Clinical Research Directory

Menstrual Cycle Mapping While Using Closed-Loop Insulin Delivery

The hypothesis is that menstrual cyclicity affects glucose and energy metabolism in women with type 1 diabetes. The rationale of the hypothesis on cycle effects builds on the assumption that fluctuations of female sex hormones across the menstrual cycle cause changes in physiological parameters of glucose metabolism and energy homeostasis and/or lifestyle aspects involved in the regulation of blood glucose and body weight. It is expected that hormone fluctuations affect insulin sensitivity, gastric emptying, eating behaviour and energy expenditure. It is anticipated that insulin sensitivity is highest in the pre-ovulatory phase and lowest in the mid-luteal phase. It is further expected that gastric emptying peaks in the follicular phase, and highest energy expenditure and dietary intake during the mid-luteal phase. The primary objective of this study is to characterize glucose and energy metabolism throughout the menstrual cycle in natural cycling women with type 1 diabetes. Further objectives are to assess the impact of the menstrual cycle on glucose control and insulin requirements, investigate how fluctuations in sex hormone levels influence glucose and energy metabolism, and quantify both inter- and intra-individual variability in metabolic changes related to the menstrual cycle. Additionally, the study will evaluate whether changes in key physiological components of glucose metabolism and behavioural factors mediate menstrual cycle-related variations in glucose control and insulin requirements.

Retrospective Monocentric Evaluation of Biomarkers Associated With Bone, Muscle and Energy Metabolism

Bone is a metabolically active tissue undergoing continuous remodeling through the coordinated actions of osteoclasts (resorption), osteoblasts (formation), and osteocytes (regulation). Under physiological conditions, bone formation and resorption are balanced and regulated by systemic hormones (PTH, vitamin D, estrogens) and local mediators. However, aging, metabolic disorders, physical inactivity, or pharmacological treatments may disrupt this equilibrium, leading to the predominance of one process over the other. Circulating biochemical markers of bone turnover-classified into formation markers (P1NP, osteocalcin, bone alkaline phosphatase) and resorption markers (CTx-I, NTx-I, DPD)-provide a means to monitor these dynamics. Beyond its mechanical role, bone also functions as an endocrine organ: osteocalcin, secreted by osteoblasts, modulates insulin secretion and sensitivity, linking bone to muscle and adipose tissue in the regulation of energy metabolism. Adipokines such as leptin and adiponectin further contribute to this complex crosstalk. Bone biomarkers are therefore essential for evaluating skeletal metabolism and identifying conditions such as osteoporosis, though the strict classification into formation versus resorption markers is limited, as some (e.g., osteocalcin) reflect both processes. This study aims to analyze IRCCS San Raffaele database records of urinary and serum biomarkers related to bone, muscle, and energy metabolism, to assess their trends and associations according to age and sex, and to develop statistical models capable of explaining their interrelationships.

Mapping Metabolic Organ Plasticity in Energy Adaptation

Brief Summary (Plain Language) Many people who lose weight experience a slowdown in their metabolism that is greater than expected. This response, called metabolic adaptation, makes it harder to continue losing weight or to keep weight off over time. The biological reasons for this slowdown are not fully understood. Some organs in the body, especially the liver and kidneys, use a large amount of energy even when the body is at rest. Although these organs make up only a small portion of body weight, they account for a large share of daily energy use. Changes in the size or function of these organs may play an important role in metabolic adaptation, but this has not been well studied in humans. The purpose of this study is to understand how different lifestyle approaches affect metabolic adaptation and the size of key metabolic organs. Specifically, the study compares three common strategies: * resistance training without calorie restriction, * a calorie-restricted diet, and * time-restricted eating (eating all daily food within a limited time window). Adults with overweight will take part in one of these approaches for 10 weeks. Before and after the study period, participants will undergo advanced measurements, including magnetic resonance imaging (MRI) scans to measure liver and kidney size, tests to measure resting metabolism, and assessments of body composition. Some participants will also undergo additional testing to measure daily energy use. By understanding how different lifestyle strategies influence metabolism and organ size, this study aims to improve knowledge about why weight loss is difficult to maintain and to support the development of more personalized approaches to long-term weight management.

