The impact of different diagnostic criteria on the association of sarcopenia with injurious falls in the CLSA

BACKGROUND

Sarcopenia definitions recommend different combinations of variables (lean mass, strength, and physical function) and different methods of adjusting lean mass. The purpose of this paper was to address the gaps in the literature regarding how differences in the operationalization of sarcopenia impact the association between sarcopenia and injurious falls.

METHODS

Participants included 9936 individuals from the Canadian Longitudinal Study on Aging aged ≥65 years at baseline (2012-2015), with complete data for sarcopenia-related variables, injurious falls, and covariates. Sarcopenia was defined using all combinations of muscle variables (lean mass, grip strength, chair rise test, and gait speed) and methods of adjusting lean mass (height² , weight, body mass index (BMI), and regressing on height and fat mass) recommended by the expert group sarcopenia definitions. Multiple cut off values for the measures were explored. The association between sarcopenia and injurious falls (0, 1, or 2+ falls) measured 18 months after baseline data collection were assessed using proportional odds regression models.

RESULTS

In men (n = 5162, 72.9 ± 5.6 years), the odds of having a higher level of injurious falls was between 1.43 and 2.14 greater when sarcopenia was defined as (i) lean mass adjusted for weight only; (ii) grip strength (<30 or <26 kg) only; (iii) lean mass adjusted for weight and grip strength (<30 or <26 kg); (iv) lean mass adjusted for BMI and grip strength (<26 kg); and (v) lean mass adjusted using the regression technique and grip strength (<30 or <26 kg). In women (n = 4774, 72.8 ± 5.6 years), only the combination of lean mass adjusted using regression with gait speed (<0.8 m/s) was associated with a significantly higher odds (1.46, 95% confidence interval: 1.01-2.10, P = 0.04) of having a higher level of injurious falls.

CONCLUSIONS

Sarcopenia definitions based on different combinations of muscle variables and methods of adjusting lean mass are not equally associated with injurious falls. In men, definitions including grip strength but not gait speed or the chair rise test, and adjusting lean mass for weight, BMI, or using the residual technique but not height² , tended to be associated with injurious falls. In women, sarcopenia was generally not associated with injurious falls regardless of the definition used.

Vitamin D supplementation in pregnancy and early infancy in relation to gut microbiota composition and C. difficile colonization: implications for viral respiratory infections

In Canada and the US, the infant diet is supplemented with vitamin D via supplement drops or formula. Pregnant and nursing mothers often take vitamin D supplements. Since little is known about the impact of this supplementation on infant gut microbiota, we undertook a study to determine the association between maternal and infant vitamin D supplementation, infant gut microbiota composition and Clostridioides difficile colonization in 1,157 mother-infant pairs of the CHILD (Canadian Healthy Infant Longitudinal Development) Cohort Study over 2009-2012. Logistic and MaAsLin regression were employed to assess associations between vitamin D supplementation, and C. difficile colonization, or other gut microbiota, respectively. Sixty-five percent of infants received a vitamin D supplement. Among all infants, infant vitamin D supplementation was associated with a lower abundance of genus Megamonas (q = 0.01) in gut microbiota. Among those exclusively breastfed, maternal prenatal supplementation was associated with lower abundance of Bilophila (q = 0.01) and of Lachnospiraceae (q = 0.02) but higher abundance of Haemophilus (q = 0.02). There were no differences in microbiota composition with vitamin D supplementation among partially and not breastfed infants. Neither infant nor maternal vitamin D supplementation were associated with C. difficile colonization, after adjusting for breastfeeding status and other factors. However, maternal consumption of vitamin-D fortified milk reduced the likelihood of C. difficile colonization in infants (adjustedOR: 0.40, 95% CI: 0.19-0.82). The impact of this compositional difference on later childhood health, especially defense against viral respiratory infection, may go beyond the expected effects of vitamin D supplements and remains to be ascertained.

IMAGINE Network's Mind And Gut Interactions Cohort (MAGIC) Study: a protocol for a prospective observational multicentre cohort study in inflammatory bowel disease and irritable bowel syndrome

INTRODUCTION

Gut microbiome and diet may be important in irritable bowel syndrome (IBS), inflammatory bowel disease (IBD) and comorbid psychiatric conditions, but the mechanisms are unclear. We will create a large cohort of patients with IBS, IBD and healthy controls, and follow them over time, collecting dietary and mental health information and biological samples, to assess their gastrointestinal (GI) and psychological symptoms in association with their diet, gut microbiome and metabolome.

