Harmonization of maternal balanced energy-protein supplementation studies for individual participant data (IPD) meta-analyses - finding and creating similarities in variables and data collection.

BACKGROUND: Public health and clinical recommendations are established from systematic reviews and retrospective meta-analyses combining effect sizes, traditionally, from aggregate data and more recently, using individual participant data (IPD) of published studies. However, trials often have outcomes and other meta-data that are not defined and collected in a standardized way, making meta-analysis problematic. IPD meta-analysis can only partially fix the limitations of traditional, retrospective, aggregate meta-analysis; prospective meta-analysis further reduces the problems. METHODS: We developed an initiative including seven clinical intervention studies of balanced energy-protein (BEP) supplementation during pregnancy and/or lactation that are being conducted (or recently concluded) in Burkina Faso, Ethiopia, India, Nepal, and Pakistan to test the effect of BEP on infant and maternal outcomes. These studies were commissioned after an expert consultation that designed recommendations for a BEP product for use among pregnant and lactating women in low- and middle-income countries. The initiative goal is to harmonize variables across studies to facilitate IPD meta-analyses on closely aligned data, commonly called prospective meta-analysis. Our objective here is to describe the process of harmonizing variable definitions and prioritizing research questions. A two-day workshop of investigators, content experts, and advisors was held in February 2020 and harmonization activities continued thereafter. Efforts included a range of activities from examining protocols and data collection plans to discussing best practices within field constraints. Prior to harmonization, there were many similar outcomes and variables across studies, such as newborn anthropometry, gestational age, and stillbirth, however, definitions and protocols differed. As well, some measurements were being conducted in several but not all studies, such as food insecurity. Through the harmonization process, we came to consensus on important shared variables, particularly outcomes, added new measurements, and improved protocols across studies. DISCUSSION: We have fostered extensive communication between investigators from different studies, and importantly, created a large set of harmonized variable definitions within a prospective meta-analysis framework. We expect this initiative will improve reporting within each study in addition to providing opportunities for a series of IPD meta-analyses.

Enhancing Nutrition and Antenatal Infection Treatment (ENAT) study: protocol of a pragmatic clinical effectiveness study to improve birth outcomes in Ethiopia.

INTRODUCTION: The WHO Nutrition Target aims to reduce the global prevalence of low birth weight by 30% by the year 2025. The Enhancing Nutrition and Antenatal Infection Treatment (ENAT) study will test the impact of packages of pregnancy interventions to enhance maternal nutrition and infection management on birth outcomes in rural Ethiopia. METHODS AND ANALYSIS: ENAT is a pragmatic, open-label, 2×2 factorial, randomised clinical effectiveness study implemented in 12 rural health centres in Amhara, Ethiopia. Eligible pregnant women presenting at antenatal care (ANC) visits at <24 weeks gestation are enrolled (n=2400). ANC quality is strengthened across all centres. Health centres are randomised to receive an enhanced nutrition package (ENP) or standard nutrition care, and within each health centre, individual women are randomised to receive an enhanced infection management package (EIMP) or standard infection care. At ENP centres, women receive a regular supply of adequately iodised salt and iron-folate (IFA), enhanced nutrition counselling and those with mid-upper arm circumference of <23 cm receive a micronutrient fortified balanced energy protein supplement (corn soya blend) until delivery. In standard nutrition centres, women receive routine counselling and IFA. EIMP women have additional screening/treatment for urinary and sexual/reproductive tract infections and intensive deworming. Non-EIMP women are managed syndromically per Ministry of Health Guidelines. Participants are followed until 1-month post partum, and a subset until 6 months. The primary study outcomes are newborn weight and length measured at <72 hours of age. Secondary outcomes include preterm birth, low birth weight and stillbirth rates; newborn head circumference; infant weight and length for age z-scores at birth; maternal anaemia; and weight gain during pregnancy. ETHICS AND DISSEMINATION: ENAT is approved by the Institutional Review Boards of Addis Continental Institute of Public Health (001-A1-2019) and Mass General Brigham (2018P002479). Results will be disseminated to local and international stakeholders. REGISTRATION NUMBER: ISRCTN15116516.

