The Potential of Carnosine Supplementation in Optimising Cardiometabolic Health

The Potential of Carnosine Supplementation in Optimising Cardiometabolic Health in Patients With Prediabetes and Type 2 Diabetes: a Randomsied, Double-blinded, Placebo-controlled Trial

The investigators hypothesise that carnosine supplementation will improve:

1. glycaemic control
2. cardiovascular risk factors
3. cognitive outcomes

in patients with prediabetes and type 2 diabetes, and this will be modulated by reduction in chronic low grade inflammation, oxidative stress and circulating advanced glycation end products levels.

3. Aims

To determine the potential of carnosine supplementation for 14 weeks to improve glycaemic control in type 2 diabetes, reduce risk factors for cardiovascular disease and improve cognitive function as well as identify metabolic pathways involved, specifically by:

1. Improving glycaemic control (HBA1c, fasting and 2 hour glucose and glucose area under the curve after oral glucose tolerance test)
2. Reducing cardiovascular risk factors (lipids; arterial (aortic) stiffness; central blood pressure (cBP); endothelial function).
3. Improve cognitive function (global cognitive score formed by a composite of 4 cognitive tests)
4. Decrease the chronic low grade inflammation, oxidative stress, advanced glycation end products, and advanced lipoxidation end products, and increase detoxification of reactive carbonyl species (RCSs).

Study Overview

• Status: Recruiting
• Conditions: Cardiovascular Risk Factors; Cognitive Function 1, Social; Poor Glycemic Control
• Intervention / Treatment: Dietary supplement: carnosine; Drug: Placebo

Detailed Description

Type 2 diabetes is a major public health problem worldwide. Obesity itself markedly increases the risk of type 2 diabetes (DM2), which now affects every second obese person. With 60% of adult Australians overweight or obese and 25% of Australians aged over 25 years having prediabetes or diabetes, the quality-of-life and cost impact is inescapable. In Australia, direct healthcare costs for DM2 are currently estimated as $1.1 billion annually, with the prospect of doubling by 2025. Obesity and DM2 dramatically increase the risk of cardiovascular disease (CVD) with ~80% of individuals with both obesity and DM2 develop CVD. The annual healthcare costs for CVD in Australia now amount to $7.7 billion; and the total aggregated costs, including loss of income, are much higher again. Treating DM2 and CVD is expensive and often unsatisfactory. Weight loss and exercise are the mainstay of prevention and therapy but they are difficult and costly to achieve on a large scale; hence the DM2 epidemic continues unabated. Therefore, interventions at low cost and easy to implement at the population level is urgently required.

Neurodegenerative diseases often occurs in people with DM2, and DM2 is in turn associated with increased risk of cognitive decline. Neurodegenerative diseases such as Alzheimer's disease are also associated with metabolic impairment. They share many common pathogenic features with DM2 such as insulin resistance, chronic low-grade inflammation, vascular disease, oxidative stress and accumulation of advanced glycation endproducts (AGEs). Progression of these diseases over years-decades is also worsened by a sedentary life-style. Therefore not surprisingly, regular physical activity is beneficial in those patients, likely due to improvement of neurological, motor and cardiometabolic profile. However, it is difficult and costly to achieve on a large scale, and thus, safe and low-cost strategies are needed.

Type 2 diabetes is associated with increased amounts of ectopic fat depots in muscle including intramyocellular lipids (IMCL), and adipocytes located between muscle groups (inter-muscular) and also between muscle fascicles (intramuscular). Both IMCL and intra- and inter-muscular adipose tissue (IMAT) may deleteriously effect muscle metabolism and insulin sensitivity through increased local secretion of pro-inflammatory adipokines, and inter-muscular fat may additionally impair insulin action through reductions in blood flow to muscle.

Could carnosine be that strategy? Strong molecular and animal data (>2000 papers) suggests that it has great potential, with all the relevant properties. Carnosine, is present in several tissues including muscle and brain, easily crosses the blood-brain barrier, and extensive animal data show that carnosine has chelating properties and modulates glucose metabolism, advanced glycation, pro-inflammatory and pro-oxidative states, as well as motor functions and neurotransmission. A promising further use may derive from its effect on cardiometabolic health and neuroprotection. Current research, confined to animal studies, supports carnosine supple¬ment¬ation for preventing and treating obesity, DM2, CVD, and neurodegenerative diseases - by virtue of its anti-inflammatory, antioxidative, anti-glycating and chelating effects. Our team's novel pilot studies provide the first human cross-sectional and interventional metabolic data, and demonstrate relationships among carnosine, obesity, insulin resistance, and dyslipidaemia. Previous clinical trials also showed that supplementation of carnosine for 2-3 months improved cognitive performance in healthy individuals and patients with neurodegenerative diseases. However, none of them showed its effect in patient with type 2 diabetes and explored the effects of change in cardiometabolic outcomes on cognitive function.

