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Tevfik Demir

Bursa Uludağ Üni̇versi̇tesi̇

ORCID: 0000-0003-0319-9572

Publishes on Thyroid Disorders and Treatments, Adrenal and Paraganglionic Tumors, Thyroid Cancer Diagnosis and Treatment. 189 papers and 2.4k citations.

189Publications
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A phase IIa active-comparator-controlled study to evaluate the efficacy and safety of efinopegdutide in patients with non-alcoholic fatty liver disease
Manuel Romero‐Gómez, Eric Lawitz, R. Ravi Shankar et al.|Journal of Hepatology|2023
Cited by 185Open Access

•There are no approved therapies for fatty liver disease.•Dual glucagon/glucagon-like peptide-1 receptor agonism may be beneficial.•Efinopegdutide (dual agonist) improved liver fat content compared with semaglutide.•Efinopegdutide’s tolerability profile was similar to that of semaglutide.•Efinopegdutide may be an effective treatment for fatty liver disease. Background & AimsThis study assessed the effects of the glucagon-like peptide-1 (GLP-1)/glucagon receptor co-agonist efinopegdutide relative to the selective GLP-1 receptor agonist semaglutide on liver fat content (LFC) in patients with non-alcoholic fatty liver disease (NAFLD).MethodsThis was a phase IIa, randomized, active-comparator-controlled, parallel-group, open-label study. A magnetic resonance imaging-estimated proton density fat fraction assessment was performed to determine LFC at screening and Week 24. Participants with an LFC of ≥10% at screening were randomized 1:1 to efinopegdutide 10 mg or semaglutide 1 mg, both administered subcutaneously once weekly for 24 weeks. Participants were stratified according to the concurrent diagnosis of type 2 diabetes mellitus (T2DM). Both drugs were titrated to the target dose over an 8-week time period. The primary efficacy endpoint was relative reduction from baseline in LFC (%) after 24 weeks of treatment.ResultsAmong 145 randomized participants (efinopegdutide n = 72, semaglutide n = 73), 33.1% had T2DM. At baseline, mean BMI was 34.3 kg/m2 and mean LFC was 20.3%. The least squares (LS) mean relative reduction from baseline in LFC at Week 24 was significantly (p <0.001) greater with efinopegdutide (72.7% [90% CI 66.8–78.7]) than with semaglutide (42.3% [90% CI 36.5–48.1]). Both treatment groups had an LS mean percent reduction from baseline in body weight at Week 24 (efinopegdutide 8.5% vs. semaglutide 7.1%; p = 0.085). Slightly higher incidences of adverse events and drug-related adverse events were observed in the efinopegdutide group compared with the semaglutide group, primarily related to an imbalance in gastrointestinal adverse events.ConclusionsIn patients with NAFLD, treatment with efinopegdutide 10 mg weekly led to a significantly greater reduction in LFC than semaglutide 1 mg weekly.Clinical Trial NumberEudraCT: 2020-005136-30; NCT: 04944992.Impact and implicationsCurrently, there are no approved therapies for non-alcoholic steatohepatitis (NASH). The weight loss associated with glucagon-like peptide-1 (GLP-1) receptor agonists has been shown to decrease hepatic inflammation in patients with NASH. In addition to reducing liver fat content (LFC) indirectly through weight loss, glucagon receptor agonism may also reduce LFC by acting on the liver directly to stimulate fatty acid oxidation and reduce lipogenesis. This study demonstrated that treatment of patients with non-alcoholic fatty liver disease with the GLP-1/glucagon receptor co-agonist efinopegdutide (10 mg weekly) led to a significantly greater reduction in LFC compared to treatment with the GLP-1 receptor agonist semaglutide (1 mg weekly), suggesting that efinopegdutide may be an effective treatment for NASH. This study assessed the effects of the glucagon-like peptide-1 (GLP-1)/glucagon receptor co-agonist efinopegdutide relative to the selective GLP-1 receptor agonist semaglutide on liver fat content (LFC) in patients with non-alcoholic fatty liver disease (NAFLD). This was a phase IIa, randomized, active-comparator-controlled, parallel-group, open-label study. A magnetic resonance imaging-estimated proton density fat fraction assessment was performed to determine LFC at screening and Week 24. Participants with an LFC of ≥10% at screening were randomized 1:1 to efinopegdutide 10 mg or semaglutide 1 mg, both administered subcutaneously once weekly for 24 weeks. Participants were stratified according to the concurrent diagnosis of type 2 diabetes mellitus (T2DM). Both drugs were titrated to the target dose over an 8-week time period. The primary efficacy endpoint was relative reduction from baseline in LFC (%) after 24 weeks of treatment. Among 145 randomized participants (efinopegdutide n = 72, semaglutide n = 73), 33.1% had T2DM. At baseline, mean BMI was 34.3 kg/m2 and mean LFC was 20.3%. The least squares (LS) mean relative reduction from baseline in LFC at Week 24 was significantly (p <0.001) greater with efinopegdutide (72.7% [90% CI 66.8–78.7]) than with semaglutide (42.3% [90% CI 36.5–48.1]). Both treatment groups had an LS mean percent reduction from baseline in body weight at Week 24 (efinopegdutide 8.5% vs. semaglutide 7.1%; p = 0.085). Slightly higher incidences of adverse events and drug-related adverse events were observed in the efinopegdutide group compared with the semaglutide group, primarily related to an imbalance in gastrointestinal adverse events. In patients with NAFLD, treatment with efinopegdutide 10 mg weekly led to a significantly greater reduction in LFC than semaglutide 1 mg weekly.

