Muneki Tanaka
Kagoshima University
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Featured researches published by Muneki Tanaka.
Psychoneuroendocrinology | 2003
Muneki Tanaka; Tetsuro Naruo; Daisuke Yasuhara; Yoshiki Tatebe; Nobuatsu Nagai; Tomomi Shiiya; Masamitsu Nakazato; Shigeru Matsukura; Shin-ichi Nozoe
Ghrelin has a role in regulating eating behavior and energy metabolism in the central nervous system, and has been reported to play an important role in the pathophysiology of anorexia nervosa (AN). The aim of the present study was to compare fasting plasma ghrelin levels in different subtypes of untreated AN patients. The subjects included 39 female AN patients and 11 female controls. The patients were then divided into two subtypes as follows: 19 AN patients with restricting (AN-R) and 20 AN patients with binge-eating/purging (AN-BP) form of the illness. Blood samples from subjects after an overnight fast were used to analyze plasma ghrelin concentrations. Plasma ghrelin concentrations in both AN-R and AN-BP were negatively correlated with body mass index (BMI). The mean plasma ghrelin levels in both AN-R and AN-BP were significantly higher than that in controls. The mean ghrelin level in AN-BP was significantly higher than that in AN-R. However, mean BMI and serum potassium in both groups were not significantly different. These results suggest that both BMI and the presence of binge-eating/purging may have some influence on fasting plasma ghrelin levels in patients with AN.
Journal of Psychiatric Research | 2003
Muneki Tanaka; Tetsuro Naruo; Nobuatsu Nagai; Nobutaka Kuroki; Tomomi Shiiya; Masamitsu Nakazato; Shigeru Matsukura; Shin-ichi Nozoe
Previous studies have reported that fasting plasma ghrelin concentrations play an important role in the pathophysiology of eating disorders. The purpose of this study was to examine the relationship between plasma ghrelin levels and frequency of abnormal eating behaviors, nutritional parameters in eating disorders. Fasting blood samples were obtained in 40 female anorexia nervosa (AN) patients, 21 restricting type (AN-R) and 19 binge-eating/purging type (AN-BP), in 31 bulimia nervosa (BN) patients, 18 purging type (BN-P) and 13 non-purging type (BN-NP), in 15 female healthy volunteers (control) before the initiation of active treatment. The fasting plasma ghrelin concentrations in all subjects were negatively correlated with nutritional parameters such as body mass index, percent body fat and serum cholinesterase concentration. The mean plasma ghrelin level in BN-P was higher than that in both BN-NP and controls despite similar nutritional parameters. The plasma ghrelin levels in both AN-R and AN-BP did not differ from BN-P despite difference of nutritional parameters. For both AN-BP and BN-P patients with habitual binge/purge behavior, there were significant correlations among plasma ghrelin values, frequencies of binge/purge cycles and serum amylase values. In BN-NP, there were no significant correlations among plasma ghrelin values, frequencies of binge-eating episodes and serum amylase values. These results suggest that habitual binge/purge behavior may have some influence on circulating plasma ghrelin levels in both BN-P and AN-BP. Habitual binge/purge cycles with vomiting as opposed to binge-eating episodes without vomiting may have a greater influence on fasting plasma ghrelin concentration in eating disorders.
Clinical Endocrinology | 2005
Shinya Kojima; Toshihiro Nakahara; Nobuatsu Nagai; Tetsuro Muranaga; Muneki Tanaka; Daisuke Yasuhara; Akinori Masuda; Yukari Date; Hiroaki Ueno; Masamitsu Nakazato; Tetsuro Naruo
Objective In recent years great advances have been made in our understanding of the peripheral signals produced within the gastrointestinal tract that regulate appetite, such as ghrelin and peptide YY (PYY). While ghrelin elicites hunger signals, PYY elicites satiety. Therefore, alterations in hormone physiology may play a role in the pathogenesis of bulimia nervosa (BN). In this study, we investigated the postprandial profile of ghrelin and PYY levels in patients with BN.
