Association between omentin-1, adiponectin and bone health under consideration of osteoprotegerin as possible mediator.

PURPOSE: Several studies implicated a crosstalk between bone and fat in the pathogenesis of osteoporosis. Few studies indicated an association between adiponectin and omentin-1 on the bone remodeling process and bone mineral density, and suggested osteoprotegerin (OPG) as a mediator of this relationship. However, only limited evidence on this relationship is available in humans. Therefore, this study aimed to investigate the association between omentin-1, adiponectin and broadband ultrasound attenuation (BUA) in peri-/premenopausal and postmenopausal women, and to assess the role of OPG as a possible mediator. METHODS: Data from the German population-based EPIC-Potsdam cohort comprising 637 women were analyzed. Multivariable-adjusted ANCOVA including age, BMI, waist circumference, smoking status, education, physical activity, adiponectin or omentin-1 and hormone use was used to investigate potential relationships between the adipokines and BUA levels. A mediation analysis assessed the mediating effect of OPG on the association of BUA and omentin-1 levels. RESULTS: Peri-/premenopausal women had higher BUA levels (112.5 ± 10.1 dB/MHz), compared to postmenopausal women (106.3 ± 10.0 dB/MHz). In peri-/premenopausal women neither adiponectin nor omentin-1 was significantly associated with BUA. In postmenopausal women, adiponectin was not associated with BUA, but 10 % increase in the omentin-1 concentration was significantly associated with 0.44 dB/MHz lower BUA levels (p = 0.01). Omentin-1 was positively associated with OPG (p = 0.02); however, OPG was not significantly related to BUA (p = 0.62). CONCLUSION: Our study provides evidence for an inverse association between circulating omentin-1 and BUA levels in postmenopausal women. However, the present findings do not support a mediating effect of OPG in the adipose tissue-bone pathway.

A Mediterranean-style diet, its components and the risk of heart failure: a prospective population-based study in a non-Mediterranean country.

BACKGROUND/OBJECTIVES: Growing evidence emerged about the role of diet in heart failure (HF) development, but data are sparse and inconclusive. We examined the association between a Mediterranean-style diet, its components and HF risk. SUBJECTS/METHODS: Analyses were carried out in 24 008 middle-aged participants of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam (Germany), including 209 incident HF cases within 8.2 years. The traditional Greek Mediterranean diet score (tMED) was used to assess dietary adherence. Cox's proportional hazards regression was applied to estimate the relationship between the adherence to the Mediterranean-style diet, its components and HF risk. RESULTS: After adjustment for age, sex and energy intake, a 2-unit increment in the tMED was associated with 26% lower risk of HF (HR (95% confidence interval (CI)): 0.76 (0.60-0.97)). After multivariable adjustment, this association was slightly attenuated and lost significance [HR (95%CI): 0.82 (0.64-1.05)]. Interestingly, we observed a significant association in multivariable adjusted models when milk products were excluded from the score (HR (95% CI): 0.75 (0.59-0.96)). Three score components were significantly associated with HF risk: alcohol (HR (95%CI): 0.73 (0.55-0.97) for moderate versus low/high intakes), meat: 2.04 (1.17-3.55) and fish: 0.59 (0.36-0.95), both for the highest versus the lowest quintile. CONCLUSIONS: The tMED was not significantly associated with HF risk, but low meat, high fish and moderate alcohol intake were inversely associated with HF risk in our non-Mediterranean population. Minor dietary changes could be valuable primary prevention measures, particularly the increase of fish consumption while reducing the intake of meat.

The association between nut consumption and the risk of total and ischemic stroke in a German cohort study.