Effect of birthweight measurement quality improvement on low birthweight prevalence in rural Ethiopia.

BACKGROUND: Low birthweight (LBW) (< 2500 g) is a significant determinant of infant morbidity and mortality worldwide. In low-income settings, the quality of birthweight data suffers from measurement and recording errors, inconsistent data reporting systems, and missing data from non-facility births. This paper describes birthweight data quality and the prevalence of LBW before and after implementation of a birthweight quality improvement (QI) initiative in Amhara region, Ethiopia. METHODS: A comparative pre-post study was performed in selected rural health facilities located in West Gojjam and South Gondar zones. At baseline, a retrospective review of delivery records from February to May 2018 was performed in 14 health centers to collect birthweight data. A birthweight QI initiative was introduced in August 2019, which included provision of high-quality digital infant weight scales (precision 5 g), routine calibration, training in birth weighing and data recording, and routine field supervision. After the QI implementation, birthweight data were prospectively collected from late August to early September 2019, and December 2019 to June 2020. Data quality, as measured by heaping (weights at exact multiples of 500 g) and rounding to the nearest 100 g, and the prevalence of LBW were calculated before and after QI implementation. RESULTS: We retrospectively reviewed 1383 delivery records before the QI implementation and prospectively measured 1371 newborn weights after QI implementation. Heaping was most frequently observed at 3000 g and declined from 26% pre-initiative to 6.7% post-initiative. Heaping at 2500 g decreased from 5.4% pre-QI to 2.2% post-QI. The percentage of rounding to the nearest 100 g was reduced from 100% pre-initiative to 36.5% post-initiative. Before the QI initiative, the prevalence of recognized LBW was 2.2% (95% confidence interval [CI]: 1.5-3.1) and after the QI initiative increased to 11.7% (95% CI: 10.1-13.5). CONCLUSIONS: A QI intervention can improve the quality of birthweight measurements, and data measurement quality may substantially affect estimates of LBW prevalence.

Author Correction: Effect of carnosine supplementation on the plasma lipidome in overweight and obese adults: a pilot randomised controlled trial.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Associations between Urinary Advanced Glycation End Products and Cardiometabolic Parameters in Metabolically Healthy Obese Women.

Advanced glycation end products (AGEs) have been implicated in the pathophysiology of type 2 diabetes and cardiovascular disease. We aimed to determine the associations of urinary carboxymethyl-lysine (CML) and methylglyoxal-hydroimidazolone (MG-H1) levels with cardiometabolic parameters in metabolically healthy obese women. Anthropometric, glycemic, cardiovascular, and urinary AGE parameters were measured in 58 metabolically healthy obese women (age: 39.98 ± 8.72 years; body mass index (BMI): 32.29 ± 4.05 kg/m2). Urinary CML levels were positively associated with BMI (r = 0.29, p = 0.02). After adjustment for age and BMI, there was a trend for positive associations between urinary CML levels and fasting (p = 0.06) and 2 h insulin (p = 0.05) levels, and insulin resistance measured by homeostatic model assessment (HOMA-IR) (p = 0.06). Urinary MG-H1 levels were positively associated with systolic and diastolic blood pressure, pulse pressure, mean arterial pressure, and total and low-density lipoprotein cholesterol after adjustment for age, BMI, and HOMA-IR (all p ˂ 0.05). There were no associations between urinary CML levels and cardiovascular parameters, and between urinary MG-H1 levels and glycemic measurements. Our data support a role of urinary AGEs in the pathophysiology of insulin resistance and cardiovascular disease; however, future studies are highly warranted.

