Marcin Mardas

The effect of vitamin D supplementation on insulin and glucose metabolism in overweight and obese individuals: systematic review with meta-analysis

The aim of this systematic review was to assess the effect of vitamin D supplementation on glucose and insulin metabolism in overweight and obese subjects. The search process was based on the selection of publications listed in the databases: PubMed, Scopus, Web of Knowledge, Embase and the Cochrane library that met the inclusion criteria. Twelve randomized controlled trials were included. The analysed population consisted of 1181 individuals with BMIs >23 kg/m2. Changes in the concentration of 25(OH)D, fasting glucose, insulin and the HOMA-IR index were assessed. In the meta-regression analysis, a restricted maximum likelihood method was applied. To combine individual study results, a meta-analysis was performed. Vitamin D supplementation did not have an effect on glucose concentrations, insulin level and HOMA-IR values when the supplemented dose, time of supplementation and baseline of 25(OH)D concentration were taken under consideration in subgroup-analysis. This meta-analysis provides evidence that vitamin D supplementation has no significant effect on glucose and insulin metabolism in overweight and obese individuals.

Long-term weight status in regainers after weight loss by lifestyle intervention: status and challenges.

After having participated in a weight loss trial, most participants do not stabilise the obtained weight loss but return to their initial weight. The aim of this review is to describe the main determinants of continued low weight status after weight loss, and the effectiveness of physical activity (PA), energy restriction and macronutrient composition of the diet for low long-term weight regain. Studies with intervention periods of at least 3 months duration of weight reduction measures and a follow-up at least 2 years after the intervention period were considered as eligible for the review. Owing to limited data, the studies describing the role of PA in weight management were eligible with a follow-up of 1 year only. It appears that a diet with self-regulation of dietary intake seems to be given a prominent role in the strategy of successful long-term weight loss among the obese. This measure could be combined with behaviour therapy and PA and tailored to the individual situation. However, considering available evidence it is difficult to conclude regarding unambiguous measures and to recommend a specific dietary intervention. Nevertheless, interventions should be effective in promoting intrinsic motivation and self-efficacy. The harmonisation and standardisation of data collection in the follow-up period of long-term weight loss studies is a major challenge.

Link between Food Energy Density and Body Weight Changes in Obese Adults.

Regulating the energy density of food could be used as a novel approach for successful body weight reduction in clinical practice. The aim of this study was to conduct a systemic review of the literature on the relationship between food energy density and body weight changes in obese adults to obtain solid evidence supporting this approach. The search process was based on the selection of publications in the English language listed in public databases. A meta-analysis was performed to combine individual study results. Thirteen experimental and observational studies were identified and included in the final analysis. The analyzed populations consist of 3628 individuals aged 18 to 66 years. The studies varied greatly in terms of study populations, study design and applied dietary approaches. The meta-analysis revealed a significant association between low energy density foods and body weight reduction, i.e., −0.53 kg when low energy density foods were eaten (95% CI: −0.88, −0.19). In conclusions, this study adds evidence which supports the energy density of food as a simple but effective measure to manage weight in the obese with the aim of weight reduction.

Dietary Habits and Nutritional Status of Female Adolescents from the Great Poland Region

Dietary Habits and Nutritional Status of Female Adolescents from the Great Poland Region The aim of this study was to assess the nutritional status and dietary habits among female adolescents. Four hundred seventy nine subjects aged from 17 to 18 years, from secondary schools of the Great Poland Region participated in the study. Anthropometric parameter measurements included those of body height and mass, skinfold thickness and circumferences of waist, hip and arm. The measurements served to calculate the percentage of fat mass and arm muscle area. Nutritional questionnaires were used to estimate the frequency and intake of selected food products. Mean values of body height and mass were approximately in the 50th percentile. However, 13.7% of females were underweight, 7.7% were overweight and 1.2% were obese. Cluster analysis resulted in 3 clusters, of which the second one showed the most detrimental nutritional habits. This cluster was characterised by the lowest intake of dairy products, fruits and vegetables, fish, meat and also by frequent long breaks between meals (longer than 5 hours). Improper nutritional behavior is a frequent finding in female adolescents, in Poland. Nevertheless, overweight and obesity are not more common than in other countries. Studies in this area should be continued and extended.