BACKGROUND/OBJECTIVES: Nuts have beneficial effects on coronary heart disease and many cardiovascular risk factors. However, their effect on stroke is less established, and no studies on the topic are available in Northern and Central European populations. Therefore, we aimed at investigating the association between nut consumption and the risk of stroke in a German population. SUBJECTS/METHODS: We used data from a prospective cohort of 26,285 participants of the European Prospective Investigation into the Cancer and Nutrition Potsdam Study. During a median follow-up time of 8.3 years (interquartile range: 7.5-9.2), 288 incident cases of stroke occurred. Nut consumption (standard portion size of 50 g) was assessed at baseline with a semiquantitative food-frequency questionnaire. RESULTS: The median nut intake was 0.82 g per day, interquartile range: 0.41-4.11. In the multivariable model, an increased risk of stroke was observed among participants who never consumed nuts (hazard ratio (HR): 1.56, 95% confidence interval: 1.17-2.08), compared with those consuming <½ portion/week. However, there was no evidence of a dose-response relationship between nut consumption and stroke. Compared with those who consumed <½ portion/week, the multivariable HR for total stroke was 1.06 (0.75-1.52) among those who consumed ½ to 1 portion/week and 1.37 (0.92-2.05) for those who consumed >1 portion/week. Similar nonsignificant associations were observed in stratified analysis for gender, or for fatal and nonfatal stroke. CONCLUSIONS: We could not observe an association between nut consumption and the risk of developing stroke (fatal/nonfatal) in a population with low habitual nut consumption.

Association between erythrocyte membrane fatty acids and biomarkers of dyslipidemia in the EPIC-Potsdam study.

BACKGROUND/OBJECTIVE: Blood proportions of fatty acids (FAs) and FA-ratios reflecting desaturase activity are associated with the risk of chronic diseases like type 2 diabetes mellitus or cardiovascular diseases. Biomarkers of dyslipidemia are considered as potential mediators of this association. We evaluated associations of erythrocyte membrane proportions of individual disease-related polyunsaturated fatty acids (PUFAs), trans-FAs, dairy-derived saturated FAs (SFAs) (15:0, 17:0) and FA-ratios with biomarkers of dyslipidemia (high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, non-HDL-cholesterol, triglycerides). SUBJECTS/METHODS: We conducted a cross-sectional analysis of a subsample (n=1759) of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study. Associations of individual FAs and FA-ratios with plasma biomarkers of dyslipidemia were evaluated by linear multivariable regression. RESULTS: Most notably, FA-ratios reflecting activity of Δ6-desaturase (D6D) and stearoyl-coenzyme A-desaturase (SCD) were positively associated with triglyceride and LDL-cholesterol concentrations (adjusted means (95% confidence interval (CI)) of triglycerides (mg/dl) across D6D tertiles: men--102 (94.7-110), 111 (104-120), 144 (134-156) and women--73.5 (70.0-77.2), 82.9 (79.0-86.9), 94.2 (89.7-98.9)); across SCD tertiles: men--99.0 (91.8-107), 115 (107-124), 144 (134-156) and women--72.4 (69.0-76.0), 81.5 (77.8-85.5), 97.2 (92.6-102)), whereas inverse associations with triglycerides were observed for the estimated Δ5-desaturase (D5D) activity (adjusted means (95% CI) of triglycerides (mg/dl) across D5D tertiles: men--128 (119-138), 121 (113-131), 106 (97.9-114) and women--92.0 (87.6-96.6), 82.8 (78.9-86.9), 75.3 (71.6-79.1), P-values for trend at least 0.0006). Furthermore, we observed generally weaker and less consistent associations of dairy-derived SFAs (mainly 17:0) with triglycerides and HDL-cholesterol. Individual PUFAs and trans-FAs were, if at all, only weakly associated with dyslipidemia markers. CONCLUSIONS: Our findings suggest that triglyceride and LDL-cholesterol concentrations may be mediators that link intake and metabolism of FAs to metabolic risk.

Associated factors of estimated desaturase activity in the EPIC-Potsdam study.

