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Dive into the research topics where Jean-Marc Kaufman is active.

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Featured researches published by Jean-Marc Kaufman.


The New England Journal of Medicine | 2001

Effect of risedronate on the risk of hip fracture in elderly women.

McClung; Piet Geusens; Pd Miller; Hartmut Zippel; Wg Bensen; Christian Roux; S. Adami; Ignac Fogelman; Terrence Diamond; Richard Eastell; Pj Meunier; Jy Reginster; Rd Wasnich; Maria Greenwald; Jean-Marc Kaufman; Ch Chestnut

BACKGROUND Risedronate increases bone mineral density in elderly women, but whether it prevents hip fracture is not known. METHODS We studied 5445 women 70 to 79 years old who had osteoporosis (indicated by a T score for bone mineral density at the femoral neck that was more than 4 SD below the mean peak value in young adults [-4] or lower than -3 plus a nonskeletal risk factor for hip fracture, such as poor gait or a propensity to fall) and 3886 women at least 80 years old who had at least one nonskeletal risk factor for hip fracture or low bone mineral density at the femoral neck (T score, lower than -4 or lower than -3 plus a hip-axis length of 11.1 cm or greater). The women were randomly assigned to receive treatment with oral risedronate (2.5 or 5.0 mg daily) or placebo for three years. The primary end point was the occurrence of hip fracture. RESULTS Overall, the incidence of hip fracture among all the women assigned to risedronate was 2.8 percent, as compared with 3.9 percent among those assigned to placebo (relative risk, 0.7; 95 percent confidence interval, 0.6 to 0.9; P=0.02). In the group of women with osteoporosis (those 70 to 79 years old), the incidence of hip fracture among those assigned to risedronate was 1.9 percent, as compared with 3.2 percent among those assigned to placebo (relative risk, 0.6; 95 percent confidence interval, 0.4 to 0.9; P=0.009). In the group of women selected primarily on the basis of nonskeletal risk factors (those at least 80 years of age), the incidence of hip fracture was 4.2 percent among those assigned to risedronate and 5.1 percent among those assigned to placebo (P=0.35). CONCLUSIONS Risedronate significantly reduces the risk of hip fracture among elderly women with confirmed osteoporosis but not among elderly women selected primarily on the basis of risk factors other than low bone mineral density.


European Urology | 2009

Investigation, Treatment, and Monitoring of Late-Onset Hypogonadism in Males: ISA, ISSAM, EAU, EAA, and ASA Recommendations

Christina Wang; Eberhard Nieschlag; Ronald S. Swerdloff; Hermann M. Behre; Wayne J.G. Hellstrom; Louis Gooren; Jean-Marc Kaufman; Jean-Jacques Legros; Bruno Lunenfeld; Alvaro Morales; John E. Morley; Claude Schulman; Ian M. Thompson; W. Weidner; Frederick C. W. Wu

The new ISA, ISSAM, EAU, EAA and ASA recommendations on the investigation, treatment and monitoring of late-onset hypogonadism in males provide updated evidence-based information for clinicians who diagnose and treat patients with adult onset, age related testosterone deficiency.


Journal of Bone and Mineral Research | 2003

The Effect of Teriparatide [Human Parathyroid Hormone (1–34)] Therapy on Bone Density in Men With Osteoporosis†

Eric S. Orwoll; Scheele Wh; Paul S; S. Adami; Syversen U; Diez-Perez A; Jean-Marc Kaufman; Clancy Ad; Gregory A Gaich

