This study was to determine serum 25-hydroxyvitamin D (25(OH)D), the complement 3 (C3), and C-reactive protein (CRP) levels, and their association with the risk of insulin resistance (IR). A case-control study was carried out among 134 participants with body mass index (BMI) ≥30 kg/m2 and BMI=18.5-24.99 kg/m2. Anthropometric and body composition indicators were measured. Serum levels of C3, CRP, 25(OH)D, insulin, and glucose were also measured. IR was assessed by the homeostasis model assessment (HOMA-IR). C3, CRP, insulin, and HOMA-IR levels were higher in participants with obesity than that of controls (p<0.001). After adjustment for the potential confounders, anthropometric and body composition indicators were correlated positively with C3 (p<0.001), and negatively with 25(OH)D (p<0.05). C3, and 25(OH)D were correlated with HOMA-IR (r=0.350; r=−0.212; p<0.05). In logistic regression analyses, C3 and CRP were significantly related to increased odds of IR among participants with obesity as compared to controls after progressively adjusting for the potential confounders (p<0.001), whereas 25(OH)D was negatively, but insignificantly, related to decreased odds of IR among participants with obesity (p>0.05). C3 was associated positively with 25(OH)D insufficiency/deficiency independent of HOMA-IR and/or BMI (β=0.183, p<0.05). Obesity is associated with elevated levels of proinflammatory biomarkers and IR. 25(OH)D insufficiency/deficiency was associated with C3 regardless of HOMA-IR or BMI, which could in turn, have a role in the augmentation of IR during obesity.
To explore the protective effects of 1,25-dihydroxy vitamin D3 (1,25-(OH)2D3) on the bone marrow microenvironment in mice after irradiation and the underlying molecular mechanisms, a total of 150 7-wk-old male BALB/c mice were randomly divided into a normal group, an irradiation (IR) group and an irradiation+1,25-(OH)2D3 (IR+VD3) group. The mice in the IR+VD3 group were treated with 6.0 Gy 60Coγ rays, and 1,25-(OH)2D3 (dissolved in DMSO, 2.5 μg/kg) was administered once per day from 2 d before to 8 d after irradiation. Mice in the IR group were treated with the same dose of γ rays and an equal volume of DMSO. Subsequently, the body weights and the numbers of peripheral white blood cells (WBCs) were measured. Histological analysis of femur bone marrow was conducted to determine the proportion of adipose area as well. Finally, the expression of peroxisome proliferator-activated receptor-gamma (PPARγ) in bone marrow was detected by immunohistochemistry. After irradiation, the percentage of adipose area in the bone marrow was significantly increased, and the WBC number and body weight were markedly reduced. Compared with irradiation alone, the co-administration of 1,25-(OH)2D3 with irradiation markedly attenuated radiation-induced adipogenesis in bone marrow, resulted in fewer bone marrow stromal cells expressing PPARγ and enhanced the recovery of body weight and WBCs. These results indicate that 1,25-(OH)2D3 could accelerate the recovery of body weight and WBCs in irradiated mice and protect the bone marrow by inhibiting radiation-induced adipogenesis via the down-regulation of PPARγ expression.
Despite the negative health consequences of a high sodium consumption, humans consume well above the recommended levels. This study examines whether or not the dietary intake of sodium was affected by individual variation of the perceived bitterness of 6-n-propylthiouracil (PROP), and examines the relationship between the perceived bitterness of PROP and the preferred NaCl concentration of broth. Female students (20-22 y old) were recruited from the university community. Genotypes of A49P and I296V polymorphism of the TAS2R38 bitter taste receptor were determined for each subject. Samples containing NaCl, PROP or broth in 5-mL portions were evaluated by sensory testing. The participants completed a food record for each diet. Our results indicate that the individuals perceiving PROP to be more bitter had consumed a greater amount of dietary sodium. In contrast, there was no significant positive correlation between an individual’s perceived saltiness and the dietary sodium intake. Those who perceived PROP to be more bitter preferred a broth containing a higher concentration of NaCl. All of these correlations were apparent even after those subjects with TAS2R38 AI/AI homozygotes (PROP non-taster) had been excluded. In conclusion, the results of this study suggest that a factor affecting the bitter rating of PROP other than the AI/AI homozygotes of TAS2R38 contributes to the variation in sodium intake and the preference for salty food.
