Internal validation of a French version of the Dutch eating behaviour questionnaire

This study is the first part of the validation of a French version of the Dutch Eating Behaviour Questionnaire (DEBQ), among a population of obese and normal-weight patients. The questionnaire was administered to 166 subjects. Construct validity was assessed by orthogonal factor analysis with a varimax procedure and reliability was measured by Cronbach's alpha coefficient. Results showed the presence of three major factors (“emotional”, “restrained” and “external eating”) with loadings similar to those of the original questionnaire. A high internal consistency was found in the different scales. This study clearly demonstrates the factorial validity and the reliability of a French version of the DEQB.

Social disparities in musculoskeletal disorders and associated mental malaise: findings from a population-based survey in France

AIMS

Various types of musculoskeletal disorders (MSDs) have comorbid mental disorders, which may in turn have a negative influence on disease course and role impairment, but the contribution of social factors to this type of comorbidity is a much under-researched area. This study investigates whether there is a socially patterned association of MSDs with different dimensions of mental malaise.

METHODS

The sample included 3,368 economically active participants aged 18-64 years, randomly selected from the Lorraine region in north-eastern France. Information was provided through a post-mailed questionnaire on fatigue, sadness/depression (Duke questionnaire) and cognitive disability during the last eight days.

RESULTS

MSDs were significantly more prevalent in manual workers, clerks and other occupations than in upper and intermediate professionals, and similar occupational disparities were found for cognitive disability, fatigue and sadness/ depression. Stratifying the sample, we found the occupational disparities in cognitive disability to be much stronger among participants suffering from MSDs than among participants not suffering from MSDs, and the occupational disparities in fatigue and sadness/depression to be limited to the subsample of subjects suffering from MSDs.

CONCLUSIONS

The findings demonstrate that the association of MSDs with mental malaise is much stronger in the lower occupational groups than in the higher groups. Given that psychological factors are implicated in disease prognosis and in the development of disabilities, awareness of the social dimension of the association and treatment of the comorbid mental disorders could open a promising avenue for reducing social inequalities in disability related to MSDs.

In vitro allergenicity of peanut after hydrolysis in the presence of polysaccharides

BACKGROUND

Peanut is a major allergenic product. Manufacturing processes used in food industries to improve the physicochemical properties of food-based peanut (stabilization, texturization), could cause a modification of the digestibility of peanut proteins and, consequently, their allergenicity.

OBJECTIVE

This study aimed at examining the influence of polysaccharides, i.e., gum arabic, low methylated pectin (LMP) and xylan, on the in vitro hydrolysis of peanut protein isolate (PPI) and the in vitro allergenicity of the digestion products.

METHODS

PPI was hydrolysed during a two-step in vitro hydrolysis by pepsin, followed by a trypsin/chymotrypsin (T/C) mixture performed in dialysis bags with molecular weight cut-offs (MWCO) of 1000 or 8000 Da. SDS-PAGE electrophoresis and immunoblotting were assessed on the peptic and T/C digestion products in (retentates) and out of the dialysis bags (dialysates).

RESULTS

Hydrolysis by all of the digestive enzymes showed retention of some proteins in the dialysis bags in the presence of gum arabic and xylan. The retentates were recognized by IgG and IgE, particularly peptides <20 kDa. The IgE binding with peptides of retentate containing xylan from the dialysis bag with an MWCO of 1000 Da was reduced. The immunoreactivity of hydrolysis products in dialysates was considerably reduced by polysaccharides, regardless of the dialysis bag.

CONCLUSION

Reduction of PPI hydrolysis was probably due to non-specific interactions between polysaccharides and peptides. In retentates, IgE-binding epitopes were reduced by digestion and the presence of xylan. In dialysates, they were reduced by all of the polysaccharides. This work highlights the possibility of modulating this food allergy through optimized formulation.

