Determinants of Glycated Hemoglobin in Subjects With Impaired Glucose Tolerance: Subanalysis of the Japan Diabetes Prevention Program.

BACKGROUND: Limited evidence is available about the relationship of lifestyle factors with glycated hemoglobin (HbA1c) in subjects with impaired glucose tolerance. The aim of study was to identify such determinant factors of HbA1c in subjects with impaired glucose tolerance. METHODS: This cross-sectional study included 121 men and 124 women with impaired glucose tolerance, who were diagnosed based on a 75-g oral glucose tolerance test. Demographic and biochemical parameters, including the body mass index (BMI), fasting plasma glucose (FPG), 2-h post-load glucose (2-h PG), and HbA1c, were measured. The pancreatic ß-cell function and insulin resistance were assessed using homeostasis model assessment (HOMA-ß). Dietary intake was assessed by a food frequency questionnaire. RESULTS: The levels of FPG, 2-h PG, and carbohydrate intake were correlated with the HbA1c level in men, while the FPG and 2-h PG levels were correlated with the HbA1c level in women. In multiple regression analyses, BMI, FPG, 2-h PG, and white rice intake were associated with HbA1c levels in men, while BMI, FPG, HOMA-ß, and bread intake were associated with HbA1c levels in women. CONCLUSIONS: The present findings suggest that a substantial portion of HbA1c may be composed of not only glycemic but also several lifestyle factors in men with impaired glucose tolerance. These factors can be taken into consideration as modifiable determinants in assessing the HbA1c level for the diagnosis and therapeutic monitoring of the disease course.

Effects of lifestyle intervention on weight and metabolic parameters in patients with impaired glucose tolerance related to beta-3 adrenergic receptor gene polymorphism Trp64Arg(C/T): Results from the Japan Diabetes Prevention Program.

The beta-3 adrenergic receptor (ADRB3), primarily expressed in adipose tissue, is involved in the regulation of energy metabolism. The present study hypothesized that ADRB3 (Trp64Arg, rs4994) polymorphisms modulate the effects of lifestyle intervention on weight and metabolic parameters in patients with impaired glucose tolerance. Data were analyzed from 112 patients with impaired glucose tolerance in the Japan Diabetes Prevention Program, a lifestyle intervention trial, randomized to either an intensive lifestyle intervention group or usual care group. Changes in weight and metabolic parameters were measured after the 6-month intervention. The ADRB3 polymorphisms were determined using the polymerase chain reaction restriction fragment length polymorphism method. Non-carriers showed a greater weight reduction compared with the carriers in both the lifestyle intervention group and usual care group, and a greater increase of high-density lipoprotein cholesterol levels than the carriers only in the lifestyle intervention group. ADRB3 polymorphisms could influence the effects of lifestyle interventions on weight and lipid parameters in impaired glucose tolerance patients.

Effect of baseline HbA1c level on the development of diabetes by lifestyle intervention in primary healthcare settings: insights from subanalysis of the Japan Diabetes Prevention Program.

OBJECTIVES: To determine the effects of a lifestyle intervention on the development of type 2 diabetes mellitus (T2DM) among participants with impaired glucose tolerance (IGT), in particular in the subgroup with baseline glycated hemoglobin (HbA1c) levels ≥5.7%, in primary healthcare settings. DESIGN: Randomized controlled trial. SETTING: 32 healthcare centers in Japan. PARTICIPANTS: Participants with IGT, aged 30-60 years, were randomly assigned to either an intensive lifestyle intervention group (ILG) or a usual care group (UCG). INTERVENTIONS: During the initial 6 months, participants in the ILG received four group sessions on healthy lifestyles by public health providers. An individual session was further conducted biannually during the 3 years. Participants in the UCG received usual care such as one group session on healthy lifestyles. OUTCOME MEASURES: The primary endpoint was the development of T2DM based on an oral glucose tolerance test. RESULTS: The mean follow-up period was 2.3 years. The annual incidence of T2DM were 2.7 and 5.1/100 person-years of follow-up in the ILG (n=145) and UCG (n=149), respectively. The cumulative incidence of T2DM was significantly lower in the ILG than in the UCG among participants with HbA1c levels ≥5.7% (log-rank=3.52, p=0.06; Breslow=4.05, p=0.04; Tarone-Ware=3.79, p=0.05), while this was not found among participants with HbA1c levels <5.7%. CONCLUSIONS: Intensive lifestyle intervention in primary healthcare setting is effective in preventing the development of T2DM in IGT participants with HbA1c levels ≥5.7%, relative to those with HbA1c levels <5.7%. TRIAL REGISTRATION NUMBER: UMIN000003136.

