Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT02237352 |
| Other study ID # |
DN-HLV0178-DV |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
September 15, 2014 |
| Est. completion date |
December 2022 |
Study information
| Verified date |
March 2020 |
| Source |
Universidad Estatal de Milagro |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational [Patient Registry]
|
Clinical Trial Summary
The prevalence of diabetes mellitus (DM) is increasing worldwide, suggesting that 45% of
diabetics are undiagnosed. DM induces a kidney disease called diabetic nephropathy (DN) which
is the largest single cause of end-stage renal disease and dialysis requirement. In South
America the prevalence of DM and chronic kidney disease has increased, and great disparity
exists among countries in regards to access to the dialysis treatment. It has been
considerate that Hispanic origin increases the risk for DM. The South Americans have
distinctive habits, culture, environment, behavior and genetic background and the factors
involved in DN have not been defined yet. The early kidney lesions such as neoangiogenesis
(pathologic generation of the new blood vessels) and extracellular matrix expansion have been
described. The vascular endothelial growth factor A (VEGF) has been linked to angiogenesis,
but the role of VEGF in DN has not been elucidated yet. VEGF signals mainly through VEGF
receptor 2 (VEGFR2). VEGFR2 interacts with alphaV beta3 integrin (AVB3) in kidney.
Additionally tenascin C is expressed in the extracellular matrix. Tenascin C and the tenascin
C/AVB3 complex have also been linked to angiogenesis, however their roles have not been
unveiled yet in the DN. Investigators hypothesize that VEGF signaling and tenascin C play an
important role in DN and that VEGFR2, AVB3 and tenascin C interact. The purposes of this
study is to characterize social, environmental and biological factors implicated in the DN in
Ecuador and define the role of VEGF signaling and tenascin C in the pathogenesis of the DN.
Investigators propose to study factors involved in DN in diabetic and non-diabetic adults
from general population, with and without DN. In a single time investigators will evaluate
demographics data, habits, personal and family history through a survey. Investigators will
measure anthropometrics parameters and blood pressure; investigators will quantify blood
glucose, glycosylated hemoglobin A1c and proteinuria. In addition investigators will examine
the role of tenascin C and VEGF signaling by analyzing paraffin embedded kidney tissue,
plasma and urine samples. Characterizing the factors involved in the DN from Hispanic people
is key to establish adequate strategies of prevention, diagnosis and treatment in this
population. Furthermore elucidating the role of proteins involved in DN may offer valuable
tools for the development of new treatments.
Description:
1. Determinations of social, environmental and biological factor implicated in diabetic
nephropathy in Ecuador Investigators will study subjects from the general population.
Investigators will contact community and religious leaders in order to invite adult
subjects from the general population to participate in this study and 10000 persons will
be enrolled.
After teaching basic concepts about prevention of diabetic nephropathy in all subjects,
investigators will collect demographics data, house conditions and localization (rural,
urban or around the cities), number of people that share a home, education level,
employment and economical condition, personal health insurance, medical checkup history,
toxic habits (alcohol, cigarette abuse of addictive substances) and physical exercises
habits. Investigators will collect personal and family antecedent of diabetes mellitus,
diabetic nephropathy, hypertension, kidney diseases, diabetes gestational, current
treatments and other chronic diseases. Investigators will measure body weight (Kg),
height (m) and investigators will calculate body mass index. Investigators will also
measure blood pressure, blood glucose, glycosylated hemoglobin, microalbuminuria and
proteinuria. Trained personnel will fill out the person's survey. Investigators will
supervise and collect data from 2% of the sample.
2. Role of extracellular matrix proteins and growth factors signaling in diabetic
nephropathy
1. Systemic and urine studies: proteins involved in diabetic nephropathy pathogenesis
as vascular endothelial factor A (VEGF) and extracellular matrix protein as
tenascin C (tenascin) concentration will be measured by a commercially available
kits in plasma and urine (respectively). Samples will be obtained from diabetics
with (n: 20) and without diabetic nephropathy (n: 20) and from non-diabetic
subjects (controls) from the general population (n: 2000). Determinations of
social, environmental and biological factor will be completed as in aim 1.