Successful maintenance of body weight reduction after individualized dietary counseling in obese subjects

The aim of this study was to describe the effectiveness of individualized dietary counseling in obese subjects based on narrative interview technique on the maintenance of body weight reduction, changes in dietary behaviors, including type of cooking and physical activity. One-hundred subjects out of four-hundred patients met the inclusion criteria. Individually, 45-minute educational program with motivation counseling was performed in 0, 6 and 12 weeks of the study. Patients were advised to follow individually well-balanced diet for 12 weeks. The individuals were asked about the changes in their dietary habits (Food Frequency Questionnaire). The mean percentage of body weight changes from the baseline were as follows: in 6th week- 5.9%, in 12th week - 10.9% and in 52th week - 9.7% (P < 0.0001), however there were no statistically significant changes while comparing body weight in 12th and 52th week. The maintenance of body weight reduction was connected with the dietary habits changes, mainly the type of cooking and increased consumption of vegetable oils. In conclusion, individualized dietary counseling, based on narrative interview technique is an effective intervention for obesity treatment that may help maintain body weight reduction and adapt the pro-healthy changes in type of cooking and sources of dietary fat.

Radiation sterilized bone response to dynamic loading.

Allogeneic bone grafts are used on a large scale in surgeries. To avoid the risk of infectious diseases, allografts should be radiation-sterilized. So far, no international consensus has been achieved regarding the optimal radiation dose. Many authors suggest that bone sterilization deteriorates bone mechanical properties. However, no data on the influence of ionizing radiation on bone dynamic mechanical properties are available. Bovine femurs from 2-year old animal were machine cut and irradiated with the doses 10, 15, 25, 35, 45 and 50 kGy. Dynamic mechanical analysis was performed at 1-10 Hz at the temperature range of 0-350 °C in 3-point bending configuration. No statistically significant differences in storage modulus were observed. However, there were significant decreased values of loss modulus between the samples irradiated with doses of 10 (↓14.3%), 15, 45 and 50 kGy (↓33.2%) and controls. It was stated that increased irradiation dose decreases the temperature where collagen denaturation process starts and increases the temperature where the collagen denaturation process finishes. It was shown that activation energy of denaturation process is significantly higher for the samples irradiated with the dose of 50 kGy (615 kJ/mol) in comparison with control samples and irradiation with other doses (100-135 kJ/mol).

Dietary and cardio-metabolic risk factors in patients with Obstructive Sleep Apnea: cross-sectional study

Background Little is known about the role of dietary intake in obstructive sleep apnea (OSA), which could prove important in improving clinical outcomes for people with obesity and/or cardiovascular disease within these populations. Reduction in energy intake typically results in weight loss, markedly improving metabolic parameters and ameliorating OSA severity. The aim of this study was to evaluate the association of dietary and cardio-metabolic risk factors with OSA severity. Methods This was a cross-sectional study. A total of 75 volunteers at risk of OSA were recruited from 153 patients suffering from sleep disturbance at the Department of Pulmonology, Allergology and Respiratory Oncology at the Poznan University of Medical Sciences. Polysomnography was used for OSA diagnosis. Sleep quality was assessed by the Pittsburgh Sleep Quality Index. Blood pressure, parameters of glucose (fasting glucose, glucose tolerance test) and lipid metabolism (TC, LDL-C, HDL-C, TG) were assessed using routine enzymatic methods. Dietary intake was evaluated by 24-hr dietary recalls and Food Frequency Questionnaire. Ordinal logistic regression models were used for association of background characteristics and dietary intake with OSA severity. All analyses were adjusted for age, sex, BMI, smoking and alcohol intake. Results A higher percentage of smokers were observed in patients with mild OSA, while alcohol intake was the highest in severe OSA patients. Approximately 60% of the studied patients were self-reported poor sleepers. Results from ordinal logistic regression models showed that higher intakes of alcohol intake were associated with increased odds of severe OSA; whereas higher HDL-C levels were associated with lower odds (OR 0.01; 95% CI [0.0003–0.55]). Significantly higher odds of high OSA severity were observed in patients with disturbed sleep stages and obstructive sleep apnea. Moreover, the investigation of nutrient intake in relation to OSA severity showed that a higher intake of dietary fiber was associated with decreased OSA severity (OR 0.84; 95% CI [0.71–0.98]). Conclusions The severity of OSA is related to higher alcohol consumption and disturbed sleep. The significantly lower dietary fiber intake in patients with severe OSA is of particular importance for dietary consulting in clinical practice, which may positively influence cardiometabolic outcomes.