METHODS AND ANALYSIS

This 5-year observational prospective cohort study is recruiting 8000 participants from 15 Canadian centres. Persons with IBS who are 13 years of age and older or IBD ≥5 years will be recruited. Healthy controls will be recruited from the general public and from friends or relatives of those with IBD or IBS who do not have GI symptoms. Participants answer surveys and provide blood, urine and stool samples annually. Surveys assess disease activity, quality of life, physical pain, lifestyle factors, psychological status and diet. The main outcomes evaluated will be the association between the diet, inflammatory, genetic, microbiome and metabolomic profiles in those with IBD and IBS compared with healthy controls using multivariate logistic regression. We will also compare these profiles in those with active versus quiescent disease and those with and without psychological comorbidity.

ETHICS AND DISSEMINATION

Approval has been obtained from the institutional review boards of all centres taking part in the study. We will develop evidence-based knowledge translation initiatives for patients, clinicians and policymakers to disseminate results to relevant stakeholders.Trial registration number: NCT03131414.

Effects of oral contraceptives on metabolic parameters in adult premenopausal women: a meta-analysis

OBJECTIVE

To estimate the effect of oral contraceptives (OC) containing different progestins on parameters of lipid and carbohydrate metabolism through a systematic review and meta-analysis.

PATIENTS AND METHODS

Premenopausal women aged 18 or older, who received oral contraceptives containing chlormadinone, cyproterone, drospirenone, levonorgestrel, desogestrel, dienogest, gestodene or norgestimate, for at least 3 months. Outcome variables were changes in plasma lipids, BMI, insulin resistance and plasma glucose. We searched MEDLINE and EMBASE for randomized trials and estimated the pooled within-group change in each outcome variable using a random-effects model. We performed subgroup analyses by study duration (<12 months vs ≥12 months) and polycystic ovary syndrome (PCOS) status.

RESULTS

Eighty-two clinical trials fulfilled the inclusion criteria. All progestins (except dienogest) increased plasma TG, ranging from 12.1 mg/dL for levonorgestrel (P < 0.001) to 35.1 mg/dL for chlormadinone (P < 0.001). Most progestins also increased HDLc, with the largest effect observed for chlormadinone (+9.6 mg/dL, P < 0.001) and drospirenone (+7.4 mg/dL, P < 0.001). Meanwhile, levonorgestrel decreased HDLc by 4.4 mg/dL (P < 0.001). Levonorgestrel (+6.8 mg/dL, P < 0.001) and norgestimate (+11.5 mg/dL, P = 0.003) increased LDLc, while dienogest decreased it (-7.7 mg/dL, P = 0.04). Cyproterone slightly reduced plasma glucose. None of the progestins affected BMI or HOMA-IR. Similar results were observed in subgroups defined by PCOS or study duration.

CONCLUSION

Most progestins increase both TG and HDLc, their effect on LDLc varies widely. OC have minor or no effects on BMI, HOMA-IR and glycemia. The antiandrogen progestins dienogest and cyproterone displayed the most favorable metabolic profile, while levonorgestrel displayed the least favorable.

Do Different Ascertainment Techniques Identify the Same Individuals as Sarcopenic in the Canadian Longitudinal Study on Aging?

BACKGROUND/OBJECTIVES

Sarcopenia is associated with poor health outcomes such as disability, institutionalization, and mortality. Efforts to manage sarcopenia clinically have been hindered by challenges in determining how to ascertain sarcopenia status correctly. The objective of this project was to assess the agreement between the different methods of ascertaining sarcopenia recommended by expert groups.

DESIGN

Cross-sectional study of baseline data (2011-2015) from the Canadian Longitudinal Study on Aging.

SETTING

Population-based multicenter study of community-dwelling participants.

PARTICIPANTS

Eligible participants (n = 12,646) aged 65 to 85 living within 25 to 50 km of 11 data collection sites in Canada. The analyses included 10,820 participants with the data required to diagnose sarcopenia.

MEASUREMENTS

Sarcopenia was operationalized as appendicular lean mass (ALM), ALM and grip strength, ALM and gait speed, and grip strength and gait speed. Within each combination, ALM was adjusted for height squared, weight, body mass index, and the residual of regressing lean mass on height and fat mass. The lowest 20th sex-specific percentile values were used as the cutoffs for low ALM. Low grip strength cutoffs of 35.5 kg for men and 20 kg for women and a gait speed cutoff of .8 m/s were used.

