The Role of Amylin in Bone Metabolism

Study Overview
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Brief Summary
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The clinical study aim to investigate the effect of the intravenously administrated amylin analogue (pramlintide) on the circulating levels of C-terminal telopeptide of type I collagen (CTX-1) (a marker of bone resorption) and N-terminal propeptide of type I procollagen (P1NP) (a marker of bone formation) in individuals with type 1 diabetes and matched healthy controls during fasting euglycemic conditions.

Detailed Description
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Using a randomised double blinded placebo-controlled crossover design we will evaluate the effects of the intravenously administrated amylin analogue (pramlintide) on circulating levels of CTX-1 and P1NP in ten individuals with type 1 diabetes and ten healthy controls matched for age, gender and body mass index (BMI) during fasting and euglycemic conditions. Each participant will receive double-blinded infusions of pramlintide (3 pmol/kg/min) and saline on two separate study days performed in randomised order. The primary endpoints are the relative changes in the plasma levels of P1NP and CTX-1. The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma CTX-1 and P1NP as well as %-changes from baseline including nadir. The secondary endpoints encompass changes in plasma concentrations of calcium, parathyroid hormone (PTH), alkaline phosphatase, osteocalcin, glucagon, insulin, C-peptide, glucose, glucose-dependent insulinotropic polypeptide and glucagon-like peptide 1 and glucagon-like peptide 2.

Official Title
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The Role of Amylin in Bone Metabolism

Conditions
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Bone Diseases, Metabolic, Type 1 Diabetes

Intervention / Treatment
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* Other: Pramlintide
* Other: Placebo (saline) infusion


Participation Criteria
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Eligibility Criteria
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Inclusion criteria type 1 diabetes: Caucasian ethnicity Age between 18 and 60 years BMI between 18.5 and 27 kg/m2 Type 1 diabetes (diagnosed according to the criteria of the World Health Organization) with HbA1c <69 mmol/mol (<8.5%) and Type 1 diabetes duration of 2-20 years C-peptide negative (stimulated C-peptide ≤30 pmol/l) Treatment with a stable basal-bolus or insulin pump regimen for ≥3 months Normal vitamin D (>50 nmol/l) Informed consent Exclusion criteria type 1 diabetes: Anaemia (haemoglobin below normal range) Liver disease (ALAT and/or ASAT >2 times normal values) or history of hepatobiliary disorder Nephropathy (eGFR <60 ml/min/1,73m2 and/or microalbuminuria) Microvascular complications except non-proliferative retinopathy Treatment with anti-osteoporosis medication or glucocorticoids No fractures within the last 6 months For women: not currently perimenopausal or postmenopausal Diseases affecting calcium metabolism (e.g. hypoparathyroidism, hyperparathyroidism, osteoporosis, vitamin D deficiency and cancer) Pregnancy or breastfeeding Any physical or psychological condition that the investigator feels would interfere with trial participation Treatment with any glucose-lowering drugs beside insulin, treatment with medication against osteoporosis or treatment with any form of glucocorticoids Inclusion criteria healthy controls: Caucasian ethnicity Age between 18 and 60 years BMI between 18.5 and 27 kg/m2 Fasting plasma glucose ≤7.0 mmol/l and glycated haemoglobin (HbA1c) <48 mmol/mol Normal blood haemoglobin (8.3-10.5 mmol/l (males) and 7.3 - 9.5 mmol/l (females)) Normal plasma vitamin D (>50 nmol/l) Informed consent Exclusion criteria healthy controls: Any form of diabetes (according to World Health Organization criteria) Anaemia (haemoglobin below normal range) Nephropathy (eGFR <60 ml/min/1,73m2 and/or microalbuminuria) Known liver disease and/or alanine transaminase (ALAT) or aspartate transaminase (ASAT) >2 × upper normal limit Any fractures within the last 6 months For women: not currently perimenopausal or postmenopausal Diseases affecting calcium metabolism (e.g. hypoparathyroidism, hyperparathyroidism, osteoporosis, vitamin D deficiency and cancer) Pregnancy or breastfeeding Any condition considered incompatible with participation by the investigators

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: We apply a randomised double blinded placebo-controlled crossover design.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pramlintide infusion<br>A stable amylin analogue. | Other: Pramlintide<br>* At time 0 min, continuous infusion of a stable amylin analogue (pramlintide) will be initiated at a rate of 3.0 pmol/kg/min. The infusion will be terminated after 180 minutes.<br>|
| Placebo Comparator: Placebo infusion<br>Isotonic saline (0.9% NaCl). | Other: Placebo (saline) infusion<br>* At time 0 min, continuous infusion of isotonic saline will be initiated at a rate of 25 ml/h. The infusion will be terminated after 180 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relative changes in the plasma levels of C-terminal telopeptide of type I collagen (CTX-1) | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma CTX-1 as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Relative changes in the plasma levels of N-terminal propeptide of type I procollagen (P1NP) | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma P1NP as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in plasma concentrations of glucagon. | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Changes in plasma concentrations of insulin. | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Changes in plasma concentrations of C-peptide. | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Changes in plasma concentrations of glucose. | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Changes in plasma concentrations of glucose-dependent insulinotropic polypeptide (GIP). | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Changes in plasma concentrations of glucagon-like peptide 1 (GLP-1). | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Changes in plasma concentrations of glucagon-like peptide 2 (GLP-2). | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Changes in plasma concentrations of calcium. | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Changes in plasma concentrations of parathyroid hormone (PTH) | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Changes in plasma concentrations of alkaline phosphatase | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes | 
| Changes in plasma concentrations of osteocalcin | The changes in plasma concentrations will be assessed by the total and incremental (baseline-subtracted) area under the curve for plasma levels as well as %-changes from baseline including nadir. | From -15 minutes to 180 minutes |