Associations between glutathione peroxidase-1 Pro198Leu polymorphism, selenium status, and DNA damage levels in obese women after consumption of Brazil nuts

Objective

Alterations in selenium (Se) status may result in suboptimal amounts of selenoproteins, which have been associated with increased oxidative stress levels. The Pro198Leu polymorphism at the glutathione peroxidase-1 (GPx1) gene is supposed to be functional. The response of Se status, GPx activity, and levels of DNA damage to a Se supplementation trial between the genotypes related to that polymorphism was investigated.

Methods

A randomized trial was conducted with 37 morbidly obese women. Participants consumed one Brazil nut, which provided approximately 290 μg of Se a day, for 8 wk. Blood Se concentrations, erythrocyte GPx activity, and DNA damage levels were measured at baseline and at 8 wk. The results were compared by genotypes.

Results

The genotype frequencies were 0.487, 0.378, and 0.135 for Pro/Pro (the wild-type genotype), Pro/Leu, and Leu/Leu, respectively. At baseline, 100% of the subjects were Se deficient, and after the supplementation, there was an improvement in plasma Se (P < 0.001 for Pro/Pro and Pro/Leu, P < 0.05 for Leu/Leu), erythrocyte Se (P = 0.00 for Pro/Pro and Pro/Leu, P < 0.05 for Leu/Leu), and GPx activity (P = 0.00 for Pro/Pro, P < 0.00001 for Pro/Leu, P < 0.001 for Leu/Leu). In addition, the Pro/Pro group showed a decrease in DNA damage after Brazil nut consumption compared with baseline (P < 0.005), and those levels were higher in Leu/Leu subjects compared with those with the wild-type genotype (P < 0.05).

Conclusion

Consumption of one unit of Brazil nuts daily effectively increases Se status and increases GPx activity in obese women, regardless of GPx1 Pro198Leu polymorphism. However, the evaluated biomarkers showed distinct results in response to the supplementation when the polymorphism was considered.     

Glutathione Peroxidase 1 Pro198Leu Polymorphism in Brazilian Alzheimer's Disease Patients: Relations to the Enzyme Activity and to Selenium Status

Background/Aims: Oxidative stress plays a central role in Alzheimer's disease (AD). Pro198Leu cytosolic glutathione peroxidase (GPx1) polymorphism seems to be associated with a lower activity of this enzyme, but there are no studies with AD patients. Thus, the aim was to determine the frequency of the GPx1 Pro198Leu polymorphism in AD patients and to verify its relation to glutathione peroxidase (GPx) activity and selenium (Se) status. Methods: The study was carried out in a group of AD elderly (n = 28) compared to a control group (n = 29). Blood Se concentrations were measured through hydride generation atomic absorption spectroscopy. GPx activity was determined using a commercial kit, and the polymorphism using amplified DNA sequencing. Results: The distribution of genotypes was not different between groups. The variant allele frequency was 0.179 (AD group) and 0.207 (control group). Although no differences regarding GPx activity were found between individuals with different genotypes, lower blood Se levels were found in Pro/Pro AD patients compared to Pro/Pro control subjects, which was not found in the Pro/Leu groups. Moreover, the association between the erythrocyte Se concentration and GPx activity was affected by the Pro198Leu genotype. Conclusions: Results indicate that this polymorphism had apparently affected Se status in AD patients and that more studies in this field are necessary.     

Effect of hereditary haemochromatosis genotypes and iron overload on other trace elements

Purpose

Hereditary haemochromatosis is a common genetic disorder involving dysregulation of iron absorption. There is some evidence to suggest that abnormal iron absorption and metabolism may influence the status of other important trace elements. In this study, the effect of abnormal HFE genotypes and associated iron overload on the status of other trace elements was examined.

Methods

Dietary data and blood samples were collected from 199 subjects (mean age = 55.4 years; range = 21–81 years). Dietary intakes, serum selenium, copper and zinc concentrations and related antioxidant enzymes (glutathione peroxidase and superoxide dismutase) in subjects with normal HFE genotype (n = 118) were compared to those with abnormal HFE genotype, with both normal iron status (n = 42) and iron overload (n = 39).

Results

For most dietary and biochemical variables measured, there were no significant differences between study groups. Red cell GPx was significantly higher in male subjects with normal genotypes and normal iron status compared to those with abnormal genotypes and normal iron status (P = 0.03) or iron overload (P = 0.001). Red cell GPx was also highest in normal women and significantly lower in the abnormal genotype and normal iron group (P = 0.016), but not in the iron overload group (P = 0.078).

