Search

Hyperinsulinemia is often observed in obese subjects because of insulin resistance, but it may occur in nonobese subjects with unknown etiology. A 72-year-old man was admitted to our hospital for the examination of hyperinsulinemia, reactive hypoglycemia, and liver dysfunction. The patient’s body mass index was 23.7 kg/m2, but he had an elevated visceral fat area (125 cm2). His laboratory data showed mildly elevated liver enzymes, whereas plasma fasting glucose and serum insulin levels were 91 mg/dL and 52.3 μU/mL, respectively. In a 75-g oral glucose tolerance test, the serum insulin level reached the highest value of 1124 μU/mL at 180 minutes. There was no obvious etiology except for mild liver steatosis shown by liver biopsy. We suspected genetic abnormalities related to hyperinsulinemia. We performed whole-exome sequencing (WES) analyses and identified a heterozygous nonsense variant p.R924X in the insulin receptor (INSR) gene, a novel heterozygous missense variant p.V416M in the AKT1 gene, and a novel hemizygous missense variant p.R310Q in the PHKA2 gene, which is the causative gene of hepatic injury as glycogen storage disease type IX. It was speculated that the INSR gene variant, in addition to visceral fat accumulation, was the main cause of hyperinsulinemia and reactive hypoglycemia, and the remaining 2 variants were also partly responsible for hyperinsulinemia. WES analysis revealed candidate gene variants of hyperinsulinemia and hepatic-type glycogenosis. Thus, WES analysis may be a useful tool for clarifying the etiology when unexplained genetic pathophysiological conditions are suspected.

IntroductionGiven an increasing use of dipeptidyl peptidase-4 (DPP-4) inhibitors to treat patients with type 2 diabetes mellitus in the real-world setting, we conducted a prospective observational study (Japan-based Clinical Research Network for Diabetes Registry: J-BRAND Registry) to elucidate the safety and efficacy profile of long-term usage of alogliptin.Research design and methodsWe registered 5969 patients from April 2012 through September 2014, who started receiving alogliptin (group A) or other classes of oral hypoglycemic agents (OHAs; group B), and were followed for 3 years at 239 sites nationwide. Safety was the primary outcome. Symptomatic hypoglycemia, pancreatitis, skin disorders of non-extrinsic origin, severe infections, and cancer were collected as major adverse events (AEs). Efficacy assessment was the secondary outcome and included changes in hemoglobin A1c (HbA1c), fasting blood glucose, fasting insulin and urinary albumin.ResultsOf the registered, 5150 (group A: 3395 and group B: 1755) and 5096 (3358 and 1738) were included for safety and efficacy analysis, respectively. Group A patients mostly (>90%) continued to use alogliptin. In group B, biguanides were the primary agents, while DPP-4 inhibitors were added in up to ~36% of patients. The overall incidence of AEs was similar between the two groups (42.7% vs 42.2%). Kaplan-Meier analysis revealed the incidence of cancer was significantly higher in group A than in group B (7.4% vs 4.8%, p=0.040), while no significant incidence difference was observed in the individual cancer. Multivariate Cox regression analysis revealed that the imbalanced patient distribution (more elderly patients in group A than in group B), but not alogliptin usage per se, contributed to cancer development. The incidence of other major AE categories was with no between-group difference. Between-group difference was not detected, either, in the incidence of microvascular and macrovascular complications. HbA1c and fasting glucose decreased significantly at the 0.5-year visit and nearly plateaued thereafter in both groups.ConclusionsAlogliptin as a representative of DPP-4 inhibitors was safe and durably efficacious when used alone or with other OHAs for patients with type 2 diabetes in the real world setting.

We herein report the case of a 37-year-old man with both pheochromocytoma and visceral fat accumulation and describe the sequential changes in his adiponectin levels throughout the clinical course from catecholamine crisis until the follow-up for adrenalectomy. His adiponectin level decreased during catecholamine crisis and increased after adrenalectomy. However, his adiponectin level decreased again at two years postoperatively when his visceral fat area greatly increased. This case suggests that catecholamines and visceral fat volume may affect adiponectin metabolism in subjects with pheochromocytoma, which may precipitate cardiovascular complications in this endocrine disease.

Insulin autoimmune syndrome (IAS) involves not only fasting hypoglycemia, but also postprandial hyperglycemia. In the present study, we hypothesized that glycated albumin (GA) levels and the GA/HbA1c ratio, which reflect fluctuations in plasma glucose levels, are elevated in IAS patients. Four IAS patients were enrolled in the present study. Thirty-two non-diabetic subjects matched for gender, age, and BMI were used as the control group. The fasting plasma glucose levels in the IAS patients were significantly lower than in the control group. However, the oral glucose tolerance test (OGTT) revealed impaired glucose tolerance or diabetes mellitus in all the IAS patients, and thus the OGTT 2-h plasma glucose levels were significantly higher than in the control group. The GA levels and the GA/HbA1c ratio in the IAS patients were significantly higher than in the control group, despite no significant difference in the HbA1c levels between the two groups. In one case in which IAS spontaneously went into remission, there was a significant correlation between anti-insulin antibodies and GA, but not HbA1c. Improvement in glucose fluctuations was observed by continuous glucose monitoring in another patient along with improvement in the clinical symptoms. Furthermore, anti-insulin antibodies, GA, and the GA/HbA1c ratio decreased, but HbA1c did not change significantly in three IAS patients along with the improvement in clinical symptoms. These results suggest that GA and the GA/HbA1c ratio are useful indicators for determining the level of disease activity in IAS patients.