Burden and trend of diet-related non-communicable diseases in Australia and comparison with 34 OECD countries, 1990-2015: findings from the Global Burden of Disease Study 2015.

BACKGROUND: Diet is a major determining factor for many non-communicable chronic diseases (NCDs). However, evidence on diet-related NCD burden remains limited. We assessed the trends in diet-related NCDs in Australia from 1990 to 2015 and compared the results with other countries of the Organization for Economic Co-operation and Development (OECD). METHODS: We used data and methods from the Global Burden of Disease (GBD) 2015 study to estimate the NCD mortality and disability-adjusted life years (DALYs) attributable to 14 dietary risk factors in Australia and 34 OECD nations. Countries were further ranked from the lowest (first) to highest (35th) burden using an age-standardized population attributable fraction (PAF). RESULTS: In 2015, the estimated number of deaths attributable to dietary risks was 29,414 deaths [95% uncertainty interval (UI) 24,697 - 34,058 or 19.7% of NCD deaths] and 443,385 DALYs (95% UI 377,680-511,388 or 9.5% of NCD DALYs) in Australia. Young (25-49 years) and middle-age (50-69 years) male adults had a higher PAF of diet-related NCD deaths and DALYs than their female counterparts. Diets low in fruits, vegetables, nuts and seeds and whole grains, but high in sodium, were the major contributors to both NCD deaths and DALYs. Overall, 42.3% of cardiovascular deaths were attributable to dietary risk factors. The age-standardized PAF of diet-related NCD mortality and DALYs decreased over the study period by 28.2% (from 27.0% in 1990 to 19.4% in 2015) and 41.0% (from 14.3% in 1990 to 8.4% in 2015), respectively. In 2015, Australia ranked 12th of 35 examined countries in diet-related mortality. A small improvement of rank was recorded compared to the previous 25 years. CONCLUSIONS: Despite a reduction in diet-related NCD burden over 25 years, dietary risks are still the major contributors to a high burden of NCDs in Australia. Interventions targeting NCDs should focus on dietary behaviours of individuals and population groups.

Carnosine supplementation reduces plasma soluble transferrin receptor in healthy overweight or obese individuals: a pilot randomised trial.

Abnormalities of iron homeostasis have been linked to insulin resistance, type 2 diabetes and cardiovascular disease. Carnosine, an over-the-counter food supplement with chelating properties, has been shown to decrease serum iron and improve glucose metabolism in diabetic rodents. We have previously demonstrated that carnosine supplementation prevented worsening of glucose metabolism in healthy overweight and obese middle-aged adults. Yet, the impact of carnosine on markers of iron metabolism in humans has not been investigated. We aimed to determine whether carnosine supplementation has an effect on iron parameters in overweight and obese, otherwise healthy adults. We included 26 participants, who were randomly allocated to receive 1 g carnosine (n = 14) or identical placebo (n = 12) twice daily for 12 weeks. Iron parameters including iron, ferritin, transferrin, soluble transferrin receptor, total iron binding capacity and iron saturation were measured in serum or plasma by standard commercial assays. Carnosine supplementation decreased plasma soluble transferrin receptor compared to placebo (mean change difference ± standard error: - 0.07 ± 0.03 mg/l, p = 0.04). None of the other iron parameters were different between carnosine and placebo groups. At follow-up, soluble transferrin receptor was associated inversely with urinary carnosine concentrations and positively with serum carnosinase-1 activity (both p < 0.02). Our findings suggest that carnosine may modulate iron metabolism in high-risk groups which could ameliorate insulin resistance and prevent type 2 diabetes. Larger human clinical trials are required to confirm our results.

Carnosine Supplementation Improves Serum Resistin Concentrations in Overweight or Obese Otherwise Healthy Adults: A Pilot Randomized Trial.