Conclusion

Although it may not be possible to exclude a small effect between the genotype groups on RBC GPx, overall, haemochromatosis genotypes or iron overload did not appear to have a significant effect on selenium, copper or zinc status.     

The genotype of the transporter associated with antigen processing gene affects susceptibility to colorectal cancer in Japanese

Objective

Although colorectal cancer (CRC) is one of the most frequent malignancies in Japan, the associated genetic factors remain to be elucidated. Functional loss of the transporter associated with antigen processing (TAP) 1 gene induces carcinogenesis. We investigated whether single nucleotide polymorphisms (SNPs) in the TAP1 gene (rs735883) are associated with susceptibility to CRC in a Japanese population.

Methods

The study participants were 143 cases and 243 clinical controls. After extracting DNA from their peripheral blood cells, genotyping was conducted by the polymerase chain reaction–restriction fragment length polymorphism method.

Results

Participants with a mutated allele had an increased risk for CRC. The adjusted odds ratios for the C/T, T/T, and the mutation type (C/T + T/T) compared to that of wild type (C/C) were 2.27 [95 % confidence interval (CI), 1.43–3.67], 1.95 (95 % CI, 0.88–4.30), and 2.22 (95 % CI, 1.42–3.55), respectively. Furthermore, a significant trend in the rate of cases was observed with an increasing number of mutated alleles (P for trend = 0.0068).

Conclusions

The genotype of the TAP1 gene is associated with susceptibility to CRC.     

Effects of varying dietary iodine supplementation levels as iodide or iodate on thyroid status as well as mRNA expression and enzyme activity of antioxidative enzymes in tissues of grower/finisher pigs

Purpose

The objective of this study was to investigate the influence of high dietary iodine supply and different iodine sources on thyroid status and oxidative stress in target tissues of the thyroid hormones in fattening pigs.

Methods

Eighty castrates (body weight: 33.3 ± 0.4 kg) were randomly allotted into five different treatments: The control diet contained 150 μg I/kg as KI, the other feeding groups were supplemented with 4,000 μg I/kg (as KI and KIO₃) and 10,000 μg I/kg (as KI and KIO₃), respectively. The mRNA expression levels of sodium/iodide symporter (NIS) and key antioxidant enzymes (Cu/Zn SOD, CAT, GPx) were analyzed in thyroid gland, liver, kidney, muscle, and adipose tissue sampled during slaughter. Furthermore, antioxidant enzyme activities and the effect on lipid peroxidation (MDA) were determined in liver and muscle.

Results

In thyroid gland, a significant downregulation of NIS and Cu/Zn SOD mRNA expression was observed in high-iodine groups. In liver, a source effect on the mRNA expression of Cu/Zn SOD between KI and KIO₃ at 4,000 μg I/kg was shown. In contrast, not SOD but GPx activity was affected by iodine source with strongest downregulation in high KIO₃ group. In muscle, GPx activity was affected by both iodine source and dose, showing stronger downregulation in KI groups. In kidney and adipose tissue, oxidative stress parameters showed no or only unsystematic changes. However, variation in iodine supply had no effect on MDA concentrations.

Conclusions

NIS expression was significantly decreased with increased iodine supplementation, which is to ensure the thyroid gland function. However, the alleviating effect of iodine supplementation observed in antioxidant enzyme mRNA expression and activity did not reflect on the lipid peroxide level.     

Postprandial glucose, insulin and gastrointestinal hormones in healthy and diabetic subjects fed a fructose-free and resistant starch type IV-enriched enteral formula

Background

Reducing the dietary glycaemic response has been proposed as a means of reducing the risk of diabetes.

Aim

To evaluate the effects of a new diabetes-specific formula (DSF) enriched with resistant starch type IV and fructose-free on postprandial glycaemia, insulinaemia and gastrointestinal hormones in healthy volunteers and in outpatient type 2 diabetics.

