Occupational ExposureSPHERLNCT02243904
Study for Promotion of Health in Recycling Lead
An observational study of Occupational Exposure, run by KU Leuven at 1 site in Belgium.
Trial summary
Study for Promotion of Health in Recycling Lead (SPHERL) is a prospective 2-year follow-up study of lead workers with exposure levels varying between and within individuals. SPHERL addresses to what extent between-subject differences or within-subject changes in lead exposure may have a measurable impact on blood… Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Occupational Exposure
- How many people
- 270 participants
- Where
- 1 siteBelgium
- Study dates
- Aug 2015to 31 Dec 2024
- Phase
- Observational
- Are there results?
- None posted in the registry
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 Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: Participants will be recruited among the work force employed at lead recycling plants in North America.
Who may be able to join
- Women and men are eligible.
- New hires without previous occupational lead exposure who will be performing tasks with lead exposure or current employees without previous occupational lead exposure moving to tasks with exposure.
- Informed written consent.
Who cannot join
- Pregnancy.
- Any serious health condition.
Trial locations and contacts
1 site in 1 country.
About this study
Study for Promotion of Health in Recycling Lead (SPHERL) is a prospective 2-year follow-up study of lead workers with exposure levels varying between and within individuals. SPHERL addresses to what extent between-subject differences or within-subject changes in lead exposure may have a measurable impact on blood pressure, the cardiovascular system, renal function, the autonomic nervous system, peripheral nervous conduction velocity, and neurocognitive function.
At the beginning of December 2015, 70 participants were included in the study.
Read the detailed description
Background
- Whether low-level lead exposure impacts on blood pressure, regulation of the cardiovascular system, glomerular or tubular renal function, sympathetic nervous modulation, peripheral nervous conduction velocity, and neurocognitive function remains uncertain.
Study Population
- SPHERL will enroll 500 lead recycling workers with changing lead exposure, who will be examined at baseline (2014-2015) and followed up at annual intervals for 2 years (2016-2017).
Methods
- Volunteers eligible for the study are (i) new and existing hires without previous occupational lead exposure who will be performing tasks with or without occupational lead exposure and (ii) existing hires with occupational lead exposure who will be transitioning to job tasks without occupational lead exposure within the next 2 years.
- Blood lead concentration will be the main biomarker of exposure.
- The main outcome variables are (i) blood pressure measured conventionally and by ambulatory monitoring, and analyzed as continuous or categorical variable, both cross-sectionally and longitudinally; (ii) indexes of glomerular and tubular renal function, (iii) heart rate variability analyzed in the frequency domain as measure of autonomous sympathetic modulation, (iv) peripheral nerve conductivity, (v) neurocognitive performance, (vi) and quality of life [the EuroQOL five dimensions (EQ-5D) questionnaire].
Expected Outcomes
- Assuming a 4-fold or higher surge in the blood lead concentration, the study is powered to demonstrate over 2 years an acceleration in the age-related rise of systolic blood pressure by 1 to 4 mm Hg or an increase of the coefficient of multiple determination (R2) from 0.22 to 0.24 by adding the change in the blood lead concentration to models relating changes in blood pressure to three other covariables. The longitudinal design of our study complies with the temporality principle of the Bradford-Hill criteria for assessing possible causality between outcomes and exposure.
- Conditions
- Occupational Exposure
- Keywords
- Autonomic nervous function, Blood pressure, Cardiovascular regulation, Lead, Occupational exposure, Renal function
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 |
|---|---|---|
| Lead exposure | Not described |
What is being measured
The primary outcome is the main question the study is designed to answer.
Annual change in systolic blood pressure as measured by 24-h ambulatory monitoring
Measured: Baseline, 1 year and 2 years
Secondary outcomes (7)
Annual change in central hemodynamics
Annual changes in the central hemodynamics, including aortic blood pressure, the central systolic augmentation index, and aortic pulse wave velocity
Measured: Baseline, 1 year and 2 years
Annual change in heart function
Annual changes in ECG-derived indexes
Measured: Baseline, 1 year and 2 years
Annual change in renal function
Annual changes in glomerular and tubular renal function measured on a continuous scale and the incidence of renal dysfunction
Measured: Baseline, 1 year and 2 years
Annual change in autonomic nervous function
Annual changes in alterations in the autonomic nervous cardiovascular modulation, as assessed by heart rate variability
Measured: Baseline, 1 year and 2 years
Annual change in peripheral nervous conduction velocity
Annual changes in nerve conduction velocity
Measured: Baseline, 1 year and 2 years
Annual change in neurocognitive performance
Annual changes in neurocognitive testing
Measured: Baseline, 1 year and 2 years
Annual change in quality of life
Annual changes in self-assessed quality of life
Measured: Baseline, 1 year and 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Sep 2014 (estimated)
- Study startAug 2015
- Primary completion1 Jul 2024 (estimated)
- Study completion31 Dec 2024 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Occupational ExposureStudies of the same condition, open and under way.
