β-alanine Supplementation in Adults With Overweight/Obesity (BASA-O)

β-alanine Supplementation in Adults With Overweight or Obesity (BASA-O): A Randomised Controlled Feasibility Trial

The study will investigate the safety, feasibility, and efficacy of beta-alanine supplementation in adults with overweight or obesity. Beta-alanine is a widely used dietary supplement that can increase the amount of carnosine in skeletal muscle. Both carnosine and beta-alanine occur naturally in animal food products and previous research shows that supplementation with beta-alanine leads to an improvement in exercise performance; more recently, the present investigators have shown that increasing carnosine can also help to improve cardiometabolic health, detoxify skeletal muscle, and improve glucose (sugar) uptake into muscle cells. The investigators will recruit 30 participants (15 per arm) with overweight or obesity who meet the study criteria (this accounts for up to 20% attrition - a minimum of 12 participants per arm). Those who are eligible will be required to receive three short telephone calls and attend three laboratory sessions. Participants will be randomised to receive either beta-alanine or placebo (an inactive sugar pill) for the 3-month study period. To see whether beta-alanine supplementation is feasible in this population the investigators will measure recruitment, adherence (how well people can stick to the supplement regime), the number and nature of side effects, and blinding to the intervention. Markers of cardiac function, glycaemic control, and metabolic health will also be explored. All measurements will take place before and after a 3-month supplementation period. This will provide us with novel information of the role of beta-alanine and carnosine in cardiometabolic health; and will aid in the planning of a larger randomised controlled trial to assess the efficacy of beta-alanine supplementation as a therapeutic strategy.

Overweight and obesity are major public health problems. Recent estimates show that 64.3% of people in the UK are living with overweight or obesity; this is projected to increase to 71% by 2040, which equates to approx. 42.2 million people (Cancer Research UK, 2022). Overweight and obesity are characterised by excess amounts of adiposity and systemic, chronic, low-grade inflammation, which is associated with a range of metabolic disorders including dyslipidaemia, hypertension, and hyperglycaemia (Calder et al., 2011). This confers an increased risk of developing prediabetes, type-2 diabetes, and cardiovascular disease, as well as associated microvascular complications such as retinopathy, neuropathy, and nephropathy (Brannick et al., 2016). Lifestyle interventions can help delay or prevent the progression of overweight or obesity, thereby reducing morbidity (Lin et al., 2017; Wing et al., 2021). Such interventions, however, can be challenging to implement and a lack of long-term adherence can limit their effectiveness (Fappa et al., 2008). It is therefore important to develop low-cost, novel adjunct therapies to improve cardiometabolic health and help delay or prevent disease progression. The multifunctional dipeptide carnosine has emerged as a candidate for improving glycaemic control and cardiometabolic health. A recent meta-analysis showed that supplementation with carnosine, or its rate-limiting precursor β-alanine, reduces fasting glucose and HbA1c in humans and rodents. Work from our Research Group shows that treatment with carnosine decreases highly toxic lipid peroxidation products in skeletal muscle cells, leading to an increase in insulin-stimulated glucose uptake under glucolipotoxic conditions. A similar role occurs in vivo, where supplementation with β-alanine leads to greater formation of carnosine-adducts in post-exercise skeletal muscle samples. Given that skeletal muscle insulin resistance is a key component of prediabetes and type 2 diabetes, and reactive aldehydes can directly interfere with insulin signalling, carnosine may exert its therapeutic actions in skeletal muscle. There is also emerging evidence that carnosine, and other histidine-containing dipeptides (HCDs), play an important role in Ca2+ handling and excitation-contraction coupling in cardiac muscle, which may have implications for cardiovascular health. A limitation of existing studies is that the low carnosine dose used is likely to have only a modest effect on tissue carnosine content. Supplementation with β-alanine, however, can increase skeletal muscle carnosine content by 60-80% in 4-10 weeks, but it has not yet been trialled in adults with overweight or obesity. Please note: a change was made to the study eligibility criteria, which was approved by the UK Health Research Authority Research Ethics Committee on 01/09/2022.

A double-blinded, randomised, placebo-controlled, parallel group, feasibility trial. The allocation ratio of treatment to placebo will be 1:1.

Slow-release beta-alanine (Natural Alternatives International, Carlsbad, CA, USA). Dose: 4.8 grams per day for 3-months (potential total intake of 432 g beta-alanine). The daily intake will be split into four doses of 2 x 600 mg. Participants will be instructed to consume each dose alongside their main daily meals (e.g., breakfast, lunch, and dinner) and before bed.

Taste and appearance-matched placebo (tapioca starch) (Natural Alternatives International, Carlsbad, CA, USA). Doses equivalent to the experimental arm.

Body weight will be measured with minimal clothing, using calibrated scales, and recorded to the nearest 0.1 kg.

Body mass index will be calculated from these measures, using the standard formula: [weight (kg) / height2 (m)].

Waist circumference will be taken as the circumference of the abdomen at its narrowest point, between the lower costal border and the top of the iliac crest.

Hand grip strength will be measured using the standardised Southampton grip-strength protocol (Roberts et al., 2011).

Analyses will be performed using a Clinical Chemistry Analyser (ABX Pentra C400, Bergman Diagnostica, Horiba Medical, France).

Analyses will be performed using commercially available kits (e.g., enzyme-linked immunosorbent assays) and other relevant analytical methods.

Analyses will be performed using commercially available kits (e.g., enzyme-linked immunosorbent assays) and other relevant analytical methods.

