Clinical studies investigating the relationship between fibroblast growth factor 23 (FGF23) and bone mass are controversial, especially in the healthy renal population. Our study is one of the forefronts investigating the relationship between FGF23 and bone mass parameters in the general population, according to age, sex, menopausal, and nutritional status. Cross-sectional study enrolling 123 volunteers between 20–80 years of age without primary osteoporosis under treatment nor secondary osteoporosis, where bone mass (bone mineral density-BMD, bone mineral content-BMC; assessed by Dual X-Ray Absorptiometry-DXA), body composition (DXA evaluation), and also the serum levels of FGF23, parathormone (PTH), 25(OH)D, bone resorption marker C-terminal telopeptide of type I collagen (CTx) and leptin were determined. FGF23 was negatively and independently associated with BMD and/or BMC in all groups. FGF23 contributed to up to 10% (p <0.05) of femoral neck BMD variance in postmenopausal women, but was not an accurate discriminator of normal versus low bone mass (AUC=0.622±0.076). FGF23 did not correlate with 25(OH)D, CTx, body weight, body composition parameters or leptin. FGF23 was independently associated with PTH in premenopausal women and men only. FGF23 was negatively associated with bone mass parameters in both sexes, but was not a fine discriminator between normal bone mass and osteopenia/osteoporosis. The mechanism through which FGF23 acts upon the bone seems independent of the nutritional status, requiring further investigation.

Introduction: Data regarding the role of fibroblast growth factor 23 (FGF23) in primary hyperparathyroidism (PHPT) are scarce and discordant. Our study aimed to evaluate the prognostic impact of FGF23 upon the clinical and biochemical evolution of PHPT. Material and methods: Forty-two patients with ages between 30 and 80 years, diagnosed with PHPT caused by a sporadic, solitary parathyroid adenoma, and referred to surgery (minimally invasive parathyroidectomy) were prospectively included in the study. Serum levels of FGF23, PTH, 25(OH)D3, calcium (Ca), phosphate (P), total procollagen type 1 N-terminal propeptide, and C-terminal telopeptide of type I collagen were determined at baseline (preoperatory), one day after surgery, and in 13 patients also prospectively at three, six, and 12 months. Bone mineral density (BMD) was also evaluated before surgery in all patients and 12 months after surgery in the 13 followed up patients. Results: In the 42 PHPT patients with D hypovitaminosis (mean 25(OH)D3 levels of 16.2 ± 1.5 ng/mL), preoperatory serum FGF23 concentration was within the normal range (75.55 ± 3.39 pg/mL) and remained unchanged one day post operation (81.69 ± 4.67 pg/mL, p = non-significant). The 13 patients followed prospectively for up to 12 months after surgery also showed unmodified FGF23 levels (80.9 ± 11.03 pg/mL, p = non-significant), despite PTH and Ca normalisation and vitamin D replenishment. Preoperatory FGF23 negatively correlated with PTH (r =-0.37, p = 0.038), but not with 25(OH)D3, Ca, P, bone mass, or metabolism markers. Conclusions: In PHPT, correlations between FGF23 and PTH seem rather an epiphenomenon. Therefore, we think that FGF23 evaluation and dynamics are not informative regarding PHPT severity.

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25Background. Numerous studies associate adipokines with colorectal malignancy, but few data deal with 26 patients suffering exclusively of rectal carcinoma (RC). Aims. We evaluated leptin and adiponectin levels 27 in RC patients compared to healthy population and their dynamics after surgery. Material and methods. 28 Serum leptin and adiponectin were evaluated before surgery in 59 RC consecutive patients (38 males and 29 21 females), and in age and weight matched healthy controls. Measurements were repeated at 24, 72 30 hours and 7 days after surgery. Results. Adipokine levels were higher in women. Controls had higher 31 leptin (32.±4.34 vs 9.51±1.73 ng/ml in women and 11±2.66 vs 2.54±0.39 ng/ml in men, p=0.00048 and 32 0.0032) and lower adiponectin (9±0.64 vs 11.85±1.02 µg/ml in women and 7.39±0.51 vs 8.5±0.62 µg/ml 33 in men, p=0.017 and 0.019) than RC patients. Surgery caused an increase of leptin from 5.11±0.8 to 34 18.7±2.42 ng/ml, p=6.85 x 10¨⁸, and a decrease of adiponectin from 9.71±0.58 to 7.87±0.47 µg/ml, p=1.4 35 x 10¨¹⁰ for all RC patients and returned thereafter to the initial range at 7 days. Adipokines were 36 correlated with body weight (BW). The significance of correlation persisted after surgery only in males, 37 but disappeared in females. Adipokines were not modified by tumor position, presurgical 38 chemoradiotherapy or surgical technique. Women with RC experiencing weight loss had higher 39 adiponectin than women without weight modifications (p<0.05 at all time points). Conclusions. 40 Adipokine levels of patients with RC differ from the healthy population, possibly reflecting an adaptation 41 to disease. Adipokine modifications after surgery may be related to acute surgical stress. Whether leptin 42 and adiponectin directly interact is not clear. Women have higher adipokine levels, more so after 43 significant weight loss, but the strength of their correlation with BW decreases after surgery. These data 44 suggest gender differences in the adipokine profile of RC patients which may find clinical applications. 45 46 69 neoplasia is the carcinoma located in the rectal region (rectal carcinoma, RC) which is usually not 70 accompanied by cachexia, a problem that might affect changes in adipokines. 71The aims of our study were therefore to observe differences in leptin and adiponectin levels 72 between patients suffering of RC operated in the same surgical center and healthy age, weight and 73 gender-matched controls. We also intended to follow the evolution of leptin and adiponectin after surgery 74 and at distance, at different time points. 157(low, right). Correlation was considered significant at p values lower than 0.05. NS = non-significant.

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