Effects of Ketone Bodies on Insulin Sensitivity

KETO-SENSE is a clinical research study investigating how ketone bodies affect energy metabolism and insulin sensitivity in humans. Ketone bodies are naturally produced by the liver during fasting or prolonged exercise and can serve as an alternative fuel for the brain, heart, and muscles. In this study, ten overweight but otherwise healthy adults aged 55-70 years will participate in four study days at Aarhus University Hospital. Participants will receive one of four interventions in a randomized crossover design: 1) growth hormone (GH) and a ketone supplement, 2) GH and placebo, 3) a saline infusion with the ketone supplement, or 4) placebo (saline infusion and placebo supplement). The study uses advanced PET/CT imaging, indirect calorimetry, and tissue biopsies to measure how ketones influence fat breakdown, glucose uptake, and energy expenditure. By understanding these mechanisms, the study aims to clarify whether oral ketone supplementation can improve insulin sensitivity and energy metabolism - findings that could be relevant for common conditions such as overweight, insulin resistance, and type 2 diabetes.

Erythrocyte Transport of Lactate During Exercise (TELE Project)

The goals of this clinical trial are: 1. to study lactate kinetic between plasma and erythrocytes during an intervallic exercise and its subsequent recovery, considering the blood pH, the genotype for the T1470A polymorphism of the SLC16A1 gene (rs1049434), and the amount of MCT1 in erythrocytes membrane; 2. to analyze the levels of MCT1 in the erythrocytes membrane according to training status and genotype for the T1470A polymorphism of SLC16A1 (rs1049434). For this, the project will have two phases: * In phase I, trained participants will perform one maximal incremental test and one intervallic submaximal test with a final active recovery. * Phase II, levels of the MCT1 protein in the erythrocyte membrane will be quantified from trained and sedentary participants.

Technologies and Systems for Assessing Human Energy Metabolism and Nutritional Rehabilitation

The objective of this observational study is to integrate the doubly labeled water (DLW) database from healthy individuals with multimodal data-including, but not limited to, weight, height, age, sex, race, elevation-from cohorts undergoing rehabilitation following movement impairments or neurological injuries. Machine learning algorithms will be used to develop injury-specific predictive models of energy requirements. The primary research question is: How does energy metabolism change during the rehabilitation process in individuals recovering from traumatic brain injury, stroke, or major surgical procedures? To answer this, participants will undergo a comprehensive set of assessments, including measurements of height and weight, body composition, resting metabolic rate, physical activity levels, total energy expenditure, psychological health, food intake and hunger ratings, sleep quality, cognitive performance, non-invasive brain function monitoring, and gait analysis. Fecal and blood samples will also be collected for untargeted metabolomics analysis.

Validating a New Machine-Learned Accelerometer Algorithm Using Doubly Labeled Water

The purpose of this study is to validate previously developed physical function-clustered specific machine-learned accelerometer algorithms to estimate total daily energy expenditure (TDEE) in individuals with general movement and functional limitations.

Bionenergetic Balance During CVVH

The bioenergetic balance is the sum of energy exchanged during CRRT and is mostly defined by citrate glucose and lactate. When CRRT was performed with the older dialysis fluids, glucose and lactate could be an important source of energy next to citrate when used as predilution (6, 7). During continuous venovenous hemofiltration (CVVH), a subgroup of CRRT which is performed with the newer dialysis fluids without lactate or glucose as advocated by the KDIGOguidelines, glucose and in a minor way lactate mostly induce a loss of energy. The first aim is to determine how this bioenergetic balance impacts energy need compared to the measured energy with indirect calorimetry and how nutrition therapy needs to be adapted. Also, disease specific predicting equation have been created for patients suffering from acute kidney injury treated with renal replacement therapy. How this predicting equation and other existing predicting equations agree with the measured REE has not been validated yet. The second aim is to determine how predictive equations correlate with measured REE in patients treated with CVVH.