Regulatory Peptides | 2004
Muneki Tanaka; Toshihiro Nakahara; Shinya Kojima; Tamotsu Nakano; Tetsuro Muranaga; Nobuatsu Nagai; Hiroaki Ueno; Masamitsu Nakazato; Shin-ichi Nozoe; Tetsuro Naruo
Circulating ghrelin and growth hormone (GH) are up-regulated in anorexia nervosa (AN) as a consequence of prolonged starvation. The current study examines the effect of nutritional rehabilitation with improvement of eating behavior on ghrelin and GH levels in AN patients during the course of inpatient treatment. The subjects included 34 female AN patients and 9 age-matched female controls. Fasting blood samples were collected before, during and after treatment. For data analysis, AN subjects were divided into three subtypes. The first group included seven patients with emergent hospitalization (E-AN), who were accompanied by severe emaciation due to their inability for food intake for more than a month. The other two groups included 14 AN with restricting (AN-R) and 13 AN with binge-eating/purging (AN-BP) patients. There were significant correlations between ghrelin, GH and body mass index (BMI) before treatment in all subjects. However, ghrelin levels were not significantly correlated with BMI and GH although there was a relationship between GH and BMI after treatment. Before treatment, E-AN patients had the highest levels of ghrelin and GH with the lowest glucose levels and liver dysfunction. The AN-BP group had a higher level of ghrelin than the AN-R group. During treatment, comparing with the controls group only the AN-R group showed higher level of ghrelin. Contrarily, the ghrelin levels in the E-AN group, who showed improved glucose levels, and the AN-BP group, who stopped vomiting behavior due to our treatment, decreased ghrelin levels. After treatment, only the AN-BP group showed a higher ghrelin level as compared to the controls. Although GH levels of the three AN groups decreased gradually according to our treatment progress, it still showed the higher value than the control group at the end of the treatment because every AN patients could not reach to more than 80% of their ideal body weight at discharge. These findings suggest that (1) severe emaciation with abnormal fasting hypoglycemia in AN patients may cause very high levels of GH and ghrelin, (2) that GH levels in AN patients may relate to nutritional status and (3) that ghrelin may be influenced by not only nutritional status but also the eating behavior of the patients.
Clinical Endocrinology | 2003
Muneki Tanaka; Yoshiki Tatebe; Toshihiro Nakahara; Daisuke Yasuhara; Ken-ichiro Sagiyama; Tetsuro Muranaga; Hiroaki Ueno; Masamitsu Nakazato; Shin-ichi Nozoe; Tetsuro Naruo
objective Ghrelin is thought to be involved in the regulation of eating behaviour and energy metabolism in acute and chronic feeding states. Circulating plasma ghrelin levels in healthy humans have been found to decrease significantly after oral glucose administration. Because it is suggested that eating behaviour may influence the secretion of ghrelin and insulin in anorexia nervosa (AN), we examined the effect of oral glucose on ghrelin and insulin secretion in subtypes of AN patients.
Psychosomatic Medicine | 2005
Daisuke Yasuhara; Tetsuro Naruo; Nobuatsu Nagai; Tetsuro Muranaga; Toshihiro Nakahara; Muneki Tanaka; Shinya Kojima; Ken-Ichiroh Sagiyama; Akinori Masuda; Akio Inui
Objective: Little is known about biologic predictors of refeeding outcome in anorexia nervosa (AN). Because nutritional status mirrors glucose metabolism during an oral glucose tolerance test (OGTT) in AN, this study investigated whether pretreatment glucose response patterns during the OGTT might be associated with refeeding progress in patients with AN. Methods: Sixty-four female patients with anorexia (33 restrictors and 31 binge/purgers) and 13 healthy control subjects underwent an OGTT before nutritional rehabilitation, including desensitization to fear of energy intake of 1000 to 1600 kcal/day. Patients were divided into flat-type responders, impaired glucose tolerance (IGT)-type responders, and normal-type glucose responders. Daily energy intake, weekly weight gain, and the duration of desensitization period were evaluated until the 12th week. Results: The patients with anorexia consisted of 20 flat-type, 21 IGT-type, and 23 normal- type responders. Normal-type responders required a shorter time to complete the desensitization period than other responders (p = .003 for restrictors, p < .001 for binge/purgers). In terms of refeeding progress, significant group effects for daily energy intake and weekly weight gain were evident in restrictors (p = .006, p = .028, respectively) and binge/purgers (p < .001, p = .003, respectively); normal-type responders showed good refeeding progress compared with other responders in both AN subtypes. Conclusions: The present study found a close relationship between pretreatment glucose responses, therapeutic progress of desensitization to fear of energy intake, and refeeding progress in both AN subtypes. Our findings suggest that glucose tolerance may be a useful predictor of short-term refeeding outcome in this disorder. AN = anorexia nervosa; ANOVA = analysis of variance; AUC = insulin area under the curve; BMI = body mass index; DM = diabetes mellitus; DSM-IV = Diagnostic and Statistical Manual of Mental Disorders, fourth edition; FBG = fasting blood glucose concentration; FIRI = fasting serum insulin concentration; HOMA-IR = homeostasis model assessment for insulin resistance; IGT = impaired glucose tolerance; II15min = insulinogenic index at 15 minutes; OGTT = oral glucose tolerance test.
