Relative bias in diet history measurements: a quality control technique for dietary intervention trials

Higher anthocyanin intake is associated with lower depressive symptoms in adults with and without major depressive disorder

Background

Major depressive disorder (MDD) is a significant cause of disability globally and an emerging body of evidence suggests that dietary components, including flavonoids, may impact depression-related biochemical pathways. Further research that characterizes dietary intake of flavonoids in diverse population groups, including people with MDD and explores the relationship between flavonoid intake and depression is needed. This study aimed to determine dietary flavonoid and subclass intake and assess the association with depressive symptomatology in a sample of adults with and without MDD.

Methodology

Participants with and without MDD (determined using DSM 5) completed the Depression, Anxiety, and Stress Scale-21 (DASS-21). Diet history interviews were analyzed using PhenolExplorer to quantify flavonoid subclasses (flavan-3-ols, flavonols, anthocyanins, flavones, flavanones, isoflavones), and total flavonoid intake. Independent t-tests and linear regression, adjusting for age, sex, and BMI were performed.

Results

Participants (n = 93; 75% female) had a mean age of 26.0 ± 8.2 years. Participants with MDD had significantly higher DASS-depression scores (n = 44; DASS-depression 27.3 ± 9.8) compared to participants without MDD (n = 49; DASS-depression 3.1 ± 4.4; p < .001). Intakes of total flavonoids and subclasses were similar between groups, except for anthocyanins where participants with MDD reported lower intakes of anthocyanins compared to participants without MDD (median intake: 0.08 mg/day and 11.6 mg/day, respectively; p = .02). In the total sample, higher anthocyanin intake was associated with lower DASS-depression score (B = -4.1; SE = 1.8; 95% CI [-7.7, -0.4]; p = .029).

Conclusion

Intake of total flavonoids and most subclasses were similar between people with and without MDD. However, a dietary deficit of anthocyanins (found in purple/red fruits and vegetables) was evident in participants with MDD, and higher anthocyanin intake was associated with lower depressive symptomatology in the total sample. Further research in larger samples is warranted to explore if the documented association is independent of MDD status.

The nutritional management of people living with amyotrophic lateral sclerosis: A national survey of dietitians

BACKGROUND

People living with amyotrophic lateral sclerosis (ALS) face many challenges with respect to taking adequate nutrition. Growing evidence links weight loss with negative prognostic outcomes. We aimed to explore the practice of dietitians in the UK with regard to the nutritional management of ALS.

METHODS

A national online survey was disseminated via professional groups, social media and newsletters to UK healthcare professionals between September and November 2018. The survey examined the nutritional management of ALS. Dietitian responses are reported in the present study.

RESULTS

In total, 130 dietitians responded to the survey. Two-thirds reported that ALS comprised less than 20% of their total patient caseload. Forty-two percent reported that nutritional screening took place in their organisation. One-half of dietitians reported that patients were referred for dietetic assessment at 'about the right time', although 44% reported referrals were made too late. The majority (83%) of dietitians used resting energy expenditure predictive equations not validated in ALS. When setting weight goals, dietitians reported most frequently recommending weight maintenance if the patient's body mass index was 18.5-25 kg m^-2 (72%), 25-30 kg m^-2 (98%), and > 30 kg m^-2 (79%). In addition, 43% reported that people with ALS were not weighed sufficiently frequently.

CONCLUSIONS

Although the importance of early nutritional assessment is recognised, the timeliness of dietetic input and on-going monitoring of nutritional status in ALS care might not currently be ideal. Dietitians report using energy requirement predictive equations and setting weight goals that may not promote positive outcomes. Further research is required to understand the optimal nutritional management of ALS.

Lower intake of saturated fatty acids is associated with persistently higher arterial stiffness in patients with type 2 diabetes

AIMS/INTRODUCTION

There are few studies to investigate the relationship between macronutrients and longitudinal changes in arterial stiffness in patients with type 2 diabetes mellitus. This exploratory study sought to determine whether macronutrients were correlated with increased arterial stiffness independently of conventional atherosclerotic risk factors.