BACKGROUND AND AIMS: Altered activity of desaturase enzymes may be involved in the development of metabolic diseases like type 2-diabetes. Desaturase activities might be modifiable by diet and lifestyle-related factors, but no study has systematically investigated such factors so far. We aimed to evaluate the association of demographic, anthropometric, dietary and lifestyle characteristics with estimated Δ5-, Δ6- and Δ9-desaturase activity. METHODS AND RESULTS: A subsample (n = 1782) of the EPIC-Potsdam study was used for a cross-sectional analysis, involving men and women, mainly aged 35-65 years. Fatty acid (FA) product-to-precursor ratios, derived from the FA composition of erythrocyte membrane phospholipids, were used to estimate desaturase activities. Multiple linear regression models were used with estimated Δ5-, Δ6- and Δ9-desaturase activity as outcome and demographic (age, sex), anthropometric (BMI, WHR), dietary intake (FAs, carbohydrates) and lifestyle (physical activity, smoking, alcohol consumption) factors as exposure variables. Alcohol intake was positively associated with estimated Δ6- (explained variance in desaturase activity: 1.52%) and estimated Δ9-desaturase activity (explained variance: 5.53%). BMI and WHR showed a weak inverse association with estimated Δ5-desaturase activity (explained variance: BMI: 1.07%; WHR: 1.02%) and weak positive associations with estimated Δ6-(explained variance: BMI: 1.17%; WHR: 1.19%) and estimated Δ9-desaturase activities (explained variance: BMI: 0.70%; WHR: 0.96%). Age, sex, physical activity, smoking and dietary factors were only weakly associated with the estimated desaturase activities. CONCLUSION: Our findings suggest that alcohol intake as well as obesity measures are associated with the FA ratios reflecting desaturase activity.

Dietary fibre intake and ischaemic heart disease mortality: the European Prospective Investigation into Cancer and Nutrition-Heart study.

BACKGROUND/OBJECTIVES: Evidence from prospective studies is consistent in showing an inverse association between dietary fibre intake and risk of ischaemic heart disease (IHD), but whether dietary fibre from various food sources differ in their effect on IHD risk is less clear. The objective of this study was to assess the associations of total and food sources of dietary fibre with IHD mortality in the European Prospective Investigation into Cancer and Nutrition-Heart study. SUBJECTS/METHODS: Participants were 306,331 men and women from eight European countries. Dietary fibre intake was assessed using centre or country-specific diet questionnaires and calibrated using a 24-h diet recall. RESULTS: After an average follow-up of 11.5 years, there were 2381 IHD deaths among participants without cardiovascular disease at baseline. The calibrated intake of dietary fibre was inversely related with IHD mortality; each 10 g/day was associated with a 15% lower risk (relative risk (RR) 0.85; 95% confidence interval (CI): 0.73-0.99, P=0.031). There was no difference in the associations of the individual food sources of dietary fibre with the risk of IHD mortality; RR for each 5 g/day higher cereal fibre intake was 0.91 (CI: 0.82-1.01), RR for each 2.5 g/day fruit fibre intake was 0.94 (CI: 0.88-1.01) and RR for each 2.5 g/day vegetable fibre intake was 0.90 (95% CI: 0.76-1.07). CONCLUSION: A higher consumption of dietary fibre is associated with a lower risk of fatal IHD with no clear difference in the association with IHD for fibre from cereals, fruits or vegetables.

Adaptation of Saccharomyces cerevisiae to saline stress through laboratory evolution.

