Obesity is less common in the Asian population, but Asian people may be susceptible to obesity-associated metabolic dysregulation. Accumulating evidence suggests that insulin resistance is closely associated with ectopic fat accumulation in the liver. Whether this correlation is due to a causal relationship between the conditions has long been the subject of debate. Insulin resistance and type 2 diabetes affects liver pathology, typically leading to nonalcoholic fatty liver disease (NAFLD) by dynamically altering the hepatic genes involved in glucose and lipid metabolism. Conversely, how overnutrition induces hepatic insulin resistance has been studied intensively, and has been shown to involve excessive energy flux into mitochondria, toxic lipids, reactive oxygen species, and hepatokines. In this review, we focus on NAFLD both as a consequence and as a cause of insulin resistance through lessons learned from the liver of patients with type 2 diabetes.
To clarify the necessity of improving glucose metabolism in polycystic ovary syndrome (PCOS) women as early as possible, 111 PCOS women with normal glucose tolerance and 92 healthy age-matched controls were recruited to investigate glucose levels distribution, insulin sensitivity and β cell function. 91 PCOS women and 33 controls underwent hyperinsulinemic-euglycemic clamp to assess their insulin sensitivity, which was expressed as M value. β cell function was estimated by homeostatic model assessment (HOMA)-β index after adjusting insulin sensitivity (HOMA-βad index). Compared with lean controls, lean PCOS women had similar fasting plasma glucose (FPG), higher postprandial plasma glucose (PPG) (6.03±1.05 vs. 5.44±0.97 mmol/L, P<0.05), lower M value but similar HOMA-βad index, while overweight/obese PCOS women had higher levels of both FPG (5.24±0.58 vs. 4.90±0.39, P<0.05) and PPG (6.15±0.84 vs. 5.44±0.97 mmol/L, P<0.05), and lower levels of both M value and HOMA-βad index. Linear regression and ROC analysis found BMI was independently associated with M value and HOMA-βad index in PCOS women separately, and the cutoff of BMI indicating impaired β cell function of PCOS women was 25.545kg/m2. In conclusion, insulin resistance and dysregulation of glucose metabolism were common in Chinese PCOS women with normal glucose tolerance. BMI ≥ 25.545kg/m2 indicated impaired β cell function in PCOS women with normal glucose tolerance.
Measurements of insulin-like growth factor-I (IGF-I) are useful not only for diagnosis and management of patients with growth hormone (GH)-related disorders but also for assessing nutritional status. We reported population-based references of serum IGF-I in 1996. However, they did not properly reflect data in the transition period from puberty to maturity. The aim of the present study was to re-establish a set of normative data for IGF-I for the Japanese population. The study included 1,685 healthy Japanese subjects (845 males, 840 females) from 0 to 83 years old. Subjects suffering from diseases that could affect IGF-I levels were excluded. Obese or extremely thin adult subjects were also excluded. IGF-I concentrations were determined by commercially available immunoradiometric assays. The reference intervals were calculated using the LMS method. Median IGF-I levels reached 310 ng/mL in males at the age of 14 years and 349 ng/mL in females at the age of 13 years, falling to 124 ng/mL and 103 ng/mL, respectively, by the age of 70 years. The mean pretreatment IGF-1 SD scores in patients with severe GH deficiency (GHD) obtained from the database of the Foundation for Growth Science and from clinical studies for adult GHD were -2.1±1.6 and -4.9±2.5, respectively. The present study established age- and gender-specific normative IGF-I data for the Japanese population and showed the utility of these references for screening patients with severe GHD.