MATERIALS AND METHODS

The study participants comprised 733 type 2 diabetes outpatients who had no apparent history of cardiovascular diseases. The dietary schedule was assessed with a validated, brief, self-administered diet history questionnaire. At baseline and at years 2 and 5, brachial-ankle pulse wave velocity was measured. A multivariable linear mixed-effects model was used to determine the predictive values of macronutrients and atherosclerotic risk factors for longitudinal changes in brachial-ankle pulse wave velocity.

RESULTS

There was a significant increase in brachial-ankle pulse wave velocity values over the 5-year follow-up period. In a multivariable linear mixed-effects model that adjusted for age and sex, lower saturated fatty acid intake was significantly correlated with persistently higher brachial-ankle pulse wave velocity, independently of other atherosclerotic risk factors. Lower intake of dairy products in particular showed this correlation.

CONCLUSIONS

Our data showed that lower saturated fatty acids intake was correlated with persistently higher brachial-ankle pulse wave velocity in type 2 diabetes patients. Among food sources of saturated fatty acids, lower dairy products specifically were correlated with elevated brachial-ankle pulse wave velocity. This might be because the consumption of dairy products in Japan is much lower than in Western countries.

Vitamin B6 intake and incidence of diabetic retinopathy in Japanese patients with type 2 diabetes: analysis of data from the Japan Diabetes Complications Study (JDCS)

PURPOSE

Although vitamin B6 has been suspected to prevent the progression of diabetic retinopathy, evidence of this in patients with type 2 diabetes based on longitudinal studies is sparse. This study investigated the relationship between vitamin B6 intake and the incidence of diabetic retinopathy in Japanese patients with type 2 diabetes.

METHODS

The study was part of an examination of a nationwide cohort of patients with type 2 diabetes aged 40-70 years with HbA1c ≥ 48 mmol/mol. After excluding nonresponders to a dietary survey using the Food Frequency Questionnaire based on food groups, 978 patients were analyzed. Primary outcome was the 8-year risk of a diabetic retinopathy event, and Cox regression analyses estimated hazard ratios (HRs) for retinopathy according to vitamin B6 intake adjusted for age, gender, body mass index, HbA1c, smoking, energy intake, and other confounders.

RESULTS

Mean vitamin B6 intake in quartiles ranged from 1.1 to 1.6 mg/day, and half of the participants had vitamin B6 intake below the recommended daily dietary allowance according to dietary reference intakes in Japanese adults (men 1.4 mg/day; women 1.2 mg/day). After adjusting for confounders, HRs for diabetic retinopathy in the 2nd, 3rd, and 4th quartile groups of vitamin B6 intake compared with the 1st quartile group were 1.17 (95% confidence interval 0.81-1.69, p = 0.403), 0.88 (0.58-1.34, p = 0.550), and 0.50 (0.30-0.85, p = 0.010), respectively.

CONCLUSIONS

Findings suggested that high vitamin B6 intake was associated with a lower incidence of diabetic retinopathy in Japanese with type 2 diabetes.

A balance of activity in brain control and reward systems predicts self-regulatory outcomes

Previous neuroimaging work has shown that increased reward-related activity following exposure to food cues is predictive of self-control failure. The balance model suggests that self-regulation failures result from an imbalance in reward and executive control mechanisms. However, an open question is whether the relative balance of activity in brain systems associated with executive control (vs reward) supports self-regulatory outcomes when people encounter tempting cues in daily life. Sixty-nine chronic dieters, a population known for frequent lapses in self-control, completed a food cue-reactivity task during an fMRI scanning session, followed by a weeklong sampling of daily eating behaviors via ecological momentary assessment. We related participants’ food cue activity in brain systems associated with executive control and reward to real-world eating patterns. Specifically, a balance score representing the amount of activity in brain regions associated with self-regulatory control, relative to automatic reward-related activity, predicted dieters’ control over their eating behavior during the following week. This balance measure may reflect individual self-control capacity and be useful for examining self-regulation success in other domains and populations.

Meat intake and incidence of cardiovascular disease in Japanese patients with type 2 diabetes: analysis of the Japan Diabetes Complications Study (JDCS)

PURPOSE

Excessive meat intake has been researched as a major cause of cardiovascular disease (CVD) among healthy adults, but data on this topic in Asian patients with diabetes are sparse. The quantity and variety of available meats vary widely between Asian and Western countries. As part of a nationwide cohort study we investigated the relationship between meat intake and incidence of CVD in Japanese patients with type 2 diabetes aged 40-70 years with HbA1c ≥ 6.5%.

