AGE Accumulation in Patients on Long-term Parenteral Nutrition

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.

• Non-invasive skin AGE measurements (Other): Non-invasive skin AGE measurements at baseline, 6 and 12 months; collection and analysis of parenteral nutrition bag samples; routine metabolic assessments; dietary records, glucose holter, plasma glycated hemoglobin and fructosamine assays.

Primary outcomes

• Skin AGE levels [Baseline, 12 months]: Change in skin AGE levels between baseline and 12 months after initiation of parenteral nutrition (Visit M12).

Secondary outcomes

• Advanced Glycation End-products [6 months]: Compare skin AGE (Advanced Glycation End-products) levels with Age levels in parenteral nutrition bags (M6)
• Risk factors [Baseline, 6 months and 12 months]: Search for risk factors for AGE accumulation linked to dietary habits
• Skin AGE and metabolic/cardiovascular status [Baseline, 6 months and 12 months]: To investigate whether there is an association between skin AGE levels and the metabolic and cardiovascular status of patients.
• AGE and hyperglycaemic episodes [Baseline, 6 months and 12 months]: To investigate whether there is an association between skin AGE levels and the number, duration and intensity of hyperglycaemic episodes during parenteral nutrition infusion.

Sex: All

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.

• Florian POULLENOT, MD, Principal investigator, University Hospital, Bordeaux