Eating speed reportedly relates to body composition and shape. Little is known about the relationship between the objectively assessed eating speed and the body composition and shape. This study examined relationships between eating speed as assessed both objectively and subjectively, and body composition and shape. The following variables of body composition and shape were measured in 84 female college students: body mass, relative body fat mass (%Fat), body mass index (BMI), and circumferences of the waist, abdomen and hip. After measuring the body composition and shape, subjects consumed a 174-kcal salmon rice ball. The following chewing variables were measured by observing videotape recordings of the subjects’ faces: number of chews per bite, total number of chews, total meal duration, number of bites, and chewing rate. The subjects were categorized into three groups (fast, moderate and slow) according to their own subjective assessments of the actual eating speed. In objective assessments of the eating speed, the total number of chews and the total meal duration were significantly negatively correlated with the body mass, %Fat, BMI, and circumferences of the waist, abdomen and hip. In subjective eating-speed assessments, the body mass, %Fat, BMI, and circumferences of the waist, abdomen and hip were greater in the fast eating group than in the slow eating group. Both the objectively and subjectively assessed eating speeds are related to the body composition and shape. The present study supports that fast eating may relate to gains in body mass and/or fat mass.
Polyphenol intake has been estimated in some populations; however, information about day-to-day and individual differences in polyphenol intake has not been well-evaluated. In this study, we aimed to examine within- and between-individual variation in polyphenol intake in Japanese male workers. First, 56 male subjects (aged 37.9±10.4 y) completed detailed 7-d dietary records (DR). We then calculated their total polyphenol intake using our polyphenol content database and the within- and between-individual variations. We also estimated the minimum number of days of dietary assessment required both to rank individuals within a group and to assess an individual’s usual polyphenol intake with acceptable accuracy. The estimated daily total polyphenol intake was 965±471 mg/d, which was largely sourced from beverages. The day-to-day variation (CVw) for polyphenol intake was 43.6%, and the variation between the individuals in the population (CVb) for polyphenol intake was 45.9%. A 4-d DR was required to rank individuals within a group with high correlation coefficients (r=0.9), and a 19-d DR was required to assess the individual’s usual polyphenol intake with 20% deviation. The CVw for polyphenol intake was intermediate between those of the other nutrients, but the CVb for polyphenol intake was largest among the nutrients. These results suggest that the dietary intake of polyphenols should be carefully estimated considering its within- and between-individual variation.
We previously reported that carbonated water ingestion induced fullness and gastric motility. In order to determine whether such satiating effects occur through oral carbonic stimulation alone, we conducted modified sham-feeding (SF) tests (carbonated water ingestion (CW), water ingestion (W), carbonated water sham-feeding (CW-SF), and water sham-feeding (W-SF)), employing an equivalent volume and standardized temperature of carbonated and plain water, in a randomized crossover design. Thirteen young women began fasting at 10 p.m. on the previous night and were loaded with each sample (15ºC, 250 mL) at 9 a.m. on separate days. Electrogastrography (EGG) recordings were obtained from 20 min before to 45 min after the loading to determine the power and frequency of the gastric myoelectrical activity. Appetite was assessed using visual analog scales. After ingestion, significantly increased fullness and decreased hunger ratings were observed in the CW group. After the load, transiently but significantly increased fullness as well as decreased hunger ratings were observed in the CW-SF group. The powers of normogastria (2-4 cpm) and tachygastria (4-9 cpm) showed significant increases in the CW and W groups, but not in the CW-SF and W-SF groups. The peak frequency of normogastria tended to shift toward a higher band in the CW group, whereas it shifted toward a lower band in the CW-SF group, indicating a different EGG rhythm. Our results suggest that CO2-induced oral stimulation is solely responsible for the feeling of satiety. Moreover, different gastric-contraction rhythms (slow or fast) were induced by oral carbonic stimulation alone and carbonated water ingestion.
