Yoshio Nakamura

Publications (8)16.93 Total impact

• Article: Case of adrenocorticotropic hormone-independent macronodular adrenal hyperplasia with possible adrenal hypersensitivity to angiotensin II

  Yoshio Nakamura, Yonsu Son, Yasuhiro Kohno, Dai Shimono, Naomitsu Kuwamura, Hiroyuki Koshiyama, Hironobu Sasano, Tadashi Matsuda
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  ABSTRACT: With increasing case reports, it has been indicated that some cases with adrenocorticotropic hormone (ACTH)-independent macronodular adrenal hyperplasia (AIMAH) show abnormal responses in cortisol to various stimulation tests. Here we report a case of AIMAH that showed an aberrant response to angiotensin II via AT1 receptor in cortisol hypersecretion. A 53-yr-old man was admitted to our division seeking further examinations for the possible diagnosis of Cushing's syndrome. He had hypertension, diabetes mellitus, and physical stigmata, such as moon face and central obesity. His plasma ACTH level was undetectable, and plasma cortisol level was high. Plasma cortisol showed no normal diurnal rhythm and was not suppressed after the administration of 8 mg of dexamethasone. Abdominal computed tomography demonstrated nodular enlargement of bilateral adrenal glands. He was diagnosed with Cushing's syndrome owing to AIMAH. An injection of arginine vasopressin (AVP) increased plasma cortisol and aldosterone levels, whereas ACTH remained undetectable. After 4 h in an upright position, plasma cortisol and aldosterone levels were increased. Pretreatment with candesartan, angiotensin II receptor AT1 antagonist, blocked the increase in plasma cortisol level. These results suggested a possibility of adrenal hypersensitivity to angiotensin II and AVP in cortisol secretion. Bilateral laparoscopic adrenalectomy was performed. The histological findings of the specimen were compatible with AIMAH. In summary, we have made the first report on a case of AIMAH with possible hypersensitivity to angiotensin II.
  Endocrine 04/2012; 15(1):57-61. · 1.42 Impact Factor
• Article: Pitavastatin reduces elevated IL-18 levels in Japanese subjects with hypercholesterolemia: sub-analysis of Kansai investigation of statin for hyperlipidemic intervention in metabolism and endocrinology (KISHIMEN).

  Yoshio Fujioka, Akira Fukuda, Tatsuro Ishida, Shinji Kagimoto, Yoshio Nakamura, Akane Iwakura, Kyoko Hara, Taizo Yamamoto, Akira Kuroe, Michihiro Ohya, [......], Yoshiyuki Hamamoto, Sachiko Honjo, Hiroki Ikeda, Koichiro Nabe, Kinsuke Tsuda, Ataru Taniguchi, Kiyoshi Tanaka, Hiroyuki Koshiyama, Noriaki Kume, Ken-ichi Hirata
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  ABSTRACT: Pitavastatin significantly improved lipid profiles and reduced serum high-sensitivity C-reactive protein (hs-CRP) levels in a multi-center and prospective study. The aim of this study was to explore the effect of pitavastatin on serum levels of another inflammatory biomarker, interleukin-18 (IL-18), in a sub-analysis of the previous multi-center prospective study. The subjects were 83 patients derived from the KISHIMEN study. Pitavastatin (1-2 mg/day) was administered for 12 months. Serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), remnant-like particle cholesterol (RLP-C), triglycerides (TG), IL-18, and high sensitivity C-reactive protein (hs-CRP) levels were measured. TC, LDL-C, and RLP-C levels were significantly reduced by 18.3%, 30.1%, and 21.0% (mean values) at 12 months after pitavastatin administration. TG levels were decreased by 9.8% in subjects whose basal TG levels were above 150 mg/dL. HDL-C levels were significantly increased at 6 months (11.9%). Pitavastatin did not significantly alter IL-18 levels in overall subjects, but reduced IL-18 levels in the highest quartile by 24.5% (median value) at 12 months. Pitavastatin significantly reduced hs-CRP levels by 28.6% in overall subjects and by 62.4% in the highest quartile at 12 months. There was a significant correlation between IL-18 and hs-CRP at baseline after both values were transformed into logarithms (Pearson's correlation coefficient, r = 0.259, p = 0.0181); however, percent changes in these levels were not significantly correlated. Pitavastatin significantly improves lipid profiles, and reduces enhanced inflammation monitored by IL-18, as well as by hs-CRP, in hypercholesterolemic subjects.
  Journal of atherosclerosis and thrombosis 10/2010; 18(1):8-15. · 2.69 Impact Factor
• Article: Effects of pitavastatin on lipid profiles and high-sensitivity CRP in Japanese subjects with hypercholesterolemia: Kansai Investigation of Statin for Hyperlipidemic Intervention in Metabolism and Endocrinology (KISHIMEN) investigatars.