Hormones and Behavior | 2006
Muneki Tanaka; Toshihiro Nakahara; Tetsuro Muranaga; Shinya Kojima; Daisuke Yasuhara; Hiroaki Ueno; Masamitsu Nakazato; Akio Inui
Patients with bulimia nervosa (BN) have bulimic and depressive symptoms, which have been associated with abnormalities in the neuroendocrine and vagal systems. Subjects included twenty-four female drug-free outpatients with BN that were selected from patients seeking treatment for eating behavior in our hospital along with twenty-five age-matched healthy females who served as controls. We investigated ghrelin and leptin levels, cardiac vagal tone and sympathovagal balance, frequency of sets of binge-eating and vomiting episodes per week and the Profile of Mood States (POMS) depression scale in BN before and after a 16-week administration of the serotonin selective reuptake inhibitor (SSRI) paroxetine combined with cognitive-behavioral therapy. Compared to controls, the BN group had higher ghrelin levels and resting cardiac vagal tone, and lower leptin levels and resting cardiac sympathovagal balance before treatment, although there was a significant difference between the two groups for the body mass index (BMI). The elevated ghrelin levels (301.7 +/- 18.9 pmol/l, mean +/- SEM vs. 202.8 +/- 15.6 pmol/l, P < 0.01), cardiac vagal tone (2246.4 +/- 335.5 ms(2) vs. 1128.5 +/- 193.3 ms(2), P < 0.01), frequency of sets of binge-eating and purging episodes and T scores for the POMS depression scale were all significantly decreased after treatment despite similar BMI, percent body fat and leptin levels. In close association with cardiac vagal function and ghrelin recoveries, abnormal eating behavior and depressive symptoms improved, indicating the usefulness of these indexes in the assessment of clinical condition and therapeutic efficacy in BN.
Biopsychosocial Medicine | 2013
Takao Munemoto; Akinori Masuda; Nobuatsu Nagai; Muneki Tanaka; Soejima Yuji
BackgroundThe prognosis of hyperventilation syndrome (HVS) is generally good. However, it is important to proceed with care when treating HVS because cases of death following hyperventilation have been reported. This paper was done to demonstrate the clinical risk of post-hyperventilation apnea (PHA) in patients with HVS.Case presentationWe treated two patients with HVS who suffered from PHA. The first, a 21-year-old woman, had a maximum duration of PHA of about 3.5 minutes and an oxygen saturation (SpO2) level of 60%. The second patient, a 22-year-old woman, had a maximum duration of PHA of about 3 minutes and an SpO2 level of 66%. Both patients had loss of consciousness and cyanosis. Because there is no widely accepted regimen for treating patients with prolonged PHA related to HVS, we administered artificial ventilation to both patients using a bag mask and both recovered without any after effects.ConclusionThese cases show that some patients with HVS develop prolonged PHA or severe hypoxia, which has been shown to lead to death in some cases. Proper treatment must be given to patients with HVS who develop PHA to protect against this possibility. If prolonged PHA or severe hypoxemia arises, respiratory assistance using a bag mask must be done immediately.
The Journal of Clinical Endocrinology and Metabolism | 2002
Tomomi Shiiya; Masamitsu Nakazato; Masanari Mizuta; Yukari Date; Muhtashan S. Mondal; Muneki Tanaka; Shin-ichi Nozoe; Hiroshi Hosoda; Kenji Kangawa; Shigeru Matsukura
European Journal of Endocrinology | 2002
Muneki Tanaka; Tetsuro Naruo; Tetsuro Muranaga; Daisuke Yasuhara; Tomomi Shiiya; Masamitsu Nakazato; Shigeru Matsukura; Shin-ichi Nozoe