METHODS

Analyzed were 1353 responders to a baseline dietary survey assessed by the Food Frequency Questionnaire based on food groups. Primary outcome was the 8-year risk of a CVD event, including coronary heart disease (CHD) and stroke. Cox regression analyses estimated hazard ratios (HRs) for dietary intake adjusted for age, gender, body mass index, HbA1c, smoking, energy intake, and other confounders.

RESULTS

Mean meat intake in quartiles ranged from 9.9 to 97.7 g/day. After adjusting for confounders, HRs of CHD in the 2nd, 3rd, and 4th quartiles for meat intake compared with the 1st quartile were 2.84 (95% confidence interval 1.29-6.24, p = 0.01), 3.02 (1.36-6.70, p < 0.01), and 2.99 (1.35-6.65, p = 0.01), respectively. In two groups according to meat intake, patients consuming ≥ 20 g/day of meat had a 2.94-fold higher risk of CHD than those consuming < 20 g/day (p < 0.01). There was no significant association of stroke with meat intake.

CONCLUSIONS

An elevated incidence of CHD in Japanese patients with type 2 diabetes was associated with high meat intake.

Energy balance components in persons with paraplegia: daily variation and appropriate measurement duration

Background

Despite obesity being highly prevalent in persons with spinal cord injury (SCI), our current understanding of the interactions between energy balance components, which may contribute to this, is limited. The primary aim of this study is to identify the intra-individual variability of physical activity dimensions across days and suggest an appropriate monitoring time frame for these constructs in adults with SCI. The secondary aim is to examine these parameters with regard to energy intake and dietary macronutrient composition.

Methods

Participants [33 men and women with chronic (> 1 year post injury) paraplegia; age = 44 ± 9 years (mean ± S.D.] wore an Actiheart™ PA monitor and completed a weighed food diary for 7 consecutive days. Spearman-Brown Prophecy Formulae, based on Intraclass Correlations of .80 (acceptable reliability), were used to predict the number of days required to measure energy balance components. Linear mixed-effects analyses and magnitude-based inferences were performed for all energy intake, expenditure and physical activity dimensions. Adjustments were made for age, injury level, wear time, sex, day of the week and measurement order as fixed effects.

Results

To reliably measure energy expenditure components; 1 day [total energy expenditure (TEE)], 2 days [physical activity energy expenditure (PAEE), light-intensity activity, moderate-to-vigorous PA (MVPA)], 3 days [physical activity level (PAL)] and 4 days (sedentary behaviour) are necessary. Device wear time (P < 0.02), injury level (P < 0.04) and sex (P < 0.001) were covariates for energy expenditure components. Four and ≤24 days are required to reliably measure total energy intake (kcal) and diet macronutrient composition (%), respectively. Measurement order (from day 1–7) was a covariate for total energy intake (P = 0.01).

Conclusions

This is the first study to demonstrate the variability of energy intake and expenditure components in free-living persons with chronic (> 1 year) paraplegia and propose suitable measurement durations to achieve acceptable reliability in outcome measures. Device wear time and measurement order play a role in the quality of energy expenditure and intake data, respectively, and should be considered when designing and analysing studies of energy balance components in persons with SCI.

Trial registration

N/A

Dietary Patterns and Clinical Outcomes in Chronic Kidney Disease: The CKD.QLD Nutrition Study

OBJECTIVE

Emerging evidence suggests that dietary patterns are associated with survival in people with chronic kidney disease (CKD). This study evaluated the relationship between dietary habits and renal-related clinical outcomes in an established CKD cohort.

DESIGN

Prospective cohort study.

SETTING

Three outpatient nephrology clinics in Queensland, Australia.

SUBJECTS

A total of 145 adult patients with Stage 3 or 4 CKD (estimated glomerular filtration rate 15-59 mL/minute/1.73 m²).

INTERVENTION

Dietary intake was measured using 24-hour recall and the HeartWise Dietary Habits Questionnaire (DHQ), which evaluates 10 components of dietary patterns in relation to cooking habits and intake of food groups.

