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Dive into the research topics where Nikolaos D. Roupas is active.

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Featured researches published by Nikolaos D. Roupas.


Annals of the New York Academy of Sciences | 2010

The influence of intensive physical training on growth and pubertal development in athletes

Neoklis A. Georgopoulos; Nikolaos D. Roupas; Anastasia Theodoropoulou; Athanasios Tsekouras; Apostolos G. Vagenakis; Kostas B. Markou

Genetic potential for growth can be fully expressed only under favorable environmental conditions. Although moderate physical activity has beneficial effects on growth, excessive physical training may negatively affect it. Sports favoring restricted energy availability, in the presence of high energy expenditure, are of particular concern. In gymnastics, a different pattern in skeletal maturation and linear growth was observed, resulting in an attenuation of growth potential in artistic gymnasts (AG), more pronounced in males than in females. In female rhythmic gymnasts (RG), the genetic predisposition to growth was preserved owing to a late catchup growth phenomenon. In all other sports not requiring strict dietary restrictions, no deterioration of growth has been documented so far. Intensive physical training and negative energy balance alter the hypothalamic pituitary set point at puberty, prolong the prepubertal stage, and delay pubertal development and menarche in a variety of sports. In elite RG and AG, prepubertal stage is prolonged and pubertal development is entirely shifted to a later age, following the bone maturation rather than the chronological age.


Peptides | 2012

Measurement of salivary resistin, visfatin and adiponectin levels

Irene Mamali; Nikolaos D. Roupas; Anastasia K. Armeni; Anastasia Theodoropoulou; Kostas B. Markou; Neoklis A. Georgopoulos

Hormonal determination in saliva offers several advantages. Peptides enter the salivary glands either by active transport mechanisms or are expressed and secreted by the salivary glands themselves. The collection of saliva is a noninvasive, easily repeatable and less stressful technique than blood withdrawal. The purpose of the present study was to introduce a method for measuring salivary resistin, visfatin and adiponectin levels and to evaluate their associations with serum levels. Resistin, visfatin and adiponectin levels were measured in serum and saliva of 50 healthy adult volunteers (17 male and 33 female) using commercial enzyme immunoassay kits for serum with minor modifications. The present study documented the determination of resistin and adiponectin levels in saliva and the significant correlation of salivary levels with serum levels (r=0.441, p<0.01 and r=0.347, p<0.05, respectively). Moreover, the identification of visfatin in saliva was achieved, but no significant correlation with serum visfatin levels was observed. To our knowledge, this is the first study to report the determination of resistin and visfatin in saliva and the significant correlation of salivary resistin with serum levels, while it confirmed the significant association between salivary and serum adiponectin. The introduction of salivary determinations of adipokines could contribute to the elucidation of the physiology and the role of the specific adipokines in various clinical conditions (obesity, insulin resistance, inflammation, reproduction, energy imbalance and stress response).


Gynecological Endocrinology | 2013

Diet, physical exercise and Orlistat administration increase serum Anti-Müllerian Hormone (AMH) levels in women with polycystic ovary syndrome (PCOS)

Christos Vosnakis; Neoklis A. Georgopoulos; David Rousso; Georgios Mavromatidis; Ilias Katsikis; Nikolaos D. Roupas; Irene Mamali; Dimitrios Panidis

The present study investigates the combined effect of diet, physical exercise and Orlistat for 24 weeks, on serum Anti-Müllerian Hormone (AMH) levels in overweight and obese women with polycystic ovary syndrome (PCOS) and in overweight and obese controls. Sixty-one (61) selected women with PCOS and 20 overweight and obese controls followed an energy-restricted diet, physical exercise plus Orlistat administration (120 mg, 3 times per day) for 24 weeks. At baseline, week 12 and week 24, serum levels of AMH, FSH, LH, PRL, androgens, sex hormone–binding globulin (SHBG), glucose, and insulin were measured and Free Androgen Index (FAI) and Insulin Resistance (IR) indices were calculated. In PCOS women, serum AMH levels increased after 12 and 24 weeks of treatment. After 12 weeks LH and SHBG were increased, while Testosterone decreased. After 12 and 24 weeks, FAI was decreased and all indices of IR were significantly improved. We concluded that in overweight and obese women with PCOS Orlistat administration, combined with diet and physical exercise, for 24 weeks, resulted in significant weight loss, improvement of hyperandrogenism and insulin sensitivity, and increased serum AMH levels.