The aim of this study was to investigate the clinical and endocrinological characteristics of adrenal incidentalomas in Osaka region, Japan. The study was a multicenter retrospective analysis of 150 patients with adrenal incidentalomas who underwent radiographic and endocrine evaluations between 2005 and 2013. Most adrenal incidentalomas were discovered by computed tomography (77.0%) and the rest were identified by abdominal ultrasonography (14.6%), magnetic resonance imaging (4.2%), or positron emission tomography (4.2%). Adrenal incidentalomas were more frequently localized on the left side than on the right. The average diameter of tumors was 21 ± 11 mm. On endocrinological evaluation, 14 patients were diagnosed with primary aldosteronism (9.3%), 10 with subclinical Cushing's syndrome (6.7%), 7 with pheochromocytoma (4.7%), 7 with Cushing's syndrome (4.7%), 2 with both subclinical Cushing's syndrome and primary aldosteronism (1.3%), and 110 with non-functioning tumors (73.3%). Patients with functioning tumors were significantly younger and had larger tumor diameters than those with non-functioning tumors. Except for hypertension, complications were comparable between patients with functioning and non-functioning tumors, including the presence of glucose intolerance, cardiovascular disease, and dyslipidemia. In conclusion, a higher prevalence of primary aldosteronism was observed compared with a previous report. Complications were comparable between patients with functioning and non-functioning tumors, including the frequencies of glucose intolerance, cardiovascular disease, and dyslipidemia. Long-term follow-up is required in patients with non-functioning tumors because the frequency of complications, such as glucose intolerance, cardiovascular disease, and dyslipidemia, was equal to that in patients with functioning tumors.

AIM Visceral fat accumulation contributes to the development of metabolic syndrome. As visceral fat accumulation increases, adiponectin levels decrease; therefore, adiponectin provides a link between visceral fat accumulation and metabolic disorders. Genome-wide association studies (GWASs) have identified genetic variations in the cadherin 13 (CDH13) gene that are associated with adiponectin levels. METHODS We investigated whether single nucleotide polymorphisms (SNPs) in CDH13 was associated with adiponectin levels and metabolic syndrome traits independent of the visceral fat area (VFA), as measured using computed tomography (CT) in 945 Japanese individuals. RESULTS We found that three CDH13 SNPs reported by recent GWASs (i.e., rs3865188, rs4783244, and rs12051272) were significantly associated with higher adiponectin levels (P ＜ 1 × 10 (-14)), even after adjustment for VFA. However, these adiponectin-inducing alleles of CDH13 SNPs were significantly associated with traits consistent with deteriorating metabolic symptoms, such as higher fasting insulin, homeostasis model assessment-insulin resistance (HOMA-IR) scores, and triglycerides and lower high-density lipoprotein (HDL)-cholesterol levels, similar to increasing VFA and decreasing adiponectin levels. CONCLUSION These results suggested that CDH13 SNPs cause an adiponectin-resistant status to compensate for increasing adiponectin levels and could result in the deterioration of metabolic syndrome traits.

Visceral fat accumulation contributes to the development of insulin resistance, leading to metabolic syndrome. Adiponectin provides a link between visceral fat accumulation and insulin resistance. In addition to environmental factors, genetic factors play important roles in visceral fat accumulation and circulating adiponectin levels. Genome-wide association studies (GWASs) have identified genetic variations in the adiponectin, C1Q and collagen domain containing (ADIPOQ) gene that are associated with adiponectin levels. In this study, we investigated whether ADIPOQ single nucleotide polymorphisms (SNPs) were associated with visceral fat accumulation and insulin resistance. We measured the visceral fat area (VFA) by computed tomography (CT) and examined the presence of the insulin resistance-related phenotype (fasting plasma glucose, fasting insulin, and homeostasis model assessment-insulin resistance [HOMA-IR]) in a set of Japanese individuals (731 men and 864 women) who were genotyped for seven ADIPOQ SNPs reported by recent GWASs (namely, rs6810075, rs10937273, rs1648707, rs864265, rs182052, rs17366568, and rs6773957). SNPs associated with the phenotype (P < 0.05) were then evaluated by association analysis using a second set of the study participants (383 men and 510 women). None of the SNPs was associated with body mass index (BMI) or VFA in men or women. However, the adiponectin-decreasing alleles of rs10937273 and rs1648707 were significantly associated with HOMA-IR (P = 0.0030 and P = 0.00074, respectively) in women, independently of BMI. These SNPs were significantly associated with decreased adiponectin levels in women. Our results suggested that rs10937273 and rs1648707 may affect insulin sensitivity by regulating adiponectin production by adipose tissue in women.

Insulinoma and insulin or insulin receptor (IR) autoantibodies are the main causes of hyperinsulinemic hypoglycemia in adults, but the exact cause in other cases remains obscure. This study is to determine the genetic basis of hyperinsulinemic hypoglycemia in two cases without the above abnormalities. Sequence analysis of IR gene in two patients with adult-onset hyperinsulinemic hypoglycemia and their relatives were performed, and the mutant gene observed in one case was analyzed. Both cases had normal levels of fasting plasma glucose (FPG), fasting hyperinsulinemia, low insulin sensitivity, and hypoglycemia with excessive insulin secretion during oral glucose tolerance test (OGTT). Both reported adult-onset postprandial hypoglycemic symptoms. In one patient, a missense mutation (Arg256Cys) was detected in both alleles of the IR gene, and his parents had the same mutation in only one allele but no hypoglycemia. The other had a novel nonsense mutation (Trp1273X) followed by a mutation (Gln1274Lys) in one allele, and his 9-year old son had the same mutation in one allele, together with hyperinsulinemic hypoglycemia during OGTT. Overexpression experiments of the mutant gene found in Case 1 in mammalian cells showed abnormal processing of the IR protein and demonstrated reduced function of Akt/Erk phosphorylation by insulin in the cells. In two cases of hyperinsulinemic hypoglycemia in adults, we found novel mutations in IR gene considered to be linked to hypoglycemia. We propose a disease entity of adult-onset hyperinsulinemic hypoglycemia syndrome associated with mutations in IR gene.