RESULTS

The mean age was 73.0 ± 5.6 years, and 51.9% of the sample was male. The agreement (Cohen's κ) between the different combinations of variables used to ascertain sarcopenia status was below .50. Agreement for the different lean mass adjustment techniques ranged from .04 to .76.

CONCLUSION

The combination of variables used to ascertain sarcopenia and many of the ALM adjustment techniques have insufficient agreement to be considered equivalent. This has important clinical implications for the management of sarcopenia because treatments may differ based on how sarcopenia is identified. To improve the clinical utility of sarcopenia, a unified definition of sarcopenia is required.

Treatment Outcomes in Patients With Opioid Use Disorder Who Were First Introduced to Opioids by Prescription: A Systematic Review and Meta-Analysis

OBJECTIVE

Prescription opioid misuse has led to a new cohort of opioid use disorder (OUD) patients who were introduced to opioids through a legitimate prescription. This change has caused a shift in the demographic profile of OUD patients from predominantly young men to middle age and older people. The management of OUD includes medication-assisted treatment (MAT), which produces varying rates of treatment response. In this study, we will examine whether the source of first opioid use has an effect on treatment outcomes in OUD. Using a systematic review of the literature, we will investigate the association between source of first opioid introduction and treatment outcomes defined as continuing illicit opioid use and poly-substance use while in MAT.

METHODS

Medline, EMBASE, CINHAL, and PsycInfo were searched from inception to December 31st, 2019 inclusive using a comprehensive search strategy. Five pairs of reviewers conducted screening and data extraction independently in duplicate. The review is conducted and reported according to the PRISMA guidelines. A random-effects model was used for meta analyses assuming heterogeneity among the included studies.

RESULTS

The initial search results in 27,345 articles that were screened, and five observational studies were included in the qualitative and quantitative analyses. Our results found that those who were introduced to opioids through a legitimate prescription were significantly less likely to have illicit opioid use (0.70, 95% CI 0.50, 0.99) while on MAT. They were also less likely to use cannabis (0.54, 95% CI 0.32, 0.89), alcohol (0.75, 95% CI 0.59, 0.95), cocaine (0.50, 95% CI 0.29, 0.85), and injection drug use (0.25, 95% CI 0.14, 0.43) than those introduced to opioids through recreational means.

CONCLUSION

This study shows that the first exposure to opioids, whether through a prescription or recreationally, influences prognosis and treatment outcomes of opioid use disorder. Although the increased pattern of prescribing opioids may have led to increased OUD in a new cohort of patients, these patients are less likely to continue to use illicit drugs and have a different prognostic and clinical profile that requires a tailored approach to treatment.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017058143.

Barriers to, and Facilitators of, Lifestyle Changes to Prevent Gestational Diabetes: An Interpretive Description of South Asian Women and Health-Care Providers Living and Working in Southern Ontario, Canada

OBJECTIVES

People of South Asian ancestry are the fastest growing non-Caucasian ethnic group in Canada and are at high risk for developing type 2 diabetes and coronary heart disease. Pregnant South Asian women have a 2-fold increased risk of developing gestational diabetes, which increases their risk of type 2 diabetes and coronary heart disease. The specific objectives of this study were to explore the perceptions of health behaviours (diet and physical activity) during pregnancy in the South Asian community.

METHODS

We used interpretive description to further understand the cultural and contextual factors that influence the knowledge, attitudes and practices of diet and physical activity of South Asian women of childbearing age and those who provide health care to this group.

RESULTS

Two major themes that emerged from the perspectives of 10 South Asian pregnant women included: (1) importance of considering an individual's locus of control; and (2) support (emotional and information exchange) from family, friends and health-care providers. Two major themes identified by the 11 health-care providers were: (1) cultural awareness in caring for South Asian women during pregnancy; and (2) clinic management, logistics and resources. A common theme for both South Asian pregnant women and health-care providers was the importance of considering the cultural landscape in relation to how knowledge is obtained, shared and valued.

CONCLUSION

A better understanding of these cultural underpinnings may support the development of interventions tailored for pregnant South Asian women and their health-care providers.

Association of nut intake with risk factors, cardiovascular disease, and mortality in 16 countries from 5 continents: analysis from the Prospective Urban and Rural Epidemiology (PURE) study

BACKGROUND

The association of nuts with cardiovascular disease and deaths has been investigated mostly in Europe, the USA, and East Asia, with few data available from other regions of the world or from low- and middle-income countries.