MAIN OUTCOME MEASURE

The primary outcome was a composite end point of all-cause mortality, commencement of dialysis, and doubling of serum creatinine. Secondary outcome was all-cause mortality alone. Multivariate cox regression analyses calculated hazard ratios (HRs) for associations between DHQ domains and occurrence of composite outcome and adjusted for confounders, including comorbidities and renal function.

RESULTS

Over a median follow-up of 36 months, 32% (n = 47) reached the composite end point, of which 21% died (n = 30). Increasing DHQ score was associated with a lower risk of the composite end point with increasing intake of fruits and vegetables (HR: 0.61; 95% CI, 0.39-0.94) and limiting alcohol consumption (HR, 0.79; 95% CI: 0.65-0.96). For the secondary outcome of all-cause mortality, there was a significant association with adequate intake of fruits and vegetables (HR: 0.35; 95% CI, 0.15-0.83).

CONCLUSION

Healthy dietary patterns consisting of adequate fruits and vegetables and limited alcohol consumption are associated with a delay in CKD progression and improved survival in patients with Stage 3 or 4 CKD.

The influence of a home-based exercise intervention on human health indices in individuals with chronic spinal cord injury (HOMEX-SCI): study protocol for a randomised controlled trial

BACKGROUND

Spinal cord injury (SCI) creates a complex pathology that can lead to an increase in sedentary behaviours and deleterious changes in body composition. Consequently, individuals with SCI are at increased risk of developing cardiovascular disease and type-2 diabetes mellitus. While the role of physical activity on the reduction of chronic disease risk is well documented in non-disabled individuals the evidence is less conclusive for persons with SCI. The aim of this methodological paper is to outline the design of a study that will assess the role of a home-based exercise intervention on biomarkers of metabolic and cardiovascular health in persons with SCI: the HOMEX-SCI study.

METHODS/DESIGN

Eligible participants will be inactive (physical activity level ≤1.60) individuals, with a chronic (more than 1 year) spinal cord lesion between the second thoracic and the fifth lumbar vertebrae, and aged between 18 and 65 years. Following baseline laboratory testing and lifestyle monitoring, participants will be randomly allocated to a control (CON) group or a 6-week home-based exercise intervention (INT) group. The INT consists of 45 minutes of moderate-intensity (60-65 % peak oxygen uptake) arm-crank exercise four times per week. Participants assigned to the CON group will be asked to maintain their normal lifestyle. The main outcomes of this study (biomarkers of metabolic and cardiovascular health) are obtained from venous blood samples, collected in the fasted and postprandial state. Eight other measurement categories will be assessed: (1) body composition, (2) physical activity, (3) energy intake, (4) measures of health and wellbeing, (5) resting metabolic rate, heart rate and blood pressure, (6) aerobic capacity, (7) immune function, and (8) adipose tissue gene expression.

DISCUSSION

This study will explore the feasibility of home-based moderate-intensity exercise and ascertain its impact on metabolic and cardiovascular health in comparison to a lifestyle maintenance CON group. Findings from this study may help to inform new evidence-based physical activity guidelines and also help to elucidate the physiological mechanisms whereby exercise might exert beneficial effects in persons with chronic SCI. The results will also act as a scientific platform for further intervention studies in other diverse and at-risk populations.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number: ISRCTN57096451 . Registered on 11 July 2014.

An Overview of the Complexities in Obesity

A recent survey, even one limited to human studies, found considerable “publication scatter” in that more than 250 different professional journals publish articles on obesity. Over the years, and particularly since the 1970s and 1980s when the so-called obesity epidemic began, there has been an explosion of clinical interest in a field that encompasses general medicine, pediatrics, surgery, psychiatry, and almost every subspecialty. And rightly so, since even by 2008, there were an estimated 1.46 billion adults worldwide who were overweight, and of these, 502 million were in the obese category, all of which translate into major public health consequences. Despite many highly publicized studies, why do we not have a greater understanding about obesity than we do? It is certainly not from a lack of trying. This article presents an overview of the limitations and challenges, that is, complexities, due to discrepant frameworks and diverse conceptualizations of obesity; potential flaws inherent in its clinical studies; and particularly, impediments due to difficulties in the measurement of body composition (and particularly adipose accumulation), food intake, and physical activity, as well as to notoriously inaccurate self-reporting by subjects. As a result, clinicians remain limited in issuing recommendations to their patients.