  Hiroyuki Koshiyama, Ataru Taniguchi, Kiyoshi Tanaka, Shinji Kagimoto, Yoshio Fujioka, Kenichi Hirata, Yoshio Nakamura, Akane Iwakura, Kyoko Hara, Taizo Yamamoto, [......], Michihiro Ohya, Shimpei Fujimoto, Yoshiyuki Hamamoto, Sachiko Honjo, Hiroki Ikeda, Koichiro Nabe, Kinsuke Tsuda, Nobuya Inagaki, Yutaka Seino, Noriaki Kume
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  ABSTRACT: The effect of pitavastatin on high-sensitivity C-reactive protein (hs-CRP) has not been reported, yet, in humans. We, therefore, investigated the effects of pitavastatin on lipid profiles and hs-CRP in Japanese subjects with hypercholesterolemia. The subjects were 178 Japanese with hypercholesterolemia, including 103 (58%) with type 2 diabetes. Pitavastatin (12 mg/day) was administered for 12 months. Serum low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), remnant-like particle cholesterol (RLP-C), triglycerides (TG) and hs-CRP levels were measured for 12 months. Serum LDL-C and RLP-C levels were significantly decreased by 30.3% and 22.8%, respectively. Serum TG levels were decreased by 15.9% in subjects with basal TG levels above 150 mg/dl. Serum HDL-C levels were significantly increased. The administration of pitavastatin reduced serum hs-CRP levels by 34.8%. No serious adverse events were observed, including changes in glycosylated hemoglobin levels of diabetic patients. These results suggest that pitavastatin significantly improves lipid profiles and reduces proinflammatory responses, without adverse effects, in Japanese subjects with hypercholesterolemia, including those with diabetes mellitus.
  Journal of atherosclerosis and thrombosis 01/2009; 15(6):345-50. · 2.69 Impact Factor
• Article: Comparison of effects of amlodipine and angiotensin receptor blockers on the intima-media thickness of carotid arterial wall (AAA study: amlodipine vs. ARB in atherosclerosis study).

  Hiroki Ikeda, Jun Minamikawa, Yoshio Nakamura, Sachiko Honjo, Yoshiyuki Hamamoto, Yoshiharu Wada, Kouichiro Nabe, Hiroyuki Koshiyama
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  ABSTRACT: Although there have been increasing reports, which suggest that angiotensin receptor blockers (ARBs) may have anti-atherogenic actions, most of them are performed in vitro and there are a few reports about anti-atherogenic action in vivo. Especially, in humans, there have been no reports about effect of ARBs on atheroslocerosis. On the other hand, there have been several reports, including ours, which indicate that amlodipine, a calcium channel blocker, has a unique property to cause a reduction in the intima-media thickness (IMT) of common carotid artery, which is established to be an indicator of early atherosclerotic lesion, in humans. The present study investigated which of amlodipine and/or ARBs might have more profound effect on IMT progression. The study included 104 hypertensive patients with type 2 diabetes. They were divided into the two groups: the amlodipine group (n=58), who received amlodipine (2.5-5mg/day) and the ARB group (n=46), who received losartan (25-50mg/day), candesartan (4-8 mg/day), valsaratan (40-80 mg/day) or telmisartan (20-40 mg/day). IMT changes were examined during an average of 56.9 weeks. The amlodipine group showed a significant decrease in IMT compared to the ARB group (-0.046 [S.E. 0.161] mm vs. 0.080 [S.E. 0.255] mm, P<0.05). These results suggest that amlodipine has an inhibitory effect on early atherosclerotic process, and that ARBs do not have any effect on it in hypertensive patients with type 2 diabetes.
  Diabetes research and clinical practice 12/2008; 83(1):50-3. · 2.16 Impact Factor
• Article: Hypovitaminosis D is frequent in Japanese subjects with type 2 diabetes.

  Hiroyuki Koshiyama, Hiroki Ikeda, Sachiko Honjo, Yoshio Nakamura, Kiyoshi Tanaka, Naoko Tsugawa, Toshio Okano
  Diabetes Research and Clinical Practice 07/2007; 76(3):470-1. · 2.75 Impact Factor
• Article: Pancreatic endocrine tumor in Japan.