OBJECTIVE

To assess the association of nuts with mortality and cardiovascular disease (CVD).

METHODS

The Prospective Urban Rural Epidemiology study is a large multinational prospective cohort study of adults aged 35-70 y from 16 low-, middle-, and high-income countries on 5 continents. Nut intake (tree nuts and ground nuts) was measured at the baseline visit, using country-specific validated FFQs. The primary outcome was a composite of mortality or major cardiovascular event [nonfatal myocardial infarction (MI), stroke, or heart failure].

RESULTS

We followed 124,329 participants (age = 50.7 y, SD = 10.2; 41.5% male) for a median of 9.5 y. We recorded 10,928 composite events [deaths (n = 8,662) or major cardiovascular events (n = 5,979)]. Higher nut intake (>120 g per wk compared with <30 g per mo) was associated with a lower risk of the primary composite outcome of mortality or major cardiovascular event [multivariate HR (mvHR): 0.88; 95% CI: 0.80, 0.96; P-trend = 0.0048]. Significant reductions in total (mvHR: 0.77; 95% CI: 0.69, 0.87; P-trend <0.0001), cardiovascular (mvHR: 0.72; 95% CI: 0.56, 0.92; P-trend = 0.048), and noncardiovascular mortality (mvHR: 0.82; 95% CI: 0.70, 0.96; P-trend = 0.0046) with a trend to reduced cancer mortality (mvHR: 0.81; 95% CI: 0.65, 1.00; P-trend = 0.081) were observed. No significant associations of nuts were seen with major CVD (mvHR: 0.91; 95% CI: 0.81, 1.02; P-trend = 0.14), stroke (mvHR: 0.98; 95% CI: 0.84, 1.14; P-trend = 0.76), or MI (mvHR: 0.86; 95% CI: 0.72, 1.04; P-trend = 0.29).

CONCLUSIONS

Higher nut intake was associated with lower mortality risk from both cardiovascular and noncardiovascular causes in low-, middle-, and high-income countries.

Association of Major Food Sources of Fructose-Containing Sugars With Incident Metabolic Syndrome: A Systematic Review and Meta-analysis

IMPORTANCE

Sugar-sweetened beverages (SSBs) are associated with increased risk of metabolic syndrome (MetS). However, the role of other important food sources of fructose-containing sugars in the development of MetS remains unclear.

OBJECTIVE

To examine the association of major food sources of fructose-containing sugars with incident MetS.

DATA SOURCES

MEDLINE, Embase, and Cochrane Library were searched from database inception to March 24, 2020, in addition to manual searches of reference lists from included studies using the following search terms: sugar-sweetened beverages, fruit drink, yogurt, metabolic syndrome, and prospective study.

STUDY SELECTION

Inclusion criteria included prospective cohort studies of 1 year or longer that investigated the association of important food sources of fructose-containing sugars with incident MetS in participants free of MetS at the start of the study.

DATA EXTRACTION AND SYNTHESIS

Study quality was assessed using the Newcastle-Ottawa Scale. Extreme quantile risk estimates for each food source with MetS incidence were pooled using a random-effects meta-analysis. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). Dose-response analyses were performed using a 1-stage linear mixed-effects model. The certainty of the evidence was assessed using GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Results were reported according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines.

MAIN OUTCOMES AND MEASURES

Pooled risk ratio (RR) of incident MetS (pairwise and dose response).

RESULTS

Thirteen prospective cohort studies (49 591 participants [median age, 51 years; range, 6-90 years]; 14 205 with MetS) that assessed 8 fructose-containing foods and MetS were included. An adverse linear dose-response association for SSBs (RR for 355 mL/d, 1.14; 95% CI, 1.05-1.23) and an L-shaped protective dose-response association for yogurt (RR for 85 g/d, 0.66; 95% CI, 0.58-0.76) and fruit (RR for 80 g/d, 0.82; 95% CI, 0.78-0.86) was found. Fruit juices (mixed and 100%) had a U-shaped dose-response association with protection at moderate doses (mixed fruit juice: RR for 125 mL/d, 0.58; 95% CI, 0.42-0.79; 100% fruit juice: RR for 125 mL/d, 0.77; 95% CI, 0.61-0.97). Honey, ice cream, and confectionary had no association with MetS incidence. The certainty of the evidence was moderate for SSBs, yogurt, fruit, mixed fruit juice, and 100% fruit juice and very low for all other food sources.