The predominant risk factor of metabolic syndrome is intra-abdominal fat accumulation, which is determined by waist circumference, waist-hip ratio measurements and visceral fat area (VFA); the latter can be accurately measured by performing computed tomography (CT). In addition to environmental factors, genetic factors play an important role in obesity and fat distribution. New genetic loci associated with body mass index (BMI) and adiposity have been identified by genome-wide association studies (GWASs). This study utilized CT to investigate whether single nucleotide polymorphisms (SNPs) that confer susceptibility to higher BMI are associated with VFA, subcutaneous fat area (SFA), and the ratio of VFA to SFA (V/S ratio). We measured the VFA and SFA of 1424 obese Japanese subjects (BMI ≥ 25 kg/m(2), 635 men and 789 women) who were genotyped for 13 single nucleotide polymorphisms (SNPs) reported by recent GWASs, namely, TNNI3K rs1514175, PTBP2 rs1555543, ADCY3 rs713586, IRS1 rs2943650, POC5 rs2112347, NUDT3 rs206936, LINGO2 rs10968576, STK33 rs4929949, MTIF3 rs4771122, SPRY2 rs534870, MAP2K5 rs2241423, QPCTL rs2287019, and ZC3H4 rs3810291. The G-allele of NUDT3 rs206936 was significantly associated with increased BMI (P = 5.3 × 10(-5)) and SFA (P = 0.00039) in the obese Japanese women. After adjustment with BMI, the association between rs206936 and SFA was not observed. This significant association was not observed in the men. The other SNPs analyzed were not significantly associated with BMI, VFA, SFA, or V/S ratio. Our results suggest that NUDT3 rs206936 is associated with BMI in Japanese women.

AIM Visceral fat accumulation plays an integral role in morbidity and mortality rates by increasing the risk of developing metabolic disorders such as type 2 diabetes, dyslipidemia, and hypertension. New genetic loci associated with fat distribution, measured by waist-hip ratios and computed tomography (CT), have recently been identified by genome-wide association studies in European-descent populations. This study used CT to investigate whether single nucleotide polymorphisms (SNPs) that confer susceptibility to fat distribution are associated with visceral fat area (VFA) and subcutaneous fat area (SFA) in the Japanese population. METHODS We measured the VFAs and SFAs of 1424 obese Japanese subjects (BMI≥25 kg/m(2), 635 men and 789 women) that were genotyped at 15 SNPs, namely, TBX15 rs984222, DNM3 rs1011731, LYPLAL1 rs4846567, GRB14 rs10195252, NISCH rs6784615, ADAMTS9 rs6795735, CPEB4 rs6861681, LY86 rs1294421, VEGFA rs6905288, RSPO3 rs9491696, NFE2L3 rs1055144, ITPR2 rs718314, HOXC13 rs1443512, ZNRF3 rs4823006 and THNSL2 rs1659258. RESULTS The G-allele of LYPLAL1 rs4846567 was borderline associated with an increased ratio of VFA to SFA (V/S ratio; p= 0.0020). LYPLAL1 rs4846567 had a stronger effect on the V/S ratio in women (p= 0.0078) than in men (p= 0.12); however, neither result was significant after Bonferroni correction for multiple comparisons. NISCH rs6784615 was nominally associated with increased VFA (p=0.040) and V/S ratio (p= 0.020). The other SNPs analyzed were not significantly associated with body mass index (BMI), VFA, or SFA. CONCLUSION Our results suggest that LYPLAL1 rs4846567 and NISCH rs6784615 may influence fat distribution in the Japanese population.

A 70-year-old woman with no history of diabetes was admitted to the hospital for the management of hypoglycemia. Her fasting plasma glucose level was 54 mg/dL with an extremely high serum immunoreactive insulin level (1,210 μU/mL). She had high titers of anti-insulin antibodies and exhibited the DRB1*0406 genotype for HLA-DR4, leading to a diagnosis of insulin autoimmune syndrome. She had been taking several health preparations for approximately 10 years; however, all were thiol group-free. Due to frequent episodes of nocturnal hypoglycemia, the health preparations were discontinued and the patient was treated with cornstarch. This protocol successfully ameliorated the hypoglycemic episodes and normalized the patient's laboratory and serological test results.

The predominant risk factor of metabolic syndrome is intra-abdominal fat accumulation, which is determined by waist circumference, waist-hip ratio measurements and visceral fat area (VFA); the latter can be accurately measured by performing computed tomography (CT). In addition to environmental factors, genetic factors play an important role in obesity and fat distribution. New genetic loci associated with body mass index (BMI) and adiposity have been identified by genome-wide association studies (GWASs). This study utilized CT to investigate whether single nucleotide polymorphisms (SNPs) that confer susceptibility to higher BMI are associated with VFA, subcutaneous fat area (SFA), and the ratio of VFA to SFA (V/S ratio). We measured the VFA and SFA of 1424 obese Japanese subjects (BMI ≥ 25 kg/m(2), 635 men and 789 women) who were genotyped for 13 single nucleotide polymorphisms (SNPs) reported by recent GWASs, namely, TNNI3K rs1514175, PTBP2 rs1555543, ADCY3 rs713586, IRS1 rs2943650, POC5 rs2112347, NUDT3 rs206936, LINGO2 rs10968576, STK33 rs4929949, MTIF3 rs4771122, SPRY2 rs534870, MAP2K5 rs2241423, QPCTL rs2287019, and ZC3H4 rs3810291. The G-allele of NUDT3 rs206936 was significantly associated with increased BMI (P = 5.3 × 10(-5)) and SFA (P = 0.00039) in the obese Japanese women. After adjustment with BMI, the association between rs206936 and SFA was not observed. This significant association was not observed in the men. The other SNPs analyzed were not significantly associated with BMI, VFA, SFA, or V/S ratio. Our results suggest that NUDT3 rs206936 is associated with BMI in Japanese women.