Prevalence of erectile dysfunction in patients with metabolic syndrome
Tevfik Demir|International Journal of Urology|2006
Cited by 115

AIM: We wished to investigate the relationship between metabolic syndrome and erectile dysfunction (ED). MATERIALS AND METHODS: A total of 268 patients were included in this study. All of the patients were asked to fill in an International Index for Erectile Function (IIEF) questionnaire. The presence of metabolic syndrome was determined when any three or more of the five risk factors were present according to the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP)-III. The relationship between risk factor for metabolic syndrome and ED status was determined according to logistic regression analysis. RESULTS: Eighty-nine patients (33%) constituted the metabolic syndrome group. IIEF-EF domain scores of patients with and without metabolic syndrome were 17.7 +/- 7.9 and 21.7 +/- 7.5, respectively (P < 0.001). Seventy-four percent of patients with metabolic syndrome and 50% of patients without metabolic syndrome had ED (P < 0.001; odds ratio 2.9; 95% CI 1.7-5.0). Erectile function domain scores significantly decreased as the number of metabolic risk factors increased (P < 0.001). Patients with the risk factor of fasting blood glucose (FBG), waist circumference (WC), or hypertension (HT) had lower erectile function domain scores than the patients with other metabolic risk factors. Logistic regression analysis revealed that FBG and WC were the most important criteria for ED. CONCLUSIONS: Metabolic syndrome seems to be a potential risk factor for ED. We recommend patients with metabolic syndrome should be questioned about ED, and WC measurement might take part in the evaluation of ED.

Natural History of Congenital Generalized Lipodystrophy: A Nationwide Study From Turkey
Barış Akıncı, Hüseyin Önay, Tevfik Demir et al.|The Journal of Clinical Endocrinology & Metabolism|2016
Cited by 97Open Access

CONTEXT: Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder characterized by near-total lack of body fat. OBJECTIVE: We aimed to study natural history and disease burden of various subtypes of CGL. DESIGN: We attempted to ascertain nearly all patients with CGL in Turkey. SETTING: This was a nationwide study. PATIENTS OR OTHER PARTICIPANTS: Participants included 33 patients (22 families) with CGL and 30 healthy controls. MAIN OUTCOME MEASURE(S): We wanted to ascertain genotypes by sequencing of the known genes. Whole-body magnetic resonance imaging was used to investigate the extent of fat loss. Metabolic abnormalities and end-organ complications were measured on prospective follow-up. RESULTS: Analysis of the AGPAT2 gene revealed four previously reported and four novel mutations (CGL1; c.144C>A, c.667_705delinsCTGCG, c.268delC, and c.316+1G>T). Analysis of the BSCL2 gene revealed four different homozygous and one compound heterozygous possible disease-causing mutations (CGL2), including four novel mutations (c.280C>T, c.631delG, c.62A>T, and c.465-468delGACT). Two homozygous PTRF mutations (c.481-482insGTGA and c.259C>T) were identified (CGL4). Patients with CGL1 had preservation of adipose tissue in the palms, soles, scalp, and orbital region, and had relatively lower serum adiponectin levels as compared to CGL2 patients. CGL4 patients had myopathy and other distinct clinical features. All patients developed various metabolic abnormalities associated with insulin resistance. Hepatic involvement was more severe in CGL2. End-organ complications were observed at young ages. Two patients died at age 62 years from cardiovascular events. CONCLUSIONS: CGL patients from Turkey had both previously reported and novel mutations of the AGPAT2, BSCL2, and PTRF genes. Our study highlights the early onset of severe metabolic abnormalities and increased risk of end-organ complications in patients with CGL.