Manganese superoxide dismutase Ala16Val polymorphism is associated with the development of type 2 diabetes in Japanese-Americans

AIMS

Recent evidence indicates that oxidative stress may play an important role in the pathogenesis of insulin resistance and that gene polymorphism (Ala16Val) of manganese superoxide dismutase (MnSOD) may protect against reactive oxygen species (ROS) function. We aimed to test the hypothesis that the Ala16Val variant could be associated with the development of type 2 diabetes.

METHODS

We examined 523 nondiabetic Japanese-Americans who underwent a 75g oral glucose tolerance test (OGTT) and were followed for an average of 9.9 years. Cox proportional hazard analysis, stratified by category of OGTT, was used to determine whether the Ala16Val polymorphism was a risk factor in the development of type 2 diabetes.

RESULTS

During the follow-up period, 65 subjects developed type 2 diabetes. Compared with Ala allele carriers, subjects with a Val homozygote showed significantly higher risk for developing diabetes (stratified hazard ratio=2.05 [95% confidence interval 1.03-4.08]; P=0.041) after adjustment for age, gender, systolic blood pressure, total cholesterol, body mass index, and homeostasis model assessment.

CONCLUSIONS

We demonstrated that the MnSOD Ala16Val polymorphism might be associated with development of type 2 diabetes among Japanese-Americans. These results suggest that insufficient ROS scavenging might be associated with a susceptibility to glucose intolerance.

Prevalence of metabolic syndrome compared between native Japanese and Japanese-Americans

Metabolic syndrome is a condition characterized by the accumulation of multiple risk factors for atherosclerosis. Japanese-Americans in the U.S. have a more rapid and intense progression of atherosclerosis than native Japanese in Japan due to a westernization of their lifestyle. We investigated the prevalence of metabolic syndrome between 416 native Japanese (194 men and 222 women) in Hiroshima and 574 Japanese-Americans (217 men and 357 women) in Los Angeles, aged 30-89 years. According to the criteria proposed by the Japanese Society of Internal Medicine, the prevalence was 13.9 and 2.7% for native Japanese men and women, and 32.7 and 3.4% for Japanese-American men and women, respectively. According to the IDF or AHA/NHLBI criteria, the prevalence was 20.1 and 6.3%, and 38.7 and 4.5%, or 13.4 and 14.4%, and 30.9 and 27.7%, respectively. Thus, the prevalence of metabolic syndrome in men was significantly higher in Japanese-American than in native Japanese by all the three criteria. However, the prevalence in women was similar between native Japanese and Japanese-American by the Japanese and IDF criteria, whereas it was significantly higher in Japanese-American than in native Japanese by the AHA/NHLBI criteria. This report demonstrates that a westernization of lifestyle can increase the prevalence of metabolic syndrome among Japanese-Americans as compared to native Japanese.

A pediatric occurrence of crescentic glomerulonephritis associated with antineutrophil cytoplasmic antibodies and mesangial IgA deposits

Antineutrophil cytoplasmic antibody-(ANCA) associated glomerulonephritis usually shows histopathologic features of pauciimmune crescentic glomerulonephritis and occurs late in life. We report a 14-year-old Japanese girl presenting with proteinuria, hematuria and mildly elevated serum creatinine. A renal biopsy specimen demonstrated crescentic glomerulonephritis, immunofluorescence showed mesangial IgA staining. Electron microscopic examination disclosed paramesangial deposits. Serum ANCA against myeloperoxidase (MPO) were detected at high titers. Myeloperoxidase-ANCA-related nephritis accompanied by IgA nephropathy is considered rare in childhood and teen years. Yet, if ANCA assays and detailed electron microscopic examination of renal specimens were performed routinely in patients with rapidly progressive glomerulonephritis, the diagnosis might be more frequent in young patients.