Visceral fat accumulation has an important role in increasing the morbidity and mortality rates, by increasing the risk of developing several metabolic disorders, such as type 2 diabetes, dyslipidemia and hypertension. New genetic loci that are associated with increased systolic and diastolic blood pressures have been identified by genome-wide association studies in Caucasian populations. This study investigates whether single nucleotide polymorphisms (SNPs) that confer susceptibility to high blood pressure are also associated with visceral fat obesity. We genotyped 1279 Japanese subjects (556 men and 723 women) who underwent computed tomography for measuring the visceral fat area (VFA) and subcutaneous fat area (SFA) at the following SNPs: FGF5 rs16998073, CACNB2 rs11014166, C10orf107 rs1530440, CYP17A1 rs1004467, NT5C2 rs11191548, PLEKHA7 rs381815, ATP2B1 rs2681472 and rs2681492, ARID3B rs6495112, CSK rs1378942, PLCD3 rs12946454, and ZNF652 rs16948048. In an additive model, risk alleles of the CYP17A1 rs1004467 and NT5C2 rs11191548 were found to be significantly associated with reduced SFA (P=0.00011 and 0.0016, respectively). When the analysis was performed separately in men and women, significant associations of rs1004467 (additive model) and rs11191548 (recessive model) with reduced VFA (P=0.0018 and 0.0022, respectively) and SFA (P=0.00039 and 0.00059, respectively) were observed in women, but not in men. Our results suggest that polymorphisms in the CYP17A1 and NT5C2 genes influence a reduction in both visceral and subcutaneous fat mass in Japanese women.

The predominant risk factor of metabolic syndrome is intra-abdominal fat accumulation, which is determined by waist circumference and waist-hip ratio measurements and visceral fat area (VFA) that is measured by computed tomography (CT). There is evidence that waist circumference and waist-hip ratio in the Caucasian population are associated with variations in several genes, including neurexin 3 (NRXN3), transcription factor AP-2β (TFAP2B), methionine sulfoxide reductase A (MSRA), lysophospholipase-like-1 (LYPLAL1), fat mass and obesity associated (FTO) and melanocortin 4 receptor (MC4R) genes. To investigate the relationship between VFA and subcutaneous fat area (SFA) and these genes in the recruited Japanese population, we genotyped 8 single-nucleotide polymorphisms (SNPs) in these 6 genes from 1228 subjects. Multiple regression analysis revealed that gender, age, and rs1558902 and rs1421085 genotypes (additive model) in FTO were significantly associated with body mass index (BMI; P=0.0039 and 0.0039, respectively), SFA (P=0.0027 and 0.0023, respectively) and VFA (P=0.045 and 0.040, respectively). However, SNPs in other genes, namely, NRXN3, TFAP2B, MSRA, LYPLAL1 and MC4R were not significantly associated with BMI, SFA or VFA. Our data suggest that some SNPs, which were identified in genome-wide studies in the Caucasians, also confer susceptibility to fat distribution in the Japanese subjects.

There is evidence that the obesity phenotype in the Caucasian populations is associated with variations in several genes, including neuronal growth regulator 1 (NEGR1), SEC16 homolog B (SCE16B), transmembrane protein 18 (TMEM18), ets variant 5 (ETV5), glucosamine-6-phosphate deaminase 2 (GNPDA2), prolactin (PRL), brain-derived neurotrophic factor (BDNF), mitochondrial carrier homolog 2 (MTCH2), Fas apoptotic inhibitory molecule 2 (FAIM2), SH2B adaptor protein 1 (SH2B1), v-maf musculoaponeurotic fibrosarcoma oncogene homolog (MAF), Niemann-Pick disease, type C1 (NPC1), melanocortin 4 receptor (MC4R) and potassium channel tetramerisation domain containing 15 (KCTD15). To investigate the relationship between obesity and these genes in the Japanese population, we genotyped 27 single-nucleotide polymorphisms (SNPs) in 14 genes from obese subjects (n=1129, body mass index (BMI) > or =30 kg m(-2)) and normal-weight control subjects (n=1736, BMI

Genetic factors are important in the development of metabolic syndrome. However, the genetic background of metabolic syndrome remains unclear. We screened polymorphisms in 85 obesity-related genes to determine which may be associated with metabolic syndrome. A total of 336 single-nucleotide polymorphisms (SNPs) in 85 genes selected from the JSNP database were genotyped. We conducted case-control association analyses using patients with metabolic syndrome (n=1080) and control individuals (n=528) who had no risk of the metabolic syndrome. Three SNPs in the McKusick-Kaufman syndrome (MKKS) gene were significantly related to metabolic syndrome by case-control association study; rs1545 (odds ratio (OR) adjusted for age and gender, 1.45; 95% confidence interval (CI), 1.21-1.74; P=0.000043 (additive model)); rs1547 (OR, 1.45; 95% CI, 1.21-1.74; P=0.000041); and rs2294901 (OR, 1.46; 95% CI, 1.22-1.75; P=0.000033). We selected five tag SNPs (rs2294901, rs221667, rs6133922, rs6077785 and rs6108572) in the MKKS gene. They were in one linkage disequilibrium (LD) block and rs6133922 (P=0.00042), rs6077785 (P=0.000013) and rs6108572 (P=0.000019) as well as rs2294901 were significantly associated with metabolic syndrome. TGAAA haplotype was protective against the metabolic syndrome (P=0.0074), and CCGTT haplotype was susceptible (P=0.00070) to the metabolic syndrome. Our data suggest that genetic variations at MKKS gene influence the risk of metabolic syndrome.

