Fibroblast Growth Factor 21 Levels and Bone Mineral Density in Metabolically Healthy and Metabolically Unhealthy Obese Children

Objective: The harmful or beneficial effect of obesity on bone mineral density (BMD) remains controversial in children and adolescents. Fibroblast growth factor 21 (FGF21) is a metabolic factor that plays a specific role in the regulation of carbohydrate and lipid metabolism. However, the role of FGF21 in bone metabolism appears paradoxical and is complex. To determine whether serum FGF21 level was associated with BMD in obese children and adolescents. Methods: The study was conducted with the participation of children and adolescents aged 8-18 years. Ninety-eight obese children were included in the study group and 44 children were included in the control group. BMD, in addition to the routine obesity workup, which includes fasting blood glucose, fasting insulin levels, lipid profile, and liver enzymes; serum FGF21 levels have been analyzed. Results: The mean age of the obese group (n=98) was 13.34±2.24 years and the mean age of controls (n=44) was 13.48±2.87 years. Based on International Diabetes Federation criteria, 15 of 98 (15.3%) patients were metabolically unhealthy. FGF21 levels were 193.54±139.62 mg/dL in the obese group and 158.69±151.81 mg/dL in the control group (p=0.06). There was no difference between the FGF21 and BMD z-score values of girls and boys in the obese and control groups (p>0.05). Conclusion: BMD-z-score was increased in obese children compared to healthy control. Moreover, BMD-z-score tended to be higher when more metabolic risk factors were present. However, there was no significant relationship between FGF21 levels and BMD z-score values in obese children.

Comparison of bone scintigraphy and Ga-68 prostate-specific membrane antigen positron emission tomography/computed tomography in the detection of bone metastases of prostate carcinoma.

AIM: This study aims to assess the diagnostic performance of Ga-68 prostate-specific membrane antigen PET/computed tomography in the comparison of planar bone scintigraphy in the detection of bone metastases. Another purpose is to define the additional benefit of bone scintigraphy subsequent to prostate-specific membrane antigen PET/computed tomography and the role of prostate-specific membrane antigen PET/computed tomography in the treatment planning. MATERIAL AND METHOD: Forty-six patients with a median interval of 19 (range: 3-90) days between prostate-specific membrane antigen PET/computed tomography and bone scintigraphy included in the analysis. Diagnostic performance of both modalities was calculated and compared. RESULTS: Prostate-specific membrane antigen PET/computed tomography and bone scintigraphy were performed for initial staging in 25 (54%), for evaluation of biochemical recurrence in 11 (24%) and metastatic castration-resistant prostate carcinoma in 10 (22%) patients. In the patient-based analysis sensitivity, specificity, accuracy, positive predictive value, and negative predictive value for bone scintigraphy for detection of bone metastases were calculated as 50%, 19-29%, 32-39%, 32-39%, and 33-39%, respectively, based on whether equivocal findings were classified as positive or negative. For prostate-specific membrane antigen PET/computed tomography, these values were found significantly higher as 100%, 95-100%, 98-100%, 96-100%, and 100%, respectively. The diagnostic performance of bone scintigraphy and PET/computed tomography in clinical subgroups was analyzed, prostate-specific membrane antigen PET/computed tomography was superior to bone scintigraphy in three groups. CONCLUSION: In this retrospective study, prostate-specific membrane antigen PET/computed tomography was found to be superior to planar bone scintigraphy in the detection of bone metastases. Additional bone scintigraphy seems to be unnecessary in patients who underwent prostate-specific membrane antigen PET/computed tomography within three months period without additional treatment.

Risk Factors for Predicting Osteoporosis in Patients Who Receive Thyrotropin Suppressive Levothyroxine Treatment for Differentiated Thyroid Carcinoma

Objectives: Endogenous hyperthyroidism accelerates bone turnover and shortens the normal bone remodeling cycle, which results in reduced bone density. It is estimated that suppressive levothyroxine (LT4) therapy also decreases bone density. The aim of this study was to define risk factors for osteoporosis development in patients under thyrotropin-stimulating hormone (TSH) suppressive treatment for differentiated thyroid cancer (DTC). Methods: Patients with a diagnosis of low or intermediate risk group DTC according to the American Thyroid Association 2015 guidelines and who have been receiving LT4 suppression therapy and were physically fit to undergo femur and lumbar vertebra bone density study were included in the study. Patients lacking information on demographic data, medical history, preoperative thyroid hormone status, or routine follow-up data were excluded from the study. A study form consisting of patient information on possible risk factors for osteoporosis such as gender, age, menopausal status, smoking, family history of osteoporosis, preoperative thyroid hormone status, postoperative hypoparathyroidism history, mean serum TSH levels, and duration of TSH suppression was created and filled out for each participant. Bone mineral densitometries of the femur and lumbar vertebrae were measured along with serum vitamin D and parathyroid hormone levels. Results: During TSH suppression (mean 7.2±4.5 years, range: 1-26), osteoporosis was detected in 89 (9.6%) patients. The mean time to develop osteoporosis was significantly different in patients with or without a family history of osteoporosis (15.3±0.4 versus 20.3±0.6 years; p=0.002). Similarly, the mean time to develop osteoporosis for was found to be significantly shorter in postmenopausal patients than that for premenopausal women (18.6±0.7 versus 20.4±0.4 years; p<0.001). Male gender (p<0.001), a family history of osteoporosis (p=0.001) and menopausal state (p<0.001) were identified as independent predictive factors for developing osteoporosis. Conclusion: Postmenopausal women, men, and patients with a family history who receive TSH-suppression treatment have a tendency to develop osteoporosis.

The role of baseline Ga-68 DOTATATE positron emission tomography/computed tomography in the prediction of response to fixed-dose peptide receptor radionuclide therapy with Lu-177 DOTATATE.

BACKGROUND/AIM: To describe the role of baseline gallium (Ga)-68 DOTATATE positron emission tomography (PET)/computed tomography (CT) in the prediction of the response to peptide receptor radionuclide therapy (PRRT) using lutetium (Lu)-177 DOTATATE. MATERIALS AND METHODS: Analysis was made of baseline Ga-68 DOTATATE PET/CT images of 29 patients (17 females and 12 males; mean age: 50.7 ± 14.6 years) with metastatic neuroendocrine tumors who received PRRT with Lu-177 DOTATATE. Maximum standardized uptake values (SUVmax) of reference lesions and their ratios to physiological uptake organs were calculated. The relationship between these values and the radiological response was analyzed. RESULTS: Partial response was observed in 8 (28%) patients, stable disease in 18 (62%) patients, and progressive disease in 3 (10%) patients. Mean SUVmax of reference lesions was calculated as 23.8 ± 20.5 (min-max: 5.1-87.3). There was no significant correlation between radiological responses and SUVmax of reference lesions and their ratios to other organs. CONCLUSION: Baseline Ga-68 DOTATATE PET/CT helps to show somatostatin receptor expression status and disease stage in patients who are candidates for PRRT. However, SUVs do not have a role in the prediction of treatment response.

18F-NaF Positive Bone Metastases of Non 18F-FDG Avid Mucinous Gastric Cancer.

Detection of gastric cancer bone metastasis is crucial since its presence is an independent prognostic factor. In this case report, we would like to present 18F-NaF positive bone metastases of non 18F-FDG avid gastric mucinous cancer.