Prevention of type 2 diabetes in a primary healthcare setting: three-year results of lifestyle intervention in Japanese subjects with impaired glucose tolerance.

BACKGROUND: A randomized control trial was performed to test whether a lifestyle intervention program, carried out in a primary healthcare setting using existing resources, can reduce the incidence of type 2 diabetes in Japanese with impaired glucose tolerance (IGT). The results of 3 years' intervention are summarized. METHODS: Through health checkups in communities and workplaces, 304 middle-aged IGT subjects with a mean body mass index (BMI) of 24.5 kg/m2 were recruited and randomized to the intervention group or control group. The lifestyle intervention was carried out for 3 years by public health nurses using the curriculum and educational materials provided by the study group. RESULTS: After 1 year, the intervention had significantly improved body weight (-1.5 ± 0.7 vs. -0.7 ± 2.5 kg in the control; p = 0.023) and daily non-exercise leisure time energy expenditure (25 ± 113 vs. -3 ± 98 kcal; p = 0.045). Insulin sensitivity assessed by the Matsuda index was improved by the intervention during the 3 years. The 3-year cumulative incidence tended to be lower in the intervention group (14.8% vs.8.2%, log-rank test: p = 0.097). In a sub-analysis for the subjects with a BMI > 22.5 kg/m2, a significant reduction in the cumulative incidence was found (p = 0.027). CONCLUSIONS: The present lifestyle intervention program using existing healthcare resources is beneficial in preventing diabetes in Japanese with IGT. This has important implications for primary healthcare-based diabetes prevention. TRIAL REGISTRATION NUMBER: UMIN000003136.

Association of Pro12Ala polymorphism in the peroxisome proliferator-activated receptor gamma2 gene with small dense low-density lipoprotein in the general population.

The Pro12Ala polymorphism of the peroxisome proliferator-activated receptor gamma2 (PPARgamma2) gene has been reported to predict a lower risk for developing type 2 diabetes mellitus. However, its effect on the lipid profile has been disputable. Among low-density lipoproteins, small dense low-density lipoprotein (sdLDL) particles have been linked to a greater risk for coronary artery disease. The purpose of this study was to investigate the genetic effect of the Pro12Ala polymorphism in the PPARgamma2 gene on the presence of sdLDL in the general Japanese population. In 379 subjects (aged 54 +/- 13 years), body mass index, percentage of body fat, blood pressure, and biochemical profiles were measured. Pro12Ala polymorphism was genotyped by polymerase chain reaction-restriction fragment length polymorphism. The area of sdLDL subfractions (sdLDL4-7) was analyzed by high-resolution polyacrylamide gel electrophoresis. The frequency of the Ala12 allele in PPARgamma2 was 0.04. There was no difference in total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels between genotypes. However, subjects with the X/Ala genotype (Pro/Ala + Ala/Ala) had significantly higher serum triglyceride levels (P = .001) and a larger area of sdLDL4-7 (P = .002) than those with the Pro/Pro genotype. Multiple regression analysis revealed that the Ala12 allele was a significant variable contributing to the variance in the increased area of sdLDL4-7 (P = .040). In conclusion, the Pro12Ala polymorphism in the PPARgamma2 gene was positively associated with an enlarged area of sdLDL4-7. This polymorphism may play a role in the genetic predisposition to increases in sdLDL4-7.

Antigenicity and irritancy tests of leukocyte-reduction filters using animal models.