The single nucleotide polymorphism (SNP) rs7566605 in the upstream region of the insulin-induced gene 2 (INSIG2) is associated with the obesity phenotype in many Caucasian populations. In Japanese, this association with the obesity phenotype is not clear. To investigate the relationship between rs7566605 and obesity in Japanese, we genotyped rs7566605 from severely obese subjects [n = 908, body mass index (BMI) ≥ 30 kg/m2] and normal-weight control subjects (n = 1495, BMI < 25 kg/m2). A case–control association analysis revealed that rs7566605 was significantly associated with obesity in Japanese. The P value in the minor allele recessive mode was 0.00020, and the odds ratio (OR) adjusted for gender and age was 1.61 [95% confidential interval (CI) = 1.24–2.09]. Obesity-associated phenotypes, which included the level of BMI, plasma glucose, hemoglobin A1c, total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, and blood pressure, were not associated with the rs7566605 genotype. Thus, rs7566605 in the upstream region of the INSIG2 gene was found to be associated with obesity, i.e., severe obesity, in Japanese.

Context: Genetic factors are important for the development of obesity. However, the genetic background of obesity still remains unclear. Objective: Our objective was to search for obesity-related genes using a large number of gene-based single-nucleotide polymorphisms (SNPs). Design and Setting: We conducted case-control association analyses using 94 obese patients and 658 controls with 62,663 SNPs selected from the SNP database. SNPs that possessed P ≤ 0.02 were further analyzed using 796 obese and 711 control subjects. One SNP (rs3764220) in the secretogranin III (SCG3) gene showed the lowest P value (P = 0.0000019). We sequenced an approximately 300-kb genomic region around rs3764220 and discovered SNPs for haplotype analyses. SCG3 was the only gene within a haplotype block that contained rs3764220. The functions of SCG3 were studied. Patients: Obese subjects (body mass index ≥ 30 kg/m2, n = 890) and control subjects (general population; n = 658, body mass index ≤ 25kg/m2; n = 711) were recruited for this study. Results: Twelve SNPs in the SCG3 gene including rs3764220 were in almost complete linkage disequilibrium and significantly associated with an obesity phenotype. Two SNPs (rs16964465, rs16964476) affected the transcriptional activity of SCG3, and subjects with the minor allele seemed to be resistant to obesity (odds ratio, 9.23; 95% confidence interval, 2.77–30.80; χ2 = 19.2; P = 0.0000067). SCG3 mRNA and immunoreactivity were detected in the paraventricular nucleus, lateral hypothalamic area, and arcuate nucleus, and the protein coexisted with orexin, melanin-concentrating hormone, neuropeptide Y, and proopiomelanocortin. SCG3 formed a granule-like structure together with these neuropeptides. Conclusions: Genetic variations in the SCG3 gene may influence the risk of obesity through possible regulation of hypothalamic neuropeptide secretion.

Visceral fat accumulation contributes to the development of insulin resistance, leading to metabolic syndrome. Adiponectin provides a link between visceral fat accumulation and insulin resistance. In addition to environmental factors, genetic factors play important roles in visceral fat accumulation and circulating adiponectin levels. Genome-wide association studies (GWASs) have identified genetic variations in the adiponectin, C1Q and collagen domain containing (ADIPOQ) gene that are associated with adiponectin levels. In this study, we investigated whether ADIPOQ single nucleotide polymorphisms (SNPs) were associated with visceral fat accumulation and insulin resistance. We measured the visceral fat area (VFA) by computed tomography (CT) and examined the presence of the insulin resistance-related phenotype (fasting plasma glucose, fasting insulin, and homeostasis model assessment-insulin resistance [HOMA-IR]) in a set of Japanese individuals (731 men and 864 women) who were genotyped for seven ADIPOQ SNPs reported by recent GWASs (namely, rs6810075, rs10937273, rs1648707, rs864265, rs182052, rs17366568, and rs6773957). SNPs associated with the phenotype (P0.05) were then evaluated by association analysis using a second set of the study participants (383 men and 510 women). None of the SNPs was associated with body mass index (BMI) or VFA in men or women. However, the adiponectin-decreasing alleles of rs10937273 and rs1648707 were significantly associated with HOMA-IR (P = 0.0030 and P = 0.00074, respectively) in women, independently of BMI. These SNPs were significantly associated with decreased adiponectin levels in women. Our results suggested that rs10937273 and rs1648707 may affect insulin sensitivity by regulating adiponectin production by adipose tissue in women.

