A plasma global metabolic profiling approach applied to an exercise study monitoring the effects of glucose, galactose and fructose drinks during post-exercise recovery

A global metabolic profiling methodology based on gas chromatography coupled to time-of-flight mass spectrometry (GC-TOFMS) for human plasma was applied to a human exercise study focused on the effects of beverages containing glucose, galactose, or fructose taken after exercise and throughout a recovery period of 6 h and 45 min. One group of 10 well trained male cyclists performed 3 experimental sessions on separate days (randomized, single center). After performing a standardized depletion protocol on a bicycle, subjects consumed one of three different beverages: maltodextrin (MD)+glucose (2:1 ratio), MD+galactose (2:1), and MD+fructose (2:1), consumed at an average of 1.25 g of carbohydrate (CHO) ingested per minute. Blood was taken straight after exercise and every 45 min within the recovery phase. With the resulting blood plasma, insulin, free fatty acid (FFA) profile, glucose, and GC-TOFMS global metabolic profiling measurements were performed. The resulting profiling data was able to match the results obtained from the other clinical measurements with the addition of being able to follow many different metabolites throughout the recovery period. The data quality was assessed, with all the labelled internal standards yielding values of <15% CV for all samples (n=335), apart from the labelled sucrose which gave a value of 15.19%. Differences between recovery treatments including the appearance of galactonic acid from the galactose based beverage were also highlighted.

Fructose and Galactose Enhance Post-Exercise Human Liver Glycogen Synthesis

Both liver and muscle glycogen stores play a fundamental role in exercise and fatigue, but the effect of different CHO sources on liver glycogen synthesis in humans is unclear. The aim was to compare the effect of maltodextrin (MD) drinks containing galactose, fructose, or glucose on postexercise liver glycogen synthesis.

Analysis of the erosive effect of different dietary substances and medications

Excessive consumption of acidic drinks and foods contributes to tooth erosion. The aims of the present in vitro study were twofold: (1) to assess the erosive potential of different dietary substances and medications; (2) to determine the chemical properties with an impact on the erosive potential. We selected sixty agents: soft drinks, an energy drink, sports drinks, alcoholic drinks, juice, fruit, mineral water, yogurt, tea, coffee, salad dressing and medications. The erosive potential of the tested agents was quantified as the changes in surface hardness (ΔSH) of enamel specimens within the first 2 min (ΔSH2-0 = SH2 min - SHbaseline) and the second 2 min exposure (ΔSH4-2 = SH4 min - SH2 min). To characterise these agents, various chemical properties, e.g. pH, concentrations of Ca, Pi and F, titratable acidity to pH 7·0 and buffering capacity at the original pH value (β), as well as degree of saturation (pK - pI) with respect to hydroxyapatite (HAP) and fluorapatite (FAP), were determined. Erosive challenge caused a statistically significant reduction in SH for all agents except for coffee, some medications and alcoholic drinks, and non-flavoured mineral waters, teas and yogurts (P < 0·01). By multiple linear regression analysis, 52 % of the variation in ΔSH after 2 min and 61 % after 4 min immersion were explained by pH, β and concentrations of F and Ca (P < 0·05). pH was the variable with the highest impact in multiple regression and bivariate correlation analyses. Furthermore, a high bivariate correlation was also obtained between (pK - pI)HAP, (pK - pI)FAP and ΔSH.

Screening and prediction of erosive potential

The literature on the erosive potential of drinks and other products is summarised, and aspects of the conduct of screening tests as well as possible correlations of the erosive potential with various solution parameters are discussed. The solution parameters that have been suggested as important include pH, acid concentration (with respect to buffer capacity and concentration of undissociated acid), degree of saturation, calcium and phosphate concentrations, and inhibitors of erosion. Based on the available data, it is concluded that the dominant factor in erosion is pH. The effect of buffer capacity seems to be pH dependent. The degree of saturation probably has a non-linear relationship with erosion. While calcium at elevated concentrations is known to reduce erosion effectively, it is not known whether it is important at naturally occurring concentrations. Fluoride at naturally occurring concentrations is inversely correlated with erosive potential, but phosphate is probably not. Natural plant gums, notably pectin, do not inhibit erosion, so they are unlikely to interfere with the prediction of erosive potential. The non-linearity of some solution factors and interactions with pH need to be taken into account when developing multivariate models for predicting the erosive potential of different solutions. Finally, the erosive potential of solutions towards enamel and dentine might differ.