  Ryuichiro Doi, Izumi Komoto, Yoshio Nakamura, Junichiro Kawamura, Koji Fujimoto, Michihiko Wada, Tsuneo Saga, Masayuki Imamura
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  ABSTRACT: Japanese clinicians and scientists have contributed significantly to reporting, investigating, and managing patients with pancreatic endocrine tumors and other multiple endocrine neoplasias for the past several decades. This article summarizes the latest progress in this field in Japan. Particularly, our contribution to the development of diagnostic and localization methods is reviewed. Further, the present use of somatostatin receptor scintigraphy and the application of the laparoscopic surgery for pancreatic endocrine tumor in Japan are discussed.
  Pancreas 05/2004; 28(3):247-52. · 2.39 Impact Factor
• Article: A case of normoreninemic aldosterone-producing adenoma associated with chronic renal failure: case report and literature review.

  Hiroyuki Koshiyama, Takeshi Fujisawa, Naomitsu Kuwamura, Yoshio Nakamura, Hiroshi Kanamori, Emi Oida, Akira Hara, Takashi Suzuki, Hironobu Sasano
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  ABSTRACT: The diagnosis of aldosterone-producing adenoma (APA) is challenging for endocrinologists, as APA does not always present with the typical constellation of clinical and laboratory features, such as hypertension, hypokalemia, suppressed plasma renin activity (PRA), and high plasma aldosterone concentration (PAC). Very recently, several studies have indicated that APA can be discovered even in normokalemic subjects with normal PRA more frequently than previously considered. Here we report a case of APA associated with chronic renal failure, which showed normokalemia and normal PRA. The patient was referred to our clinic for evaluation of an incidentally discovered adrenal mass with abnormally high PAC. After 6 yr, it was found that the right adrenal tumor showed a marked increase in size. Endocrinological examinations indicated normal PRA and markedly high PAC. Aldosterone showed a better response to the upright posture test than that to ACTH stimulation test. The diagnosis of APA was made based on the markedly high PAC to PRA ratio and the adrenocortical scintigraphy, which showed unequivocal uptake into the tumor. Right laparoscopic adrenalectomy was performed, revealing a right adrenocortical adenoma with massive hemorrhage. Histopathological examinations revealed the presence of two independent adrenocortical adenomas, one APA with predominant clear tumor cells and few c17 (17alpha-hydroxylase) immunoreactivity and the other, cortisol producing adenoma with compact cytoplasm and abundant C17 immunoreactivity. This case indicates a difficulty of diagnosis of "normoreninemic APA" with renal failure. This case is in line with the recent concept that APA is a continuous condition in which only a minority of patients have the classical clinical picture of primary aldosteronism such as hypokalemia. It is possible that normokalemic APA constitutes the most common presentation of the disease.
  Endocrine 09/2003; 21(3):221-6. · 1.42 Impact Factor
• Article: High-dose calcium stimulation test in a case of insulinoma masquerading as hysteria.

  Yoshio Nakamura, Ryuichiro Doi, Yasuhiro Kohno, Dai Shimono, Naomitsu Kuwamura, Koichi Inoue, Hiroyuki Koshiyama, Masayuki Imamura
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  ABSTRACT: It is reported that some cases with insulinoma present with neuropsychiatric symptoms and are often misdiagnosed as psychosis. Here we report a case of insulinoma masquerading as hysteria, whose final diagnosis could be made using high-dose calcium stimulation test. A 28-yr-old woman was referred presenting with substupor, mutism, mannerism, restlessness, and incoherence. Laboratory examinations revealed hypoglycemia (33 mg/dL) and detectable insulin levels (9.7 microU/mL), suggesting the diagnosis of insulinoma. However, neither imaging studies nor selective arterial calcium injection (SACI) test with a conventional dose of calcium (0.025 mEq/kg) indicated the tumor. High-dose calcium injection (0.05 mEq/kg) evoked insulin secretion when injected into superior mesenteric artery. A solitary tumor in the head of the pancreas was resected, and her plasma glucose returned to normal. Postoperatively, iv injection of secretin resulted in a normal response of insulin, which was not found preoperatively. This case suggests the usefulness of the SACI test with high-dose of calcium in the case of insulinoma when the standard dose fails to detect such a tumor.
  Endocrine 12/2002; 19(2):127-30. · 1.42 Impact Factor