Challenges associated with identifying the environmental determinants of the inflammatory bowel diseases

In the last several years there has been an explosion in the discovery of inflammatory bowel disease (IBD) susceptibility genes; however, similar advances in identifying and defining environmental risk factors associated with IBD have lagged behind. Moreover, many studies that have explored the same or similar environmental risk factors of IBD have demonstrated disparate results and come to conflicting conclusions. In order for the field to move forward, it is important to understand and resolve why these differences exist. This significant heterogeneity has blurred the identification of the fundamental environmental determinants of IBD. The purpose of this review article is to explore the factors that have likely contributed to the heterogeneity among observational studies of environmental risk factors in IBD. In doing so, it is hoped that methodological standardization may lead to consistent environmental associations.

Interactions between genetic variants in glucose transporter type 9 (SLC2A9) and dietary habits in serum uric acid regulation

AIM

To investigate possible interactions between genetic variants in glucose transporter type 9 (SLC2A9) gene and dietary habits in serum uric acid regulation.

METHODS

Participants for this study were recruited from two isolated Croatian island communities of Vis (n=918) and Korcula (n=898). Three single nucleotide polymorphisms (SNP) from the SLC2A9 gene (rs1014290, rs6449213, rs737267) were correlated with dietary habits and uric acid.

RESULTS

A significant decrease in uric acid levels was recorded with increasing consumption of milk, sour cream, duck and turkey, and eggs. The only significant interaction was found between potato consumption and rs737267 and a near-significant interaction was found between soft drinks and rs1014290 (interaction P=0.068). Increased consumption of soft drinks interacting with the TT genotype at rs1014290 increased serum uric acid. No significant interactions were observed between food products consumption and rs6449213.

CONCLUSION

There is a certain extent of interaction between SLC2A9 and dietary patterns in serum uric acid determination. The metabolic effect of soft drinks seems to be determined by the underlying genotype of rs1014290.

Methodological evaluation of method for dietary heavy metal intake

Exposure to environmental pollutants is an important problem of environmental toxicology. Heavy metals are regarded as toxic to living organisms because of their tendency to accumulate in selected tissues. Moreover, their presence is a causative agent of various sorts of disorders, including neuro-, nephro-, carcino-, terato-, and immunological. Exposures of human to environmental chemicals can occur simultaneously from various sources. One exposure route is ingestion of hazardous chemicals through contaminated food and beverages. Considering the above-mentioned menace, efforts should be focused on the estimation of dietary intakes of potential toxic agents by consumers. Dietary exposure assessment to nonnutrients is usually performed by combining 2 sets of data-the concentration of elemental contaminants in various food products and the consumption data of these food items. A variety of approaches exist for evaluating exposure to food chemicals, and the method chosen is influenced, among others, by the intended goal, the availability of data, cost, and time frame. Moreover, it is also important to note how accurate and detailed the information concerning toxic elements intake needs to be. There are a number of sources of food consumption data currently used in exposure assessments, which range from 1 d to habitual intake. Frequently, the heavy metals for which dietary exposure is of interest are present in trace and ultra-trace quantities. Hence, an analytical technique with sufficient sensitivity is required for the accurate determination of these chemicals in food samples. It is important to remember that the accuracy of quantitative analysis is strongly dependent on the sampling and preparation steps.

The Use of Novel Foods Enriched with Long-Chain n-3 Fatty Acids to Increase Dietary Intake: A Comparison of Methodologies Assessing Nutrient Intake

OBJECTIVE

To evaluate the effect of consuming a variety of foods enriched in long-chain n-3 fatty acids in low fish eaters.

DESIGN

Evaluation of reported dietary intakes in a 6-month, double-blind, randomized, controlled parallel design trial.

SUBJECTS/SETTING

Eighty-five men and women with overweight and mildly elevated triglyceride levels who have a low habitual intake of fish.

INTERVENTION

Subjects were randomized to consume foods either enriched in long-chain n-3 fats or control foods (not enriched). Subjects were asked to consume eight portions per day (equivalent to approximately 1 g/day long-chain n-3 fatty acid if randomized to the intervention).

MAIN OUTCOME MEASURE

Reported energy, macronutrient, and fatty acid intakes were measured by diet history, 3-day food records, and body weight.

STATISTICAL ANALYSES

Repeated measures analysis of variance, Kruskall-Wallis test, Pearson's correlation coefficient, and Bland-Altman plots were conducted.

