Short-term low carbohydrate/high-fat diet intake increases postprandial plasma glucose and glucagon-like peptide-1 levels during an oral glucose tolerance test in healthy men.

BACKGROUND/OBJECTIVES: Postprandial hyperglycemia increases the risks of development of type 2 diabetes and cardiovascular diseases. The purpose of this study was to determine whether a 3-day low-carbohydrate/high-fat diet (LC/HFD) alters postprandial plasma glucose and incretin levels during oral glucose tolerance test (OGTT) in healthy men. SUBJECTS/METHODS: Nine healthy young men (age (mean ± s.e.), 27 ± 1 years; body mass index, 22 ± 1 kg/m(2)) consumed either a normal diet (ND: energy from ∼22% fat) or a LC/HFD (energy from ∼69% fat) for 3 days each. The total energy intake from each diet was similar. An OGTT was performed after each 3-day dietary intervention. Postprandial plasma glucose, insulin, free fatty acid and glucagon-like peptide-1 (GLP-1) levels were determined at rest and during the OGTT. RESULTS: Plasma glucose levels and incremental area under the curve during the OGTT were significantly higher in the LC/HFD trial than in the ND trial (P=0.024). In addition, increase in GLP-1 levels was significantly higher in the LC/HFD trial than in the ND trial (P=0.025). The first-phase insulin secretion indexes were significantly lower in the LC/HFD trial than in the ND trial (P<0.041). CONCLUSIONS: These results demonstrate that even short-term LC/HFD increased postprandial plasma glucose and GLP-1 levels in healthy young men. A decrease in first-phase insulin secretion may partially contribute to the short-term LC/HFD-induced increase in postprandial plasma glucose levels.

Indirect lifestyle intervention through wives improves metabolic syndrome components in men.

OBJECTIVES: It is well known that body weight loss through a direct (supervised) lifestyle intervention (LSI) improves obesity-related metabolic disorders. The purpose of this study was to investigate the effects of an indirect LSI on weight loss and metabolic syndrome (MetS) in spouses of LSI participants. METHODS: A total of 104 men (abdominal circumference > or = 85 cm; age, 52.1 + or - 9.3 years) were assigned to one of three groups: no intervention (NI, n = 34), direct intervention (DI, n = 34) or indirect intervention (II, n = 36), the last of which consisted of subjects who did not participate in the direct LSI but whose wives did. Body weight and MetS components were measured before and after a 14-week intervention. Daily energy intake and activity-related energy expenditure were assessed before and during the intervention. The LSI program was mainly consisted of dietary modifications with a physical activity program. RESULTS: No differences were observed across the three groups in any of the measures at baseline. Significant differences were observed among the groups in weight loss (NI, -0.7 + or - 1.4; DI, -6.2 + or - 3.3 and II, -4.4 + or - 3.7 kg) during the intervention. Along with the body weight reductions, significant improvements were observed in most of MetS components within the DI and II groups. When analyzing the spouse pairs in group II, significant correlations were observed in weight loss (r = 0.57) and decreased total energy intake (r = 0.54) between wives and husbands. CONCLUSIONS: Indirect LSI in abdominally obese men whose wives were undergoing LSI led to loss of weight and a decreased incidence of MetS, suggesting that indirect LSI may be an effective program for eliciting beneficial change in health status.

Effects of obesity phenotype on fat metabolism in obese men during endurance exercise.

OBJECTIVE: The effects of obesity phenotype on fat metabolism during endurance exercise are unclear. This study aimed to investigate in obese men whether body fat distribution would influence plasma fat availability and oxidation during endurance exercise. DESIGN: Fourteen sedentary men (body mass index (BMI) > 25 kg/m2) were divided into two groups by visceral fat (VF) area: VF obese (VF-Ob) (n = 7, age; 52.0 +/- 2.5 (s.e.) years) and abdominal subcutaneous fat obese (SF-Ob) (n = 7, age; 57.3 +/- 2.8 (s.e.) years). All participants performed stationary cycling exercise for 60 min at 50% of peak oxygen uptake. MEASUREMENTS: Blood and respiratory gas samples were taken for analysis of hormone, metabolite and substrate oxidation in each participant at rest and during exercise. RESULTS: There is a significant group x time interaction in the plasma concentration of free fatty acid (FFA) (P < 0.05) and glycerol (P < 0.05) during the exercise bout. In addition, total plasma concentration of FFA (area under the curve) was 59.2% higher in VF-Ob compared with SF-Ob men during endurance exercise (1.99 +/- 0.24 and 1.25 +/- 0.13 mEq/l/min, respectively; P < 0.05). Total plasma concentration of glycerol (area under the curve) was 102.3% higher in VF-Ob than SF-Ob men during the exercise (69.6 +/- 12.5 and 34.4 +/- 5.1 mg/dl/min, respectively; P < 0.05). However, fat oxidation was not different throughout the exercise between VF-Ob and SF-Ob men (176.5 +/- 25.7 and 183.0 +/- 12.8 kcal/60 min, respectively). CONCLUSION: During moderate endurance exercise, plasma fat availability may be higher in men with VF obesity compared to men with SF obesity. However, total fat oxidation is similar between obesity phenotype.