2. Kidney tissue studies: investigators will determine the role of protein involved in
diabetic nephropathy, VEGF signaling and tenascin in:
I) Paraffin embedded kidney tissue obtained from the sample libraries of pathology
laboratories will be studied. Slides from non-diabetics (n: 10) and diabetics with diabetic
nephropathy (n: 20) and without diabetic nephropathy (n: 10) will be collected. The role of
proteins involved in diabetic nephropathy as VEGF signaling and tenascin will be studied by
immunohistochemistry and proximity link assay.
II) Paraffin embedded kidney slides from diabetics with diabetic nephropathy (n: 12),
non-diabetic control (n: 6) with primary glomerulopathy as minimal change disease, and
diabetic controls without diabetic nephropathy (n: 6), will be studied. Investigators will
recruit patients with kidney biopsy indicated, and scheduled to be performed, by their
medical doctors. After pathology diagnosis completion, some of the remnant paraffin embedded
tissue will be used for this study. The role of proteins involved in diabetic nephropathy,
VEGF signaling and tenascin will be studied by immunohistochemistry and proximity link assay.
Urine and plasma will be collected prior to the kidney biopsy in order to measure protein
concentration of potentially useful biomarkers of diabetic nephropathy; VEGF and tenascin
levels will be quantified. Patients will be informed and signed consent will be required.
Blood glucose will be measured by the blood glucose meter and test strip. Glycosylated
hemoglobin A1c and microalbuminuria (albumin/creatinine in spot urine) will be quantified
using the portable machine (Siemens).
In fasting conditions investigators will consider normal blood glucose values <99 mg%,
pre-diabetes between 100 and 125 mg% and diabetes ≥126 mg%. In non-fasting conditions values
of blood glucose >200mg% will be considered as diabetes. Investigators will deem normal
glycosylated A1c hemoglobin values <5.6 %, pre-diabetes between 5.7 and 6.4% and diabetes
≥6.5%.
Investigators will deem normal albuminuria values of albumin/creatinine ratio <29mg/g,
microalbuminuria values between 30 and 299 mg/g and macro-albuminuria values ≥300mg/g.
Proteinuria will also be evaluated by reactive urine strips.
In the case of inconsistent results or out of range values the analysis will be repeated in
the same sample or re analyzed by standard laboratory equipment and techniques.
Investigators will consider diabetic nephropathy as persistent proteinuria associated to
diabetic retinopathy and decreased endogen glomerular filtration rate (in subjects without a
diagnosis of other kidney or urinary tract diseases). In Type 1 diabetics, diabetic
nephropathy will be diagnosed if the history of diabetes is longer than 10 years prior to the
onset of proteinuria; in diabetic type 2, proteinuria associated to a decreased glomerular
filtration rate at diagnosis time, investigators will deem diabetic nephropathy.
In all paraffin embedded kidney samples we will measure the protein expression and
localization. Investigators will use kits, primary and secondary antibodies commercially
available to perform immunohistochemistry and proximity link assay. Investigators will
perform those experiments in cooperation with pathologist.
All subjects recruited from general population will be identified by a unique code. Number
and capital letters code will be placed in the survey and in the sample labels as M0001 (M:
city, number 0001: person number 0001). Data will be uploaded and saved in a secure data
base. Trained personnel will be in charge of handling the data base. Investigators will
supervise the data entry. An investigator at least once every 6 months will randomly select
2% survey and will match it against the information uploaded in the database. Furthermore,
investigators will analyze and report all collected data from the surveys even if they are
incomplete by adjusting the analysis parameters of the incomplete ones.
Investigators will use descriptive statistic tools to describe groups (mean, standard
deviation and standard error or median and interquartile range). For group comparisons,
unpaired T test, Mann Whitney or Fisher's test will be used. ANOVA, Kruskal Wallis and Chi
Square test will be performed for to compare unmatched groups; to quantify association
between two variables Pearson and Spearman correlation test will be used. Simple or multiple
regressions will be considered to predict value from variables. P value <0.05 will be deemed
significant. A sample from the general population was calculated considering the adult
population between 21-70 years old in Ecuador.