RESULTS

The two groups did not differ in mean dietary intake of long-chain n-3 fatty acid intake at baseline (258 mg and 313 mg for the intervention and control groups, respectively). At 6 months the intervention group members increased their intake of long-chain n-3 fats 4.5-fold compared with baseline and with the control group (P<.001). The data from the diet histories correlated well with the food records for all reported macronutrient and fatty acid values. Food pattern analysis showed that milk (13.8%), cereal (12.1%), and bread (11.3%) contributed the most to the overall long-chain n-3 fatty acid intake in the intervention group.

CONCLUSIONS

This long-term study in free-living subjects indicates that population intakes of long-chain n-3 fatty acids could be substantially increased through the availability of a variety of n-3 fatty acid-enriched processed foods.

Low energy reporting may increase in intervention participants enrolled in dietary intervention trials

OBJECTIVE

To examine differences in low energy intake reporting between intervention and control groups during a dietary intervention trial.

DESIGN

Retrospective data analysis from a subcohort of participants in the Polyp Prevention Trial (PPT), a 4-year, multisite, randomized, controlled dietary intervention trial. Intervention consisted of educational material and counseling sessions supporting a low-fat, high-fiber diet. Baseline and annual demographics, behavioral characteristics, energy intake (EI) based on self-reported 4-day food records, and height and weight of participants were collected at baseline and annually. Basal metabolic rate (BMR) was estimated (using the Schofield equation) to calculate EI/BMR.

SUBJECTS

Of the 443 participants (302 male, 141 female) at baseline, 195 (43.3%) were younger than 60 years, and 394 (91%) were white. At Year 4, 383 participants remained: 186 (122 men, 64 women) in the intervention group, and 197 (133 men, 64 women) in the control group.

STATISTICAL ANALYSES

Using either paired t tests or analysis of variance, the differences between the means for EI, weight, and EI/BMR were compared at baseline, Year 1, and Year 4 for the participants who remained at Year 4. The Goldberg EI/BMR cutoff value of 1.06 (for plausible EI) identified participants who reported low EI. Linear regression was used to quantify the association of various risk factors to EI/BMR and for multivariate analyses within groups. chi(2) contingency table analysis quantified differences of low energy reporting within groups.

RESULTS

At baseline, 46.8% of women and 11.6% of men reported lower than plausible EI. Only men had a significant increase in low energy reporting after randomization. At Year 1, 18.9% of intervention group men reported low EI compared with 9.8% of control group men (P<.05). At Year 4, 23.0% of intervention group men reported low EI compared with 12.8% of control group men (P<.05).

CONCLUSIONS/APPLICATIONS

Difference in low EI reporting between intervention and control groups could distort results from dietary intervention trials; interpretation of findings from dietary trials must include this potential bias. Intervention study design should include dietary intake data collection methods that are not subject to such bias (ie, biomarkers and performance criteria) to measure intervention compliance.

Relative validity of a diet history interview in an intervention trial manipulating dietary fat in the management of Type II diabetes mellitus

BACKGROUND

This study assesses the relative validity of a diet history interview in 56 free-living individuals with Type II diabetes mellitus.

METHODS

The diet history interview was compared to a 3-day food record in a 1-year dietary intervention trial. The plausibility of energy intake data was examined throughout the trial. Paired data were compared for differences and the presence of systematic error was determined by Bland Altman analysis. Changes in accuracy and responsiveness were assessed over time.

RESULTS

The proportion of underreporters was larger in the diet history at baseline. Underrecording with the food record was more common in subjects with BMIs > 30 kg/m(2). There was no difference between paired dietary data from the two methods; however, data on fatty acids failed to correlate. These correlations improved when outliers were removed. There was no evidence of a relationship between bias and mean intake of dietary variables. Accuracy of diet history measurement did not change during the trial for energy or macronutrients, but data on protein and monounsaturated fat were both affected by BMI. The diet history was more responsive than the food record to changes in monounsaturated fatty acid intake after 3 months, but this changed at the end of the trial.

CONCLUSION

The diet history provided good estimates of energy and macronutrient intakes in a sample group with Type II diabetes mellitus. However, energy intake data revealed a high prevalence of underreporting especially in people with higher BMIs.