CONCLUSIONS AND RELEVANCE

The findings of this meta-analysis suggest that the adverse association of SSBs with MetS does not extend to other food sources of fructose-containing sugars, with a protective association for yogurt and fruit throughout the dose range and for 100% fruit juice and mixed fruit juices at moderate doses. Therefore, current policies and guidelines on the need to limit sources of free sugars may need to be reexamined.

Serum nonesterified fatty acids have utility as dietary biomarkers of fat intake from fish, fish oil, and dairy in women

Nutritional studies rely on various biological specimens for FA determination, yet it is unclear how levels of serum NEFAs correlate with other circulating lipid pools. Here, we used a high-throughput method (<4 min/sample) based on multisegment injection-nonaqueous capillary electrophoresis-mass spectrometry (MSI-NACE-MS) to investigate whether specific serum NEFAs have utility as biomarkers of dietary fat intake in women. We first identified circulating NEFAs correlated with long-term/habitual food intake among pregnant women with contrasting dietary patterns (n = 50). Acute changes in serum NEFA trajectories were also studied in nonpregnant women (n = 18) following high-dose (5 g/day) fish oil (FO) supplementation or isoenergetic sunflower oil placebo over 56 days. In the cross-sectional study, serum ω-3 FAs correlated with self-reported total ω-3 daily intake, notably EPA as its NEFA (r = 0.46; P = 0.001), whereas pentadecanoic acid was associated with full-fat dairy intake (r = 0.43; P = 0.002), outcomes consistent with results from total FA serum hydrolysates. In the intervention cohort, serum ω-3 NEFAs increased 2.5-fold from baseline within 28 days following FO supplementation, and this increase was most pronounced for EPA (P = 0.0004). Unlike for DHA, circulating EPA as its NEFA also strongly correlated to EPA concentrations measured from erythrocyte phospholipid hydrolysates (r = 0.66; P = 4.6 × 10-10) and was better suited to detect dietary nonadherence. We conclude that MSI-NACE-MS offers a rapid method to quantify serum NEFAs and objectively monitor dietary fat intake in women that is complementary to food-frequency questionnaires.

Ethnic differences in maternal diet in pregnancy and infant eczema

BACKGROUND

The global prevalence of childhood eczema has increased over the last few decades, with a marked increase in high-income countries. Differences in prevalence of childhood eczema between countries and ethnicities suggest that genetic and early modifiable environmental factors, such as dietary intake, may underlie this observation. To investigate the association between pregnancy diet and infant eczema in a consortium of prospective Canadian birth cohorts predominantly comprised of white Europeans and South Asians.

METHODS

We evaluated the association of maternal dietary patterns reported during pregnancy (assessed at 24-28 weeks gestation using a semi-quantitiative food-frequency questionnaire) with parent-reported physician-diagnosed infant eczema at 1-year from 2,160 mother-infant pairs. Using three dietary patterns ("Western", "plant-based", and "Balanced") previously derived in this cohort using principal component analysis, we used multivariable logistic regression to determine the association of these dietary patterns with infant eczema, adjusted for potential confounders.

RESULTS

We observed a lower odds of eczema in the full sample combining white Europeans and South Asians with greater adherence to a plant-based (OR = 0.65; 95% CI: 0.55, 0.76; <0.001) and Western dietary pattern (OR = 0.73; 95% CI: 0.60, 0.89; P<0.01), after adjusting for other known predictors of eczema, including ethnicity, which was not significant. No associations were observed for the balanced diet. An interaction between the Western diet and ethnicity was observed (P<0.001). Following stratification by ethnicity, a protective association between the plant-based diet and infant eczema was confirmed in both white Europeans (OR = 0.59; 95% CI: 0.47, 0.74; P<0.001) and South Asians (OR = 0.77; 95% CI: 0.61, 0.97; P = 0.025). In white Europeans only, a Western diet was associated with a lower odds of infant eczema (OR = 0.69; 95% CI: 0.56, 0.87; P = 0.001) while a balanced diet increased the odds of infant eczema (OR = 1.23; 95% CI: 1.02, 1.49; P = 0.03). Beyond a plant-based diet, no significant associations with other dietary patterns were observed in South Asians.

CONCLUSION

A plant-based diet during pregnancy is associated with a lowered odds of infant eczema at 1 year in all participants. Future studies of the components of plant-based diet which underlie the lower risk of eczema are needed.