We assessed the efficacy and adverse effects of febuxostat in male hyperuricemia patients.This was a 12-week, multicenter, open-label, uncontrolled study. The enrolled subjects were 89 hyperuricemic male patients (12 overexcretors, 56 normal excretors, and 21 underexcretors). The endpoint was percent change in serum urate level.The concentration of urate in serum before and 12 weeks after beginning administration of febuxostat in the overexcretors was 9.34 ± 1.48 and 5.59 ± 1.17 mg/dl, respectively, while those were 8.59 ± 1.24 and 5.41 ± 1.35 mg/dl, respectively, in the normal excretors, and 8.29 ± 1.01and 5.11 ± 1.71 mg/dl, respectively, in the underexcretors. After 12 weeks, the rate of change in serum urate after beginning administration of febuxostat was - 0.384 ± 0.186 in the overexcretors, - 0.368 ± 0.128 in the normal excretors, and - 0.365 ± 0.217 in the underexcretors, with no significant differences among them. A common adverse event related to febuxostat was gout flare.Febuxostat effectively reduced the concentration of urate in serum in hyperuricemic patients regardless of the level of uric acid excreted in urine without severe adverse effects.

Mouse cDNA for the heart-type (H) isoform of AMP deaminase (EC 3.5.4.6., AMPD) has been isolated and characterized. The cDNA for the Ampd gene expressed in heart is predicted to encode a peptide of 766 amino acids with a molecular mass of 88 kDa. The coding region of this cDNA was quite homologous to the human AMPD3 gene which encodes the erythrocyte-type (E) isoform of AMPD, although the H-isoform of rodent AMPD was reported to be immunologically distinct from the E-isoform of human AMPD. The non-coding region of the isolated cDNA is not homologous to human AMPD3 , while rodent Ampd1 has similarity to human AMPD1 in the non-coding region as well as in the coding region. The transcripts for the cloned cDNA were expressed in heart, slow-twitch skeletal muscle and non-muscle tissues. Prokaryotic expression showed that this cDNA encodes a catalytically active enzyme which reacts to the specific antibody raised to the H-isoform of AMPD. © 1997 Elsevier Science B.V. All rights reserved.

To elucidate the mechanism of the differential processing of proglucagon, we analyzed the processing products of proglucagon in three types of rodent endocrine cells and their relation to prohormone convertases PC1 (PC3) and PC2. Proglucagon gene was transfected into AtT-20 cells and GH3 cells, which are derived from pituitary tumors. InR1-G9 cells, which are insulinoma-derived cells, express an endogenous proglucagon gene. Oxyntomodulin was the predominant processing product in AtT-20 cells, which contained abundant PC1 mRNA. In contrast, glucagon was the major product in GH3 cells, which expressed PC2 mRNA. Oxyntomodulin and glucagon were produced in equal amounts in InR1-G9 cells, which expressed both PC1 and PC2 mRNAs. These findings suggest that PC1 and PC2 preferentially cleave proglucagon into oxyntomodulin and glucagon, respectively, thus contributing to the cell-specific processing of proglucagon.

The association of muscle glycogenosis with hyperuricemia led to the identification of a unique purine disorder. Myogenic hyperuricemia is ascribed to excessive degradation of muscle purine nucleotides, secondary to impaired ATP generation. Although this pathophysiological condition has been observed not only in glycolytic defects but also in mitochondrial diseases affecting lipid and carbohydrate oxidation, it is most common and prominent in muscle phosphofructokinase deficiency, in which neither glycogen nor glucose can be used as metabolic fuels. The first key reaction of muscle purine degradation is catalysis by AMP deaminase. Numerous studies have indicated that AMP deaminase may play an important role in energy metabolism in contracting muscle. Arguments against this hypothesis have emerged through analyses on muscle AMP deaminase deficiency. According to a recent study, the mutant allele is extremely frequent among Caucasians and African-Americans, suggesting that many individuals with this enzyme defect may be clinically asymptomatic. Further study is required to explain the significance of muscle purine degradation in energy metabolism.

Muscle phosphofructokinase (PFK) deficiency includes both clinically and genetically heterogeneous conditions. A 22-year-old man with muscle PFK deficiency due to previously unrecognized mutation was admitted because of gastric ulcer. He had noticed mild fatigability on vigorous exercise, but had never experienced painful cramps and myoglobinuria. His history included five time relapses of gastric ulcer and gouty arthritis at ages 19 and 21 years. His laboratory data showing impaired muscle glycolysis, increased hemolysis, and myogenic hyperuricemia had aspects in common with those reported for the classic form of this disease, except that lactate concentrations in his blood increased considerably after exercise. The mutant PFK enzyme of this patient, who was demonstrated to have a missense mutation, could exert some catalytic activity that permitted glycolytic flux in vivo, thus leading to the absence of typical myopathic symptoms. The association of relapsing gastric ulcer with muscle PFK deficiency was detected for the first time. There is a possibility that oxygen radical-induced tissue damage resulting from increased hypoxanthine on exertion plays a role in the pathogenesis of ulceration, since the patient is more tolerant to exercise than reported cases with the classic form of muscle PFK deficiency © 1995 John Wilev & Sons. Inc.