Quality of life, depression and dietary intake in Obstructive Sleep Apnea patients

BackgroundThe aim of this study was to analyze the association between depression, quality of life and dietary intake in newly diagnosed Obstructive Sleep Apnea (OSA) patients.MethodsFrom 153 eligible patients suffering from sleep disturbances, 64 met inclusion and exclusion criteria. The polysomnography was used for OSA diagnosis. The quality of life (QOL) was assessed by WHOQOL-BREF questionnaire, self-reported chronotype by morningness-eveningness questionnaire and level of depression by Beck’s Depression Inventory. Blood pressure and parameters of glucose and lipid metabolism were assessed by routine methods. The dietary intake was evaluated by 24-hr dietary recalls.ResultsSignificantly negative associations were found between depression inventory and QOL. Better QOL for physical health and social relationships was observed in the “definitely morning” chronotype. The “morning type” of patients was positively related to the intake of fat, monounsaturated fatty acids and vitamin B12. Correlations between QOL and diastolic blood pressure, HDL-cholesterol, TG, fasting glucose, as well as protein and vitamin B6 intake were found.ConclusionsIn conclusion, both chornotype and depression influence QOL in OSA patients where morning type is associated with better physical health and social relationships and increase in depression index deteriorate physical health, psychological and social relationship QOL domains. QOL as well as depression and chornotype are also influenced by selected cardio-metabolic factors and dietary intake.

The influence of low temperatures on dynamic mechanical properties of animal bone

The influence of low temperatures on dynamic mechanical properties of animal bone Different preservation methods are currently used in bone banks, even though their effects on allograft quality are not fully understood. Freezing is one of the most popular methods of preservation in tissue banking. Yet, there is not a lot of data on dynamic mechanical properties of frozen bone. Material used in this study was femoral bones from adult bovine that were machine cut and frozen to the temperature 140°C. Both elastic modulus and loss modulus were measured at 1, 3, 5, 10, and 20 Hz in the temperature range of 30-200°C. Differences between frozen and control samples were observed. The frequency increase always led to the increase in elastic modulus values and decrease in loss modulus values. Freezing reduced the elastic modulus values of about 25% and the loss modulus values of about 45% when measured at 20°C.

Clinical Utility of Berlin Questionnaire in Comparison to Polysomnography in Patients with Obstructive Sleep Apnea

The aim of this study was to assess the utility of the Berlin questionnaire (BQ) in adult patients at high risk of obstructive sleep apnea (OSA). The study consisted of 64 patients recruited for the polysomnography diagnostics of sleep respiratory disturbances. The anthropometric assessment included body weight, height, and body mass index (BMI), all related to the risk of OSA. The BQ consisted of the following three categories: 1 - snoring, 2 - daytime somnolence, and 3 - hypertension. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were evaluated. Likelihood ratio was used to assess the diagnostic accuracy. We found that patients were, on average obese; the mean BMI amounted to 31.9 ± 6.0 kg/m2. Polysomnography identified OSA in 73.4% of patients (AHI >5), where the BQ categorized 87.5% of patients at high risk of OSA. Sensitivity of the BQ was 87.2%, specificity 11.8%, PPV 73.2%, and NPV 25.0%. Diagnostic accuracy assessed by the likelihood ratio had a value of 1.00. The BQ had a false discovery rate of 31.2% and misclassification rate of 32.8%. We conclude that the BQ is a sensitive tool that should be used in clinical settings in which the benefit of high sensitivity outweighs the disadvantage of low specificity.