Methods

(1) Twenty-four healthy volunteers were divided into two groups: Group 1 ( n = 10) was provided 50 g of the carbohydrate (CHO) constituent of the new product and 50 g of glucose separated by 1 week; Group 2 ( n = 14) was provided 400 ml of the new DSF (T-Diet Plus^® Diabet NP) and 400 ml of a control product separated by 1 week. (2) Ten type 2 diabetic patients received 400 ml of the new DSF and two other commercially available DSF (Glucerna^® SR and Novasource^® Diabet) on three occasions separated by 1 week. Venous blood samples were drawn at time 0 and at different times until 120 min. Glucose, insulin and gastrointestinal hormones were determined. Glycaemic and insulinaemic indices and glycaemic load were calculated.

Results

The CHO constituent and the new DSF showed low glycaemic index and glycaemic load. In healthy subjects, insulin and C-peptide release were lower after administration of the CHO constituent as well as after the new DSF (P < 0.001). Ghrelin, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) production were lower after intake of the CHO constituent (P ranging from <0.001 to 0.019) compared with glucose, and GIP was lower after ingestion of the new DSF (P = 0.002) than after the control product. In type 2 diabetic patients, glucose AUC was lower after the administration of the new DSF (P = 0.037) compared with the others.

Conclusions

Our results indicate that this new product could be beneficial for diabetic patients.     

Gender-specific changes in physical activity pattern in Iran: national surveillance of risk factors of non-communicable diseases (2007–2011)

Objectives

This study describes the gender-specific pattern of physical activity (PA) in Iran 2011. The 4-year changes in PA levels (domains) are also determined according to the Iran’s national surveys conducted on 2007 and 2011.

Methods

Physical activity assessed based on the global physical activity questionnaire. In all, 4,121 (2007), and 7,436 (2011) adults were analyzed.

Results

Based on 2011 survey, 56.4 %, 39.2 %, and 74.4 % of participants were physically inactive at work, commuting and recreation, respectively. In all domains of PA, males showed a higher degree of activity (min/day) than females (P value <0.001). The overall prevalence of physical inactivity was increased from 15 % (2007) to 21.5 % (2011) (P value <0.001). Over the 4 years, a significant decline in total physical activity (MET × min/week) and the duration of commuting activity were noted in both genders. Work-related activity was dramatically decreased in females. However, the time spent in recreational activity remained relatively constant.

Conclusions

This report indicating that the Iranian population, particularly females, have become less active during the survey period. Physical inactivity should receive more attention as a public health issue.     

Changes in mineral status are associated with improvements in insulin sensitivity in obese patients following l-arginine supplementation

Purpose

The aim of this study is to evaluate the long-term influence of l-arginine intake on mineral concentration in patients with obesity and to assess the changes in lipid serum levels, fat content, and insulin resistance that result.

Methods

A randomized double-blind placebo-controlled study was conducted. 88 obese patients were randomly assigned to receive either 9 g of l-arginine or placebo daily, for 6 months. At baseline and after 6 months, selected anthropometrical measurements and blood biochemical analyses were performed and mineral levels were assessed. To assess insulin sensitivity, the gold-standard euglycemic clamp methodology was used.

Results

We found that 6 months of l-arginine supplementation resulted in significant increases in insulin sensitivity (Δ1.1 mg/kg/min, P < 0.01) and zinc levels (Δ1.5 μmol/L, P < 0.001). Moreover, a positive correlation between the change in zinc concentration in serum and the change in insulin sensitivity was observed (R = 0.80, P < 0.01). In the group of patients treated with l-arginine, a negative correlation between the change in zinc concentration in serum and the change in body fat content was noted (R = ?0.38, P < 0.05).

Conclusions

l-Arginine supplementation affects zinc status in obese patients. One beneficial influence is related to the improvements in insulin sensitivity.     

Active hexose-correlated compound and Bifidobacterium longum BB536 exert symbiotic effects in experimental colitis

Purpose

Active hexose-correlated compound (AHCC) is a commercial extract obtained from Basidiomycetes under controlled conditions, yielding a 74 % content in oligosaccharides, especially α-glucans. AHCC has a number of therapeutic effects, including intestinal anti-inflammatory activity. Bifidobacterium longum BB536 is a probiotic with potential health-promoting effect at the gut level. The purpose of the present study was to evaluate the possibility of synergism between AHCC, which is believed to act as a prebiotic, and B. longum BB536.

Methods

We used the trinitrobenzene sulfonic acid model (TNBS) of colitis in rats. AHCC (100 or 500 mg kg^?1) and B. longum BB536 (5 × 10⁶ CFU rat^?1 day^?1) were administered together or separately for 7 days prior to colitis induction and then for another 7 days and compared with control (noncolitic) and TNBS rats.