We experienced a patient who showed severe allergic symptoms immediately after blood transfusion using a filter for removal of leukocytes. To investigate the cause of this incident, we conducted a maximization test on the antigenicity of substances extracted from filters used for leukocyte removal. The tests were performed in guinea pigs. Acetone extracts were obtained from filters made by three manufacturers (A, B and C) and sensitization and evocation were tested at 10% concentration. It was confirmed that extracts from one filter (B) induced sensitization in guinea pigs. Sensitization of the extracts was also tested at 1%, 0.1% and 0.01%, and was induced at 1% but not at 0.1% and 0.01%. Next, skin irritation and sensitization of the substances were tested using mice. 5%-ethanol extracts were prepared from filters made by 2 manufacturers (A and B) and the extracts (5% or 0.5% concentrations) were injected intradermally into the auricle and the ear swelling was observed 1, 24 and 48 hours and 7 days after injection. Significant ear swelling was induced by the extracts from B-filters. In the skin sensitization test, 5% extracts were injected subcutaneously into the back of mice for 3 continuous days for sensitization, and 0.5% extracts were injected intradermally into the auricle of mice to evoke a response, after which changes in ear swelling were observed. Biphasic ear swelling observed 1 hour (immediate response) and 24 hours (delayed response) after challenge was induced by the extracts from B-filters. In conclusion, our study showed that filters used for leukocyte removal may contain substances that cause skin irritation and sensitization and that antigenicity and irritancy tests of the filters might prevent the adverse reactions after blood transfusion.

Effects of sex, age and BMI on screening tests for impaired glucose tolerance.

The discriminating abilities of fasting plasma glucose (FPG) and HbA1c were compared on screening tests for impaired glucose tolerance (IGT) and IGT plus diabetes mellitus by the receiver operating characteristic (ROC) curve analysis. Furthermore, effects of sex, age and BMI were examined on sensitivity and specificity of the optimal cutoff points. This study included 997 subjects who were recruited for 75 g OGTT after the first screening of the Japan Diabetes Prevention Program. According to the 1997 criteria of the American Diabetes Association (ADA), 140 subjects were classified as diabetic and 256 as IGT. The areas under the ROC curves of FPG were significantly larger than those of HbA1c. The optimal cutoff points of FPG were 102 mg/dl for IGT and 105 mg/dl for IGT plus diabetes mellitus. Those of HbA1c were both 5.3%. In screening with FPG, females had significantly lower sensitivity and higher specificity than males, and the specificity for IGT plus diabetes mellitus was the lowest in the obese group. In screening with HbA1c, the specificity was low in the older and the obese groups. We concluded that FPG was superior to HbA1c for screening of IGT and IGT plus diabetes mellitus and the optimal cutoff point of FPG would be 102 mg/dl or greater.

Induction of apoptosis by mono(2-ethylhexyl)phthalate (MEHP) in U937 cells.

Treatment of U937 cells with mono(2-ethylhexyl)phthalate (MEHP) for 20 h led to a dose-dependent loss of cell viability, assessed by propidium iodide (PI) staining with fluorescent activated cell sorting (FACS) analysis. The cytotoxic behavior of MEHP is attributed to the induction of apoptosis. MEHP induced activation of caspase-3, internucleosomal DNA fragmentation and the morphological features of nuclear apoptosis. Analysis with LightCycler quantitative RT-PCR demonstrated the decrease of bcl-2 and increase of bax mRNA levels. Peroxisome proliferator-activated receptor (PPAR) gamma antagonists, bisphenol A diglycidyl ether (BADGE) and GW9662, significantly inhibited the MEHP-induced caspase-3 activity and apoptotic nuclear morphological changes. Furthermore, a PPARgamma ligand, rosiglitazone synergized the MEHP-induced caspase-3 activity. These results suggest that MEHP can induce apoptosis in U937 cells through modulation of the balance of bcl-2/bax in part by PPARgamma activation.

Nucleotide sequence of the p53 cDNA of beluga whale (Delphinapterus leucas).

The cDNA (DNA complementary to RNA) of the p53 gene of the beluga whale (Delphinapterus leucas) was sequenced by the method of 5'- and 3'-rapid amplification of cDNA ends (RACE) with the cDNA made for the RNA obtained from fresh peripheral blood leukocytes isolated from two animals. Primers for the RACE method were synthesized based on the sequence of the DNA of beluga whale corresponding to exon 5 of the human p53 gene, which was determined after amplification of the DNA isolated from the liver from a beluga whale by using a pair of primers for the human sequence. The sequenced cDNA had a 2150-nucleotide length and contained the whole region corresponding to human exons 1 through 11. The reading frame was 1164 bp (base pair) long and began in exon 2 and ended in exon 11, coding for a 387-amino acid protein. The nucleotide sequence of the reading frame showed high similarity over 85% with pig, sheep, cow, and human genes. The similarities with the former two animals at the amino acid level were also more than 85%. Lower similarity of the beluga whale p53 gene was also found with those of lower tetrapods, fish and invertebrates.