Adipokines play an important role in the regulation of glucose metabolism. We have previously shown that carnosine supplementation in overweight or obese non-diabetic individuals improves glucose metabolism but does not change adiponectin concentrations. However, its effect on other adipokines has not been investigated. Herein we further determined the effect of carnosine supplementation on serum adipsin, resistin and leptin. Twenty-two overweight or obese otherwise healthy adults were randomly assigned to receive either 2 g of carnosine (n = 13) or identically looking placebo (n = 9) for 12 weeks. Serum adipsin, leptin and resistin were analyzed using a bead-based multiplex assay. Carnosine supplementation decreased serum resistin concentrations compared to placebo (mean change from baseline: -35 ± 83 carnosine vs. 35 ± 55 ng/mL placebo, p = 0.04). There was a trend for a reduction in serum leptin concentrations after carnosine supplementation (-76 ± 165 ng/mL carnosine vs. 20 ± 28 ng/mL placebo, p = 0.06). The changes in leptin and resistin concentrations were inversely related to the change in concentration for urinary carnosine (r = -0.72, p = 0.0002; r = -0.67, p = 0.0009, respectively), carnosine-propanal (r = -0.56, p = 0.005; r = -0.63, p = 0.001, respectively) and carnosine-propanol (r = -0.61, p = 0.002; r = -0.60, p = 0.002, respectively). There were no differences between groups in change in adipsin concentrations. Our findings show carnosine supplementation may normalize some, but not all, of the serum adipokine concentrations involved in glucose metabolism, in overweight and obese individuals. Further clinical trials with larger samples are needed to confirm these results.

Effect of carnosine supplementation on the plasma lipidome in overweight and obese adults: a pilot randomised controlled trial.

Carnosine has been shown to reduce oxidation and glycation of low density lipoprotein hence improving dyslipidaemia in rodents. The effect of carnosine on human plasma lipidome has thus far not been investigated. We aimed to determine whether carnosine supplementation improves the plasma lipidome in overweight and obese individuals. Lipid analysis was performed by liquid chromatography mass spectrometry in 24 overweight and obese adults: 13 were randomly assigned to 2 g carnosine daily and 11 to placebo, and treated for 12 weeks. Carnosine supplementation maintained trihexosylceramide (0.01 ± 0.19 vs -0.28 ± 0.34 nmol/ml, p = 0.04), phosphatidylcholine (77 ± 167 vs -81 ± 196 nmol/ml, p = 0.01) and free cholesterol (20 ± 80 vs -69 ± 80 nmol/ml, p = 0.006) levels compared to placebo. Trihexosylceramide was inversely related with fasting insulin (r = -0.6, p = 0.002), insulin resistance (r = -0.6, p = 0.003), insulin secretion (r = -0.4, p = 0.05) and serum carnosinase 1 activity (r = -0.3, p = 0.05). Both phosphatidylcholine and free cholesterol did not correlate with any cardiometabolic parameters. Our data suggest that carnosine may have beneficial effects on the plasma lipidome. Future larger clinical trials are needed to confirm this.

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.

INTRODUCTION: Carnosine, an over-the-counter food supplement, has a promising potential for the prevention and treatment of chronic diseases such as type 2 diabetes (T2DM), cardiovascular and neurodegenerative diseases through its anti-inflammatory, antiglycation, antioxidative and chelating effects. We have previously shown that supplementation with carnosine preserves insulin sensitivity and secretion in non-diabetic overweight and obese individuals. The effect of carnosine on cardiometabolic risk and related cognitive outcomes in patients with pre-diabetes and T2DM has thus far not been studied. We therefore aim to investigate whether supplementation with carnosine improves cardiometabolic health and cognitive function in patients with pre-diabetes and T2DM. METHODS AND ANALYSIS: We will employ a parallel design randomised controlled trial. Fifty participants with pre-diabetes (impaired fasting glycaemia and impaired glucose tolerance) and T2DM (with HbA1c level < 8%) aged between 18 to 70 years will be randomly assigned to the intervention or control group. At baseline, participants will undergo a medical review and series of tests including anthropometric measurements (body mass index, a dual X-ray absorptiometry and peripheral quantitative computed tomography scan), an oral glucose tolerance test, cardiovascular measurements (central blood pressure, endothelial function and arterial stiffness), cognitive function, physical activity measurement, heart rate variability and liver fibroscan as well as questionnaires to assess dietary habits, sleep quality, depression and quality of life. The intervention group will receive 2 g of carnosine daily in two divided doses while the control group will receive identical placebo capsules for 14 weeks. All baseline measurements will be repeated at the end of the intervention. The change in glycaemic, cardiovascular and cognitive parameters as well as other measures will be compared between the groups. ETHICS AND DISSEMINATION: This study is approved by the Human Research Ethics Committee of Monash Health and Monash University, Australia. The findings will be disseminated via peer-reviewed publications and conference presentations. TRIAL REGISTRATION: NCT02917928; Pre-results.