Results

The results show that both treatments had intestinal anti-inflammatory activity separately, which was enhanced when used in combination, as shown by changes in body weight gain, colonic weight to length ratio, myeloperoxydase activity and iNOS expression. Interestingly, the association of AHCC 100 mg kg^?1 + B. longum BB536 showed the highest anti-inflammatory activity.

Conclusions

Our data provide a preclinical experimental basis for the synergistic effect of AHCC and B. longum BB536 on inflammatory bowel disease.     

Evaluation of physical activity and its relationship to health-related quality of life in patients on chronic hemodialysis

Objective

The aim of this study was to investigate the relationship between physical activity and health-related quality of life (HRQOL) in patients on chronic hemodialysis.

Methods

A total of 31 men (69.0 ± 11.1 years) and 17 women (66.9 ± 10.0 years) among 61 male and 30 female patients on chronic hemodialysis at Innoshima General Hospital, Onomichi, Japan, were enrolled in this cross-sectional study. Physical activity was evaluated using tri-axial accelerometers. HRQOL and psychological distress were also evaluated using the EuroQol questionnaire (EQ-5D) and the K6 questionnaire, respectively.

Results

Physical activity evaluated by Σ[metabolic equivalents × h per week (METs·h/w)] was 8.1 ± 6.0 METs·h/w, and EQ-5D score was 0.754 ± 0.177. Among all patients, EQ-5D scores were significantly correlated with physical activity over 4 METs on non-hemodialysis treatment days (r = 0.426, p = 0.003). In women, EQ-5D scores were also correlated with physical activity over 4 METs on hemodialysis treatment days and non-hemodialysis treatment days. By stepwise multiple regression analysis, physical activity over 4 METs on non-hemodialysis treatment days was a determinant factor of EQ-5D even after adjusting for age and K6 scores.

Conclusion

Physical activity over 4 METs on non-hemodialysis treatment days might be associated with EQ-5D in patients on chronic hemodialysis, especially in women.     

Effect of a combination of genistein, polyunsaturated fatty acids and vitamins D3 and K1 on bone mineral density in postmenopausal women: a randomized, placebo-controlled, double-blind pilot study

Purpose

Many postmenopausal women desire non-pharmaceutical alternatives to hormone therapy for protection against osteoporosis. Soybean isoflavones, especially genistein, are being studied for this purpose. This study examined the effects of synthetic genistein in combination with other potential bone-protective dietary molecules on bone mineral density (BMD) in early postmenopausal women.

Methods

In this 6-month double-blind pilot study, 70 subjects were randomized to receive daily either calcium only or the geniVida? bone blend (GBB), which consisted of genistein (30 mg/days), vitamin D3 (800 IU/days), vitamin K1 (150 μg/days) and polyunsaturated fatty acids (1 g polyunsaturated fatty acids as ethyl ester: eicosapentaenoic acid/docosahexaenoic acid ratio = ~2/1). Markers of bone resorption and formation and BMD at the femoral neck, lumbar spine, Ward’s triangle, trochanter and intertrochanter, total hip and whole body were assessed.

Results

Subjects supplemented with the GBB (n = 30) maintained femoral neck BMD, whereas in the placebo group (n = 28), BMD significantly decreased (p = 0.007). There was also a significant difference (p < 0.05) in BMD between the groups at Ward’s triangle in favor of the GBB group. Bone-specific alkaline phosphatase and N-telopeptide significantly increased in the GBB group in comparison with those in baseline and in the placebo group. The GBB was well tolerated, and there were no significant differences in adverse events between groups.

Conclusions

The GBB may help to prevent osteoporosis and reduce fracture risk, at least at the hip, in postmenopausal women. Larger and longer-term clinical trials are warranted.     

Modulation of detoxification enzymes by watercress: in vitro and in vivo investigations in human peripheral blood cells

Background

Epidemiological studies indicate that consumption of cruciferous vegetables (CV) can reduce the risk of cancer. Supposed mechanisms are partly the inhibition of phase I and the induction of phase II enzymes.

Aim

The aim of this study was to investigate in vitro and in vivo effects of watercress (WC), a member of the CV family, on chemopreventive parameters using human peripheral blood mononuclear cells (PBMC) as surrogate cells. We investigated the hypothesis that WC reduces cancer risk by inducing detoxification enzymes in a genotype-dependent manner.