Hormones (Greece) | 2013

The effect of prolonged aerobic exercise on serum adipokine levels during an ultra-marathon endurance race.

Nikolaos D. Roupas; Irene Mamali; Spyros Maragkos; Lydia Leonidou; Anastasia K. Armeni; George Markantes; Athanasios Tsekouras; George Sakellaropoulos; Kostas B. Markou; Neoklis A. Georgopoulos

OBJECTIVE: To evaluate the effect of prolonged intensive aerobic exercise and acute energy deficit (180 km ultra-marathon race) on serum leptin, adiponectin, resistin and visfatin levels and their association and interaction with serum cortisol and insulin levels in highly trained ultra-endurance runners. DESIGN: The study included 17 highly trained ultra-endurance male athletes (mean age 51.29±6.84 years and body mass index (BMI) 23.51±1.90) participating in the 5th Olympian Race held in Greece on May 2010. Anthropometric values were assessed; serum cortisol, insulin, leptin, adiponectin, resistin and visfatin levels were measured at baseline, post-exercise and ∼20 hours after the end of the race. RESULTS: All hormonal values of the post-exercise and recovery status were corrected for plasma volume changes. The estimated energy deficit during the ultra-endurance event was about 5000 Kcal. At the end of the race serum resistin levels were elevated (p<0.001) and serum leptin levels were reduced (p<0.001) and failed to reach pre-exercise levels, although showing a tendency towards restoration. No significant changes were noted in serum adiponectin and visfatin levels. CONCLUSIONS: Ultra-endurance aerobic exercise and acute negative energy balance lead to an up-regulation of serum resistin levels and a down-regulation of serum leptin levels.


Hormones (Greece) | 2014

Elevated serum androstenedione is associated with a more severe phenotype in women with polycystic ovary syndrome (PCOS)

Neoklis A. Georgopoulos; Efstathios Papadakis; Anastasia K. Armeni; Ilias Katsikis; Nikolaos D. Roupas; Dimitrios Panidis

OBJECTIVETo evaluate the impact of elevated serum Δ4A levels on the hormonal and metabolic features of the different phenotypes of PCOS.DESIGN1276 women with PCOS according to the Rotterdam criteria were included, in whom serum hormonal levels were determined.RESULTSIn PCOS women as a whole, as well as in patients presenting clinical and/or biochemical hyperandrogenemia (phenotypes I and II), Δ4A levels >3.8 ng/ml were positively related to LH, LH/FSH ratio, T, DHEAS, 17 OH progesterone and FAI and negatively related to T/Δ4A ratio. In the milder phenotype III, a positive correlation between Δ4A levels >3.8 ng/ml and T, DHEAS, 17 OH progesterone and FAI and a negative one between increased Δ4A and T/Δ4A ratio were reported. In the whole PCOS group with androstenedione >3.8 ng/ml, an increased ovarian volume was observed, while a greater mean follicular number was found only in phenotypes I and II.CONCLUSIONSIncreased serum Δ4A levels, which are associated with more severe PCOS phenotypes, possibly contribute to the worsening of PCOS features and therefore could be a valuable marker of biochemical hyperandrogenemia.


The Journal of Clinical Endocrinology and Metabolism | 2013

Despite a High Prevalence of Menstrual Disorders, Bone Health Is Improved at a Weight-Bearing Bone Site in World-Class Female Rhythmic Gymnasts

Laurent Maïmoun; Olivier Coste; Neoklis A. Georgopoulos; Nikolaos D. Roupas; Krishna Kunal Mahadea; Alexandra Tsouka; Thibault Mura; Pascal Philibert; Laura Gaspari; Denis Mariano-Goulart; Michel Leglise; Charles Sultan

