Cardiovascular Risk Factors After Single Pancreas Transplantation (Diamant)
Assessment of Cardiovascular Risk Factors, Including Endothelial Function, After Restoration of Normoglycemia Following Single Pancreas Transplantation
Patients accepted for the waiting list for single pancreas transplantation suffer from severe glucose instability with hyperglycemia due to diabetes type 1, but do not have significant diabetes-related complications. Pancreas transplantation restores normoglycemia in diabetes type 1 patients with unstable control of glycemia. Both hypo- and hyperglycemic events are abolished, and 70-80 % of the patients obtain satisfactory HbA1c levels (HbA1c 5.0-6.0 %) without the need of exogenous insulin. Endothelial dysfunction is considered as an early and potentially reversible stage in the atherosclerotic process. The endothelium is involved in homeostasis, leucocyte adhesion and vasomotor activity. Reduced endothelium-dependent vasodilation is associated with increments in cardiovascular risk factors, and endothelial dysfunction is a predictor for future cardiovascular disease. It has also been hypothesized that endothelial dysfunction may be involved in the impaired glycemic control by reducing the availability of glucose in peripheral muscles.Establishing normoglycemia by pancreas transplantation alone in previously diabetic type 1 patients has recently been shown to improve left ventricular ejection fraction, assessed by Doppler echocardiographic examination. In diabetic patients receiving a new pancreas it is possible to assess the effect of changing blood glucose excursions on cardiovascular risk factors, including endothelial function, without the use of antidiabetic drugs (exclude pleiotropic effects).
The primary objective of the present study is to assess if endothelial function (assessed by flow-mediated dilatation of arteria brachialis) is improved when hyperglycemia is reversed by single pancreas transplantation in patients with type 1 diabetes.
Secondary objectives are to investigate the changes in the following parameters by reversal of hyperglycemia by pancreas transplantation; Peripheral arterial tonometry, serum/plasma concentrations of endothelial dysfunction markers, blood pressure, lipid and lipoprotein concentrations.
調査の概要
研究の種類
入学 (実際)
段階
- 適用できない
連絡先と場所
研究場所
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Oslo、ノルウェー、N-0424
- Oslo University Hospital, Rikshospitalet
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参加基準
適格基準
就学可能な年齢
健康ボランティアの受け入れ
受講資格のある性別
説明
Inclusion Criteria:
- Patients with type 1 diabetes accepted for the waiting list for single pancreas transplantation
- Healthy volunteers (non-diabetic, non-transplanted)
- Over 18 years of age
- Signed informed consent
Exclusion Criteria:
- Non-functioning pancreas graft (defined as HbA1c ≥ 6.5 % with the need of insulin injections and fasting C-peptide concentration < 300 pmol/L).
- Active infection
- Active autoimmune disease other than diabetes
- Severe liver disease
研究計画
研究はどのように設計されていますか？
デザインの詳細
- 主な目的：基礎科学
- 割り当て：なし
- 介入モデル：単一グループの割り当て
- マスキング：なし（オープンラベル）
武器と介入
参加者グループ / アーム |
介入・治療 |
|---|---|
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実験的：Single pancreas transplantation
This is an explorative analysis to assess the impact of establishing normoglycemia in previously hyperglycemic patients, without using antidiabetic drugs, by investigating patients before and after single pancreas transplantation.
Active patients on the waiting list for single pancreas transplantation will be investigated while on the waiting list and subsequently 8 weeks and 1 year after transplantation if they have a functioning pancreas graft.
A control group of healthy volunteers (non-diabetic, non-transplanted), frequency-matched for age and gender with regards to the pancreas transplanted patients, will be investigated once.
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この研究は何を測定していますか？
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
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Endothelial function
時間枠：1 year post-transplant
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This is an explorative analysis to assess the impact of establishing normoglycemia in previously hyperglycemic patients, without using antidiabetic drugs, by investigating patients before and after single pancreas transplantation.
Active patients on the waiting list for single pancreas transplantation will be investigated while on the waiting list and subsequently 8 weeks and 1 year after transplantation if they have a functioning pancreas graft.
Flow-mediated dilatation (FMD) of large vessels (arteria brachialis) will be assessed by measuring vessel diameter by ultrasound and the FMD of micro vessels in the finger tip will be assessed by Endo-PAT (PAT=Peripheral Arterial Tonus) following reactive hyperperfusion induced by occlusion of the artery by a sphygmomanometer cuff.
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1 year post-transplant
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二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
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Peripheral arterial tonometry
時間枠：1 year post-transplant
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1 year post-transplant
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Changes in cardiac performance
時間枠：1 year post-transplant
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An echocardiographic examination will be performed to assess changes in cardiac performance, such as left ventricular ejection fraction
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1 year post-transplant
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Pulse wave velocity (arterial stiffness)
時間枠：1 year post-transplant
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Pulse wave velocity, using a SphygmoCor device, measuring arterial stiffness will be performed in addition to pulse wave analysis evaluating the shape and amplitude of the aortic pulse wave.
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1 year post-transplant
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Heart rate variability
時間枠：1 year post-transplant
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Heart rate variability will be assessed, using a Vagus device, analyzing short-term electrocardiogram recordings.
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1 year post-transplant
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Plasma concentrations of endothelial dysfunction markers
時間枠：1 year post-transplant
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Fasting plasma samples (6 mL EDTA vacutainer) will be drawn for determination of relevant markers for endothelial dysfunction, such as von Willebrand factors (vWF) and vascular cell adhesion molecule-1 (VCAM-1).
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1 year post-transplant
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Blood pressure
時間枠：1 year post-transplant
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Blood pressure will be measured seated after ten minutes rest by Dyna Map (Tuff.-Cuff,
CAS Medical system Inc.) and the mean of the lower two out of three measurements will be used.
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1 year post-transplant
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Lipid and lipoprotein concentrations
時間枠：1 year post-transplant
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1 year post-transplant
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Bone mineral density and body composition
時間枠：1 year post-transplant
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Measurement of bone mineral density, using low dosage radiation (dual-energy X-ray absorptiometry (DEXA) scan) to assess the amount (grams) of mineral that are packed into a segment of bone.
In addition a body composition (visceral fat, metabolic measurement) will be determined using the DEXA scan.
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1 year post-transplant
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Glomerular filtration rate
時間枠：1 year post-transplant
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Renal function, defined as glomerular filtration rate, will be evaluated by measuring iohexol clearance.
The concentration of iohexol (Omnipaque), a low dose non-ionic x-ray contrast medium of low osmolality, extensively used in clinical radiology and considered essentially free from side effects, will be measured 2 hours and 5 hours after iv injection of iohexol.
Like other iodine-containing contrast media, it is completely eliminated from the body by excretion in the urine, thus it is an ideal marker for kidney function.
It will be quantitated by chemical measurement based on the determination of iodine.
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1 year post-transplant
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Oral glucose tolerance test
時間枠：1 year post-transplant
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Measurements of plasma glucose, C-peptide and serum insulin before, 30 and 120 minutes following an oral administration of 75 g glucose.
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1 year post-transplant
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協力者と研究者
スポンサー
捜査官
- 主任研究者：Trond G Jenssen, Professor、Oslo University Hospital
研究記録日
主要日程の研究
研究開始
一次修了 (実際)
研究の完了 (実際)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (見積もり)
学習記録の更新
投稿された最後の更新 (実際)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
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