The aim of the present study was to compare the associations of anti-Müllerian hormone (AMH) with clinical or biochemical characteristics between women with and without polycystic ovary syndrome (PCOS). We also explored the optimal cutoff point of AMH to diagnose PCOS. A cross-sectional study was performed in 87 women diagnosed with PCOS and 53 healthy control subjects. Body mass index (BMI), indices of insulin resistance, metabolic syndrome-related variables, reproductive hormones and serum AMH were measured in all subjects. We conducted receiver operating characteristic (ROC) curve analysis to determine the cutoff of AMH for diagnosis of PCOS. Serum AMH levels were significantly (p <0.001) higher in women with PCOS after adjustment for age and BMI. AMH levels were not significantly related with obesity, indices of insulin resistance, and metabolic syndrome-related variables in both PCOS and control groups. In the control group, AMH levels showed positive correlations with total testosterone (p <0.001), free testosterone (p=0.024), and adiponectin (p=0.002), and showed negative correlations with age (p=0.010) and estradiol (E2) (p=0.012). However, only total (p=0.044) and free testosterone (p=0.012) levels showed significant positive correlations with serum AMH level in PCOS group. ROC curve analysis showed a cutoff point for AMH of 7.82 ng/mL (sensitivity 75.9%, specificity 86.8%) for diagnosis of PCOS. Differences of the association of AMH with clinical or biochemical characteristics between women with PCOS and control groups were observed. This might contribute to the pathogenesis of PCOS, although further investigation is necessary to elucidate the detailed mechanism.
A 67-year-old woman with familial clustering of thyroid papillary adenocarcinoma was diagnosed with acromegaly due to pituitary macroadenoma. She had multiple skin vegetations, but had no parathyroid and pancreas diseases. Before transsphenoidal surgery, she was further diagnosed as having a duodenal tumor and multiple hypervascular liver nodules. Biopsy specimens from the duodenal tumor and liver nodules were diagnosed histologically as moderately differentiated adenocarcinoma. Immunohistochemically, the tumor cells were positive for chromogranin, synaptophysin and somatostatin receptor 2a, suggestive for neuroendocrine features. After surgery, the patient was not in biochemical remission, and octreotide treatment was initiated. The duodenal cancer was treated with chemotherapy (neoadjuvant cisplatin and S-1). After 24 months, the patient’s insulin-like growth factor I level had been normalized, and her liver tumors had not progressed macroscopically. This is a rare case of acromegaly associated with multiple endocrine tumors, not being categorized as conventional multiple endocrine neoplasia. Octreotide treatment might have had beneficial effects on our patient’s duodenal adenocarcinoma and liver metastases, both directly via SSTR2a and indirectly via GH suppression, thereby contributing to their slow progression.
The morbidity and mortality of individuals with multiple endocrine neoplasia type 1 (MEN1) can be reduced by early diagnosis of MEN1 and related endocrine tumors. To find factors contributing to early diagnosis, we collected clinical information on MEN1 patients through a MEN study group, “MEN Consortium of Japan” and analyzed the time of initial symptom-dependent detection of parathyroid tumors, gastro-entero-pancreatic neuroendocrine tumors (GEPNETs) and pituitary tumors, and that of tumor detection-dependent MEN1 diagnosis in 560 patients. Main tumors were identified up to 7.0 years after symptoms appeared and there was no difference in age at the diagnosis of GEPNETs alone between probands and family members. In patients with typical symptoms (peptic ulcers, urolithiasis, fasting hypoglycemia, bone fracture/loss and amenorrhea), the mean interval between symptom manifestation and tumor detection was extended up to 9.6 years. In particular, 21.7% (5/23) of patients with amenorrhea were diagnosed with pituitary tumors in under one year. In patients with peptic ulcers (from parathyroid tumors or GEPNETs) and urolithiasis (from parathyroid tumors), the interval was positively correlated with age at tumor detection. The interval between tumor detection and MEN1 diagnosis was also prolonged to approximately four years in patients with fasting hypoglycemia (from GEPNETs) and amenorrhea. A substantial delay in the diagnosis of symptom-related tumors and subsequent MEN1 and inadequate screening of GEPNETs in family members were indicated. A greater understanding of MEN1 may assist medical practitioners to make earlier diagnoses, to share patients’ medical information and to give family members sufficient disease information.