Fenofibrate increases high molecular weight adiponectin in subjects with hypertriglyceridemia

Beneficial effects of peroxisome proliferator-activated receptor alpha (PPAR alpha) agonists have been reported in improving insulin sensitivity and raising serum total adiponectin. High molecular weight (HMW) adiponectin, which is secreted from adipocytes, and visfatin, which is also expressed in adipose tissue, is related to glucose metabolism. In view of the additive effects of PPAR alpha agonists on these adipocytokines and glucose metabolism, we investigated male hypertriglyceridemic subjects who were treated with fenofibrate. Eleven male subjects with hypertriglyceridemia were treated with fenofibrate and serum total cholesterol (T-cho), triglyceride, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), fasting glucose, fasting insulin, total and HMW adiponectin, and serum visfatin levels were determined before and 3 months after treatment. Fenofibrate treatment significantly lowered T-cho, triglyceride, and LDL-C levels. There was a statistically significant increase of HDL-C. No differences in insulin sensitivity indices (G/I ratio and HOMA-IR) were observed between before and after treatment with fenofibrate. The treatment did not alter the levels of serum total adiponectin and visfatin in the hypertriglyceridemic patients, while serum HMW adiponectin increased significantly. This study demonstrates that fenofibrate increases serum HMW adiponectin levels, whereas visfatin is not regulated by fenofibrate in hypertriglyceridemic subjects. Further investigations are warranted to determine whether the elevation of HMW adiponectin caused by fenofibrate might improve insulin sensitivity.

Serum leptin and adiponectin are positively associated with bone mineral density at the distal radius in patients with type 2 diabetes mellitus

There have been several reports about associations of serum leptin or adiponectin with bone mineral density and biochemical markers of bone turnover. However, the precise roles of adipocytokines in bone metabolism have not been fully elucidated. We investigated the associations of serum level of leptin or adiponectin with bone mineral density, serum osteocalcin, and urinary N-terminal telopeptide of type I collagen (NTX) in 40 Japanese patients with type 2 diabetes mellitus. Bone mineral density was measured by using dual-energy x-ray absorptiometry at different sites (distal radius, femoral neck, and lumbar spine) and was expressed as z score. Multiple regression analysis revealed that there were significant positive correlations between serum leptin or adiponectin level and z score at the distal radius, but not at the femoral neck or the lumbar spine. Although no correlation was observed between serum leptin and serum osteocalcin, there was a significant negative correlation between serum leptin and urinary NTX, a marker of bone resorption. No correlation was observed between serum adiponectin and serum osteocalcin or urinary NTX. These results indicate that leptin and adiponectin may have a protective effect on bone metabolism in patients with type 2 diabetes mellitus.

Basic and clinical aspects of parathyroid hyperplasia in chronic kidney disease

Marked parathyroid hyperplasia develops in patients with chronic kidney disease, especially those with long dialysis vintage. Although progression of hyperplasia is associated with downregulation of vitamin D receptor and calcium-sensing receptor, initial abnormality that triggers and maintains parathyroid cell proliferation, as well the critical abnormality for the progression of diffuse hyperplasia to nodular hyperplasia, still remains to be elucidated. It is quite important for the optimal management of renal osteodystrophy to recognize the development of nodular hyperplasia, because the cells in nodular hyperplasia are usually resistant to medical therapy and further treatment of such patients often leads to vascular calcification. For this purpose, size and blood supply of enlarged parathyroid glands have been used as good clinical markers. Furthermore, we have recently shown that the serum fibroblast growth factor 23 level can be used for predicting refractory hyperparathyroidism. Once nodular hyperplasia develops in any of the enlarged parathyroid glands, such patients need to be treated by parathyroid intervention including percutaneous ethanol injection therapy. In addition, as direct vitamin D injection therapy has been shown to induce regression of hyperplasia, it may become possible to reverse or normalize established nodular hyperplasia if we can develop new agents with such effects in the near future.

Decreased total and high molecular weight adiponectin are independent risk factors for the development of type 2 diabetes in Japanese-Americans

CONTEXT

Adiponectin is a hormone secreted by adipocytes that acts as an antidiabetic adipokine. Adiponectin exists as multimers in plasma, and high molecular weight (HMW) adiponectin is particularly thought to be the active form of the protein.