Important Food Sources of Fructose-Containing Sugars and Incident Hypertension: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

Background Sugar-sweetened beverages are associated with hypertension. We assessed the relation of important food sources of fructose-containing sugars with incident hypertension using a systematic review and meta-analysis of prospective cohort studies. Methods and Results We searched MEDLINE, EMBASE, and Cochrane (through December week 2, 2018) for eligible studies. For each food source, natural log-transformed risk ratios (RRs) for incident hypertension were pooled using pair-wise meta-analysis and linear and nonlinear dose-response meta-analyses. Certainty in our evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation. We identified 26 reports, including 15 prospective cohorts (930 677 participants; 363 459 cases). Sugar-sweetened beverages showed harmful (RRper-355-mL, 1.10 [95% CI, 1.08, 1.12]) whereas fruit (RRper-240-g, 0.94 [95% CI, 0.96, 0.99]) and yogurt showed protective associations (RRper-125-g, 0.95 [95% CI, 0.94, 0.97]) with incident hypertension throughout the dose range. One hundred percent fruit juice showed a protective association only at moderate doses (RRat-100-mL, 0.97 [95% CI, 0.94, 0.99]). The pair-wise protective association of dairy desserts was not supported by linear dose-response analysis. Fruit drinks or sweet snacks were not associated with hypertension. Certainty of the evidence was "low" for sugar-sweetened beverages, 100% fruit juice, fruit, and yogurt and "very low" for fruit drinks, sweet snacks, and dairy desserts. Conclusions The harmful association between sugar-sweetened beverages and hypertension does not extend to other important food sources of fructose-containing sugars. Further research is needed to improve our estimates and better understand the dose-response relationship between food sources of fructose-containing sugars and hypertension. Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02702375.

Explaining the variability in cardiovascular risk factors among First Nations communities in Canada: a population-based study

BACKGROUND

Historical, colonial, and racist policies continue to influence the health of Indigenous people, and they continue to have higher rates of chronic diseases and reduced life expectancy compared with non-Indigenous people. We determined factors accounting for variations in cardiovascular risk factors among First Nations communities in Canada.

METHODS

Men and women (n=1302) aged 18 years or older from eight First Nations communities participated in a population-based study. Questionnaires, physical measures, blood samples, MRI of preclinical vascular disease, and community audits were collected. In this cross-sectional analysis, the main outcome was the INTERHEART risk score, a measure of cardiovascular risk factor burden. A multivariable model was developed to explain the variations in INTERHEART risk score among communities. The secondary outcome was MRI-detected carotid wall volume, a measure of subclinical atherosclerosis.

FINDINGS

The mean INTERHEART risk score of all communities was 17·2 (SE 0·2), and more than 85% of individuals had a risk score in the moderate to high risk range. Subclinical atherosclerosis increased significantly across risk score categories (p<0·0001). Socioeconomic advantage (-1·4 score, 95% CI -2·5 to -0·3; p=0·01), trust between neighbours (-0·7, -1·2 to -0·3; p=0·003), higher education level (-1·9, -2·9 to -0·8, p<0·001), and higher social support (-1·1, -2·0 to -0·2; p=0·02) were independently associated with a lower INTERHEART risk score; difficulty accessing routine health care (2·2, 0·3 to 4·1, p=0·02), taking prescription medication (3·5, 2·8 to 4·3; p<0·001), and inability to afford prescription medications (1·5, 0·5 to 2·6; p=0·003) were associated with a higher INTERHEART risk score. Collectively, these factors explained 28% variation in the cardiac risk score among communities. Communities with higher socioeconomic advantage and greater trust, and individuals with higher education and social support, had a lower INTERHEART risk score. Communities with difficulty accessing health care, and individuals taking or unable to afford prescription medications, had a higher INTERHEART risk score.

INTERPRETATION

Cardiac risk factors are lower in communities with high socioeconomic advantage, greater trust, social support and educational opportunities, and higher where it is difficult to access health care or afford prescription medications. Strategies to optimise the protective factors and reduce barriers to health care in First Nations communities might contribute to improved health and wellbeing.

FUNDING

Heart and Stroke Foundation of Canada, Canadian Partnership Against Cancer, Canadian Institutes for Health Research.

Relation of Total Sugars, Sucrose, Fructose, and Added Sugars With the Risk of Cardiovascular Disease: A Systematic Review and Dose-Response Meta-analysis of Prospective Cohort Studies

OBJECTIVE

To determine the association of total and added fructose-containing sugars on cardiovascular (CVD) incidence and mortality.