Methods

In vitro gene expression and enzyme activity experiments used PBMC incubated with a crude extract from fresh watercress (WCE, 0.1–10 μL/mL with 8.2 g WC per 1 mL extract) or with one main key compound phenethyl isothiocyanate (PEITC, 1–10 μM). From an in vivo perspective, gene expression and glutathione S-transferase (GST) polymorphisms were determined in PBMC obtained from a human intervention study in which subjects consumed 85 g WC per day for 8 weeks. The influence of WC consumption on gene expression was determined for detoxification enzymes such as superoxide dismutase 2 (SOD2) and glutathione peroxidase 1 (GPX1), whilst the SOD and GPX activities in red blood cells were also analysed with respect to GST genotypes.

Results

In vitro exposure of PBMC to WCE or PEITC (24 h) increased gene expression for both detoxification enzymes GPX1 (5.5-fold, 1 μL/mL WCE, 3.7-fold 1 μM PEITC) and SOD2 (12.1-fold, 10 μL/mL WCE, 7.3-fold, 10 μM PEITC), and increased SOD2 activity (1.9-fold, 10 μL/mL WCE). The WC intervention had no significant effect on in vivo PBMC gene expression, as high individual variations were observed. However, a small but significant increase in GPX (p = 0.025) and SOD enzyme activity (p = 0.054) in red blood cells was observed in GSTM1*0, but not in GSTM1*1 individuals, whilst the GSTT1 genotype had no impact.

Conclusion

The results indicate that WC is able to modulate the enzymes SOD and GPX in blood cells in vitro and in vivo, and suggest that the capacity of moderate intake of CV to induce detoxification is dependent in part on the GSTM1 genotype.     

High dietary taurine inhibits myocardial apoptosis during an atherogenic diet: association with increased myocardial HSP70 and HSF-1 but not caspase 3

Background and aim

Apoptosis is a major cause of myocyte death, and taurine is anti-apoptotic. Heat shock protein 70 (HSP70) (which is regulated by heat shock factor—HSF-1) is also anti-apoptotic, and caspase 3 stimulates the apoptotic pathway. This study investigated whether taurine affects atherogenic diet-induced myocardial apoptosis, and whether HSP70, HSF-1 and caspase 3 are involved.

Methods

New Zealand white rabbits were divided into 3 groups for 4 weeks according to their diet. Group 1 (control) was fed a normal rabbit diet; Group 2 (MC) received a normal rabbit diet with 1 % methionine plus 0.5 % cholesterol. Group 3 received MC diet + 2.5 % taurine (MCT).

Results

The atherogenic diet did not affect myocardial HSP70 or HSF-1 protein, but increased myocardial apoptotic nuclei to 40 % (p < 0.01) versus 7 % in con and 12 % in MCT (p < 0.01). However, in MCT, myocardial HSP70 expression increased by 42.7 % versus con and MC (p = 0.016), HSF-1 by 12 % versus con and MC (p < 0.05), and total nuclei count increased by 37 % versus MC (p < 0.05). Caspase 3 subunits remained unchanged in all groups, and HSP70 was increased approximately twofold in endothelial layer of arterioles (p = 0.01).

Conclusion

This study shows that taurine could reduce myocardial apoptotic nuclei and thus confer myocardial cytoprotection via stimulating myocardial HSP70 via HSF-1 and caspase 3-independent mechanisms.     

Physical activity and quality of life in older adults: an 18-month panel analysis

Purpose

Although physical activity has been associated with quality of life (QOL), the empirical evidence regarding the mechanisms underlying this relationship is limited. In the present study, we examined the mediating roles played by self-efficacy and health status in the physical activity–QOL relationship from baseline to 18-month follow-up in a sample of community-dwelling older adults.

Methods

Community-dwelling adults (N = 321, M age = 63.8 years) were recruited to participate in a cross-sectional study and were later contacted to participate in an 18-month follow-up. Individuals completed a battery of questionnaires assessing physical activity, self-efficacy, physical self-worth, disability limitations, and quality of life. A panel analysis within a covariance modeling framework was used to analyze the data.