Visceral fat accumulation has an important role in the development of several metabolic disorders, such as type 2 diabetes, dyslipidemia and hypertension. New genetic loci that contribute to the development of type 2 diabetes have been identified by genome-wide association studies. To examine the association of type 2 diabetes susceptibility loci and visceral fat accumulation, we genotyped 1279 Japanese subjects (556 men and 723 women), who underwent computed tomography for measurements of visceral fat area (VFA) and subcutaneous fat area (SFA) for the following single-nucleotide polymorphisms (SNPs): NOTCH2 rs10923931, THADA rs7578597, PPARG rs1801282, ADAMTS9 rs4607103, IGF2BP2 rs1470579, VEGFA rs9472138, JAZF1 rs864745, CDKN2A/CDKN2B rs564398 and rs10811661, HHEX rs1111875 and rs5015480, TCF7L2 rs7901695, KCNQ1 rs2237892, KCNJ11 rs5215 and rs5219, EXT2 rs1113132, rs11037909, and rs3740878, MTNR1B rs10830963, DCD rs1153188, TSPAN8/LGR5 rs7961581, and FTO rs8050136 and rs9939609. None of the above SNPs were significantly associated with VFA. The FTO rs8050136 and rs9939609 risk alleles exhibited significant associations with body mass index (BMI; P=0.00088 and P=0.0010, respectively) and SFA (P=0.00013 and P=0.00017, respectively). No other SNPs were significantly associated with BMI or SFA. Our results suggest that two SNPs in the FTO gene are associated with subcutaneous fat accumulation. The contributions of other SNPs are inconclusive because of a limitation of the sample power.

We examined the influence of alcohol drinking habits on the serum uric acid level after the ingestion of a small amount of ethanol. Subjects were divided into two groups according to their alcohol drinking habits--regular drinkers, who consume more than 60 g ethanol every day, and nondrinkers/occasional drinkers, who consume less than 20 g ethanol occasionally. Drinking 0.5 g ethanol/kg increased serum uric acid levels in regular drinkers by 52.6 +/- 26.3 mumol/L (0.8 +/- 0.4 mg/dL), whereas it did not in nondrinkers/occasional drinkers. Urinary excretion of uric acid was unaltered in both groups. Hypoxanthine and xanthine in both plasma and urine and serum acetate were increased more in regular drinkers than in nondrinkers/occasional drinkers. Accelerated adenine nucleotide degradation secondary to enhanced ethanol oxidation likely explains the ethanol-induced hyperuricemia in regular drinkers.

Metabolic syndrome is defined as a cluster of multiple risk factors, including central obesity, dyslipidemia, hypertension and impaired glucose tolerance, that increase cardiovascular disease morbidity and mortality. Genetic factors are important in the development of metabolic syndrome, as are environmental factors. However, the genetic background of metabolic syndrome is not yet fully clarified. There is evidence that obesity and obesity-related phenotypes are associated with variations in several genes, including NEGR1, SEC16B, TMEM18, ETV5, GNPDA2, BDNF, MTCH2, SH2B1, FTO, MAF, MC4R, KCTD15, SCG3, MTMR9, TFAP2B, MSRA, LYPLAL1, GCKR and FADS1. To investigate the relationship between metabolic syndrome and variations in these genes in the Japanese population, we genotyped 33 single-nucleotide polymorphisms (SNPs) in 19 genes from 1096 patients with metabolic syndrome and 581 control individuals who had no risk factors for metabolic syndrome. Four SNPs in the FTO gene were significantly related to metabolic syndrome: rs9939609 (P=0.00013), rs8050136 (P=0.00011), rs1558902 (P=6.6 × 10(-5)) and rs1421085 (P=7.4 × 10(-5)). rs3764220 in the SCG3 gene (P=0.0010) and rs2293855 in the MTMR9 gene (P=0.0015) were also significantly associated with metabolic syndrome. SNPs in the FTO, SCG3 and MTMR9 genes had no SNP × SNP epistatic effects on metabolic syndrome. Our data suggest that genetic variations in the FTO, SCG3 and MTMR9 genes independently influence the risk of metabolic syndrome.

Visceral fat accumulation has an important role in increasing morbidity and mortality rate by increasing the risk of developing several metabolic disorders, such as type 2 diabetes, dyslipidemia and hypertension. New genetic loci that contribute to the development of obesity have been identified by genome-wide association studies in Caucasian populations. We genotyped 1279 Japanese subjects (556 men and 723 women), who underwent computed tomography (CT) for measuring visceral fat area (VFA) and subcutaneous fat area (SFA), for the following single-nucleotide polymorphisms (SNPs): NEGR1 rs2815752, SEC16B rs10913469, TMEM18 rs6548238, ETV5 rs7647305, GNPDA2 rs10938397, BDNF rs6265 and rs925946, MTCH2 rs10838738, SH2B1 rs7498665, MAF rs1424233, and KCTD15 rs29941 and rs11084753. In the additive model, none of the SNPs were significantly associated with body mass index (BMI). The SH2B1 rs7498665 risk allele was found to be significantly associated with VFA (P=0.00047) but not with BMI or SFA. When the analysis was performed in men and women separately, no significant associations with VFA were observed (P=0.0099 in men and P=0.022 in women). None of the other SNPs were significantly associated with SFA. Our results suggest that there is a VFA-specific genetic factor and that a polymorphism in the SH2B1 gene influences the risk of visceral fat accumulation.

Renal handling of urate, xanthine and hypoxanthine was studied in a hypouricemic patient who had increased plasma concentrations of xanthine and hypoxanthine. The patient, a 50-year-old man, had been suffering from Parkinson's disease, while neither systemic disorders nor particular renal diseases known to affect plasma purine levels were found. His serum urate level was 58 +/- 6 mumol/l (healthy controls for males, 310 +/- 48 mumol/l, mean +/- SD) and the renal uric acid clearance was 3 times higher than that of the controls, establishing a diagnosis of renal hypouricemia. Xanthine and hypoxanthine concentrations in the plasma were elevated to 1.3 +/- 0.1 mumol/l (controls, 0.5 +/- 0.3) and 5.9 +/- 3.5 mumol/l (controls, 1.6 +/- 0.4), respectively. Both renal xanthine and hypoxanthine clearance was only half the value of the controls, indicating reduced urinary excretion of xanthine, and hypoxanthine appears to be responsible for their elevation in plasma. A probenecid loading test revealed no response of urinary urate excretion but normal responses of xanthine and hypoxanthine excretion. However, urinary excretion of urate, xanthine or hypoxanthine did not respond at all to pyrazinamide administration. These findings indicate that the patient had a defective renal handling of xanthine and hypoxanthine as well as urate.