OBJECTIVE

The aim of the study was to assess whether decreased total and HMW adiponectin are independent risk factors for the development of type 2 diabetes.

DESIGN

Study subjects were Japanese-Americans enrolled in the Hawaii-Los Angeles-Hiroshima study between 1992 and 2002. Duration of follow-up was an average of 5.4 yr.

PARTICIPANTS

We investigated 321 men and 445 women who were nondiabetic Japanese-Americans. Glucose tolerance was evaluated according to 1997 American Diabetes Association criteria, and 112 subjects developed type 2 diabetes during the follow-up period.

MAIN OUTCOME MEASURE

The influence of baseline total and HMW adiponectin on the development of type 2 diabetes was the main outcome measure.

RESULTS

Subjects who developed type 2 diabetes had significantly decreased plasma total and HMW adiponectin compared with those who did not develop the disease (P < 0.001, respectively). In a Cox proportional hazards model, both decreased total and HMW adiponectin levels were independent risk factors for the progression to type 2 diabetes after adjusting for sex, age, body mass index, waist-to-hip ratio, homeostasis model assessment, and classification of 75-g glucose tolerance test (hazards ratio: total, 0.600, P = 0.018; HMW, 0.614, P = 0.001, respectively). Dividing tertiles of adiponectin, hazards ratios in the lowest vs. highest tertile were total, 1.787 (95% confidence interval, 1.006-3.173); and HMW, 2.493 (95% confidence interval, 1.342-4.632), after similar adjustments.

CONCLUSIONS

Decreased total adiponectin is an independent risk factor for the progression to type 2 diabetes in Japanese-Americans. Moreover, HMW adiponectin more closely associates with the progression to type 2 diabetes when compared with total adiponectin.

A case of polyglandular autoimmune syndrome type III complicated with autoimmune hepatitis

A 58-year-old woman complaining of finger tremor was referred to our hospital. The diagnosis of Graves' disease was made based on increased free triiodothyronine (18.88 pg/ml) and free thyroxine (7.47 ng/dl), low TSH (<0.005 microIU/ml) and increased TSH receptor binding antibody activity (70.9%). Serum level of AST (62 U/l) and ALT (93 U/l) were increased and liver biopsy revealed linkage of adjacent portal areas by lymphoplasmacytic infiltrates and fibrosis with piecemeal necrosis. Although antinuclear antibody was negative, these findings indicated that she had autoimmune hepatitis (AIH) according to the criteria of the International Autoimmune Hepatitis Scoring System. Slowly progressive type 1 diabetes mellitus (DM) was confirmed by a diabetic response pattern due to 75 g-oral glucose tolerance test, and seropositivity towards anti-glutamic acid decarboxylase (725 U/ml) and islet cell (80 JDF Units) antibodies. This case exhibited an extremely rare combination of three different autoimmune diseases, including Graves' disease, slowly progressive type 1 DM and AIH, and had no known sensitive human leukocyte antigen (HLA) typing or haplotype for these disorders. Although it is common for patients with Graves' disease to exhibit abnormal liver function, it is important to make an accurate diagnosis of AIH because of this life-threatening disorder.

Association of Chlamydia pneumoniae infection and carotid intima-media wall thickness in Japanese Americans

BACKGROUND

Chlamydia pneumoniae (Cp) infection has been proposed as a risk factor for coronary artery disease (CAD), but it remains unclear whether Cp plays a role in the progression of early stage carotid atherosclerosis.

METHODS AND RESULTS

The associations among Cp IgG/IgA antibodies, inflammation markers such as C-reactive protein (CRP) and interleukin (IL)-6, and the maximal progression of carotid intima-media wall thickness (max IMT) were evaluated using ultrasonography in 259 Japanese Americans. The presence of Cp IgG or IgA antibodies itself did not show significant correlation with max IMT after adjustment for age and sex. However, in the Cp IgG seropositive group, the subjects with high IL-6 levels showed more pronounced max IMT progression than those with low IL-6 levels after adjustment of the other CAD risk factors. Moreover, in the Cp IgA seropositive group, the subjects with high CRP or IL-6 levels had significantly higher levels of max IMT compared with those with low CRP or IL-6.

