This prospective and observational study aims to evaluate the accumulation of advanced glycation end-products (AGEs) in adult and pediatric patients starting long-term parenteral nutrition, by non-invasive skin AGE measurements over a 12-month follow-up.

Advanced Glycation End-products (AGEs) result from non-enzymatic glycation of proteins, lipids, or amino acids, and accumulate progressively with age, hyperglycemia, and oxidative stress. Their accumulation is associated with metabolic and cardiovascular complications in chronic diseases. Preliminary data suggest that patients on long-term parenteral nutrition may experience increased AGE accumulation due to high intravenous glucose exposure. However, prospective data evaluating AGE kinetics from the initiation of parenteral nutrition are lacking.

Skin AGE levels will be measured non-invasively at baseline, 6 months, and 12 months using the AGE Reader© device. Nutrition bag samples will be analyzed for AGE content via HPLC-MS.

Patients will be monitored during routine consultations every 6 months. Biological metabolic parameters (HbA1c, fructosamine, lipid profile), nutritional data, and 3-day dietary records will be collected at each time point. Samples from parenteral nutrition bags will be frozen at -20°C or colder and analyzed centrally after the last patient visit.

Inclusion Criteria:

• Patients (adults and children, all ages) initiating long-term parenteral nutrition
• Followed at CHU de Bordeaux or Robert Debré Hospital (APHP)
• Covered by French Social Security system
• Written informed consent obtained from patient (if adult) or legal guardian (if minor)

Exclusion Criteria:

• Fitzpatrick skin type ≥ V (darker skin tones)
• Forearm tattoos at the site of measurement
• For patients included under 1 year of age: patients born prematurely (before 37 weeks of amenorrhea)
• Pregnant or breastfeeding women.