Effects of different levels of gum arabic, low methylated pectin and xylan on in vitro digestibility of beta-lactoglobulin

Plant hydrocolloids used in the food industry to improve texture and stability of food, such as dairy products, can reduce protein digestibility and, consequently, modify the bioavailability of amino acids. We studied the in vitro hydrolysis at 37 degrees C of beta-lactoglobulin (beta-lg) in mixed dispersions containing either gum arabic or low-methylated pectin or xylan at levels of 0, 1, 10, 20, 30, and 50% weight. Proteolysis used either pepsin alone by progressive reduction of pH during proteolysis or pepsin followed by trypsin and chymotrypsin in two different dialysis bags with a molecular weight (MW) cutoff of 1000 or 8000 Da. Results showed that beta-lg was almost resistant to pepsin digestion and that the three plant hydrocolloids inhibited significantly beta-lg digestibility as determined using dialysis bag with a 1000-Da MW cutoff. Among the three polysaccharides used, xylan showed a digestibility decrease greater than that obtained with gum arabic and low-methylated pectin. On the other hand, no significant effect of polysaccharides on the in vitro beta-lg digestibility was detected using the dialysis bag with an 8000 Da MW cutoff. This mainly suggests that peptides with MW in the range 1000 to 8000 Da may interact with polysaccharides more than peptides and proteins with a greater molecular weight to decrease the protein digestibility, and that the nature of the polysaccharides plays a role in the interaction.

[Food allergy: effect of proteins-lipids and proteins-polysaccharides interactions]

The most widely used ingredients in food formulation are proteins, lipids and polysaccharides. Proteins-lipids and proteins-polysaccharides interactions play a key role in the structure, stability, sensorial and nutritional properties of formulated foods. The objective of the present study is to highlight the importance of proteins-lipids and proteins-polysaccharides interactions, on the immuno-reactivity of allergenic proteins. Two models have been studied, on the one hand refined and not refined oils (soya and sunflower) and soya lecithin, on the other hand mixtures based on peanut proteins and polysaccharides (arabic gum, pectin, xylan). STUDY OF OILS: We have extracted proteins, using a PBS buffer, from refined and not refined oils from soya, sunflower and from soya lecithin, determined protein concentrations and identified allergenic proteins using SDS-PAGE electrophoresis and immuno-blotting. Phospholipids are determined by atomic absorption spectrometry. The protein determination and SDS-PAGE show the presence of a higher amount of proteins in not refined oils and lecithin as compared to refined oils. An important amount of proteins associated to phospholipids are eliminated by degumming on the form of lecithin. On the other hand, residual proteins from refined oils are accompanied by phospholipids. Immuno-blots reveal the presence of a 56 kDa allergen in oils issued from soya seeds and soya lecithin, and the presence of a 67 kDa allergen in oils issued from sunflower seeds. We conclude that the presence or elimination of proteins, especially allergens from oils is linked to amphiphilic association to phospholipids. STUDY OF PEANUT PROTEINS-POLYSACCHARIDES MIXTURES: We have digested in vitro proteins in a dialysis bag using a multi-enzymatic method and characterized proteins and peptides using SDS-PAGE electrophoresis and immuno-blotting. Our results confirm that peanut proteins alone are digested by proteases and that a number of large peptides still have epitopes recognized by anti-peanut proteins antibodies. Our results also show that the presence of polysaccharides changes the peptidic profile after digestion and that, depending on the polysaccharide type, smaller or larger peptides can be obtained in the dialysis bag. Smaller peptides are obtained using pectin whereas larger peptides are obtained using arabic gum and xylan. In the latter case, an increasing amount of peptides reacts to antibodies. Our first observations clearly show the need to better understand modifications of proteins allergenicity induced by the presence of other ingredients such as polysaccharides and lipids, in relation to technological treatments.

Beta-lactoglobulin/polysaccharide interactions during in vitro gastric and pancreatic hydrolysis assessed in dialysis bags of different molecular weight cut-offs