CONTEXT Regular physical activity during puberty improves bone mass acquisition. However, it is unknown whether extreme intense training has the same favorable effect on the skeleton. OBJECTIVE We evaluated the bone mass acquisition in a unique cohort of world-class rhythmic gymnasts. STUDY PARTICIPANTS A total of 133 adolescent girls and young women with a mean age of 18.7 ± 2.7 (14.4-26.7) years participated in this study: 82 elite rhythmic gymnasts (RGs) and 51 controls (CONs). MAIN OUTCOME MEASURES Anthropometric variables and body composition were assessed, and all participants completed questionnaires on their general medical, menstrual, and training histories. Broadband ultrasound attenuation (BUA in decibels per megahertz) was determined by quantitative ultrasound at the heel. RESULTS RGs presented lower weight (-8.5%, P < .001), body mass index (-11.7%, P < .001), and body fat mass (-43%, P < .001) and higher muscle mass (6.3%, P < .01) and height (+2.8 cm, P < .01). RGs presented an age of menarche significantly delayed compared with CONs (15.6 ± 1.6 vs 12.7 ± 1.7 years; P < .001) and a high prevalence of menstrual disorders (64%). BUA values were higher in RGs vs CONs (68.6 ± 4.6 and 65.4 ± 3.3 dB/Mhz, respectively; P < .001). This difference was exacerbated when BUA was adjusted for age and body weight. BUA values in RGs were not affected by menstrual or training status. Among RGs with menarche, BUA was higher (71.5 ± 4.1 and 67.9 ± 3.5 dB/Mhz) for delayed (14.4 ± 0.8 years) vs severely delayed (17.3 ± 1.4 years) menarcheal age. BUA was positively correlated with body weight and body mass index and tended to be correlated with age. CONCLUSION Conversely to expectations for adolescents and young women with a high prevalence of menstrual disorders and/or delayed menarche, intense training in rhythmic gymnastics appeared to have a beneficial effect on the bone health of a weight-bearing site. This effect was nevertheless modulated by the age of menarche. The high mechanical loading generated by this activity may counterbalance the negative effect of menstrual disorders.


Hormones (Greece) | 2012

Growth velocity and final height in elite female rhythmic and artistic gymnasts

Neoklis A. Georgopoulos; Anastasia Theodoropoulou; Nikolaos D. Roupas; Loredana Rottstein; Athanasios Tsekouras; Panagiotis Mylonas; George A. Vagenakis; Eftychia Koukkou; Anastasia K. Armeni; George Sakellaropoulos; Michel Leglise; Apostolos G. Vagenakis; Kostas B. Markou

PURPOSEThe aim of this study was to determine the impact of intensive training on adult final height in elite female rhythmic and artistic gymnasts.METHODSThe study included 215 rhythmic gymnasts (RG) and 113 artistic gymnasts (AG).RESULTSAG were below the 50th percentile, while RG were taller than average. Final adult height was lower than target height in AG, while in RG, it exceeded target height. AG started training earlier than RG (p<0.001) and reported lower intensity of training (p<0.001). RG were taller than AG, with higher target height, greater final height-target height and lower body fat and BMI (p<0.001). Using multiple regression analysis, the main factors influencing final height were weight SDS (p<0.001), target height SDS (p<0.001) and age of menarche (p<0.001) for RG, and weight SDS (p<0.001) and target height SDS (p<0.001) for AG.CONCLUSIONIn both elite female RG and AG, genetic predisposition to final height was not disrupted and remained the main force of growth. Although in elite RG genetic predisposition for growth was fully preserved, in elite female AG final adult height falls shorter than genetically determined target height, though within the standard error of prediction.


European Journal of Endocrinology | 2012

Increased frequency of the DI genotype of the angiotensin-I converting enzyme and association of the II genotype with insulin resistance in polycystic ovary syndrome

Vasiliki Koika; Neoklis A. Georgopoulos; Athanasia Piouka; Nikolaos D. Roupas; Anastasia Karela; Anastasia K. Armeni; Eleni Katsantoni; Dimitrios Panidis

OBJECTIVE The polycystic ovary syndrome (PCOS) is a common and complex disease with unclear pattern of inheritance, characterized by an androgen excess, while hyperinsulinemia and insulin resistance (IR) are common features of the syndrome. The angiotensin I converting enzyme (ACE) insertion (I)/deletion (D) gene polymorphism was proved to be involved in many pathophysiological conditions, including hypertension and IR. DESIGN The purpose of this study was to evaluate the involvement of the ACE gene polymorphism in the pathogenesis of PCOS. METHODS In a case-control association study involving 801 PCOS women and 266 healthy controls, hormonal determinations and ACE polymorphism genotyping were performed. The PCOS women were classified into three groups: Group A presented biochemical hyperandrogenism, combined with anovulation and polycystic ovarian morphology; Group B, clinical hyperandrogenism combined with anovulation and polycystic ovarian morphology; and Group C, chronic anovulation and polycystic ovarian morphology. RESULTS A significant increase in the frequency of the DI genotype of the ACE polymorphism was detected in PCOS women as a whole (P=0.035), in PCOS Group A (P=0.039) and Group B (P=0.010), while there was no difference in Group C (P=0.939). Significant difference was also observed in hyperandrogenic PCOS women as a whole (Group A+B) (P=0.017). The II genotype was positively correlated with HOMA-IR and QUICKI and with fasting insulin and glucose/insulin ratio in these groups. CONCLUSIONS The association study of the ACE I/D polymorphism in PCOS women demonstrates an increase in the DI genotype incidence and an association of the II genotype with IR.