Teriparatide [rhPTH(1–34)] increases bone mineral density and reduces the risk of vertebral fracture in women. We randomized 437 men with spine or hip bone mineral density more than 2 SD below the young adult male mean to daily injections of placebo, teriparatide 20 μg, or teriparatide 40 μg. All subjects also received supplemental calcium and vitamin D. The study was stopped after a median duration of 11 months because of a finding of osteosarcomas in rats in routine toxicology studies. Biochemical markers of bone formation increased early in the course of therapy and were followed by increases in indices of osteoclastic activity. Spine bone mineral density was greater than in placebo subjects after 3 months of teriparatide therapy, and by the end of therapy it was increased by 5.9% (20 μg) and 9.0% (40 μg) above baseline (p < 0.001 vs. placebo for both comparisons). Femoral neck bone mineral density increased 1.5% (20 μg; p = 0.029) and 2.9% (40 μg; p < 0.001), and whole body bone mineral content increased 0.6% (20 μg; p = 0.021) and 0.9% (40 μg; p = 0.005) above baseline in the teriparatide subjects. There was no change in radial bone mineral density in the teriparatide groups. Bone mineral density responses to teriparatide were similar regardless of gonadal status, age, baseline bone mineral density, body mass index, smoking, or alcohol intake. Subjects experienced expected changes in mineral metabolism. Adverse events were similar in the placebo and 20‐μg groups, but more frequent in the 40‐μg group. This study shows that teriparatide treatment results in an increase in bone mineral density and is a potentially useful therapy for osteoporosis in men.


Arthritis & Rheumatism | 2001

Two-year effects of alendronate on bone mineral density and vertebral fracture in patients receiving glucocorticoids: A randomized, double-blind, placebo-controlled extension trial

Jonathan D. Adachi; Kenneth G. Saag; Pierre D. Delmas; Uri A. Liberman; Ronald Emkey; Ego Seeman; Nancy E. Lane; Jean-Marc Kaufman; Patrice E. Poubelle; Federico Hawkins; Ricardo Correa-Rotter; Charles J. Menkès; Jose A. Rodriguez-Portales; Thomas J. Schnitzer; Joel A. Block; Jeffrey Wing; Harris H. McIlwain; Rene Westhovens; Jacques P. Brown; Jose Melo-Gomes; Barry L. Gruber; Melissa J. Yanover; Maria Odette Ribeiro Leite; Kerry Siminoski; Michael C. Nevitt; John T. Sharp; Marie Pierre Malice; Thomas Dumortier; Michelle Czachur; Wendy Carofano

OBJECTIVE To evaluate the continued efficacy and safety of alendronate (ALN) for up to 2 years in patients receiving glucocorticoids. METHODS This is a 12-month extension of a previously completed 1-year trial of daily ALN, performed to evaluate the effects of ALN over a total of 2 years in 66 men and 142 women continuing to receive at least 7.5 mg of prednisone or equivalent daily. All patients received supplemental calcium and vitamin D. The primary end point was the mean percentage change in lumbar spine bone mineral density (BMD) from baseline to 24 months. Other outcomes included changes in hip and total body BMD, biochemical markers of bone turnover, radiographic joint damage of the hands, and vertebral fracture incidence. RESULTS The mean (+/-SEM) lumbar spine BMD increased by 2.8 +/- 0.6%, 3.9 +/- 0.7%, and 3.7 +/- 0.6%, respectively, in the groups that received 5 mg, 10 mg, and 2.5/10 mg of ALN daily (P < or = 0.001) and decreased by -0.8 +/- 0.6% in the placebo group (P not significant) over 24 months. In patients receiving any dose of ALN, BMD was increased at the trochanter (P < or = 0.05) and maintained at the femoral neck. Total body BMD was increased in patients receiving 5 or 10 mg ALN (P < or = 0.01). These 2 dose levels of ALN were more effective than placebo at all sites (P < or = 0.05). Bone turnover markers (N-telopeptides of type I collagen and bone-specific alkaline phosphatase) decreased 60% and 25%, respectively, during treatment with ALN (P < or = 0.05). There were fewer patients with new vertebral fractures in the ALN group versus the placebo group (0.7% versus 6.8%; P = 0.026). The safety profile was similar between treatment groups. CONCLUSION Alendronate is an effective, well-tolerated therapy for the prevention and treatment of glucocorticoid-induced osteoporosis, with sustained treatment advantages for up to 2 years.