Detection of noncovalent complex between alpha-amylase and its microbial inhibitor tendamistat by electrospray ionization mass spectrometry.

Electrospray ionization mass spectrometry (ESI-MS) is now routinely used for detection of noncovalent complexes. However, detection of noncovalent protein-protein complexes is not a widespread practice and still produces some challenges for mass spectrometrists. Here we demonstrate the detection of a noncovalent protein-protein complex between alpha-amylase and its microbial inhibitor tendamistat using ESI-MS. Crude porcine pancreatic alpha-amylase was purified using a glycogen precipitation method. Noncovalent complexes between porcine pancreatic alpha-amylase and its microbial inhibitor tendamistat are probed and detected using ESI-MS. The atmosphere-vacuum ESI conditions along with solution conditions and the ratio of inhibitor over enzyme strongly affect the detection of noncovalent complexes in the gas phase. ESI mass spectra of alpha-amylase at pH 7 exhibited charge states significantly lower than that reported previously, which is indicative of a native protein conformation necessary to produce a noncovalent complex. Detection of noncovalent complexes in the gas phase suggests that further use of conventional biochemical approaches to provide a qualitative, and in some cases even quantitative, characterization of equilibria of noncovalent complexes in solution is possible.

Identification of Asp197 as the catalytic nucleophile in the family 38 alpha-mannosidase from bovine kidney lysosomes.

Bovine kidney lysosomal alpha-mannosidase is a family 38 alpha-mannosidase involved in the degradation of glycoproteins. The mechanism-based reagent, 5-fluoro-beta-L-gulosyl fluoride, was used to trap a glycosyl-enzyme intermediate, thereby labelling the catalytic nucleophile of this enzyme. After proteolytic digestion and high performance liquid chromatography/tandem mass spectrometry (MS) analysis, a labelled peptide was localised, and the sequence: HIDPFGHSRE determined by fragmentation tandem MS analysis. Taking into consideration sequence alignments of this region with those of other alpha-mannosidases of the same family, this result strongly suggests that the catalytic nucleophile in this enzyme is Asp197.

Cloning, mutagenesis, and structural analysis of human pancreatic alpha-amylase expressed in Pichia pastoris.

Human pancreatic alpha-amylase (HPA) was expressed in the methylotrophic yeast Pichia pastoris and two mutants (D197A and D197N) of a completely conserved active site carboxylic acid were generated. All recombinant proteins were shown by electrospray ionization mass spectrometry (ESI-MS) to be glycosylated and the site of attachment was shown to be Asn461 by peptide mapping in conjunction with ESI-MS. Treatment of these proteins with endoglycosidase F demonstrated that they contained a single N-linked oligosaccharide and yielded a protein product with a single N-acetyl glucosamine (GlcNAc), which could be crystallized. Solution of the crystal structure to a resolution of 2.0 A confirmed the location of the glycosyl group as Asn461 and showed that the recombinant protein had essentially the same conformation as the native enzyme. The kinetic parameters of the glycosylated and deglycosylated wild-type proteins were the same while the k(cat)/Km values for D197A and D197N were 10(6)-10(7) times lower than the wild-type enzyme. The decreased k(cat)/Km values for the mutants confirm that D197 plays a crucial role in the hydrolytic activity of HPA, presumably as the catalytic nucleophile.

Family environment, hobbies and habits as psychosocial predictors of survival for surgically treated patients with breast cancer.

Many psychosocial factors have been reported to influence the duration of survival of breast cancer patients. We have studied how family members, hobbies and habits of the patients may alter their psychosocial status. Female patients with surgically treated breast cancer diagnosed between 1986 and 1995 at the Tochigi Cancer Center Hospital, who provided information on the above-mentioned factors, were used. Their subsequent physical status was followed up in the outpatients clinic. The Cox regression model was used to evaluate the relationship between the results of the factors examined and the duration of the patients' survival, adjusting for the patients' age, stage of disease at diagnosis and curability, as judged by the physician in charge after the treatment. The following factors were revealed to be significant with regard to the survival of surgically treated breast cancer patients: being a widow (hazard ratio 3.29; 95% confidence interval 1.32-8.20), having a hobby (hazard ratio 0.43; 95% confidence interval 0.23-0.82), number of hobbies (hazard ratio 0.64; 95% confidence interval 0.41-1.00), number of female children (hazard ratio 0.64; 95% confidence interval 0.42-0.98), smoker (hazard ratio 2.08; 95% confidence interval 1.02-4.26) and alcohol consumption (hazard ratio 0.10; 95% confidence interval 0.01-0.72). These results suggest that psychosocial factors, including the family environment, where patients receive emotional support from their spouse and children, hobbies and the patients' habits, may influence the duration of survival in surgically treated breast cancer patients.