Impact of acquired enamel pellicle modification on initial dental erosion

The acquired enamel pellicle that forms on the tooth surface serves as a natural protective barrier against dental erosion. Numerous proteins composing the pellicle serve different functions within this thin layer. Our study examined the effect of incorporated mucin and casein on the erosion-inhibiting potential of the acquired enamel pellicle. Cyclic acidic conditions were applied to mimic the erosive environment present at the human enamel interface during the consumption of soft drinks. One hundred enamel specimens were prepared for microhardness tests and distributed randomly into 5 groups (n = 20) that received the following treatment: deionized water, humidity chamber, mucin, casein, or a combination of mucin and casein. Each group was exposed to 3 cycles of a 2-hour incubation in human saliva, followed by a 2-hour treatment in the testing solution and a 1-min exposure to citric acid. The microhardness analysis demonstrated that the mixture of casein and mucin significantly improved the erosion-inhibiting properties of the human pellicle layer. The addition of individual proteins did not statistically impact the function of the pellicle. These data suggest that protein-protein interactions may play an important role in the effectiveness of the pellicle to prevent erosion.

Is dental erosion really a problem?

Dental erosion is the non-carious dental substance loss induced by direct impact of exogenous or endogenous acids. It results in a loss of dental hard tissue, which can be serious in some groups, such as those with eating disorders, in patients with gastroesophageal reflux disease, and also in persons consuming high amounts of acidic drinks and foodstuffs. For these persons, erosion can impair their well-being, due to changes in appearance and/or loss of function of the teeth, e.g., the occurrence of hypersensitivity of teeth if the dentin is exposed. If erosion reaches an advanced stage, time- and money-consuming therapies may be necessary. The therapy, in turn, poses a challenge for the dentist, particularly if the defects are diagnosed at an advanced stage. While initial and moderate defects can mostly be treated non- or minimally invasively, severe defects often require complex therapeutic strategies, which often entail extensive loss of dental hard tissue due to preparatory measures. A major goal should therefore be to diagnose dental erosion at an early stage, to avoid functional and esthetic impairments as well as pain sensations and to ensure longevity of the dentition.

Dental erosion in children

Erosive tooth wear in children is a common condition. The overlapping of erosion with mechanical forces like attrition or abrasion is probably in deciduous teeth more pronounced than in permanent teeth. Early erosive damage to the permanent teeth may compromise the dentition for the entire lifetime and require extensive restorative procedures. Therefore, early diagnosis of the condition and adequate preventive measures are of importance. Knowledge of the etiological factors for erosive tooth wear is a prerequisite for such measures. In children and adolescents (like in adults) extrinsic and intrinsic factors or a combination of them are possible reasons for the condition. Such factors are frequent and extensive consumption of erosive foodstuffs and drinks, the intake of medicaments (asthma), gastro-esophageal reflux (a case history is discussed) or vomiting. But also behavioral factors like unusual eating and drinking habits, the consumption of designer drugs and socio-economic aspects are of importance.

Extrinsic causes of erosion. Diet. Chemical factors

pH value, calcium, and phosphate and to a lesser extent fluoride content of a drink or foodstuff are important factors explaining erosive attack. They determine the degree of saturation with respect to tooth minerals, which is the driving force for dissolution. Solutions oversaturated with respect to dental hard tissue will not dissolve it. Addition of calcium (and phosphate) salts to erosive drinks showed protection of surface softening. Today, several Ca-enriched soft drinks are on the market or products with naturally high content in Ca and P are available (such as yoghurt), which do not soften the dental hard tissue. The greater the buffering capacity of the drink or food, the longer it will take for the saliva to neutralize the acid. The buffer capacity of a solution has a distinct effect on the erosive attack when the solution remains adjacent to the tooth surface and is not replaced by saliva. A higher buffer capacity of a drink or foodstuff will enhance the processes of dissolution because more ions from the tooth mineral are needed to render the acid inactive for further demineralization. Further, the amount of drink in the mouth in relation to the amount of saliva present will modify the process of dissolution. There is no clear-cut critical pH for erosion as there is for caries. Even at a low pH, it is possible that other factors are strong enough to prevent erosion.

Fruit yogurt: any erosive potential regarding teeth?