There has been an explosive increase in the prevalence of hyperuricemia and gout in Japan, suggesting the recent lifestyle change may be a key factor leading to this pathophysiological condition. In addition, people with hyperuricemia are often associated with various morbid conditions constituting the metabolic syndrome, such as abdominal obesity, hypertension, dyslipidemia and impaired glucose tolerance. Therefore, healthy lifestyle interventions would be a basic therapeutic approach not only to hyperuricemia but to metabolic syndrome, though it is not easy to promote behaviour changes. This review focuses on strategies for lifestyle intervention for clinical practice, including how we advise patients on appropriate diets, physical activity and alcoholic beverage consumption.

Two brothers with hereditary xanthinuria (xanthine oxidase deficiency) and several members of their family were studied. In both subjects, plasma and urinary concentrations of uric acid were low whereas xanthine and hypoxanthine concentrations were markedly elevated. Xanthine oxidase activity was virtually absent in the patients' duodenal mucosa, a finding that established the diagnosis of hereditary xanthinuria. In their parents (obligate heterozygotes), the duodenal xanthine oxidase activity was about 50% of that in control subjects (father 9.3 and mother 12.8 mU/g tissue compared with 21.3 +/- 5.0 mU/g tissue, mean +/- SD). The residual xanthine oxidase from the parents exhibited normal kinetics with respect to hypoxanthine. The parents' urinary xanthine and hypoxanthine concentrations were significantly greater than those of control subjects, while their plasma concentrations of oxypurines were normal. Similar findings were observed in at least 6 other relatives, a finding that suggested that they were heterozygotes. This study suggests that obligate hereditary xanthinuria heterozygotes have only 50% of the xanthine oxidase activity of controls; this deficiency results in a partial metabolic blockage at this enzymatic step in heterozygotes.

Genetic factors are clearly involved in the development of obesity, but the genetic background of obesity remains largely unclear. Starting from 62 663 gene-based single-nucleotide polymorphisms (SNPs) in three sequential case-control association studies, we identified a replicated association between the obesity phenotype (BMI > or =30 kg/m(2)) and a SNP (rs2293855) located in the myotublarin-related protein 9 (MTMR9) gene in the chromosomal segment 8p23-p22. P-values (minor allele dominant model) of the first set (93 cases versus 649 controls) and the second set (564 cases versus 562 controls) were 0.008 and 0.0002, respectively. The association was replicated in the third set [394 cases versus 958 controls, P = 0.005, odds ratio (95% CI) =1.40 (1.11-1.78)]. The global P-value was 0.0000005. A multiple regression analysis revealed that gender, age BMI and rs2293855 genotype (minor allele dominant model) were significantly associated with both systolic and diastolic blood pressures. MTMR9 was shown to be the only gene within the haplotype block that contained SNPs associated with obesity. Both the transcript and protein of MTMR9 were detected in the rodent lateral hypothalamic area as well as in the arcuate nucleus, and the protein co-existed with orexin, melanin concentrating hormone, neuropeptide Y and proopiomelanocortin. The levels of MTMR9 transcript in the murine hypothalamic region increased after fasting and were decreased by a high-fat diet. Our data suggested that genetic variations in MTMR9 may confer a predisposition towards obesity and hypertension through regulation of hypothalamic neuropeptides.

Purine metabolism is one mechanism to maintain cellular ATP concentration. The pathway to degrade adenosine nucleotide directly involves in stabilization of the energy charge during ATP consumption. AMP deaminase (E.C.3.5.4.6.; AMPD), which catalyzes the hydrolytic deamination of AMP and converts it to IMP, is thought to play an important role in purine metabolism in all eukaryotic cells. In higher eukaryotes, AMPD has multiple isoforms encoded by a family of AMPD multigenes.1 There are three genes in human: AMPD1, AMPD2, AMPD3, whose products are predominant in muscle (M), liver (L) and erythrocyte (E), respectively.2–4 In rodent, two genes, Ampd1 and Ampd2 that are equivalent to the human AMPD1 and AMPD2, respectively, have been known,2–5 but the gene corresponding to AMPD3 has not been reported. From the analogy of human AMPD, this hypothetical gene has been inferred to code for heart(H)-type AMPD, but molecular studies with rodent heart AMPD has not been done. In this study, mouse cDNA and the gene encoding H-isoform of AMPD have been isolated and characterized for the first time.

Article abstract-We investigated the effect of glucose infusion on adenosine triphosphate degradation in skeletal muscle of patients with glycogen storage disease type VII. Three patients and six healthy subjects exercised on a bicycle ergometer twice, once with 20% glucose infusion and once with saline infusion. The glucose infusion increased plasma glucose levels to 170 to 182 mg/dl and serum insulin levels to 30 to 50 microunits/ml, while it markedly decreased plasma free fatty acid levels. The exercise-induced increases in plasma ammonia, inosine, and hypoxanthine were much larger with glucose than with saline infusion in the patients. Urinary excretion of inosine and hypoxanthine with glucose infusion was twice as high as that with saline infusion. No such differences were present between glucose and saline infusion in the healthy subjects. Glucose infusion therefore accelerates the energy crisis in working muscle of patients with glycogen storage disease type VII, probably due to a decrease in fatty acid utilization.NEUROLOGY 1995;45: 161-164