The Journal of Clinical Endocrinology and Metabolism | 2013

Increased Frequency of the Anti-Müllerian-Inhibiting Hormone Receptor 2 (AMHR2) 482 A>G Polymorphism in Women With Polycystic Ovary Syndrome: Relationship to Luteinizing Hormone Levels

Neoklis A. Georgopoulos; Eleni Karagiannidou; Vasiliki Koika; Nikolaos D. Roupas; Anastasia K. Armeni; Dimitra Marioli; Efstathios Papadakis; Corrine K. Welt; Dimitrios Panidis

CONTEXT The polycystic ovary syndrome (PCOS) is a common and complex disease without a clear pattern of inheritance. Anti-Müllerian hormone (AMH) has an inhibitory effect on FSH-stimulated follicle growth. Serum AMH levels are higher in women with PCOS than in normo-ovulatory women. The elevated AMH levels may reflect abnormalities in AMH signaling. OBJECTIVE The purpose of this study was to evaluate the association of the anti-Müllerian hormone receptor 2 (AMHR2) -482 A>G polymorphism (rs2002555) with the pathophysiology of PCOS. DESIGN AMHR2 -482 A>G polymorphism genotyping were performed in a large cohort of women with PCOS and in a healthy control group. SETTING/SUBJECTS A total of 858 Caucasian Greek women with PCOS and 309 healthy control women were studied. INTERVENTIONS Genotyping and hormonal measurements were preformed. MAIN OUTCOME MEASURES Hormone levels in women with PCOS were analyzed. RESULTS The AMHR2 polymorphism was more common in women with PCOS than in control women (P = .026). Homozygous AMHR2 -482 A>G gene polymorphisms (GG) were associated with decreased levels of LH (P = .003) and lower LH to FSH ratios (P = .01) in women with PCOS, as well as with lower prolactin levels (P = .004). No other associations related to AMHR2 -482 A>G polymorphisms were observed in women with PCOS or control women. CONCLUSION In this study, the role of the AMHR2 -482 A>G gene polymorphism in the pathogenesis of PCOS was suggested by the association of the variant with PCOS risk. Thus, further research is needed to elucidate a possible association of the AMHR2 -482 A>G gene polymorphism with AMH signaling and impaired ovarian function and its clinical significance in women with PCOS.


Gynecological Endocrinology | 2012

The influence of obesity on Androstenedione to Testosterone ratio in women with polycystic ovary syndrome (PCOS) and hyperandrogenemia

G. Misichronis; Neoklis A. Georgopoulos; Dimitra J. Marioli; Anastasia K. Armeni; Ilias Katsikis; Athanasia Piouka; Alexandros D. Saltamavros; Nikolaos D. Roupas; Dimitrios Panidis

The aim of the present study was to evaluate the impact of obesity and insulin resistance on testosterone formation from androstenedione and its contribution to biochemical hyperandrogenemia in all different phenotypic subgroups of PCOS patients. The case-control study included 1087 PCOS women and 206 regularly menstruating, ovulatory controls. The main clinical measurements included anthropometric and basal hormonal characteristics and evaluation of hyperandrogenic and insulin resistance-related features. The results were the following: In PCOS women with biochemical hyperandrogenemia, obesity significantly lowers serum A levels and increases T to A ratio. These findings were not present in PCOS women with clinical hypeandrogenemia and in normal ovulatory controls.

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Dimitrios Panidis

Aristotle University of Thessaloniki

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Michel Leglise

International Olympic Committee

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Efstathios Papadakis

Aristotle University of Thessaloniki

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Ilias Katsikis

Aristotle University of Thessaloniki

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