Results

Overall, the model was a good fit to the data (χ² = 61.00, df = 29, p < 0.001, standardized root mean residual = 0.05, Comparative Fit Index = 0.97) with changes in physical activity indirectly influencing change in life satisfaction from baseline to 18 months via changes in exercise self-efficacy, physical self-worth, and disability limitations independent of baseline relationships and demographic factors. Specifically, increases in physical activity were associated with increases in exercise self-efficacy which, in turn, was associated with higher physical self-worth and fewer disability limitations which were associated with greater life satisfaction.

Conclusions

The findings from this study suggest the relationship between physical activity and global QOL in older adults may be mediated by more proximal modifiable outcomes that can be targeted in physical activity programs and interventions.     

The effect of antioxidant vitamins E and C on cognitive performance of the elderly with mild cognitive impairment in Isfahan,Iran: a double-blind,randomized, placebo-controlled trial

Purpose

This study was carried out to investigate the effect of vitamins E and C on cognitive performance among the elderly in Iran.

Methods

About 256 elderly with mild cognitive impairment, aged 60–75 years, received 300 mg of vitamin E plus 400 mg of vitamin C or placebo daily just for 1 year.

Background

Demographic characteristics, anthropometric variables food consumption, cognitive function by Mini-Mental State Examination (MMSE), and some of the oxidative stress biomarkers were examined.

Results

Antioxidant supplementation reduced malondialdehyde level (P < 0.001) and raised total antioxidant capacity (P < 0.001) and glutathione (P < 0.01). The serum 8-hydroxydeoxyguanosine remained unchanged (P < 0.4). After adjusting for the covariates effects, MMSE scores following 6- (25.88 ± 0.17) and 12-month antioxidant supplementation (26.8 ± 0.17) did not differ from control group (25.86 ± 0.18 and 26.59 ± 0.18, respectively).

Conclusion

Despite significant improvement in most of the oxidative stress biomarkers, antioxidants’ supplementation was not observed to enhance cognitive performance. A large number of kinetic and/or dynamic factors could be suspected.     

The effect of workplace smoking bans on heart rate variability and pulse wave velocity of non-smoking hospitality workers

Objectives

To investigate the effect of a change in second-hand smoke (SHS) exposure on heart rate variability (HRV) and pulse wave velocity (PWV), this study utilized a quasi-experimental setting when a smoking ban was introduced.

Methods

HRV, a quantitative marker of autonomic activity of the nervous system, and PWV, a marker of arterial stiffness, were measured in 55 non-smoking hospitality workers before and 3–12 months after a smoking ban and compared to a control group that did not experience an exposure change. SHS exposure was determined with a nicotine-specific badge and expressed as inhaled cigarette equivalents per day (CE/d).

Results

PWV and HRV parameters significantly changed in a dose-dependent manner in the intervention group as compared to the control group. A one CE/d decrease was associated with a 2.3 % (95 % CI 0.2–4.4; p = 0.031) higher root mean square of successive differences (RMSSD), a 5.7 % (95 % CI 0.9–10.2; p = 0.02) higher high-frequency component and a 0.72 % (95 % CI 0.40–1.05; p < 0.001) lower PWV.

Conclusions

PWV and HRV significantly improved after introducing smoke-free workplaces indicating a decreased cardiovascular risk.     

Calcium co-ingestion augments postprandial glucose-dependent insulinotropic peptide1–42, glucagon-like peptide-1 and insulin concentrations in humans

Purpose

This study determined whether calcium co-ingestion potentiates postprandial GIP_1–42 and GLP-1 concentrations in humans and the concomitant impact on insulin, appetite sensations and substrate metabolism.

Methods

Ten healthy males consumed two energy- and macronutrient-matched meals in a double-blind, randomized, crossover design. The calcium content of the control meal was 3 mg/kg body mass, which was increased to 15 mg/kg body mass with calcium co-ingestion. Circulating concentrations of GIP_1–42, GLP-1 and insulin were determined over a 180-min postprandial period, followed by 60 min of exercise. Visual analogue scales were used to determine subjective appetite sensations. Rates of energy expenditure and substrate (lipid and carbohydrate) oxidation were estimated using indirect calorimetry.

Results

Calcium co-ingestion resulted in a 47 % increase in GIP_1–42, a 22 % increase in GLP-1 and a 19 % increase in insulin areas under the curve for the 120 min following consumption (all P < 0.05). Furthermore, appetite sensations were suppressed by calcium co-ingestion by 12 % (P = 0.034). No differences, however, were observed in substrate metabolism (P > 0.05).