In the present study, we measured carotid artery intima-media thickness (CIMT) and assessed several metabolic factors in middle-aged healthy Japanese men to clarify the relation between testosterone and atherosclerosis. The study comprised 176 male employees aged ≥40 years who visited Osaka University Healthcare Center for their annual health examinations. Serum total testosterone (TT) concentration was measured using radioimmunoassay (RIA) and serum free testosterone concentration was measured using analog ligand RIA (aFT). A multivariate model adjusted for age, body mass index, mean arterial pressure and treatment for hypertension demonstrated a significant association between aFT and CIMT. Even after adjustment for other clinically relevant factors, the significant association between aFT and CIMT was not attenuated. After adjustment for all other clinically relevant factors, both univariate and multivariate models ascertained the stepwise association that a level of aFT of ≤10.0 pg/mL was significantly associated with CIMT. However, the association between TT and CIMT was not significant in either univariate or multivariate models. We conclude that our finding showing that low serum aFT level is an influencing and independent risk factor for CIMT is of value in the clinical setting because no other studies, to our knowledge, have conducted multivariate analyses using the various metabolic factors included in the present analyses.
Papillary thyroid carcinoma (PTC) often has poorly differentiated components, and it is discriminated from others and classified as an independent entity in the General Rules for the Description of Thyroid Cancer by Japanese Society of Thyroid Surgery (JSTS). In this study, we compared the prognostic significance between this type of poorly differentiated carcinoma (PDC-JSTS) and our risk classification system based on pre- and intraoperative findings in a series of PTC patients. The 10-year lymph node- and distant organ recurrence-free survival (LN-DFS and DRFS) and cause-specific survival (CSS) of high-risk patients were much poorer than in PDC-JSTS patients. In multivariate analysis, PDC-JSTS independently predicted a poor prognosis, but prognostic impacts for LN-DFS, DRFS, and CSS of high-risk in our risk classification were stronger than those of PDC-JSTS. In conclusion, it is appropriate that PDC-JSTS is defined as a subtype of PTC rather than as an independent entity.
A 24-year-old female patient with cushingoid appearance was admitted in May 2000. The endocrine studies showed ACTH-independent Cushing’s syndrome. A 2-day high-dose dexamethasone suppression test (HDDST) revealed paradoxical increase of 24 h urinary free cortisol (UFC). Abdominal computed tomography demonstrated a left adrenal nodule (3 x 2 cm in diameter). An adrenal scintigram with 131I-6β-iodomethyl-19-norcholesterol showed uptake of the isotope in the left adrenal gland and non-visualization in the right adrenal gland throughout the examination course. A retroperitoneoscopic left total adrenalectomy was performed in July 2000. The cut surface of the left adrenal was yellow-tan grossly. Microscopically, the left adrenal nodule contained a nonpigmented adrenocortical adenoma (NP) and another focal primary pigmented nodular adrenocortical disease (PPNAD, FP) mixed lesion. The immunohistochemical studies of CYP17 demonstrate positive in NP and FP of the left adrenal gland. Very low baseline morning plasma cortisol (0.97 μg/dL) and subnormal ACTH (8.16 pg/mL) levels were measured 1.5 months after left adrenalectomy. Right adrenal gland recovered its function 6 months after left adrenalectomy. Plasma cortisol could be suppressed to 3.47 μg/dL by overnight low-dose dexamethasone suppression test 65 months after left adrenalectomy. Cushingoid features still did not appear 122 months after left adrenalectomy. In May 2011, this patient was readmitted due to cushingoid characteristics. Paradoxical rise of 24-h UFC to 2-day HDDST was demonstrated. Ultrasonography of thyroid showed bilateral thyroid cysts. Subtotal right adrenalectomy about 80% of right adrenal was performed. Diffuse PPNAD of the right adrenal was proved pathologically. Immunohischemical stain for CYP17 is positive in the right adrenal gland but weaker positive than that in the left adrenal gland. The genetic study of the peripheral blood, left adrenocortical nodule, and right PPNAD all showed p.R16X (c.46C>T) mutation of the PRKAR1A gene.