Diabetes | 2011

Dipeptidyl Peptidase 4 Is a Novel Adipokine Potentially Linking Obesity to the Metabolic Syndrome

Daniela Lamers; Susanne Famulla; Nina Wronkowitz; Sonja Hartwig; Stefan Lehr; D. Margriet Ouwens; Kristin Eckardt; Jean-Marc Kaufman; Mikael Rydén; Stefan Müller; Franz-Georg Hanisch; Johannes Ruige; Peter Arner; Henrike Sell; J Eckel

OBJECTIVE Comprehensive proteomic profiling of the human adipocyte secretome identified dipeptidyl peptidase 4 (DPP4) as a novel adipokine. This study assessed the functional implications of the adipokine DPP4 and its association to the metabolic syndrome. RESEARCH DESIGN AND METHODS Human adipocytes and skeletal and smooth muscle cells were used to monitor DPP4 release and assess the effects of soluble DPP4 on insulin signaling. In lean and obese subjects, depot-specific expression of DPP4 and its release from adipose tissue explants were determined and correlated to parameters of the metabolic syndrome. RESULTS Fully differentiated adipocytes exhibit a substantially higher release of DPP4 compared with preadipocytes or macrophages. Direct addition of DPP4 to fat and skeletal and smooth muscle cells impairs insulin signaling. A fivefold higher level of DPP4 protein expression was seen in visceral compared with subcutaneous fat of obese patients, with no regional difference in lean subjects. DPP4 serum concentrations significantly correlated with adipocyte size. By using adipose tissue explants from lean and obese subjects, we observed a twofold increase in DPP4 release that strongly correlated with adipocyte volume and parameters of the metabolic syndrome and was decreased to the lean level after weight reduction. DPP4 released from adipose tissue correlated positively with an increasing risk score for the metabolic syndrome. CONCLUSIONS DPP4 is a novel adipokine that may impair insulin sensitivity in an autocrine and paracrine fashion. Furthermore, DPP4 release strongly correlates with adipocyte size, potentially representing an important source of DPP4 in obesity. Therefore, we suggest that DPP4 may be involved in linking adipose tissue and the metabolic syndrome.


The Aging Male | 2002

Estradiol in elderly men

Alex Vermeulen; Jean-Marc Kaufman; Stefan Goemaere; I. Van Pottelberg

The role of estrogens in male physiology has become more evident, as a consequence of the discovery of human models of estrogen deficiency such as estrogen resistance or aromatase deficiency. In males, testosterone is the major source of plasma estradiol, the main biologically active estrogen, only 20% of which is secreted by the testes. Plasma estrone, 5% of which is converted to plasma estradiol, originates from tissue aromatization of, mainly adrenal, androstenedione. The plasma concentration of estradiol in males is 2-3 ng/dl and its production rate in blood is 25-40 μg/24 h; both of these values are significantly higher than in postmenopausal women. Plasma levels of estradiol do not necessarily reflect tissue-level activity as peripherally formed estradiol is partially metabolized in situ; thus, not all enters the general circulation, with a fraction remaining only locally active. Of the factors influencing plasma estradiol levels, plasma testosterone is a major determinant. However, the age-associated decrease in testosterone levels is scarcely reflected in plasma estradiol levels, as a result of increasing aromatase activity with age and the age-associated increase in fat mass. Free and bioavailable estradiol levels do decrease modestly with age as does the ratio of free testosterone to free estradiol, the latter testifying to the age-associated increasewd aromatization of testosterone. Estradiol levels are highly significantly positively related to body fat mass and more specifically to subcutaneous abdominal fat, but not to visceral (omental) fat. Indeed, aromatase activity in omental fat is only one-tenth of the activity in gluteal fat. Estrogens in males play an important role in the regulation of the gonadotropin feedback, several brain functions, bone maturation, regulation of bone resorption and in lipid metabolism. Moreover, they affect skin metabolism and are an important factor determining sex interest in man.


Hormone Research in Paediatrics | 1995

Ageing of the hypothalamo-pituitary-testicular axis in men.