Conclusion

Ingestion of a high-calcium meal potentiates postprandial GIP_1–42, GLP-1 and insulin concentrations in humans. Subjective appetite is also temporarily suppressed, although substrate metabolism is unaffected.     

Leisure-time physical activity does not fully explain the higher body mass index in irregular-shift workers

Purpose

To elucidate the influence of leisure-time physical activity on body mass index (BMI), appetite-related hormones, and sleep when working irregular shifts.

Methods

A cross-sectional study was undertaken of 57 male truck drivers, 31 irregular-shift workers and 26 day-shift workers. Participants completed the International Physical Activity Questionnaire and were assessed for BMI. Subjects also provided a fasting blood sample for analysis of appetite-related hormones and wore an actigraphy device for seven consecutive days.

Results

Although leisure-time physical activity (LTPA) was generally low (<150 min/week) in both groups, the irregular-shift workers were more physically active than day-shift workers (99 ± 166 vs. 23 ± 76 min/week, p < 0.01). In spite of this, mean BMI of irregular-shift workers was 2 kg/m² greater than day-shift workers (28.4 ± 3.8 vs. 26.4 ± 3.6 kg/m², p = 0.04). Mean leptin concentration was 61 % higher in irregular-shift workers (5,205 ± 4,181 vs. 3,179 ± 2,413 pg/ml, p = 0.04). Among obese individuals, irregular-shift workers had higher leptin concentration (p < 0.01) and shorter sleep duration (p = 0.01) than obese day-shift workers.

Conclusion

Elevated BMI was associated with high leptin and low ghrelin levels in this population of irregular-shift workers. No influence of LTPA on appetite-related hormones or sleep duration was found. We conclude that moderate LTPA is insufficient to attenuate the higher BMI associated with this type of irregular-shift work in truck drivers.     

Prolonged fatigue is associated with sickness absence in men but not in women: prospective study with 1-year follow-up of white-collar employees

Purpose

Prolonged fatigue adversely affects an individual’s performance and functioning. The present study investigated the prospective associations between prolonged fatigue and sickness absence (SA) during 1-year follow-up.

Methods

At baseline, a convenience sample of white-collar employees received the 20-item Checklist Individual Strength (CIS), which measures prolonged fatigue by covering the dimensions fatigue severity, reduced concentration, reduced motivation, and reduced physical activity. SA episodes were registered during the 1-year follow-up distinguishing between short-term (1–7 days) and long-term (>7 days) SA episodes. Baseline CIS scores were linked to SA during follow-up by negative binomial regression models in which age, gender, job grade, and prior SA were controlled for.

Results

Six hundred and thirty-three (56 %) employees participated in the study of which 598 had complete data and were eligible for analysis. Gender was a significant effect modifier of the relationship between prolonged fatigue and SA. Therefore, the results were stratified for men (N = 365) and women (N = 233). In white-collar men, fatigue severity and reduced concentration were positively associated with the number of long-term SA episodes, while other fatigue dimensions were not significantly related to SA. In white-collar women, prolonged fatigue was not associated with SA during 1-year follow-up.

Conclusion

The results of this study warrant more attention for prolonged fatigue in occupational healthcare practice and research. Early identification of and treatment for prolonged fatigue might prevent future health problems and SA, especially in white-collar men.     

Correlates of objectively measured physical activity in adults and older people: a cross-sectional study of population-based sample of adults and older people living in Norway

Objectives

The aims of the study were to identify correlates of objectively measured physical activity and to determine whether the explanatory power of the correlates differed with sex, weight status or level of education.

Methods

Physical activity was assessed objectively in 3,867 participants, aged 20–85 years, for a consecutive 7 days using the ActiGraph GT1M activity monitor. Demographic and biological variables and levels of psychological, social environmental and physical environmental correlates were self-reported.

Results

The complete set of correlates explained 18.6 % (p < 0.001) of the variance in overall physical activity. Age and physical activity identity were the most important factors, explaining 4.8 and 3.2 % of the variance, respectively, whereas social environmental and physical environmental correlates did not significantly increase the amount of explained variance. Small interaction effects between demographic and biological variables and the correlates were observed.

Conclusions

Self-efficacy, perceived behavioural control and physical activity identity might be important targets for intervention. Intervention efforts aimed at influencing psychological correlates of physical activity may prove equally effective regardless of sex, weight status and level of education.