The diagnosis of pheochromocytoma depends on the documentation of catecholamine overproduction. The use of urinary fractionated metanephrines has recently become common for the diagnosis of pheochromocytoma. In order to avoid false positive and false negative results, optimal cut-off levels are necessary; however, there have been few published reports on whether different cut-off levels are needed to diagnose pheochromocytoma according to sex. We reviewed the medical records of 815 subjects (including 103 pheochromocytoma patients) whose of 24-h urinary fractionated metanephrine was measured using high-performance liquid chromatography methods and adrenal imaging at Samsung Medical Center. Receiver operating characteristic (ROC) curves were used to determine cut-off values according to sex. The upper limit values of fractionated metanephrine in healthy volunteers and the control group were significantly higher in male subjects compared with females. When we applied cut-off values according to sex, the diagnostic efficacies (defining a positive test as either metanephrine or normetanephrine levels above the cut-off value) were a sensitivity of 96% in male subjects and 98.1% in female subjects and a specificity of 88.6% in male subjects and 94.1% in female subjects. However, when we applied cut-off values without considering sex, the specificity decreased from 88.6% to 77.8% in male subjects. In this study, urinary fractionated metanephrines had a high level of sensitivity and specificity for the diagnosis of pheochromocytoma. However, diagnostic cut-off values were higher in male subjects than in female subjects. Therefore, different cut-off values may be needed according to sex to diagnose pheochromocytoma in Koreans.
Papillary thyroid carcinoma (PC) can occasionally include a squamous cell carcinoma (SCC) component. In this study, we evaluated the effect of weekly paclitaxel chemotherapy in 3 patients with PC including an SCC component. None of these patients had lesions of anaplastic carcinoma on pathological examination. Weekly paclitaxel chemotherapy was performed as an induction chemotherapy for 2 patients. All 3 patients underwent locally curative surgery and weekly paclitaxel chemotherapy after surgery as an adjuvant therapy. The response to the chemotherapy was evaluated based on the RECIST guideline (version 1.1). Two patients had partial responses (PRs) and the remaining 1 had stable disease (SD). The response rate was 67% and the clinical benefit rate (PR+SD) was 100%. One patient died of the growth of lung metastases that had been detected before surgery 22 months after the diagnosis. The remaining 2 are still alive, 14 and 22 months after the diagnosis, respectively. Taken together, weekly paclitaxel may be one of the effective adjuvant therapies for PC with an SCC component.
We investigated the effect of metformin on hepatic glucose production and peripheral glucose uptake in Asian patients with type 2 diabetes mellitus. We recruited ten Japanese patients whose fasting glucose levels remained poorly controlled under meal-time injection of short-acting insulin. Metformin was added to their insulin therapy, and both hepatic glucose production and peripheral glucose uptake were assessed before and one week after metformin treatment, with the use of stable isotope [6,6-2H2] glucose. Metformin was titrated to a maximum dose of 500 mg. As a result, fasting glucose levels and hepatic glucose production were significantly improved after the metformin treatment (p < 0.01 and 0.02), whereas their peripheral glucose uptake was not significantly changed (p = 0.63). Furthermore, the change of fasting glucose levels was significantly correlated with that of hepatic glucose production, whose coefficient ρ was 0.76 (p = 0.01). On the other hand, there was no significant correlation between the change of fasting glucose levels and that of peripheral glucose uptake (p = 0.43). In conclusion, low dose of metformin significantly reduced hepatic glucose production in Japanese patients with type 2 diabetes mellitus. The efficacy of metformin on correcting fasting hyperglycemia was strongly associated with reduced hepatic glucose production, rather than ameliorated peripheral glucose uptake.