Apart from its excellent side-effect profile, carnosine is cheap and safe (it is an over-the-counter dietary supplement), making it prima facie ideal for widespread, low cost use. Robust human research is now urgently needed to test the therapeutic potential of carnosine in improving cardiometabolic profile and cognitive function, and study the mechanisms involved.

• Study Type: Interventional
• Enrollment (Anticipated): 40
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Barbora de Courten, MD,PHD,MPH; Phone Number: +61 385722651; Email: barbora.decourten@monash.edu

Study Locations

• Australia
  • Victoria
    • Melbourne, Victoria, Australia, 3168
      • Recruiting
      • Monash Centre for Health Research and Implementation
      • Contact: Barbora de Courten, MD,PHD,MPH; Phone Number: +61 3 857 22651; Email: barbora.decourten@monash.edu
      • Principal Investigator: Barbora de Courten, MD,PHD,MPH
      • Sub-Investigator: Helena Teede, MBBS,PhD
      • Sub-Investigator: James Cameron, MBBS,MD
      • Sub-Investigator: Alexander Hodge, BSc,MBBS,PHD
      • Sub-Investigator: David Scott, BSc,MBBS,PHD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age >=18 or <=70 years
• Weight change < 5 kg in last 6 months
• HbA1c level <= 8%
• Patients with prediabetes (Impaired glucose tolerance and impaired fasting glycaemia) or type 2 diabetes (diet controlled or on oral therapy)
• Patients will have to be on oral therapy for diabetes (without changes in treatment) at least for 3 months.
• Patients will be advised not to change their pre-existing therapy for diabetes and cardiovascular risk factors for the duration of the study if HbA1c is not above 8%
• No recent blood transfusion (3 months)
• No current intake of anti-inflammatory medications and supplements
• No significant kidney, cardiovascular, haematological, respiratory, gastrointestinal, or central nervous system disease, as well as no psychiatric disorders, no active cancer within the last five years; no presence of acute inflammation (by history, physical or laboratory examination)
• Pregnant or lactating

Exclusion Criteria:

• Age <18 or > 70 years
• HbA1c level of >= 8%
• Weight change > 5 kg in last 6 months
• Morbid obesity (body mass index >40 kg/m2)
• Current smoking habit and high alcohol use
• Patients on insulin
• Taking anti-inflammatory medications or supplements
• Recent blood transfusion history
• Kidney (estimated glomerular filtration rate < 30 ml/min), cardiovascular, haematological, respiratory, gastrointestinal, or central nervous system disease, as well as psychiatric disorder, active cancer within the last five years; presence of acute inflammation (by history, physical or laboratory examination)
• Pregnancy or lactation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Intervention; Each participant will be given a daily oral dose 2 g of carnosine (4 tablets of 500mg each) for 14 weeks	Dietary supplement: carnosine; Each participant will be given a daily oral dose 2 g of carnosine (4 tablets of 500mg each) for 14 weeks; Other Names: Pure Carnosine
Placebo Comparator: Control; Each participant will be given a daily oral dose 2 g of placebo (4 tablets of 500mg each) for 14 weeks	Drug: Placebo; Each participant will be given a daily oral dose 2 g of placebo (4 tablets of 500mg each) for 14 weeks; Other Names: Methylcellulose