CONCLUSIONS

The results support the hypothesis that a chronic latent Cp infection with inflammation might accelerate the development of early stage atherosclerotic lesions.

Circulating aminopeptidase N/CD13 is an independent prognostic factor in patients with non-small cell lung cancer

PURPOSE

Aminopeptidase N, also known as CD13, has important roles in tumor metastasis and angiogenesis. Its expression in tumor tissue has been reported to be associated with poor prognosis. However, the clinical significance of circulating aminopeptidase N/CD13 in patients with solid tumors is unknown. We previously developed an aminopeptidase N/CD13-specific monoclonal antibody (mAb) MH8-11, which inhibits cell motility and angiogenesis in vitro. The aim of this study was to evaluate the clinical significance of circulating aminopeptidase N/CD13 protein detected by mAb MH8-11 in patients with non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

We used electrochemiluminescence immunoassay with mAb MH8-11 to determine circulating aminopeptidase N/CD13 levels in 90 healthy volunteers and 90 patients with NSCLC. Circulating aminopeptidase N/CD13 levels were measured in sera taken before treatment and evaluated for a relationship with clinical outcomes.

RESULTS

A significant correlation was found between tumor progression and serum aminopeptidase N/CD13 concentrations (r=0.23, P=0.029). High serum aminopeptidase N/CD13 levels (n=17) were associated with advanced stage (P=0.004) or poor performance status (P=0.001). The overall survival rate for patients with high serum aminopeptidase N/CD13 levels (n=17) was significantly less than that of patients with low serum aminopeptidase N/CD13 levels (n=73, P<0.0001). In a multivariate survival analysis in patients with NSCLC, serum aminopeptidase N/CD13 levels had an independent influence on survival (relative risk, 4.1; 95% confidence interval, 1.9-8.8).

CONCLUSIONS

Our data suggest that a high level of circulating aminopeptidase N/CD13 at diagnosis is an independent prognostic factor in patients with NSCLC.

Effects of a westernized lifestyle on the association between fasting serum nonesterified fatty acids and insulin secretion in Japanese men

The effects of the prolonged elevation of nonesterified fatty acid (NEFA) levels on insulin secretion have been controversial and thought to be sex-specific. To investigate the association between a westernized lifestyle and the effects of NEFA on insulin secretion in Japanese men, we examined 67 nondiabetic Japanese-American men and 220 nondiabetic native Japanese men who underwent a 75-g oral glucose tolerance test (OGTT). Most Japanese Americans we surveyed are genetically identical to Japanese living in Japan, but their lifestyle is more westernized. Sets of multiple regression analyses were performed to evaluate the relationship between the sum of the immunoreactive insulin (IRI) levels during the OGTT ((Sigma)IRI) and clinical parameters. Japanese Americans had higher levels of fasting IRI, (Sigma)IRI, and a higher insulin resistance index (homeostasis model assessment for insulin resistance [HOMA-IR]) than native Japanese, whereas there were no significant differences in fasting NEFA and triglyceride levels. A multiple regression analysis adjusted for age, fasting triglycerides, and body mass index (BMI) demonstrated that the fasting NEFA level was an independent determinant of the (Sigma)IRI only in Japanese-American men ( P = .001), but not in native Japanese men ( P = .054). Even when HOMA-IR was included in models instead of BMI, the NEFA level was a significant variable of (Sigma)IRI only in Japanese Americans ( P < .001), and not in native Japanese ( P = .098). In addition, a multiple regression analysis adjusted for age, fasting triglycerides, and BMI demonstrated that the fasting NEFA level was the only independent determinant of (Sigma)C-peptide in Japanese-American men ( P = .041). In conclusion, NEFA seems to be associated with insulin secretion independent of obesity or HOMA-IR. A westernized lifestyle may increase the effects of serum fasting NEFA levels on total insulin secretion after a glucose load in Japanese men.