HOMA2-S% will be used to estimate insulin sensitivity using the Oxford computer method (available from https://dtu.ox.ac.uk/homacalculator/) (Wallace et al., 2004).

HOMA2-β% will be used to estimate β-cell function using the Oxford computer method (available from https://dtu.ox.ac.uk/homacalculator/) (Wallace et al., 2004).

The QUICKI will be used as an additional measure of insulin sensitivity, using the standard formula: QUICKI = 1 / [log(fasting insulin) + log(fasting glucose)] (Katz et al., 2000).

Analyses will be performed using a Clinical Chemistry Analyser (ABX Pentra C400, Bergman Diagnostica, Horiba Medical, France).

Analyses will be performed using a Clinical Chemistry Analyser (ABX Pentra C400, Bergman Diagnostica, Horiba Medical, France).

High density lipoprotein (HDL), low density lipoprotein (LDL), total cholesterol (TC), triglycerides, LDL:HDL, and TC:HDL. Analyses will be performed using a Clinical Chemistry Analyser (ABX Pentra C400, Bergman Diagnostica, Horiba Medical, France).

Analyses will be performed using a Clinical Chemistry Analyser (ABX Pentra C400, Bergman Diagnostica, Horiba Medical, France), commercially available kits (e.g., enzyme-linked immunosorbent assays) and other relevant analytical methods.

Analyses will be performed using a Clinical Chemistry Analyser (ABX Pentra C400, Bergman Diagnostica, Horiba Medical, France), commercially available kits (e.g., enzyme-linked immunosorbent assays) and other relevant analytical methods.

Blood and urine analyses will be performed using commercially available kits (e.g., enzyme-linked immunosorbent assays) and other relevant analytical methods.

Blood and urine analyses will be performed using commercially available kits (e.g., enzyme-linked immunosorbent assays) and other relevant analytical methods.

Liver function: alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, gamma-glutamyl transferase, lactate dehydrogenase, creatine kinase (U/L).

Blood analyses will be performed using a Clinical Chemistry Analyser (ABX Pentra C400, Bergman Diagnostica, Horiba Medical, France); commercially available kits (e.g., enzyme-linked immunosorbent assays); and other relevant analytical methods.

Blood analyses will be performed using a Clinical Chemistry Analyser (ABX Pentra C400, Bergman Diagnostica, Horiba Medical, France); commercially available kits (e.g., enzyme-linked immunosorbent assays); and other relevant analytical methods.

Blood analyses will be performed using a Clinical Chemistry Analyser (ABX Pentra C400, Bergman Diagnostica, Horiba Medical, France); commercially available kits (e.g., enzyme-linked immunosorbent assays); and other relevant analytical methods.

Blood analyses will be performed using a Clinical Chemistry Analyser (ABX Pentra C400, Bergman Diagnostica, Horiba Medical, France); commercially available kits (e.g., enzyme-linked immunosorbent assays); and other relevant analytical methods.

Calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, which uses serum creatinine (µmol/L), age, sex, and race.

Analyses will be performed using commercially available kits (e.g., enzyme-linked immunosorbent assays) and other relevant analytical methods.

Non-invasive continuous haemodynamic measurements will be recorded using the CNAP Monitor (CNSystems, Graz; Austria), which uses fingertip plethysmography to accurately measure the beat-to-beat blood pressure wave form; or SBP/DBP will be measured using an automated sphygmomanometer.

Calculated from measurements of stroke volume (mL) and heart rate (bpm), using the CNAP Monitor (CNSystems, Graz; Austria); and/or from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated using body index from measurements using the CNAP Monitor (CNSystems, Graz; Austria); and/or from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated using body index from measurements using the CNAP Monitor (CNSystems, Graz; Austria); and/or from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from the sum of isovolumic contraction time (ICT) and isovolumic relaxation time (IRT) divided by ejection time (ET).

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer. Reported as % or % per second.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer. Reported as degrees or degrees per second.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer. Reported as % or % per second.

Calculated from resting transthoracic echocardiographic (TTE) measurements using a portable ultrasound system (Siemens, USA) and a 4 mHz cardiac transducer.

The reduction of the length of the end-diastolic diameter that occurs by the end of systole, calculated as: (((LVEDD - LVESD) / LVEDD)) * 100).

Inclusion Criteria: Males and females aged 18 to 75 years Body Mass Index (BMI) ≥25 to <40 kg/m2 Able to provide informed consent Exclusion Criteria: Weight loss or gain ≥5 kg in the prior 6 months Current participation in another clinical research trial Substance abuse, presence of an eating disorder or purging behaviour Known mental health illness requiring active treatment Known cognitive impairment Inability to understand conversational English Presence of type-1 or type-2 diabetes mellitus Use of carnosine or β-alanine supplements in the prior 6 months Current breastfeeding, pregnancy, or consideration of pregnancy Known comorbidities which may impact on study aims (e.g., cancer, heart failure, or chronic kidney disease) or measurement of study outcomes (e.g., sickle cell anaemia or previously known haemoglobinopathy) Use of weight loss or glucose lowering drugs (e.g., orlistat, thyroxine, metformin, insulin, glucagon-like-peptide-1 analogues), long-term corticosteroids, or other drugs which may impact on measurement of study outcomes

Research data will be deidentified and preserved for at least 10 years in an open-access data repository (e.g., Zenodo). This will allow anyone else (including other researchers and the general public) to also use the deidentified data for relevant analyses.