 45 years with essential arterial hypertension. Participants will undergo 14 days of wrist actigraphy using the CamNtech MotionWatch 8, 24-hour ambulatory blood pressure monitoring, cardiovascular assessment, laboratory testing, and validated questionnaires assessing perceived stress and insomnia symptoms. Circadian disruption will be classified using a predefined five-component research index based on actigraphy measures. Participants with three or more abnormal circadian indicators will be classified as Circadian Disruption Index-positive and compared with participants with zero to two abnormal indicators. The primary outcome is mean 24-hour systolic blood pressure. Secondary outcomes include nocturnal blood pressure patterns, cardiac structure and function, heart-rate variability, stress, insomnia symptoms, and individual circadian measures. The Circadian Disruption Index is a study-specific research classification and is not intended to diagnose a circadian rhythm sleep-wake disorder.
Detailed description
This study is designed to investigate the relationship between circadian organization, sleep-wake patterns, and cardiovascular characteristics in young adults with established essential arterial hypertension. The study is based on the hypothesis that circadian disruption may be associated with an adverse cardiovascular phenotype, particularly alterations in the 24-hour blood pressure profile and early markers of cardiovascular remodeling.
Circadian organization will be assessed using prolonged ambulatory wrist actigraphy. A predefined research index will integrate five complementary indicators of circadian rhythmicity and sleep-wake regularity. The index is intended to provide an operational and reproducible classification of the degree of circadian disruption within the study population rather than to establish a clinical diagnosis of a circadian rhythm sleep-wake disorder.
Cardiovascular assessment will include ambulatory blood pressure monitoring, echocardiographic assessment of cardiac structure and function, heart-rate variability, and selected metabolic and inflammatory biomarkers. Psychological and sleep-related factors will also be assessed in order to explore the potential contribution of perceived stress and insomnia symptoms to the relationship between circadian organization and cardiovascular characteristics.
The primary analytical approach will compare participants classified as having a positive Circadian Disruption Index with those classified as negative. Multivariable statistical models will subsequently be used to determine whether the observed association between circadian disruption and cardiovascular parameters persists after adjustment for relevant demographic, anthropometric, hypertension-related, treatment-related, and sleep-related factors.
An additional exploratory objective is to evaluate whether a combination of cardiovascular, metabolic, behavioral, and psychological characteristics can identify participants with a higher probability of circadian disruption. This exploratory analysis may contribute to the development of a preliminary cardiovascular-circadian risk metric that could subsequently be evaluated and validated in independent cohorts.
The study is observational and does not assign participants to a therapeutic intervention. The research classification of circadian disruption should not be interpreted as a diagnosis of a circadian rhythm sleep-wake disorder, and the findings will be interpreted in the context of the overall clinical characteristics of the participants.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 14 Days
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| CDI-Positive | – | –Participants with three or more abnormal criteria among the five predefined components of the Circadian Disruption Index. |
| CDI-Negative | – | –Participants with zero to two abnormal criteria among the five predefined components of the Circadian Disruption Index. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- The study population will consist of adults aged 18 to 45 years with established essential arterial hypertension who meet all predefined eligibility criteria. Participants will be recruited from the clinical population of the participating study center. The study population will include both male and female participants. Individuals with shift work or night-duty work, secondary hypertension, previously diagnosed circadian rhythm sleep-wake disorders, clinically significant sleep-related breathing disorders, diabetes mellitus, significant cardiovascular disease other than uncomplicated essential hypertension, clinically significant renal or endocrine disease, or other conditions likely to substantially affect circadian rhythm or blood pressure measurements will be excluded.
Key inclusion criteria (6 listed)
- Adults aged 18 to 45 years.
- Established diagnosis of essential arterial hypertension.
- Stable antihypertensive treatment for at least 4 weeks before enrollment, when pharmacological treatment is prescribed.
- Ability and willingness to undergo 14 consecutive days of wrist actigraphy using the CamNtech MotionWatch 8.
- Ability and willingness to undergo 24-hour ambulatory blood pressure monitoring.
Key exclusion criteria (13 listed)
- Shift work or night-duty work.
- Known secondary hypertension.
- Previously diagnosed circadian rhythm sleep-wake disorder.
- Known obstructive sleep apnea or other clinically significant sleep-related breathing disorder.
- Known clinically significant cardiovascular disease other than uncomplicated essential arterial hypertension.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Mean 24-Hour Systolic Blood Pressure
Time frame: During the 14-day actigraphy period
Mean systolic blood pressure over a valid 24-hour ambulatory blood pressure monitoring period performed during the 14-day actigraphy recording period.
17 secondary outcomes
Mean 24-Hour Diastolic Blood Pressure
Time frame: During the 14-day actigraphy period
Mean Nocturnal Systolic Blood Pressure
Time frame: During the 14-day actigraphy period
Mean Nocturnal Diastolic Blood Pressure
Time frame: During the 14-day actigraphy period
Nocturnal Systolic Blood Pressure Dipping
Time frame: During the 14-day actigraphy period
Non-Dipping and Reverse-Dipping Blood Pressure Pattern
Time frame: During the 14-day actigraphy period
Left Ventricular Mass Index
Time frame: At baseline assessment
Left Atrial Volume Index
Time frame: At baseline assessment
E/e' Ratio
Time frame: At baseline assessment
Global Longitudinal Strain
Time frame: At baseline assessment
Heart Rate Variability
Time frame: During the 14-day actigraphy period
Perceived Stress
Time frame: At baseline assessment
Insomnia Severity
Time frame: At baseline assessment
Interdaily Stability
Time frame: During the 14-day actigraphy period
Intradaily Variability
Time frame: During the 14-day actigraphy period
Relative Amplitude
Time frame: During the 14-day actigraphy period
Sleep-Onset Time Variability
Time frame: During the 14-day actigraphy period
Wake-Time Variability
Time frame: During the 14-day actigraphy period
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Aug 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be shared with other researchers because the study involves clinical and health-related data collected from a single-center cohort. Data will be used for the analyses specified in the study protocol and will be reported in aggregate form to protect participant confidentiality and privacy.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Essential Arterial Hypertension and Circadian Disruption, run by Medical University of Sofia at 1 site in Bulgaria.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 13 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 19 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Bulgaria. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean 24-Hour Systolic Blood Pressure (time frame: During the 14-day actigraphy period). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Aug 2026.