A comparison between Japanese-Americans living in Hawaii and Los Angeles and native Japanese: the impact of lifestyle westernization on diabetes mellitus

We have been conducting the Hawaii-Los Angeles-Hiroshima Study since 1970, mainly to determine the effects of environmental changes on various diseases by comparing Japanese-Americans with native Japanese subjects. Japanese-Americans living in Hawaii and Los Angeles are originated mainly from Hiroshima, Japan and are genetically identical with native Japanese. Through this study, we made several clear observations about Japanese-Americans. First, Japanese-Americans were highly exposed to a westernized lifestyle ; in other words, a relatively high fat and simple carbohydrate diet with low physical activity as compared to native Japanese. Second, the prevalence of type 2 diabetes among Japanese-Americans and death from ischemic heart disease among Japanese-American diabetic patients were higher. Third, the serum fasting insulin level as well as the insulin level after a glucose load, was higher among Japanese-Americans, even when the serum glucose levels were not statistically different as compared to native Japanese. Accordingly, Japanese-Americans were thought to have a high insulin resistance status. However, the initial insulin response after a glucose load was low, which was more similar to Japanese people than to Caucasians. Fourth, the total cholesterol and triglyceride levels were higher among Japanese-Americans. These results are supposed to be derived from the insulin resistant status by the westernization of lifestyle, as well as from the weakness of pancreatic beta cell function that is supposed to be genetically regulated among Japanese. In conclusion, it appears that for genetically Japanese people, environmental factors are important for the development of metabolic diseases such as diabetes mellitus and cardiovascular disease.

A protective effect of adiponectin against oxidative stress in Japanese Americans: the association between adiponectin or leptin and urinary isoprostane

Adiponectin, which is produced by adipose tissue, is thought to play an important role in inflammation. On the other hand, adiposity, or the hypertrophy of adipose tissue, has been reported to increase oxidative stress. Accordingly, the possibility exists that adiponectin, as well as leptin, influences oxidative stress, resulting in a proinflammatory state. However, the relationship between adiponectin and oxidative stress is unclear. We examined 259 Japanese Americans living in Hawaii who were diagnosed as having normal glucose tolerance (NGT), impaired glucose tolerance, or diabetes by a 75-g oral glucose tolerance test. First, we measured their serum adiponectin, leptin, and high-sensitivity C-reactive protein levels as markers of inflammation, and urinary 8-iso-protaglandin F(2 alpha) (isoprostane) as a relevant marker of oxidative stress. We investigated the relationship between adiponectin or leptin and isoprostane among these subjects. In the diabetic subjects, the adiponectin and leptin levels were significantly lower and higher, respectively, than among the NGT subjects. Urinary isoprostane levels tended to decrease significantly after a rise in adiponectin levels (P = .014) among the NGT subjects. Next, we investigated the association between the 2 adipocytokines and isoprostane by regression models. Adiponectin was negatively but significantly associated with urinary isoprostane levels adjusted for age, gender, and smoking status, whereas leptin was positively and significantly correlated with urinary isoprostane levels (P = .014 and .004, respectively). With respect to adiponectin, this association was attenuated but still significant when further adjustments were made for waist-to-hip ratio, body mass index, percent body fat, C-reactive protein levels, glucose tolerance status, or homeostasis model assessment. In conclusion, this study suggests that adiponectin and leptin might be associated with oxidative stress levels. These results also suggest the possibility that adiponectin might modulate oxidative stress, leading to antidiabetic and anti-arteriosclerotic effects.

Relationship between HbA(1)c and mortality in a Japanese population

AIM/HYPOTHESIS

HbA(1)c concentrations are known to be associated with all-cause excess mortality risk in Caucasians. However, the relationship has not been clarified well in the Japanese. In addition, studies of the relationship between HbA(1)c and mortality from malignant neoplasms are scarce.

