Nutrition Impact on PRGF Treatment for Tendinopathy

Given the close correlation reported in the literature between onset and progression of tendon pathology in subjects affected by the alteration of metabolic disorders such as obesity, diabetes mellitus and lipidic metabolic alterations, with the present study the association between the nutritional state, metabolic profile and clinical outcome of patients following treatment with blood-derived orthobiological for shoulder tendinopathies will be evaluated.

The primary aim of this study is to identify the proportion of tendinopatic patients responsive and non-responsive to treatment with "Platelet rich growth factors" PRGF at six months follow up and the correlation with their nutritional status.

This is a single-center, observational study with an additional procedure (extra blood sampling routine, food questionnaires, anthropometric measurements for the evaluation of nutritional status), prospective, uncontrolled.

Male and female patients, between 18 and 70 years old suffering from tendinopathy of the shoulder who undergo conservative regenerative medicine procedures with autologous PRGF material at the IRCCS Galeazzi-Sant'Ambrogio Hospital of Milan and participants in the observational study "Use of Patient- Reported Outcome Measures (PROMs), objective clinical assessments and biomolecular technologies for monitoring patients undergoing treatments regenerative medicine" \[REGAIN\] will be enrolled for this study.

46 patients will be needed:

1. 23 subjects with body mass index (BMI) between 18.5 and 25 therefore considered normal weight, who undergo treatment with PRGF;
2. 23 subjects with BMI values that exceed the considered range normal weight, therefore with BMI\>25, who undergo the PRGF treatment.

The general aim of the present study is to evaluate the correlation between the nutritional status of patients, the characteristics of the orthobiological product used for the treatment of shoulder tendon pathology and clinical outcomes after one-step conservative regenerative medicine treatment with PRGF in order to identify the ideal nutritional conditions to obtain the best clinical outcome from this type of treatment.

The primary objective of this study is to identify the proportion of tendinopatic patients responsive and non-responsive to treatment with orthobiological "Platelet rich growth factors" PRGF at six month follow up and the correlation with their nutritional status. To this end, responsive patients and non-responsive will be identified on the basis of the results of the VAS, ASES, Quick Dash, SPADI, WOOS scores, and Work index.

The secondary objectives of the study will be:

1) to Identify the proportion of responsive and non-responsive patients presenting shoulder tendinopathy to treatment with orthobiological "Platelet rich growth factors" PRGF at two and twelve months follow up and the correlation with their nutritional status. For this purpose, responsive and non-responsive patients will be identified on the basis of the results of the VAS, ASES, Quick Dash, SPADI scores, WOOS, and Work index.

Characterization of the PRGF product used for the treatment of each patient that will occur by qualitative and quantitative analysis of the content in extracellular vesicles, analysis of a panel of cytokines, chemokines and growth factors linked to inflammation and correlated to the state nutritional information of patients (e.g. resistin, P-selectin, interleukins etc.).

Eligibility Criteria:
Inclusion Criteria:

* Male and female
* Age ≥18 years and ≤ 70 years
* Patients presenting shoulder tendinopathy
* Signing of the Informed Consent of the Regain observational study
* Signature of informed consent of the present study.

Exclusion Criteria:

* Pregnancy (ascertained by self-declaration), breastfeeding
* Inability to follow the study protocol
* Heart, kidney, oncological disease
* Neuropsychiatric disease
* Other conditions that, at the discretion of the investigator or physician, exclude enrollement