The effects of gum arabic, low methylated (LM) pectin or xylan at levels of 0 and 50 wt.% on beta-lactoglobulin (beta-lg) digestibility were studied as well as the interactions between the two macromolecules during in vitro hydrolysis. The proteolysis was performed in a system involving a two-step hydrolysis: either pepsin alone, or pepsin followed by a trypsin/chymotrypsin (T/C) mixture in dialysis bags with molecular weight cut-offs (MWCO) 1000 or 8000 Da. Digestibility was estimated by the N release and by a SDS-PAGE electrophoresis of retentates from the two dialysis bags after hydrolysis. Turbidimetric measurements monitored the structural evolution of mixtures during the two-step hydrolysis. Results showed that beta-lg was almost resistant to peptic digestion and that polysaccharides increased the N release despite a reduction of pepsin activity. This is due to the formation of electrostatic complexes between polysaccharides and beta-lg, which reduced beta-lg aggregation, increasing its solubility. The polysaccharides reduced significantly the beta-lg T/C digestibility as determined using a dialysis bag with a MWCO 1000 Da, without a modification of their enzymatic activities. No significant effect of polysaccharides on the beta-lg digestibility was detected using the dialysis bag with a MWCO 8000 Da. The electrophoresis pattern did not show differences in the profile of retentates in relation with the dialysis bag used. This suggests that non-specific interactions could occur during the second step of hydrolysis between polysaccharides and amino acids or peptides smaller than 8000 Da.

Obesity is associated with decreasing levels of the circulating soluble leptin receptor in humans

OBJECTIVE

Leptin plays a major role in the regulation of body weight. It circulates in both free and bound form. One of the leptin receptor isoforms exists in a circulating soluble form that can bind leptin. In the present study, we measured the soluble leptin receptor (SLR) levels in lean and obese humans. We investigated the relationship between plasma SLR levels, plasma leptin levels and the degree of obesity. We also examined whether SLR concentrations could be modulated by fat mass loss induced by a 3 month weight-reducing diet.

SUBJECTS

A total of 112 obese (age 18-50 y; body mass index (BMI) 30-44 kg/m2; 23 men and 89 women), 38 overweight (age 19-48 y; BMI 25-29 kg/m2; 10 men and 28 women) and 63 lean (age 18-50 y; BMI 17-24 kg/m2; 16 men and 47 women) humans.

MEASUREMENTS

A direct double monoclonal sandwich enzyme-linked immunosorbent assay (ELISA) was used for the quantitative measurement of the soluble human leptin receptor. Leptin was measured by radioimmunoassay (RIA). Body composition was assessed by biphotonic absorptiometry DEXA (dual energy X-ray absorptiometry).

RESULTS

We observed that the SLR is present in human plasma (range 10-100 ng/ml). SLR levels were lower in obese and overweight than lean subjects (28.7+/-8.8, 40.2+/-14.9, 51.2+/-12.5 ng/ml, respectively) and were inversely correlated to leptin and percentage of body fat (r=-0.74 and r=-0.76; respectively; P<0.0001). The ratio of circulating leptin to SLR was strongly related to the percentage of body fat (r=0.91; P<0.0001). Interestingly a gender difference was observed in SLR levels, which were higher in obese and overweight men than in obese and overweight women. In obese subjects after a 3 month low-calorie diet, SLR levels increased in proportion to the decrease in fat mass. In the gel filtration profile, SLR coeluted exactly with the bound leptin fractions.

CONCLUSION

Obesity, in humans is associated with decreasing levels of the circulating soluble leptin receptor (SLR). The relationship of SLR with the degree of adiposity suggests that high SLR levels may enhance leptin action in lean subjects more than in obese subjects.

Dietary intakes, eating style and overweight in the Stanislas Family Study

OBJECTIVES

To describe the eating patterns of members of French families and to assess the relationships between dietary intakes, eating style and overweight.

DESIGN

Cross-sectional analysis of nutritional and behavioural characteristics.

SUBJECTS

1,320 members of 387 families (age 11-65y) attending the Centre for Preventive Medicine for a routine medical check-up.

MEASUREMENTS

Individual body weight and height were measured. Food intake was assessed using a three day dietary record. Eating style was measured using the French validated version of the Dutch Eating Behaviour Questionnaire.

RESULTS

In each of the four groups (men, women, boys and girls), dietary restraint was positively correlated with overweight (P< or =0.001) and associated with lower energy intakes (P < or = 0.05-P < or = 0.001). A negative association between energy intake and overweight was found in girls only (P< or =0.001). In all cases, overweight and dietary restraint exaggerated any existing macronutrient imbalance in energy intake (ie higher protein and fat contributions, lower carbohydrate contribution). Emotional eating was positively correlated to body mass index in women only (P< or =0.01). External eating was mainly a characteristic of children (P< or =0.001).