METHODS

HbA(1)c was measured for 3,710 people of a cohort composed of A-bomb survivors and controls. At baseline they were divided into five groups: a normal HbA(1)c group of 1,143 individuals with HbA(1)c of <5.5%, a slightly high but normal HbA(1)c group of 1,341 individuals with HbA(1)c > or =5.5% to <6.0%, a slightly high HbA(1)c group of 589 individuals with HbA(1)c > or =6.0% to <6.5%, a high HbA(1)c group of 259 individuals with HbA(1)c > or =6.5%, and a group of 378 individuals known to have type 2 diabetes. Using a Cox proportional hazards model, hazard ratios based on comparisons with the normal HbA(1)c group were obtained.

RESULTS

During the observation period there were 754 deaths. For all-cause and cardiovascular disease mortality, a significant increase of the hazard ratio was observed for the slightly high HbA(1)c group. A similar increase in malignant neoplasm-related mortality was observed for both the high HbA(1)c group and the diabetes group.

CONCLUSIONS/INTERPRETATION

Our results suggest that individuals in the Japanese population with HbA(1)c levels of 6% or more might have increased mortality risk. The results indicate that HbA(1)c measurements should be sought even for people who have not been diagnosed with diabetes.

Effectiveness of Semmes-Weinstein monofilament examination for diabetic peripheral neuropathy screening

OBJECTIVE

To evaluate the effectiveness of the Semmes-Weinstein monofilament examination (SWME) for diabetic peripheral neuropathy (DPN) screening at an outpatient clinic.

METHODS

Eighty-two type 2 diabetic outpatients were questioned about 13 subjective symptoms and tested for deep reflexes. They were examined using two types of quantitative sensory testing: SWME (using 4.31/2 g and 5.07/10 g monofilaments) and vibration testing (using the C-64 quantitative tuning fork). The patients were diagnosed with DPN when two of the following three criteria from both legs were met: (1) the presence of either pain, numbness, or paraesthesia; (2) a diminished or absent ankle reflex; or (3) a scale below 4 for their vibration perception thresholds (VPT).

RESULTS

The most common subjective symptoms were muscle cramps and numbness in the extremities. SWME 4.31/2 g at the great toe or the plantar aspect of the fifth metatarsal was the most useful diagnostic test for DPN, providing 60.0% sensitivity and 73.8% specificity. SWME 4.31/2 g was correlated with lower limb VPT (P=.029) and three subjective symptoms including fainting. SWME 5.07/10 g was correlated with lower limb VPT (P=.011), the ankle reflex (P=.013), the knee reflex (P=.031), and two subjective symptoms. However, the sensitivity to diagnose DPN was low (30.0%).

CONCLUSIONS

The abnormalities indicated by SWME correlated well with those identified by lower limb VPT. Moreover, SWME 4.31/2 g correlated with fainting, suggesting that it could detect abnormalities in the small fibers. Considering the minimal time for this examination, SWME 4.31/2 g is a useful examination in an outpatient setting along with lower limb VPT and ankle reflex testing.

Increasing of oxidative stress from mitochondria in type 2 diabetic patients

BACKGROUND

Recent evidence increasingly indicates that oxidative stress may play an important role in the pathogenesis of diabetic vascular complications. Mitochondria has received much attention as an important organ in the generation of oxidative stress. However, the importance of oxidative stress among diabetic patients without vascular complications is unclear.

METHODS

We compared oxidative stress produced from mitochondria of the mononuclear cells in peripheral blood obtained from 26 diabetic subjects without clinical vascular complications and 52 healthy age-matched subjects using a flow cytometer. Oxidative stress from the mononuclear cells was evaluated by measuring fluorescence of oxidized production from dihydrorhodamine-123, which is a pro-fluorescent compound that selectively accumulates in the mitochondria of living cells. Stimulation of the cells was carried out with phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator. We then calculated the relative fluorescence variation (RFV) that indicated an increasing rate of oxidative stress levels by stimulation with PMA against the levels obtained at baseline. Additionally, we measured the urinary stress markers, 8-hydroxydeoxyguanosine (8OHdG) and 8-epi-prostaglandin F2alpha (isoprostane).