Most laboratory evolution studies that characterize evolutionary adaptation genomically focus on genetically simple traits that can be altered by one or few mutations. Such traits are important, but they are few compared with complex, polygenic traits influenced by many genes. We know much less about complex traits, and about the changes that occur in the genome and in gene expression during their evolutionary adaptation. Salt stress tolerance is such a trait. It is especially attractive for evolutionary studies, because the physiological response to salt stress is well-characterized on the molecular and transcriptome level. This provides a unique opportunity to compare evolutionary adaptation and physiological adaptation to salt stress. The yeast Saccharomyces cerevisiae is a good model system to study salt stress tolerance, because it contains several highly conserved pathways that mediate the salt stress response. We evolved three replicate lines of yeast under continuous salt (NaCl) stress for 300 generations. All three lines evolved faster growth rate in high salt conditions than their ancestor. In these lines, we studied gene expression changes through microarray analysis and genetic changes through next generation population sequencing. We found two principal kinds of gene expression changes, changes in basal expression (82 genes) and changes in regulation (62 genes). The genes that change their expression involve several well-known physiological stress-response genes, including CTT1, MSN4 and HLR1. Next generation sequencing revealed only one high-frequency single-nucleotide change, in the gene MOT2, that caused increased fitness when introduced into the ancestral strain. Analysis of DNA content per cell revealed ploidy increases in all the three lines. Our observations suggest that evolutionary adaptation of yeast to salt stress is associated with genome size increase and modest expression changes in several genes.

Diet and hip fractures among elderly Europeans in the EPIC cohort.

BACKGROUND/OBJECTIVES: Evidence on the role of diet during adulthood and beyond on fracture occurrence is limited. We investigated diet and hip fracture incidence in a population of elderly Europeans, participants in the European Prospective Investigation into Cancer and nutrition study. SUBJECTS/METHODS: 29, 122 volunteers (10,538 men, 18,584 women) aged 60 years and above (mean age: 64.3) from five countries were followed up for a median of 8 years and 275 incident hip fractures (222 women and 53 men) were recorded. Diet was assessed at baseline through validated dietary questionnaires. Data were analyzed through Cox proportional-hazards regression with adjustment for potential confounders. RESULTS: No food group or nutrient was significantly associated with hip fracture occurrence. There were suggestive inverse associations, however, with vegetable consumption (hazard ratio (HR) per increasing sex-specific quintile: 0.93, 95% confidence interval (CI): 0.85-1.01), fish consumption (HR per increasing sex-specific quintile: 0.93, 95% CI: 0.85-1.02) and polyunsaturated lipid intake (HR per increasing sex-specific quintile: 0.92, 95% CI: 0.82-1.02), whereas saturated lipid intake was positively associated with hip fracture risk (HR per increasing sex-specific quintile: 1.13, 95% CI: 0.99-1.29). Consumption of dairy products did not appear to influence the risk (HR per increasing sex-specific quintile: 1.02, 95% CI: 0.93-1.12). CONCLUSIONS: In a prospective study of the elderly, diet, including consumption of dairy products, alcohol and vitamin D, did not appear to play a major role in hip fracture incidence. There is however, weak and statistically non-significant evidence that vegetable and fish consumption and intake of polyunsaturated lipids may have a beneficial, whereas saturated lipid intake a detrimental effect.

Non-fasting lipids and risk of cardiovascular disease in patients with diabetes mellitus.

AIMS/HYPOTHESIS: The aim of this study was to examine the effect of postprandial time on the associations and predictive value of non-fasting lipid levels and cardiovascular disease risk in participants with diabetes. METHODS: This study was conducted among 1,337 participants with diabetes from the Dutch and German (Potsdam) contributions to the European Prospective Investigation into Cancer and Nutrition. At baseline, total cholesterol, LDL- and HDL-cholesterol and triacylglycerol concentrations were measured and the ratio of total cholesterol/HDL-cholesterol was calculated. Participants were followed for incidence of cardiovascular disease. RESULTS: Lipid concentrations changed minimally with increasing postprandial time, except for triacylglycerol which was elevated just after a meal and declined over time (1.86 at 0.1 h to 1.33 at >6 h, p for trend <0.001). During a mean follow-up of 8 years, 116 cardiovascular events were documented. After adjustment for potential confounders, triacylglycerol (HR for third tertile compared with first tertile (HR(t)3(to)1), 1.73 [95% CI 1.04, 2.87]), HDL-cholesterol (HR(t)3(to)1, 0.41 [95% CI 0.23, 0.72]) and total cholesterol/HDL-cholesterol ratio (HR(t)3(to)1, 1.65 [95% CI 0.95, 2.85]) were associated with cardiovascular disease, independent of postprandial time. Cardiovascular disease risk prediction using the UK Prospective Diabetes Study risk engine was not affected by postprandial time. CONCLUSIONS/INTERPRETATION: Postprandial time did not affect associations between lipid concentrations and cardiovascular disease risk in patients with diabetes, nor did it influence prediction of cardiovascular disease. Therefore, it may not be necessary to use fasting blood samples to determine lipid concentrations for cardiovascular disease risk prediction in patients with diabetes.