CONCLUSION

As in overweight subjects, clear relationships were found in this sample of general population between dietary intakes and eating style. The population will be followed up for 10y. In the long term, these results should have implications in the prevention of obesity.

Effects of soybean (Glycine max) germination on biologically active components, nutritional values of seeds, and biological characteristics in rats

We briefly reviewed the effects of soybean germination on biologically active components, nutritive value of seed and biological characteristics in rats. The purpose of this review is to evaluate the effects of soybean germination on nutritional values of seeds and the potential importance for the use of germinated soybeans, from a contemporary conception, in food preparation as well as on soybean possible influence in optimal health. Germination induced a substantial increase in the content of saponin, oestrogenic compounds and almost all phytosterols, particularly beta-sitosterol of seeds. Lecithin content increased slightly and gradually during germination process. Lipase and alpha-galactosidase activities increased whereas lipoxygenase activities reduced after a short period of germination (< or = 72 h). Therefore, the substantial odour and flavour scores of germinated soybean flour were improved. Germinated seeds were also beneficial to heat penetration, their thermolabile antinutritional factors were easier to inhibit than those of dry beans, also the seeds did not require a long cooking time to be palatable. Duration of the germination process greatly influenced the nutritional value and palatability of seeds and biological characteristics in rats. In rat bioassay, one-day germination of soybeans induced a significant increase of daily body weight gain, daily protein intake in rats and protein efficiency ratio (PER) of seed meal. Palatability of seeds was also improved whereas a 5-day germination resulted in a decrease of PER of seed meal (less than the value of unheated seeds) and induced thyroid enlargement in rats. A vapour thermal treatment (100 degrees C, 20 min) eliminated thyroid-active agents and improved PER of seed meal, food intake and final weight of rats. Well prepared germinated soybeans can be used as a good alternate to animal proteins for more balanced nutritional diet. Development of food products from germinated soybean may be another way to further increase the versatility and utility of soybeans for both developing and industrialized countries, as germination induced the modification of certain specific biologically active components, palatability and nutritive value of seeds.

Composition of pulp, skin and seeds of prickly pears fruit (Opuntia ficus indica sp.)

The proximate composition of pulp, skin and seeds of prickly pear cactus (Opuntia ficus indica) was investigated and is reported on a dry weight basis. The most abundant component of the pulp and skin was ethanol-soluble carbohydrates. Pulp contained glucose (35%) and fructose (29%) while the skin contained essentially glucose (21%). Protein content was 5.1% (pulp), 8.3% (skin) and 11.8% (seeds). Starch was found in each of the three parts of the fruit. Pulp fibers were rich in pectin (14.4%), skin and seeds were rich in cellulose (29.1 and 45.1%, respectively). Skin was remarkable for its content of calcium (2.09%) and potassium (3.4%). Prickly pear is a neglected nutritional source which should be more widely used because of its potential nutrient contribution.

Accessibility of human apolipoprotein B-100 epitopes in insulin-dependent diabetes: relation with the surface lipid environment of atherogenic particles

The physicochemical modifications (composition and conformation) of lipoproteins containing apolipoprotein B-100 (apo B-100) were studied in normocholesterolaemic adequately controlled Type 1 insulin-dependent diabetic patients. Thirty-one normocholesterolaemic (serum cholesterol < 6.50 mmol/l) diabetic male patients and 31 age-and body mass index-adjusted healthy normolipaemic male controls were studied. Cholesterol and choline-containing phospholipids were measured in total serum and in two lipoprotein subfractions containing or not apo B (LpB and LpnoB respectively). These subfractions were separated by precipitation with concanavalin A. Total apo B-100 and two lipoprotein particles defined according to their apo B-100 epitope accessibility were determined using respectively anti-apo B polyclonal and two monoclonal antibodies that reacted with specific epitopes on the apo B molecule. Despite a classical lipid profile (cholesterol and triglyceride levels), which was quite normal in plasma from patients as compared to controls, a depletion of choline-containing phospholipid content in serum and more specifically in LpB particles was observed in diabetic patients. Decreased cholesterol content was also observed in LpB particles. Immunological analysis demonstrated an increased number of lipoprotein particles (a condition previously related to coronary artery disease) and decreased immunoaccessibility of a conformationally expressed apo B-100 epitope. These conformational changes were correlated with modifications of the surface phospholipid environment of LpB particles. It is concluded that subtle abnormalities in the composition and conformation of atherogenic apo-B-containing lipoproteins occur in Type 1 diabetes mellitus. These structural modifications may be one factor accounting for the increased rate of atherosclerosis in diabetes, despite the existence of a normal classical lipid profile.