Alex Vermeulen; Jean-Marc Kaufman

In distinction to the course of reproductive ageing in women, men do not experience a rapid decline of Leydig cell function or irreversible arrest of reproductive capacity in old age. Hence, strictu sensu, the andropause does not exist. Nevertheless, both spermatogenesis and fertility as well as Leydig cell function do decline with age, as shown by a decrease of +/- 35% of total and of 50% of free testosterone levels between the age of 20 and 80 years. The origin of this decline of Leydig cell function resides on the one hand in the testes, and is essentially characterized by a decreased number of Leydig (and Sertoli) cells and on the other hand in the hypothalamo-pituitary complex characterized by a decreased luteinzing hormone (LH) pulse amplitude, LH pulse frequency being maintained. As the responsiveness of the gonadotrophs to gonadotropin-releasing hormone (GnRH) remains unimpaired, one may assume that the amount of GnRH released at each pulse is also reduced, possibly as the consequence of a reduction of the cellular mass of GnRH neurones. Plasma levels of testosterone below the lower normal limit occur, however, only in a minority of elderly men from 7% in the age group 40-60, to 20% in the age group 60-80 and 35% in the age group over 80 years old. Factors influencing testosterone levels in elderly men are multiple: hereditary, environmental (obesity, stress), psychosocial (depression, smoking, drugs) or socioeconomical (diet, hygiene). Whether these elderly men should be substituted with androgens remains controversial.(ABSTRACT TRUNCATED AT 250 WORDS)


Journal of Bone and Mineral Research | 2006

Strontium ranelate reduces the risk of vertebral and nonvertebral fractures in women eighty years of age and older

Ego Seeman; Bruno Vellas; Claude Laurent Benhamou; J. P. Aquino; Jutta Semler; Jean-Marc Kaufman; Krzysztof Hoszowski; Alfredo Roces Varela; Carmelo Erio Fiore; Kim Brixen; Jean-Yves Reginster; Steven Boonen

Strontium ranelate produces an early and sustained reduction of both vertebral and nonvertebral fractures in patients ≥80 years of age.


Heart | 2011

Endogenous testosterone and cardiovascular disease in healthy men: a meta-analysis

Johannes Ruige; Ahmed Mahmoud; Dirk De Bacquer; Jean-Marc Kaufman

Context The literature provides no clear answer as to whether low endogenous testosterone increases risk of cardiovascular disease (CVD) in healthy men. Objective Our purpose was to estimate the predictive value of testosterone for CVD and to identify study features explaining conflicting results. Data Sources Articles were identified by a Medline and Embase search and citation tracking. Study Selection Eligible were prospective population-based cohort and nested case-control studies of testosterone and atherosclerosis, stroke, myocardial infarction, ischaemic heart disease, death from coronary heart disease or mortality. Data extraction Two independent researchers re-expressed associations of testosterone and CVD in a uniform manner to be used in meta-regression analyses for identification of study features explaining conflicting results, and to estimate the predictive value of testosterone for CVD. Results and Conclusions 19 potentially eligible articles were identified. Overall, a weak independent association was found with an estimated summary RR of 0.89 for a change of one standard deviation in total testosterone level (95% CI 0.83 to 0.96). Age of study population and year of publication modified the relationship between testosterone and CVD. The estimated summary RR was 1.01 (0.95 to 1.08) for studies of men younger than 70 years of age, and 0.84 (0.76 to 0.92) for studies including men over 70 years of age. The latter studies showed a particular pronounced association if published after 1 January 2007. Results were largely confirmed by separate analyses of free- and bioavailable testosterone. The systematic review displayed no association between endogenous testosterone and risk for CVD in middle-aged men. In elderly men, testosterone may weakly protect against CVD. Alternatively, low testosterone may indicate a poor general health.


Clinical Endocrinology | 1993

Short and long‐term effects of growth hormone treatment on bone turnover and bone mineral content in adult growth hormone‐deficient males

Mark Vandeweghe; Paul Taelman; Jean-Marc Kaufman

OBJECTIVE In view of the fact that GH‐deficient adults present with pronounced osteopaenia and can be considered at risk for osteoporotic fractures, we wanted to investigate the effects of biosynthetic GH replacement therapy (0.25 IU/kg/week) on biochemical indices of bone turnover and on bone mineral content (BMC) in a group of GH‐deficient adult males.

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Stefan Goemaere

Ghent University Hospital

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Youri Taes

Ghent University Hospital

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Jean-Pierre Devogelaer

Université catholique de Louvain

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Bruno Lapauw

Ghent University Hospital

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Steven Boonen

Catholic University of Leuven

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Kaatje Toye

Ghent University Hospital

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Alex Vermeulen

Ghent University Hospital

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