Satoshi Tanaka

Tokyo Women's Medical University, Edo, Tokyo, Japan

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Publications (6)11.62 Total impact

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    ABSTRACT: In Japan, the growth hormone (GH) assay has been standardized since April 2005 through use of a uniform recombinant human GH (rhGH) standard. Since then, GH values measured using the rhGH standard have been approximately 40% lower than previous values measured using kit standards based on the WHO standards for hGH of pituitary origin. However, the Japanese criteria for evaluating treatment outcomes for acromegaly have remained the same: a nadir GH during a 75 g OGTT <1 µg/L is considered cured, 1≤GH<2.5µg/L is considered inadequately controlled, and ≥2.5 µg/L is considered poorly controlled, instead of these levels were lowered to 60%, i.e. from 1 to 0.6 µg/L for cured and from 2.5 to 1.5µg/L for inadequately controlled (termed as "newly proposed criteria" in this study). We investigated the effects of standardization of the GH assay on the evaluation of post-surgical disease activity in 50 patients with acromegaly (M/F 19/31, 21-72 yr.). Post-surgical nadir GH levels during OGTT were positively correlated with the IGF-I SD score 3 months after TSS. Five of 6 patients whose post-surgical nadir GH levels ranged between 0.6 and 1 µg/L had normal serum IGF-I levels 3 months after TSS. Rates of improvement in glucose metabolism did not differ when patients were classified based on the present criteria vs. the newly proposed criteria. In conclusion, the current Japanese remission criteria for acromegaly still accurately reflect post-surgical disease activity in most patients, though long-term observation is still required.
    No preview · Article · Jun 2011 · Endocrine Journal
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    ABSTRACT: To describe the unique association of corticotropin-independent Cushing syndrome caused by cortisol- and androgen-secreting black adrenal cortical adenomas with myelolipomatous change. We report the clinical, laboratory, radiologic, and pathologic findings from 2 patients who presented with androgen excess and typical signs and symptoms of Cushing syndrome. Endocrine investigations showed high serum cortisol concentrations that lacked diurnal rhythm, undetectable plasma corticotropin concentrations, and absence of serum cortisol suppression after overnight dexamethasone suppression tests. Serum levels of adrenal androgens were elevated. Computed tomography of the abdomen revealed unilateral adrenal masses (largest lesional diameters 4.0 and 3.1 cm). On the basis of the plurihormonal hypersecretion and the imaging characteristics, adrenocortical carcinoma was considered as a possible diagnosis. However, histopathologic analysis in both patients revealed black adrenal cortical adenomas with myelolipomatous change. After surgery, adrenal androgens normalized, and the signs and symptoms of Cushing syndrome and androgen excess resolved. There was no evidence of recurrent disease at last follow-up. A unique form of corticotropin-independent Cushing syndrome is described: cortisol- and androgen-secreting black adrenal cortical adenomas with myelolipomatous change. Although most patients with corticotropin-independent Cushing syndrome associated with androgen excess prove to have adrenocortical carcinoma, the clinician should be aware of the possibility of benign, black adrenal adenomas in this clinical setting.
    No preview · Article · May 2011 · Endocrine Practice
  • Satoshi Tanaka · Izumi Fukuda · Naomi Hizuka · Kazue Takano
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    ABSTRACT: Gender affects the GH secretory pattern both in normal subjects and in patients with acromegaly by an uncertain mechanism. Here, we report the influence of gender on the relationship between serum GH and IGF-I levels and the GH response to dynamic tests in patients with acromegaly. Seventy-four patients with untreated acromegaly (M/F 27/47, age range 22-86 yr.) were studied. The serum GH levels did not differ between male and female (6.1 vs. 8.7 ng/ml; p=0.26), while serum IGF-I levels, IGF-I SDS and the IGF-I/GH ratio were lower in female than those in male (679 vs. 769 ng/ml; p<0.02, 7.3 vs. 9.2 SDS; p<0.02 and 79.6 vs. 141.5; p<0.05). When the subjects were divided into two groups: age <or=50 yr, and age >50 yr, serum IGF-I levels and IGF-I/GH ratios were lower in female than those in male in patients <or=50 yrs (650 vs. 1002 ng/ml; p<0.05 and 59.8 vs. 142.9; p<0.05), but not in patients >50 yrs (684 vs. 680 ng/ml; p=0.39 and 98.7 vs. 118.4; p=0.40). The GH responses to OGTT, TRH, octreotide, and bromocriptine tests were similar in male and female. In conclusion, IGF-I/GH ratio was significantly lower in female than that in male particularly in younger patients with acromegaly. These data suggest that gender, presumably sex steroids in female, may partially modulate the relationship between circulating IGF-I and GH levels in patients with acromegaly.
    No preview · Article · Mar 2010 · Endocrine Journal
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    ABSTRACT: Turner syndrome (TS) is associated with a number of complications including thyroid disease. In this study, the prevalence of thyroid disease was evaluated in Japanese women with TS. The medical charts of 65 TS women (age 30+/-9 years old, range: 15-61), treated with estrogen replacement therapy or with antiosteoporotic pharmaceuticals at our outpatient clinic, were reviewed. History of thyroid disease, titer of thyroid autoantibodies, and thyroid function were recorded. Thyroid autoantibodies were undetectable in 28 of 65 women (43%), and thyroid function was normal in all these women. Of the 37 women with thyroid autoantibodies (57%), 3 had Graves' disease and 20 women were hypothyroidism and diagnosed as Hashimoto' s thyroiditis. The resting 14 women with euthyroidism were also considered to be so-called probable cases of Hashimoto' s thyroiditis. In 20 women with hypothyroidism, 14 (70%) received replacement therapy with levothyroxine. The replacement with levothyroxine started between age 17 and 60 (median: 31 years old). These data showed that more than half of Japanese women with TS in adulthood had thyroid autoantibodies. In women with TS, monitoring of thyroid hormone is important to detect hypothyroidism earlier and start adequate replacement therapy.
    No preview · Article · Sep 2009 · Endocrine Journal

  • No preview · Article · Nov 2006 · Growth Hormone & IGF Research

  • No preview · Article · Nov 2006 · Growth Hormone & IGF Research