Increased erythrocyte aggregation in insulin-dependent diabetes mellitus and its relationship to plasma factors: a multivariate analysis

Red blood cell aggregation in vitro (kinetics and shear resistance) was studied in 13 healthy controls and 13 type I (insulin-dependent) diabetic patients free of severe degenerative complications who were matched for age, sex, and body mass index. Measurements were performed with a device that analyzes the laser light backscattered by a blood suspension. Both the velocity of rouleau formation and the cohesion of the rouleau network were significantly increased in diabetic patients. Plasma viscosity and whole-blood viscosity measured at low shear rate (0.95 s-1) were also significantly elevated in the diabetic group. Multivariate analyses of the whole population sample and the diabetic patients confirmed the influence of plasma proteins on the kinetics of aggregation. Fibrinogen levels, which were close to normal, affected mainly the shear resistance of the aggregates. Triglyceride and apolipoprotein (apo) B levels and indexes of metabolic control or protein glycation (fasting blood glucose and fructosamine) also appeared to influence markedly both the kinetics of rouleau formation and the cohesion of the rouleau networks. These rheological abnormalities occurred in diabetic patients before the appearance of any severe degenerative complications. We suggest that these rheological abnormalities are linked to plasma or erythrocyte factors, and are not due to angiopathy.

[Refeeding after ingestion of diets containing 10% soybean protein associated with various concentrations of alginate or sodium carrageenan. Effects on growth and lipid parameters in the rat]

Male 21-d-old Wistar rats were fed over 3 experimental periods. During the first period of 4 wk, diets contained 10% casein or defatted soy flour proteins, with or without 0.5, 1, 2 or 3% sodium alginate or sodium carrageenan, and were heated. During the second period, they were fed a standard diet for 16 wk with 17% proteins, and during the third period, they received the same diet as in the first period, but with 20% proteins. Rat body weights were measured throughout the study period; plasma lipid levels were then determined after fasting. Presence of sodium alginate in the diet had no effect on growth, but rats fed carrageenan presented growth retardation at the end of the experimental period, which was not altered by refeeding the standard diet. Sodium alginate did not modify rat triglyceridemia, except at the 1% level. Carrageenan had a hypotriglyceridemic effect. Alginate and carrageenan had no effect on blood cholesterol. Compared to soybean protein, casein intake did not increase plasma cholesterol levels as generally described. The effect of carrageenans on growth and plasma triglyceride levels could be a result of their physico-chemical properties.

Effect of germinated and heated soybean meals on plasma cholesterol and triglycerides in rats

Soybean may be useful in diets for the prevention of cardiovascular disease and the treatment of type II hyperlipoproteinemia as it lowers blood cholesterol levels. However, unpleasant organoleptic qualities and the presence of antinutritional substances hinder its use. Some of these problems may be partially solved by germinating the seeds or heating the meals. The effects of the duration of soybean germination and of heating the meal were studied in Wistar rats. Dietary meal composition, plasma cholesterol and triglyceride levels were evaluated after feeding rats with various soybean meal or casein diets containing 10% protein for 6 weeks. Plasma cholesterol and triglyceride levels were 0.81 +/- 0.11 and 0.82 +/- 0.23 g/l respectively after the casein diet and 0.90 +/- 0.10 and 0.51 +/- 0.17 g/l after the raw soybean diet. Soybean germination had a hypercholesterolemic effect (1.05 +/- 0.11 g/l after 5 d). Heating the raw meal or germinated soybean meal did not affect cholesterol levels, though it suppressed the hypotriglyceridemic effect. The triglyceride-lowering effect of soybean was probably caused by the presence of thermolabile substances or by the quantity of food ingested. The unexpected increase in blood cholesterol levels may have been due to the effect of the low dietary protein levels.