METHODS

MEDLINE, EMBASE and Cochrane Library were searched from January 1, 1980, to July 31, 2018. Prospective cohort studies assessing the association of reported intakes of total, sucrose, fructose and added sugars with CVD incidence and mortality in individuals free from disease at baseline were included. Risk estimates were pooled using the inverse variance method, and dose-response analysis was modeled.

RESULTS

Eligibility criteria were met by 24 prospective cohort comparisons (624,128 unique individuals; 11,856 CVD incidence cases and 12,224 CVD mortality cases). Total sugars, sucrose, and fructose were not associated with CVD incidence. Total sugars (risk ratio, 1.09 [95% confidence interval, 1.02 to 1.17]) and fructose (1.08 [1.01 to 1.15]) showed a harmful association for CVD mortality, there was no association for added sugars and a beneficial association for sucrose (0.94 [0.89 to 0.99]). Dose-response analyses showed a beneficial linear dose-response gradient for sucrose and nonlinear dose-response thresholds for harm for total sugars (133 grams, 26% energy), fructose (58 grams, 11% energy) and added sugars (65 grams, 13% energy) in relation to CVD mortality (P<.05). The certainty of the evidence using GRADE was very low for CVD incidence and low for CVD mortality for all sugar types.

CONCLUSION

Current evidence supports a threshold of harm for intakes of total sugars, added sugars, and fructose at higher exposures and lack of harm for sucrose independent of food form for CVD mortality. Further research of different food sources of sugars is needed to define better the relationship between sugars and CVD. REGISTRATION: clinicaltrials.gov, NCT01608620.

Metabolic Trajectories Following Contrasting Prudent and Western Diets from Food Provisions: Identifying Robust Biomarkers of Short-Term Changes in Habitual Diet

A large body of evidence has linked unhealthy eating patterns with an alarming increase in obesity and chronic disease worldwide. However, existing methods of assessing dietary intake in nutritional epidemiology rely on food frequency questionnaires or dietary records that are prone to bias and selective reporting. Herein, metabolic phenotyping was performed on 42 healthy participants from the Diet and Gene Intervention (DIGEST) pilot study, a parallel two-arm randomized clinical trial that provided complete diets to all participants. Matching single-spot urine and fasting plasma specimens were collected at baseline, and then following two weeks of either a Prudent or Western diet with a weight-maintaining menu plan designed by a dietician. Targeted and nontargeted metabolite profiling was conducted using three complementary analytical platforms, where 80 plasma metabolites and 84 creatinine-normalized urinary metabolites were reliably measured (CV < 30%) in the majority of participants (>75%) after implementing a rigorous data workflow for metabolite authentication with stringent quality control. We classified a panel of metabolites with distinctive trajectories following two weeks of food provisions when using complementary univariate and multivariate statistical models. Unknown metabolites associated with contrasting dietary patterns were identified with high-resolution MS/MS, as well as co-elution after spiking with authentic standards if available. Overall, 3-methylhistidine and proline betaine concentrations increased in both plasma and urine samples after participants were assigned a Prudent diet (q < 0.05) with a corresponding decrease in the Western diet group. Similarly, creatinine-normalized urinary imidazole propionate, hydroxypipecolic acid, dihydroxybenzoic acid, and enterolactone glucuronide, as well as plasma ketoleucine and ketovaline increased with a Prudent diet (p < 0.05) after adjustments for age, sex, and BMI. In contrast, plasma myristic acid, linoelaidic acid, linoleic acid, α-linoleic acid, pentadecanoic acid, alanine, proline, carnitine, and deoxycarnitine, as well as urinary acesulfame K increased among participants following a Western diet. Most metabolites were also correlated (r > ± 0.30, p < 0.05) to changes in the average intake of specific nutrients from self-reported diet records reflecting good adherence to assigned food provisions. Our study revealed robust biomarkers sensitive to short-term changes in habitual diet, which is needed for accurate monitoring of healthy eating patterns in free-living populations, and evidence-based public health policies for chronic disease prevention.

Methods for the Selection of Covariates in Nutritional Epidemiology Studies: A Meta-Epidemiological Review

BACKGROUND

Observational studies provide important information about the effects of exposures that cannot be easily studied in clinical trials, such as nutritional exposures, but are subject to confounding. Investigators adjust for confounders by entering them as covariates in analytic models.