OBJECTIVE: The capability of drinks and foods to resist pH changes brought about by salivary buffering may play an important role in the dental erosion process in children. The aim of the present study was to test fruit yogurt, a popular snack for children, and the degrees of saturation (pK-pl) with respect to hydroxyapatite and fluorapatite to determine their erosive potential. METHOD AND MATERIALS: A variety of fruit yogurt was tested. To test the pH, 8 readings were taken with a pH electrode for each yogurt. Calcium content was detected by atomic absorption spectrophotometer, phosphorus by the inductively coupled plasma method, and fluoride content by ion chromatography. The degrees of saturation of hydroxyapatite and fluorapatite were calculated by use of a computer program. Statistical analysis was performed using 2-tailed analysis of variance (P < .05) and a post hoc test (Tukey) to determine differences between groups. RESULTS: The pH of each fruit concentrate was significantly different, except for banana yogurt. Except for the phosphorus content of raspberry yogurt, the calcium and phosphorus content for each fruit concentrate were significantly different. Fluoride levels were the same for all yogurts tested, and the degrees of saturation of hydroxyapatite and fluorapatite was positive, indicating supersaturation. CONCLUSION: It could be stated that fruit yogurt has no erosive potential.

Extrinsic causes of erosion. Behavioral factors

During and after an erosive challenge, behavioral factors play a role in modifying the extent of erosive tooth wear. The manner that dietary acids are introduced into the mouth (gulping, sipping, use of a straw) will affect how long the teeth are in contact with the erosive challenge. The frequency and duration of exposure to an erosive agent is of paramount importance. Night-time exposure (e.g. baby bottle-feeding) to erosive agents may be particularly destructive because of the absence of salivary flow. Health-conscious individuals tend to ingest acidic drinks and juices more frequently and tend to have higher than average oral hygiene. While good oral hygiene is of proven value in the prevention of periodontal disease and dental caries, frequent toothbrushing with abrasive oral hygiene products may enhance erosive tooth wear. Unhealthy lifestyles such as consumption of designer drugs, alcopops and alcohol abuse are other important behavioral factors.

Erosive and buffering capacities of yogurt

OBJECTIVE: The capability of drinks and foods to resist pH changes brought about by salivary buffering may play an important role in the erosion of dental enamel. The aim of the present study was to measure the initial pH of several types of yogurt and to test the degrees of saturation (pK-pl) with respect to hydroxyapatite and fluorapatite to determine the buffering capacity and related erosive potential of yogurt. METHOD AND MATERIALS: Twenty-five milliliters of 7 types of freshly opened yogurt was titrated with 1 mol/L of sodium hydroxide, added in 0.5 mL increments, until the pH reached 10, to assess the total titratable acidity, a measure of the drink's own buffering capacity. The degrees of saturation (pK-pl) with respect to hydroxyapatite and fluorapatite were also calculated, using a computer program developed for this purpose. For statistical analysis, samples were compared using Kruskal-Wallis test. RESULTS: The buffering capacities can be ordered as follows: fruit yogurt >low-fat yogurt >bioyogurt >butter yogurt >natural yogurt >light fruit yogurt >light yogurt. The results suggest that, in vitro, fruit yogurt has the greatest buffering capacity. CONCLUSION: It can be stated that it is not possible to induce erosion on enamel with any type of yogurt.

Erosion--diagnosis and risk factors

Dental erosion is a multifactorial condition: The interplay of chemical, biological and behavioural factors is crucial and helps explain why some individuals exhibit more erosion than others. The erosive potential of erosive agents like acidic drinks or foodstuffs depends on chemical factors, e.g. pH, titratable acidity, mineral content, clearance on tooth surface and on its calcium-chelation properties. Biological factors such as saliva, acquired pellicle, tooth structure and positioning in relation to soft tissues and tongue are related to the pathogenesis of dental erosion. Furthermore, behavioural factors like eating and drinking habits, regular exercise with dehydration and decrease of salivary flow, excessive oral hygiene and, on the other side, an unhealthy lifestyle, e.g. chronic alcoholism, are predisposing factors for dental erosion. There is some evidence that dental erosion is growing steadily. To prevent further progression, it is important to detect this condition as early as possible. Dentists have to know the clinical appearance and possible signs of progression of erosive lesions and their causes such that adequate preventive and, if necessary, therapeutic measures can be initiated. The clinical examination has to be done systematically, and a comprehensive case history should be undertaken such that all risk factors will be revealed.