Jujube (Ziziphus jujuba Mill.), a traditional folk medicine and functional food in China and South Korea, is known for its beneficial properties, which include anti-cancer, anti-oxidative, and anti-obesity effects. To assess the anti-hyperglycemic effect of jujube in this study, we investigated the glucose uptake-promoting activity of jujube in rat L6 myotubes. After determining that the jujube extract induces muscle glucose uptake, we identified the following active compounds by bioassay-guided fractionation: betulonic acid, betulinic acid, and oleanonic acid. Ursonic acid, known to be present in jujube, was semi-synthesized from ursolic acid and also observed to enhance glucose uptake. These four triterpenic acids induced glucose uptake in a glucose transporter 4-dependent manner. Comparison experiments of jujube fruits from three countries, namely, China, South Korea, and Japan, revealed that Japanese jujube has a higher content of active triterpenoids and is the most potent enhancer of glucose uptake.
Coffee consumption reduces the risk of type 2 diabetes in humans, but the mechanism remains unclear. In this study, we investigated the effect of coffee on pancreatic β-cells in the induction of diabetes by streptozotocin (STZ) treatment in mice. We examined the effect of coffee, caffeine, or decaffeinated coffee ingestion on STZ-induced hyperglycemia. After STZ injection in Exp. 1 and 2, serum glucose concentration and water intake in coffee ingestion (Coffee group) tended to be lowered or was significantly lowered compared to those in water ingestion (Water group) instead of coffee. In Exp. 1, the values for water intake and serum glucose concentration in caffeine ingestion (Caffeine group) were similar to those in the Water group. In Exp. 2, serum glucose concentrations in the decaffeinated coffee ingestion (Decaf group) tended to be lower than those in the Water group. Pancreatic insulin contents tended to be higher in the Coffee and Decaf groups than in the Water group (Exp. 1 and 2). In Exp. 3, subsequently, we showed that coffee ingestion also suppressed the deterioration of hyperglycemia in diabetic mice which had been already injected with STZ. This study showed that coffee ingestion prevented the development of STZ-induced diabetes and suppressed hyperglycemia in STZ-diabetic mice. Caffeine or decaffeinated coffee ingestion did not significantly suppress STZ-induced hyperglycemia. These results suggest that the combination of caffeine and other components of decaffeinated coffee are needed for the preventive effect on pancreatic β-cell destruction. Coffee ingestion may contribute to the maintenance of pancreatic insulin contents.
D-Allulose-containing rare sugar sweeteners have been categorized into two types, rare sugar syrup (RSS), consisting of 4 rare monosaccharides, and modified glucose syrup (MGS), rich in D-allulose, which was previously referred to D-psicose. The anti-obesity effect of RSS and D-allulose has been already clarified, but that of rare monosaccharides other than D-allulose in RSS has not yet been well understood. Here, we investigated and compared the anti-obesity effect of RSS and MGS in rats. Male Wistar rats were divided into 4 dietary groups: a high-sucrose control diet group (S), a high-fructose corn syrup diet group (HFCS), an RSS diet group (RSS), and an MGS diet group (MGS). RSS significantly suppressed abdominal adipose tissue weight and total body fat accumulation in comparison to sucrose. On the other hand, MGS reduced body weight gain, but not abdominal fat accumulation, relative to sucrose. The weight of the liver and kidneys was significantly higher in the RSS and MGS groups than in the S and HFCS groups, but serum biochemical parameters and hepatic lipids contents were not significantly different among the groups. The present study shows that two types of D-allulose-containing rare sugar sweeteners can suppress body fat accumulation or weight gain in a different manner and that RSS could be used as more effective sweeteners in place of sucrose and HFCS to maintain healthy body weight.