Ultradian, circadian and circannual rhythms of blood glucose and injected insulins documented in six self-controlled adult diabetics

The aim of the study was to document during one to two years individual rhythmic patterns in blood glucose and injected insulin in self-controlled insulin dependent (C-peptide negative) diabetics with home blood glucose monitoring. Two females and four males with diurnal activity from 0700 to 2300 self-determined their blood glucose three to six times a day over a period of 12-27 months. Circadian and ultradian rhythms were analysed for each subject on a monthly basis to document annual rhythms. Blood glucose (BG) estimated circadian acrophases were located between 2200 and 0300 for all patients and months with few exceptions. A correlation was found between circadian mesors and amplitudes of BG in four subjects. Annual changes in BG were validated for each subject with large interindividual differences in peak times. The individual mean of injected insulin (II) varied from 40 to 80 iU with annual changes validated for each subject. A group pattern was observed with a peak time either in the autumn (four patients) or in the summer (two patients). A circadian rhythm of II was detected in almost all monthly means and for all patients. Locations of computed peak time phi of II exhibited a great stability for a given individual but large interindividual differences. Thus the rather constant phi location of BG for all subjects contrasted with interindividual differences in phi locations of II. These results suggest that rhythmic changes in BG and II should be recognized when forming a realistic strategy for timing and dosing time(s) of insulin.

Comparative study of four HDL-cholesterol assay methods

Four methods for HDL-cholesterol assay are compared using the plasma of 119 subjects. Results for the entire population and for subgroups defined by triglyceridemia and cholesterolemia levels are determined. The methods used are: ultracentrifugation, electrophoresis, dextran sulfate precipitation, and concanavalin A precipitation. The results indicate that ultracentrifugation and electrophoresis are not easily adapted to routine work, require large investments and do not separate the lipoproteins according to physiopathological criteria. The HDL values obtained with the different methods show significant differences, even though the correlations between the methods are highly significant. The precipitation methods are easiest to perform; however, the HDL-cholesterol values from dextran sulfate precipitation are higher than those from concanavalin A precipitation. The authors discuss the best choice for determining the atherogenic risks of hyperlipoproteinemia in clinical practice.

[One year fenofibrate treatment of type II primary hyperlipidaemia. Effects on lipoproteins and biological tolerance (author's transl)]

The study involved 18 patients aged from 17 to 71 years with idiopathic type IIa hypercholesterolaemia and 10 patients aged from 34 to 67 years with type IIb mixed hyperlipidaemia (HLP). During a first period of at least 3 months, the patients were established on a diet adapted to each type of HLP. Fenofibrate in daily doses of 5 mg/kg bodyweight was then added to the dietetic regimen. The effectiveness of the drug was assessed after 6 months and 1 year. In type IIa HLP patients LDL-cholesterol decreased by 29-30%. In type IIb HLP patients there was a decrease of 45-70% in VLDL-cholesterol of 12-15% in LDL-cholesterol and of 38-61% in VLDL-triglycerides. HDL levels measured before treatment were slightly higher than those reported in the literature and were not significantly modified by fenofibrate, except for HDL-triglycerides in type IIa patients after 12 months' treatment. As in all previous studies on lipoprotein fractions, the decrease in VL-DL-cholesterol was not accompanied by an increase in LDL-cholesterol. Fenofibrate was well tolerated, both clinically and biologically. There were no changes in serum bilirubin levels. Alkaline phosphatase levels were significantly reduced but remained within physiological values. A slight increase in mean transaminase levels due to a transient rise in 4 patients was observed after 3 and 65 months' treatment. Routine measurements of these parameters are advised during long-term fenofibrate treatment.

Determination of the K2 lipid clearance coefficient by centrifugation. A comparison with the Gordis test and spectrophotometric measurement

The K2 lipid clearance coefficient was calculated for the intravenous fat tolerance test (iv FTT), after estimating triglycerides by spectrophotometry, the Gordis technique or by preparative ultracentrifugation. The best correlation between the K2 values (r = 0.95, p < 0.001) is for the results of the Gordis test and ultracentrifugation. Spectrophotometry shows poorer correlations: r = 0.66 and p < 0.05 with the Gordis test, and r = 0.78 and p < 0.01 with ultracentrifugation. Spectrophotometry is only suitable for detection but the two other techniques can be applied to more detailed studies. Ultracentrifugation is faster, less laborious and less liable to error.