RESULTS

Compared to healthy subjects, diabetic subjects did not exhibit significantly elevated oxidative stress levels at baseline, but did have significantly elevated basal urinary 8OHdG, urinary isoprostane and oxidative stress levels after PMA stimulation as well as RFV.

CONCLUSIONS

Among diabetic subjects without clinical vascular complications, there was a possibility that mitochondrial oxidative stress balance between generation and scavenging against the additive PKC stimulation was thought to have already been lost.

Erectile dysfunction is strongly linked with decreased libido in diabetic men

Erectile dysfunction frequently occurs with diabetes mellitus. A survey of diabetic men was conducted by anonymous questionnaire to investigate the associations of erectile dysfunction with various predictive factors. A total of 112 diabetic males without an obvious history of erectile dysfunction were available for analyses. The mean age and duration of diabetes were 53.7 +/- 12.2 years and 10.2 +/- 8.6 years (mean +/- standard deviation), respectively. The questionnaire included questions on the presence or absence of smoking, hypertension, libido and subjective symptoms of diabetic neuropathy that may be associated with erectile dysfunction. Analysis of the answers to the questionnaire revealed that 40% of the patients complained of erectile dysfunction (erection 'always insufficient'). Erectile dysfunction was significantly correlated with age (p = 0.005), but not with duration of diabetes (p = 0.25), adjusted for age. Erectile dysfunction was also associated with sensory neuropathy and reduced libido, independently of age. The logistic regression analysis revealed that erectile dysfunction was positively associated with reduced libido and age. The odds ratio of erectile dysfunction for reduced compared to unreduced libido was 18.21, suggesting that psychogenic factors have a marked influence on erectile dysfunction. It is concluded that the presence of erectile dysfunction should be considered when symptoms related to diabetic neuropathy are observed; psychological approaches, such as sexual counseling, could be applied for the treatment of erectile dysfunction.

Relation between QT duration and mortality in an elderly Japanese population

The effects of prolonged QTc intervals on mortality were investigated in about 3,500 elderly Japanese patients followed for approximately 8.8 years. Prolonged QTc was found to be a marker for risk for all-cause mortality and mortality from heart disease or from coronary heart disease (CHD) after adjusting for other CHD risk factors. Even in Japanese subjects, who have a lower coronary heart disease rate than that of Caucasians, the careful observation of subjects with a prolonged QTc is believed to be necessary.

The effect of polymorphism in the intestinal fatty acid-binding protein 2 gene on fat metabolism is associated with gender and obesity amongst non-diabetic Japanese-Americans

AIM

The role of the codon 54 polymorphism of the fatty acid-binding protein 2 (FABP2) gene on fat metabolism has been controversial. Assuming that the effects of the polymorphism were modulated by gender and obesity which were related to lipid and glucose metabolism, we investigated this polymorphism and its effect on fat metabolism according to such factors.

METHODS

Subjects were Japanese-Americans (123 men and 126 women) who were diagnosed as non-diabetic by a 75 g oral glucose tolerance test at the baseline.

RESULTS

During approximately 7.8 years, 49 (24 men and 25 women) were diagnosed with type 2 diabetes. In a Cox proportional hazards model, this polymorphism was not a significant variable in the incidence of diabetes in either gender. Amongst non-obese men with the Thr54 allele, there was a significant elevation of triglycerides (TGs) (p=0.033) compared with alanine (Ala) homozygotes. Women with the Thr54 allele had significantly elevated total cholesterol (p=0.033) and low-density lipoprotein-cholesterol (LDL-C) (p=0.023) compared with Ala54 homozygotes.

CONCLUSIONS

These results therefore suggested that the effects of the FABP2 polymorphism on TG, LDL-C and body mass index were associated with gender difference and obesity amongst non-diabetic Japanese-American subjects.