Effects of buffering properties and undissociated acid concentration on dissolution of dental enamel in relation to pH and acid type

To quantify the relationships between buffering properties and acid erosion and hence improve models of erosive potential of acidic drinks, a pH-stat was used to measure the rate of enamel dissolution in solutions of citric, malic and lactic acids, with pH 2.4-3.6 and with acid concentrations adjusted to give buffer capacities (β) of 2-40 (mmol·l(-1))·pH(-1) for each pH. The corresponding undissociated acid concentrations, [HA], and titratable acidity to pH 5.5 (TA5.5) were calculated. In relation to β, the dissolution rate and the strength of response to β varied with acid type (lactic > malic ≥ citric) and decreased as pH increased. The patterns of variation of the dissolution rate with TA5.5 were qualitatively similar to those for β, except that increasing pH above 2.8 had less effect on dissolution in citric and malic acids and none on dissolution in lactic acid. Variations of the dissolution rate with [HA] showed no systematic dependence on acid type but some dependence on pH. The results suggest that [HA], rather than buffering per se, is a major rate-controlling factor, probably owing to the importance of undissociated acid as a readily diffusible source of H(+) ions in maintaining near-surface dissolution within the softened layer of enamel. TA5.5 was more closely correlated with [HA] than was β, and seems to be the preferred practical measure of buffering. The relationship between [HA] and TA5.5 differs between mono- and polybasic acids, so a separate analysis of products according to predominant acid type could improve multivariate models of erosive potential.

Prevalence of dentine hypersensitivity and study of associated factors: a European population-based cross-sectional study

OBJECTIVES Dentine hypersensitivity (DH) manifests as a transient but arresting oral pain. The incidence is thought to be rising, particularly in young adults, due to increases in consumption of healthy, yet erosive, diets. This study aimed to assess the prevalence of DH and relative importance of risk factors, in 18-35 year old Europeans. METHODS In 2011, 3187 adults were enrolled from general dental practices in France, Spain, Italy, United Kingdom, Finland, Latvia and Estonia. DH was clinically evaluated by cold air tooth stimulation, patient pain rating (yes/no), accompanied by investigator pain rating (Schiff 0-3). Erosive toothwear (BEWE index 0-3) and gingival recession (mm) were recorded. Patients completed a questionnaire regarding the nature of their DH, erosive dietary intake and toothbrushing habits. RESULTS 41.9% of patients reported pain on tooth stimulation and 56.8% scored ≥1 on Schiff scale for at least one tooth. Clinical elicited sensitivity was closely related to Schiff score and to a lesser degree, questionnaire reported sensitivity (26.8%), possibly reflecting the transient nature of the pain, alongside good coping mechanisms. Significant associations were found between clinically elicited DH and erosive toothwear and gingival recession. The questionnaire showed marked associations between DH and risk factors including heartburn/acid reflux, vomiting, sleeping medications, energy drinks, smoking and acid dietary intake. CONCLUSION Overall, the prevalence of DH was high compared to many published findings, with a strong, progressive relationship between DH and erosive toothwear, which is important to recognise for patient preventive therapies and clinical management of DH pain.

Motivation as a predictor of drinking outcomes after residential treatment programs for alcohol dependence

OBJECTIVES: Patients' motivation to change their substance use is usually viewed as a crucial component of successful treatment. The objective of this study was to examine whether motivation contributes to drinking outcomes after residential treatment for alcohol dependence. METHODS: Our sample included 415 Swiss patients from 12 residential alcohol treatment programs. We statistically controlled for important predictors, such as sex, employment, alcohol consumption before admission, severity of alcohol dependence, severity of psychiatric symptoms at admission, and alcohol-related self-efficacy at discharge. Abstinence, alcohol consumption, and time to first drink were used as primary outcome measures and were assessed 1 year after discharge from treatment. RESULTS: Action-oriented motivation to change substance use had a modest impact on drinking outcomes. At the 1-year follow-up, only the Taking Steps subscale of the Stages of Change Readiness and Treatment Eagerness Scale and alcohol-related self-efficacy were found to be significant predictors of abstinence and the number of standard drinks. CONCLUSIONS: The impact of action-oriented motivation at admission to residential treatment is modest but still relevant, compared with other outcome predictors. It may be useful to focus treatment on improving action-oriented motivation to reduce substance use