Intra-individual Variability and Circadian Rhythm of VEGF Levels and Interaction With Biomarkers

Intra-individual Variability and Circadian Rhythm of Systemic Vascular Endothelial Growth Factor (VEGF) Levels and Interaction With Biomarkers of Inflammation in Subjects With Normal Glucose Tolerance (NGT) and Patients With Type 2 Diabetes Without Diabetic Macular Edema (DME)

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT02325271

Enrollment

Registered

2014-12-24

Start date

2015-02-28

Completion date

2016-01-31

Last updated

2017-09-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Diabetic Macular Edema

Brief summary

The study evaluates the intra-individual variability of VEGF levels over a period of 6 months as well as the circadian variation of VEGF levels, both under standardized conditions in patients with type 2 diabetes without DME and matched subjects with normal glucose tolerance (NGT). Secondary objectives of the study are to evaluate the relationship of individual VEGF-levels to biomarkers of inflammation, HbA1c and major cardiovascular risk factors.

Interventions

OTHERFrequent blood and urine sampling and blood pressure measurement

Blood and urine sampling for the determination of VEGF and biomarkers

Study design

Observational model

CASE_CONTROL

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

50 Years to 80 Years

Healthy volunteers

Yes

Inclusion criteria

* Written informed consent * Age equal to or between 50 and 80 years * Subjects with normal glucose tolerance confirmed by glucose tolerance test (control group) or patients with type 2 diabetes: diabetes duration 5-25 years; HbA1c equal to or between 6.5 and 9% (diabetes group) * Ability to understand and follow study-related instructions

Exclusion criteria

* DME * hsCRP \> 10 mg/dl * Acute infections * Acute or chronic inflammatory diseases * Immune diseases * Treatment with immune suppressive drugs * Treatment with glucocorticoids * Myocardial infarction and stroke within 1 year before inclusion * Hemorrhage within the previous 5 years * Surgeries within the previous 3 months * Oncological diseases * Women who are pregnant or breast-feeding

Design outcomes

Primary

Measure	Time frame	Description
VEGF-A	Baseline, month 1, 2, 3, 4, 5 and 6	Plasma levels determined in the morning under fasted conditions
VEGF-B	Baseline, month 1, 2, 3, 4, 5 and 6	Plasma levels determined in the morning under fasted conditions
VEGF-C	Baseline, month 1, 2, 3, 4, 5 and 6	Plasma levels determined in the morning under fasted conditions
Placental growth factor	Baseline, month 1, 2, 3, 4, 5 and 6	Plasma levels determined in the morning under fasted conditions

Secondary

Measure	Time frame	Description
Adiponectin	Baseline, month 1, 2, 3, 4, 5 and 6	Serum levels determined in the morning under fasted condition
Cystatin C	Baseline, month 1, 2, 3, 4, 5 and 6	Serum levels determined in the morning under fasted condition
Glycated hemoglobin (HbA1c)	Baseline, month 1, 2, 3, 4, 5 and 6	Plasma levels determined in the morning under fasted conditions
Creatinine	Baseline, month 1, 2, 3, 4, 5 and 6	Urine levels determined in the morning under fasted condition
Blood pressure	Baseline, month 1, 2, 3, 4, 5 and 6, once over 24 hours	—
Albumin	Baseline, month 1, 2, 3, 4, 5 and 6	Urine levels determined in the morning under fasted condition
High-sensitivity C-reactive protein (hCRP)	Baseline, month 1, 2, 3, 4, 5 and 6	Serum levels determined in the morning under fasted conditions
Matrix metallopeptidase 9 (MMP-9)	Baseline, month 1, 2, 3, 4, 5 and 6	Plasma levels determined in the morning under fasted conditions
MMP-9	Hourly over 12 hours	Plasma levels determined over the day

Countries

Germany

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 26, 2026