2.5. Awakening Cortisol and Analysis of Biomarkers in Blood 
TGF-β1
BLOOD, TRANSFORMING
The Cortisol Awakening Response (CAR) is the change in cortisol concentration that occurs in the first hour after waking from a night’s sleep [Blood samples for assessing biomarkers were collected at baseline and after 12 weeks. Serum and plasma were separated by centrifugation for 10 min at 3000 rpm at 4 °C. The samples were thereafter stored at −80 °C until analysis. The biomarkers assessed were Transforming Growth Factor β 1 (TGF-β1), galectin-3, fractalkine/CX3CL/CX3CL1, brain-derived neurotrophic factor (BDNF), tryptophan, L-kynurenine, and high-sensitivity C-reactive protein (hs-CRP). ELLA Protein Simple plex (BioTechne, Dublin, Ireland) was used to analyze BDNF (#898072, detection limit 9.4–36,000 pg/mL), fractalkine (#898143, detection limit 56.8–86,710 pg/mL), TGF-β1 (#898477, detection limit 20.8–12,684 pg/mL), and galectin-3 (#898088, detection limit 3.11–4741 pg/mL) in serum. Plasma levels of tryptophan and L-kynurenine were measured with commercially available ELISA kits (ImmuSmol, Bordeaux, France). The L-kynurenine kit (BA E-2200) had a detection limit of 45.7 ng/mL, and the tryptophan kit (BA E-2700) had a measuring range of 0.73–250 µg/mL. Hs-CRP was measured by the medical service at Skåne University Hospital (University and regional laboratories in Region Skåne, Sweden) using an immune turbidimetric analysis with a detection range between 0.16 and 10 mg/L. 