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Oral Glucose Tolerance Test	After a 10-12 h overnight fast, participants will ingest 75g of glucose over 2 mins. Blood samples will be drawn at 0, 30, 60, 90 and 120 min for plasma glucose and insulin concentrations. We will evaluate the area under the curve.	baseline and 14 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in HbA1c	Blood samples will be measured using High Performance Liquid Chromatography.	baseline and 14 weeks
Change in lipid profile	Blood samples will be analysed using High Performance Liquid Chromatography	baseline and 14 weeks
Change in systolic and diastolic blood pressure	Resting systolic and diastolic blood pressure and pulse rate will be measured using an automated oscillometric measurement system (Dinamap, USA) after a 30 minute rest.	baseline and 14 weeks
Change in arterial stiffness and central blood pressure	Aortic (carotid-femoral) pulse wave velocity (aPWV) will be measured using the non-invasive Complior device (Alam Medical, French).	baseline and 14 weeks
Change in markers of endothelial dysfunction	This is done using non-invasive peripheral arterial tomography (PAT; endothelium-dependent digital pulse amplitude testing (EndoPAT), Itamar Medical Ltd, Israel), which records continuous plethysmographic signals of the finger arterial pulse wave. Finger plethysmographic probes are placed on each index finger; and after a 5 min equilibration period, a blood pressure cuff on the non-dominant arm is inflated to 60 mmHg above systolic for 5 min and then deflated to induce reactive hyperaemia. Measurements of post-occlusion changes (reactive hyperaemia PAT: RH-PAT) are continued for 10 min. Results are normalised to the non-occluded arm, compensating for potential systemic changes (RH-PAT ratio).	baseline and 14 weeks
Change in heart rate variability	The Zephyr Biomodule BH3 (Black Sensor, produced by Zephyr Technology) will be used to measure heart rate and heart rate variability for three consecutive days.	baseline and 14 weeks
Change in interleukins	Interleukins will be measured by quantitative sandwich enzyme immunoassays (R & D Systems Inc, USA).	baseline and 14 weeks
Change in tumour necrosis factor α	Tumour necrosis factor α (TNFα) will be measured by quantitative sandwich enzyme immunoassays (R & D Systems Inc, USA).	baseline and 14 weeks
Change in macrophage migration inhibitory factor	Macrophage migration inhibitory factor will be measured by quantitative sandwich enzyme immunoassays (R & D Systems Inc, USA).	baseline and 14 weeks
Change in plasma C- reactive protein	Plasma C- reactive protein (hsCRP) will be measured using high sensitivity assay (BN-II nephelometer; Dade Behring Diagnostics, NSW).	baseline and 14 weeks
Change in plasma and urinary advanced glycation end products	Measured by liquid chromatography-tandem mass spectrometry and ELISA tests. Circulating receptor for AGEs will be measured by ELISA. Protein modifications and the effect of carnosine supplementation will be determined by proteomic approaches.	baseline and 14 weeks
Change in plasma and urinary advanced lipoxidation end products	This will be determined by measuring the advanced oxidation protein products and by measuring the cysteinate form of albumin by mass spectrometry. Mercapturic acid adducts with the main reactive carbonyls species will also be quantitatively determined by liquid chromatography electrospray ionization mass spectrometry/mass spectrometry analysis (LC-MS/MS).	baseline and 14 weeks
Change in general cognitive function	Participants' cognitive function will be assessed using Cambridge Neuropsychological Test Automated Battery (CANTAB) battery for Prodromal Alzheimer's disease, Victoria Stroop test, Trail Making Test and Digit Symbol Substitution Test.	baseline and 14 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in liver stiffness and fat	A non-invasive transient elastography (Fibroscan, EchoSens, Paris) will be used to assess liver fibrosis based on the measurement of liver fat and stiffness	baseline and 14 weeks
Change in Serum and urine carnosine	This will be measured by ELISA for human carnosinase 1 (CN1) with a monoclonal antibody (clone ATLAS, Abcam plc) and peroxidase substrate .	baseline and 14 weeks
Change in skeletal muscle fat and density	We will also measure the change in muscle and fat tissue density of participants' non-dominant leg using Quantitative Computed Tomography (pQCT). Participants will be seated in their non-dominant leg positioned inside the machine gantry. Muscle cross sectional area (mm2) and muscle density (mg/cm3) will be determined using the manufacturer's algorithms.	baseline and 14 weeks
Change in body composition	body composition by dual energy x-ray absorptiometry (DEXA), which is a non-invasive assessment of soft tissue composition by region with a precision of 4-5%; central adiposity assessed in duplicate using a constant-tension tape for taking waist, and hip circumference. Bioimpedance measurement will be also collected for validation purposes.	baseline and 14 weeks

Collaborators and Investigators

• Sponsor: Monash University
• Investigators: Principal Investigator: Barbora de courten, MD,PHD,MPH, Monash University

Publications and helpful links

General Publications

• Baye E, Menon K, de Courten MP, Earnest A, Cameron J, de Courten B. Does supplementation with carnosine improve cardiometabolic health and cognitive function in patients with pre-diabetes and type 2 diabetes? study protocol for a randomised, double-blind, placebo-controlled trial. BMJ Open. 2017 Sep 1;7(9):e017691. doi: 10.1136/bmjopen-2017-017691.

Study record dates

Study Major Dates

• Study Start: October 1, 2016
• Primary Completion (Anticipated): January 1, 2023
• Study Completion (Anticipated): July 1, 2023

Study Registration Dates

• First Submitted: September 19, 2016
• First Submitted That Met QC Criteria: September 26, 2016
• First Posted (Estimate): September 28, 2016

Study Record Updates

• Last Update Posted (Actual): June 28, 2022
• Last Update Submitted That Met QC Criteria: June 22, 2022
• Last Verified: June 1, 2022

More Information

Terms related to this study

• Keywords: carnosine, type 2 diabetes, cardiovascular factors
• Other Study ID Numbers: 16061AI

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No