- More trials run by KU LeuvenThe sponsor's other registered studies.
- 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
- 270 participants (actual)
Sponsor and investigators
- Lead sponsor
- KU Leuven
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jan A. Staessen, KU Leuven
- Investigators
- Jan A Staessen, MD, PhD, Principal investigator, University of Leuven
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02243904
- Sponsor's protocol ID
- SPHERL
- Acronym
- SPHERL
- Status last verified
- Mar 2020
- First submitted
- 10 Sep 2014
- Last updated
- 3 Mar 2020
- Results posted
- No
- Data monitoring committee
- No
Publications
Hara A, Gu YM, Petit T, Liu YP, Jacobs L, Zhang ZY, Yang WY, Jin Y, Thijs L, Wei FF, Nawrot TS, Staessen JA. Study for Promotion of Health in Recycling Lead - Rationale and design. Blood Press. 2015 Jun;24(3):147-57. doi: 10.3109/08037051.2014.996409. Epub 2015 Jan 26.
PubMed 25620211Yu YL, An DW, Yang WY, Verhamme P, Allegaert K, Nawrot TS, Staessen JA. Blood pressure and renal function responses in workers exposed to lead for up to six years. J Clin Hypertens (Greenwich). 2023 Dec;25(12):1086-1095. doi: 10.1111/jch.14748. Epub 2023 Nov 8.
PubMed 37938055Yu YL, Thijs L, Saenen N, Melgarejo JD, Wei DM, Yang WY, Yu CG, Roels HA, Nawrot TS, Maestre GE, Staessen JA, Zhang ZY. Two-year neurocognitive responses to first occupational lead exposure. Scand J Work Environ Health. 2021 Apr 1;47(3):233-243. doi: 10.5271/sjweh.3940. Epub 2020 Dec 4.
PubMed 33274751Yu YL, Yang WY, Thijs L, Melgarejo JD, Yu CG, Wei DM, Wei FF, Nawrot TS, Zhang ZY, Staessen JA. Two-Year Responses of Office and Ambulatory Blood Pressure to First Occupational Lead Exposure. Hypertension. 2020 Oct;76(4):1299-1307. doi: 10.1161/HYPERTENSIONAHA.120.15590. Epub 2020 Sep 9.
PubMed 32903104Yu CG, Wei FF, Yang WY, Zhang ZY, Mujaj B, Thijs L, Feng YM, Staessen JA. Heart rate variability and peripheral nerve conduction velocity in relation to blood lead in newly hired lead workers. Occup Environ Med. 2019 Jun;76(6):382-388. doi: 10.1136/oemed-2018-105379. Epub 2019 Mar 30.
PubMed 30928907
Study at a glance
From the registry record, last updated by the sponsor on 3 Mar 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Study for Promotion of Health in Recycling Lead
- ClinicalTrials.gov ID
- NCT02243904
- Acronym / sponsor ID
- SPHERL / SPHERL
- Conditions
- Occupational Exposure
- Keywords
- Autonomic nervous function, Blood pressure, Cardiovascular regulation, Lead, Occupational exposure, Renal function
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 270 participants (actual)
- Lead sponsor
- KU LeuvenUniversity, hospital or other
- Study start
- Aug 2015
- Primary completion
- 1 Jul 2024 (estimated)
- Study completion
- 31 Dec 2024 (estimated)
- First posted
- 18 Sep 2014 (estimated)
- 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.
Study for Promotion of Health in Recycling Lead (SPHERL) is a prospective 2-year follow-up study of lead workers with exposure levels varying between and within individuals. SPHERL addresses to what extent between-subject differences or within-subject changes in lead exposure may have a measurable impact on blood pressure, the cardiovascular system, renal function, the autonomic nervous system, peripheral nervous conduction velocity, and neurocognitive function.
At the beginning of December 2015, 70 participants were included in the study.
Detailed description
Background
- Whether low-level lead exposure impacts on blood pressure, regulation of the cardiovascular system, glomerular or tubular renal function, sympathetic nervous modulation, peripheral nervous conduction velocity, and neurocognitive function remains uncertain.
Study Population
- SPHERL will enroll 500 lead recycling workers with changing lead exposure, who will be examined at baseline (2014-2015) and followed up at annual intervals for 2 years (2016-2017).
Methods
- Volunteers eligible for the study are (i) new and existing hires without previous occupational lead exposure who will be performing tasks with or without occupational lead exposure and (ii) existing hires with occupational lead exposure who will be transitioning to job tasks without occupational lead exposure within the next 2 years.
- Blood lead concentration will be the main biomarker of exposure.