Health Effects of Overweight and Obesity in 195 Countries over 25 Years.

BACKGROUND: Although the rising pandemic of obesity has received major attention in many countries, the effects of this attention on trends and the disease burden of obesity remain uncertain. METHODS: We analyzed data from 68.5 million persons to assess the trends in the prevalence of overweight and obesity among children and adults between 1980 and 2015. Using the Global Burden of Disease study data and methods, we also quantified the burden of disease related to high body-mass index (BMI), according to age, sex, cause, and BMI in 195 countries between 1990 and 2015. RESULTS: In 2015, a total of 107.7 million children and 603.7 million adults were obese. Since 1980, the prevalence of obesity has doubled in more than 70 countries and has continuously increased in most other countries. Although the prevalence of obesity among children has been lower than that among adults, the rate of increase in childhood obesity in many countries has been greater than the rate of increase in adult obesity. High BMI accounted for 4.0 million deaths globally, nearly 40% of which occurred in persons who were not obese. More than two thirds of deaths related to high BMI were due to cardiovascular disease. The disease burden related to high BMI has increased since 1990; however, the rate of this increase has been attenuated owing to decreases in underlying rates of death from cardiovascular disease. CONCLUSIONS: The rapid increase in the prevalence and disease burden of elevated BMI highlights the need for continued focus on surveillance of BMI and identification, implementation, and evaluation of evidence-based interventions to address this problem. (Funded by the Bill and Melinda Gates Foundation.).

Effect of dietary advanced glycation end products on inflammation and cardiovascular risks in healthy overweight adults: a randomised crossover trial.

Diets high in advanced glycation end products (AGEs) are thought to be detrimental to cardiovascular health. However, there remains uncertainty about the beneficial effect of a low AGE diet on cardiovascular risk factors and inflammatory markers in overweight individuals. We thus performed a randomised, double blind, crossover trial to determine whether consumption of low AGE diets reduce inflammation and cardiovascular risks in overweight and obese otherwise healthy adults. All participants (n = 20) consumed low and high AGE diets alternately for two weeks and separated by a four week washout period. Low AGE diets did not change systolic (p = 0.2) and diastolic blood pressure (p = 0.3), mean arterial pressure (p = 0.8) and pulse pressure (p = 0.2) compared to high AGE diets. Change in total cholesterol (p = 0.3), low-density lipoprotein (p = 0.7), high-density lipoprotein (p = 0.2), and triglycerides (p = 0.4) also did not differ and there was no difference in inflammatory markers: interleukin-6 (p = 0.6), monocyte chemoattractant protein-1 (p = 0.9), tumour necrosis factor α (p = 0.2), C-reactive protein (p = 0.6) and nuclear factor kappa beta (p = 0.2). These findings indicate that consumption of low AGE diets for two weeks did not improve the inflammatory and cardiovascular profiles of overweight and obese adults.

Treatment with high dose salicylates improves cardiometabolic parameters: Meta-analysis of randomized controlled trials.