Dietary intake of the water-soluble vitamins B1, B2, B6, B12 and C in 10 countries in the European Prospective Investigation into Cancer and Nutrition.

OBJECTIVES: To describe the intake of vitamins thiamine (B1), riboflavin (B2), B6 (pyridoxine), B12 (cobalamine) and C (ascorbic acid) and their food sources among 27 centres in 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. METHODS: Between 1995 and 2000, 36 034 persons aged between 35 and 74 years were administered a standardized 24-h dietary recall using a computerized interview software programme (EPIC-SOFT). Intakes of the four B vitamins and vitamin C were estimated using the standardized EPIC Nutrient Database (ENDB). Mean intakes were adjusted for age and weighted by season and day of recall. RESULTS: Intake of B vitamins did not vary considerably between centres, except in the UK health-conscious cohort, in which substantially higher intakes of thiamine and lower intakes of vitamin B12 were reported compared with other centres. Overall, meat was the most important contributor to the B vitamins in all centres except in the UK health-conscious group. Vitamin C showed a clear geographical gradient, with higher intakes in the southern centres as compared with the northern ones; this was more pronounced in men than in women. Vegetables and fruits were major contributors to vitamin C in all centres, but juices and potatoes were also important sources in the northern centres. CONCLUSIONS: This study showed no major differences across centres in the mean intakes of B vitamins (thiamine, riboflavin, B6, B12), whereas a tendency towards a north-south gradient was observed for vitamin C.

Dietary fat intake in the European Prospective Investigation into Cancer and Nutrition: results from the 24-h dietary recalls.

OBJECTIVES: This paper describes the dietary intake of total fat, saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) and cholesterol of participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) in 27 centres across 10 countries. METHODS: Between 1995 and 2000, a stratified random sample of 36 034 participants (age range 35-74 years) completed a standardized 24-h dietary recall, assessed by means of the computer software EPIC-SOFT. Lipid intake data were calculated using a standardized nutrient database. RESULTS: On average, the contribution of fat to total energy intake was >or=34% of energy intake (%en) in women and >or=36%en in men for most EPIC centres, except for the British, Dutch and most Italian cohorts. Total fat (>40%en) and MUFA intakes (21%en, mainly from olive oil) were highest in Greece. Except for the Greek, Spanish and Italian centres, the average MUFA intake ranged between 10 and 13%en, with a high proportion derived from animal sources. SFA intake in women and men was lowest in the Greek, Spanish, Italian and UK cohorts with an average of

Modified Mediterranean diet and survival after myocardial infarction: the EPIC-Elderly study.

Mediterranean diet is associated with lower incidence of coronary heart disease, and two randomised trials indicated that it improves prognosis of coronary patients. These trials, however, relied on a total of 100 deaths and evaluated designer diets in the clinical context. We have evaluated the association of adherence to the modified Mediterranean diet, in which unsaturates were substituted for monounsaturates, with survival among elderly with previous myocardial infarction within the European Prospective Investigation into Cancer and nutrition (EPIC) study. As of December 2003, after a median follow-up of 6.7 years, 2671 EPIC participants from nine countries were 60 years or older and had prevalent myocardial infarction but no stroke or cancer at enrolment, complete information on dietary intakes and important covariates and known survival status. Adherence to the modified Mediterranean diet was assessed through a 10-unit-scale. Mortality ratio in relation to modified Mediterranean diet was estimated through Cox regression controlling for possible confounding. Increased adherence to modified Mediterranean diet by two units was associated with 18% lower overall mortality rate (95% confidence interval 7-27%, fixed effects model). There was no significant heterogeneity by sex, age at enrolment, or country, although the association tended to be less evident among northern Europeans. Associations between food groups contributing to the modified Mediterranean diet and mortality were generally weak. A diet inspired by the Mediterranean pattern that can be easily adopted by Western populations is associated with substantial reduction of total mortality of coronary patients in the community.