- The main outcome variables are (i) blood pressure measured conventionally and by ambulatory monitoring, and analyzed as continuous or categorical variable, both cross-sectionally and longitudinally; (ii) indexes of glomerular and tubular renal function, (iii) heart rate variability analyzed in the frequency domain as measure of autonomous sympathetic modulation, (iv) peripheral nerve conductivity, (v) neurocognitive performance, (vi) and quality of life [the EuroQOL five dimensions (EQ-5D) questionnaire].
Expected Outcomes
- Assuming a 4-fold or higher surge in the blood lead concentration, the study is powered to demonstrate over 2 years an acceleration in the age-related rise of systolic blood pressure by 1 to 4 mm Hg or an increase of the coefficient of multiple determination (R2) from 0.22 to 0.24 by adding the change in the blood lead concentration to models relating changes in blood pressure to three other covariables. The longitudinal design of our study complies with the temporality principle of the Bradford-Hill criteria for assessing possible causality between outcomes and exposure.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Lead exposure | – | – |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Participants will be recruited among the work force employed at lead recycling plants in North America.
Key inclusion criteria (3 listed)
- Women and men are eligible.
- New hires without previous occupational lead exposure who will be performing tasks with lead exposure or current employees without previous occupational lead exposure moving to tasks with exposure.
- Informed written consent.
Key exclusion criteria (2 listed)
- Pregnancy.
- Any serious health condition.
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
Annual change in systolic blood pressure as measured by 24-h ambulatory monitoring
Time frame: Baseline, 1 year and 2 years
7 secondary outcomes
Annual change in central hemodynamics
Time frame: Baseline, 1 year and 2 years
Annual change in heart function
Time frame: Baseline, 1 year and 2 years
Annual change in renal function
Time frame: Baseline, 1 year and 2 years
Annual change in autonomic nervous function
Time frame: Baseline, 1 year and 2 years
Annual change in peripheral nervous conduction velocity
Time frame: Baseline, 1 year and 2 years
Annual change in neurocognitive performance
Time frame: Baseline, 1 year and 2 years
Annual change in quality of life
Time frame: Baseline, 1 year and 2 years
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Mar 2020.
- Results publication: PubMed 25620211Hara A, Gu YM, Petit T, Liu YP, Jacobs L, Zhang ZY, Yang WY, Jin Y, Thijs L, Wei FF, Nawrot TS, Staessen JA. Study for Promotion of Health in Recycling Lead - Rationale and design. Blood Press. 2015 Jun;24(3):147-57. doi: 10.3109/08037051.2014.996409. Epub 2015 Jan 26.
- Derived from this study: PubMed 37938055Yu YL, An DW, Yang WY, Verhamme P, Allegaert K, Nawrot TS, Staessen JA. Blood pressure and renal function responses in workers exposed to lead for up to six years. J Clin Hypertens (Greenwich). 2023 Dec;25(12):1086-1095. doi: 10.1111/jch.14748. Epub 2023 Nov 8.
- Derived from this study: PubMed 33274751Yu YL, Thijs L, Saenen N, Melgarejo JD, Wei DM, Yang WY, Yu CG, Roels HA, Nawrot TS, Maestre GE, Staessen JA, Zhang ZY. Two-year neurocognitive responses to first occupational lead exposure. Scand J Work Environ Health. 2021 Apr 1;47(3):233-243. doi: 10.5271/sjweh.3940. Epub 2020 Dec 4.
- Derived from this study: PubMed 32903104Yu YL, Yang WY, Thijs L, Melgarejo JD, Yu CG, Wei DM, Wei FF, Nawrot TS, Zhang ZY, Staessen JA. Two-Year Responses of Office and Ambulatory Blood Pressure to First Occupational Lead Exposure. Hypertension. 2020 Oct;76(4):1299-1307. doi: 10.1161/HYPERTENSIONAHA.120.15590. Epub 2020 Sep 9.
- Derived from this study: PubMed 30928907Yu CG, Wei FF, Yang WY, Zhang ZY, Mujaj B, Thijs L, Feng YM, Staessen JA. Heart rate variability and peripheral nerve conduction velocity in relation to blood lead in newly hired lead workers. Occup Environ Med. 2019 Jun;76(6):382-388. doi: 10.1136/oemed-2018-105379. Epub 2019 Mar 30.
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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.
Jan A Staessen, MD, PhD principal investigator
University of Leuven
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 Occupational Exposure, run by KU Leuven at 1 site in Belgium.
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 3 inclusion and 2 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: status not confirmed, as of the sponsor's last update on 3 Mar 2020. 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 Belgium. 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?
Results are not available in the source record.
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?
Annual change in systolic blood pressure as measured by 24-h ambulatory monitoring (time frame: Baseline, 1 year and 2 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02243904, which also lists 5 linked publications.
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 3 Mar 2020.