INTRODUCTION: There is conflicting evidence regarding the efficacy of high dose salicylates in improving cardiometabolic risk in healthy and type 2 diabetes patients. We aimed to determine whether treatment with salicylates at an anti-inflammatory dose (≥1g daily) would improve cardiometabolic risk in healthy individuals and type 2 diabetes patients, compared to placebo. METHODS: Medline, Medline-in-process, Embase, and all EBM databases were searched for studies published up to December 2016. Twenty-eight articles from 24 studies comprising 1591 participants were included. Two reviewers independently assessed the risk of bias and extracted data from included studies. Meta-analyses using random-effects model were used to analyze the data. RESULTS: High dose salicylates (≥3g/d) decreased fasting glucose (MD -0.4mmol/l, 95% CI -0.54, -0.27) and glucose area under the curve (MD -0.41mmol/l, 95% CI -0.81, -0.01). Salicylates (≥3g/d) also increased fasting insulin (MD 2.4 µU/ml, 95% CI 0.3, 4.4), 2-h insulin (MD 25.4 µU/ml, 95% CI 8.2, 42.6), insulin secretion (MD 79.2, 95% CI 35, 123) but decreased fasting C-peptide (MD -0.11nmol/l, 95% CI -0.2, -0.04), insulin clearance (MD -0.26l/min, 95% CI -0.36, -0.16) and triglycerides (MD -0.36mmol/l, 95% CI -0.51, -0.21) and increased total adiponectin (MD 1.97µg/ml, 95% CI 0.99, 2.95). A lower salicylate dose (1-2.9g) did not change any cardiometabolic parameters (p>0.1). No significant difference was observed between those receiving salicylates and placebo following withdrawal due to adverse events. CONCLUSIONS: High dose salicylates appear to improve cardiometabolic risk factors in healthy individuals and type 2 diabetes patients. PROSPERO REGISTRATION NUMBER: CRD42015029826.

Consumption of diets with low advanced glycation end products improves cardiometabolic parameters: meta-analysis of randomised controlled trials.

Studies examining the effects of consumption of diets low in advanced glycation end products (AGEs) on cardiometabolic parameters are conflicting. Hence, we performed a meta-analysis to determine the effect of low AGE diets in reducing cardiometabolic risk factors. Seventeen randomised controlled trials comprising 560 participants were included. Meta-analyses using random effects models were used to analyse the data. Low AGE diets decreased insulin resistance (mean difference [MD] -1.3, 95% CI -2.3, -0.2), total cholesterol (MD -8.5 mg/dl, 95% CI -9.5, -7.4) and low-density lipoprotein (MD -2.4 mg/dl, 95% CI -3.4, -1.3). There were no changes in weight, fasting glucose, 2-h glucose and insulin, haemoglobin A1c, high-density lipoprotein or blood pressure. In a subgroup of patients with type 2 diabetes, a decrease in fasting insulin (MD -7 µU/ml, 95% CI -11.5, -2.5) was observed. Tumour necrosis factor α, vascular cell adhesion molecule-1, 8-isoprostane, leptin, circulating AGEs and receptor for AGEs were reduced after consumption of low AGE diets with increased adiponectin and sirtuin-1. Our findings suggest that diets low in AGEs may be an effective strategy for improving cardiometabolic profiles in individuals with and without type 2 diabetes.

Child and Adolescent Health From 1990 to 2015: Findings From the Global Burden of Diseases, Injuries, and Risk Factors 2015 Study.