Co-overexpression of RspAB improves recombinant protein production in Escherichia coli.

The Escherichia coli mutant CWML2 was previously reported to exhibit improved physiological characteristics, including recombinant protein production. Here we investigate the molecular basis of this phenotype by comparing the cellular level of three RNA polymerase sigma subunits by immunoblot analysis. While the level of housekeeping sigma(D) was similar in parent and mutant, the levels of the flagella synthesis regulator sigma(F) and the stationary phase regulator sigma(S) were higher in the mutant strain, indicating a different motility and stationary phase phenotype. Evidence for this conclusion was provided by the significantly higher motility of CWML2, compared to its parent. Based on these results, we hypothesized that alterations in ppGpp regulation via a homoserine lactone-dependent mechanism may be relevant for the mutant phenotype. Indeed, transcription of the rspAB operon, which was previously described to be involved in the degradation of homoserine lactone, was found to be deregulated in CWML2 in a plasmid-based reporter protein assay. By overexpression of the E. coli rspAB operon, we could partly mimic the mutant phenotype and demonstrate that co-overexpression of RspAB is a pertinent metabolic engineering strategy to improve recombinant protein production.

Increased phenylalanine production by growing and nongrowing Escherichia coli strain CWML2.

Chemostat selection at low dilution rate in glycerol-limited minimal medium was previously employed to isolate the mutant Escherichia coli strain CWML2 which exhibits shorter lag phases, decreased acetate production, and higher specific growth rates and biomass yields in batch culture (Weikert, C.; Sauer, U.; Bailey, J. E. Microbiology 1997, 143, 1567-1574). In this study, CWML2 was analyzed for its biochemical production capabilities in batch culture and under nongrowing conditions. Both CWML2 and MG1655 were transformed with plasmid pSY130-14, which encodes feedback resistant mutants of the enzymes chorismate mutase P-prephenate synthase and 3-hydroxy-d-arabinoheptulosonate-7-phosphate dehydratase, to enable phenylalanine production. In batch culture, transformed CWML2 produced twice as much phenylalanine as did MG1655:pSY130-14. In contrast to the reference strain, substantial growth-independent production of phenylalanine was calculated for CWML2:pSY130-14 by using Luedeking-Piret kinetic analysis. Over a period of 30 h, nongrowing cells of CWML2:pSY130-14 exhibited a 2.5-fold higher specific phenylalanine production rate. The apparent capability of E. coli CWML2 to partly uncouple metabolic activity from growth suggests a potentially general advantage of this class of modified hosts for production of biochemicals.

An Escherichia coli host strain useful for efficient overproduction of secreted recombinant protein.

Periplasmic secretion of overexpressed Bacillus stearothermophilus alpha-amylase was analyzed in batch and fed-batch cultivations of Escherichia coli MG1655:pCSS4-p and the mutant strain CWML2:pCSS4-p. Under all conditions investigated, growth and product formation of MG1655:pCSS4-p were severely impaired by heterologous protein expression and/or processing, while E. coli CWML2:pCSS4-p was found to be more robust and to accumulate 2- to 3-fold higher maximum alpha-amylase levels. While this strain is itself potentially interesting for applications, its properties also illustrate the potential of the selection procedure that was employed to obtain it from its progenitor MG1655 (Weikert, C., Sauer, U., Bailey, J. E., 1997. Microbiol. 143: 1567-1574. Application of this procedure to existing industrial strains may lead to significantly improved process organisms.