Importance: Comprehensive and timely monitoring of disease burden in all age groups, including children and adolescents, is essential for improving population health. Objective: To quantify and describe levels and trends of mortality and nonfatal health outcomes among children and adolescents from 1990 to 2015 to provide a framework for policy discussion. Evidence Review: Cause-specific mortality and nonfatal health outcomes were analyzed for 195 countries and territories by age group, sex, and year from 1990 to 2015 using standardized approaches for data processing and statistical modeling, with subsequent analysis of the findings to describe levels and trends across geography and time among children and adolescents 19 years or younger. A composite indicator of income, education, and fertility was developed (Socio-demographic Index [SDI]) for each geographic unit and year, which evaluates the historical association between SDI and health loss. Findings: Global child and adolescent mortality decreased from 14.18 million (95% uncertainty interval [UI], 14.09 million to 14.28 million) deaths in 1990 to 7.26 million (95% UI, 7.14 million to 7.39 million) deaths in 2015, but progress has been unevenly distributed. Countries with a lower SDI had a larger proportion of mortality burden (75%) in 2015 than was the case in 1990 (61%). Most deaths in 2015 occurred in South Asia and sub-Saharan Africa. Global trends were driven by reductions in mortality owing to infectious, nutritional, and neonatal disorders, which in the aggregate led to a relative increase in the importance of noncommunicable diseases and injuries in explaining global disease burden. The absolute burden of disability in children and adolescents increased 4.3% (95% UI, 3.1%-5.6%) from 1990 to 2015, with much of the increase owing to population growth and improved survival for children and adolescents to older ages. Other than infectious conditions, many top causes of disability are associated with long-term sequelae of conditions present at birth (eg, neonatal disorders, congenital birth defects, and hemoglobinopathies) and complications of a variety of infections and nutritional deficiencies. Anemia, developmental intellectual disability, hearing loss, epilepsy, and vision loss are important contributors to childhood disability that can arise from multiple causes. Maternal and reproductive health remains a key cause of disease burden in adolescent females, especially in lower-SDI countries. In low-SDI countries, mortality is the primary driver of health loss for children and adolescents, whereas disability predominates in higher-SDI locations; the specific pattern of epidemiological transition varies across diseases and injuries. Conclusions and Relevance: Consistent international attention and investment have led to sustained improvements in causes of health loss among children and adolescents in many countries, although progress has been uneven. The persistence of infectious diseases in some countries, coupled with ongoing epidemiologic transition to injuries and noncommunicable diseases, require all countries to carefully evaluate and implement appropriate strategies to maximize the health of their children and adolescents and for the international community to carefully consider which elements of child and adolescent health should be monitored.

Carnosine and the processes of ageing.

The causes of ageing are usually regarded as multifactorial; thus effective regulation might be achieved by intervention at multiple sites. It has been suggested that the endogenous dipeptide carnosine, also available as a food supplement, possesses anti-ageing activity and may achieve its reported age-alleviating effects via a number of mechanisms. Carnosine's possible anti-ageing mechanisms are therefore discussed; the evidence suggests that inhibition of the mechanistic target of rapamycin and carbonyl scavenging may be involved.

Physiological and therapeutic effects of carnosine on cardiometabolic risk and disease.

Obesity, type 2 diabetes (T2DM) and cardiovascular disease (CVD) are the most common preventable causes of morbidity and mortality worldwide. They represent major public health threat to our society. Increasing prevalence of obesity and T2DM contributes to escalating morbidity and mortality from CVD and stroke. Carnosine (ß-alanyl-L-histidine) is a dipeptide with anti-inflammatory, antioxidant, anti-glycation, anti-ischaemic and chelating roles and is available as an over-the-counter food supplement. Animal evidence suggests that carnosine may offer many promising therapeutic benefits for multiple chronic diseases due to these properties. Carnosine, traditionally used in exercise physiology to increase exercise performance, has potential preventative and therapeutic benefits in obesity, insulin resistance, T2DM and diabetic microvascular and macrovascular complications (CVD and stroke) as well as number of neurological and mental health conditions. However, relatively little evidence is available in humans. Thus, future studies should focus on well-designed clinical trials to confirm or refute a potential role of carnosine in the prevention and treatment of chronic diseases in humans, in addition to advancing knowledge from the basic science and animal studies.