OBJECTIVE

The aim of this study was to evaluate the reporting and credibility of methods for selection of covariates in nutritional epidemiology studies.

METHODS

We sampled 150 nutritional epidemiology studies published in 2007/2008 and 2017/2018 from the top 5 high-impact nutrition and medical journals and extracted information on methods for selection of covariates.

RESULTS

Most studies did not report selecting covariates a priori (94.0%) or criteria for selection of covariates (63.3%). There was general inconsistency in choice of covariates, even among studies investigating similar questions. One-third of studies did not acknowledge potential for residual confounding in their discussion.

CONCLUSION

Studies often do not report methods for selection of covariates, follow available guidance for selection of covariates, nor discuss potential for residual confounding.

Composition and Variation of the Human Milk Microbiota Are Influenced by Maternal and Early-Life Factors

Breastmilk contains a complex community of bacteria that may help seed the infant gut microbiota. The composition and determinants of milk microbiota are poorly understood. Among 393 mother-infant dyads from the CHILD cohort, we found that milk microbiota at 3-4 months postpartum was dominated by inversely correlated Proteobacteria and Firmicutes, and exhibited discrete compositional patterns. Milk microbiota composition and diversity were associated with maternal factors (BMI, parity, and mode of delivery), breastfeeding practices, and other milk components in a sex-specific manner. Causal modeling identified mode of breastfeeding as a key determinant of milk microbiota composition. Specifically, providing pumped breastmilk was consistently associated with multiple microbiota parameters including enrichment of potential pathogens and depletion of bifidobacteria. Further, these data support the retrograde inoculation hypothesis, whereby the infant oral cavity impacts the milk microbiota. Collectively, these results identify features and determinants of human milk microbiota composition, with potential implications for infant health and development.

Important food sources of fructose-containing sugars and incident gout: a systematic review and meta-analysis of prospective cohort studies

OBJECTIVE

Sugar-sweetened beverages (SSBs) are associated with hyperuricaemia and gout. Whether other important food sources of fructose-containing sugars share this association is unclear.

DESIGN

To assess the relation of important food sources of fructose-containing sugars with incident gout and hyperuricaemia, we conducted a systematic review and meta-analysis of prospective cohort studies.

METHODS

We searched MEDLINE, Embase and the Cochrane Library (through 13 September 2017). We included prospective cohort studies that investigated the relationship between food sources of sugar and incident gout or hyperuricaemia. Two independent reviewers extracted relevant data and assessed the risk of bias. We pooled natural-log transformed risk ratios (RRs) using the generic inverse variance method with random effects model and expressed as RR with 95% confidence intervals (CIs). The overall certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

We identified three studies (1 54 289 participants, 1761 cases of gout), comparing the highest with the lowest level of exposure for SSBs, fruit juices and fruits. No reports were found reporting incident hyperuricaemia. Fruit juice and SSB intake showed an adverse association (fruit juice: RR=1.77, 95% CI 1.20 to 2.61; SSB: RR=2.08, 95% CI 1.40 to 3.08), when comparing the highest to lowest intake of the most adjusted models. There was no significant association between fruit intake and gout (RR 0.85, 95% CI 0.63 to 1.14). The strongest evidence was for the adverse association with SSB intake (moderate certainty), and the weakest evidence was for the adverse association with fruit juice intake (very low certainty) and lack of association with fruit intake (very low certainty).

CONCLUSION

There is an adverse association of SSB and fruit juice intake with incident gout, which does not appear to extend to fruit intake. Further research is needed to improve our estimates.

TRIAL REGISTRATION NUMBER

NCT02702375; Results.

Correction to: Nuts as a replacement for carbohydrates in the diabetic diet: a reanalysis of a randomised controlled trial

In contrast to statements made in the above paper, measurements of waist and hip circumference were in fact available.

The Effect of Vitamin D Supplementation on Prostate Cancer: A Systematic Review and Meta-Analysis of Clinical Trials

Vitamin D has received attention for its potential to disrupt cancer processes. However, its effect in the treatment of prostate cancer is controversial. This study aimed to assess the effect of vitamin D supplementation on patients with prostate cancer. In the present study, PubMed, Scopus, ISI Web of Science, and Google Scholar were searched up to September 2017 for trials that evaluated the effect of vitamin D supplementation on prostate specific antigen (PSA) response, mortality, and its possible side effects in participants with prostate cancer. The DerSimonian and Laird inverse-weighted random-effects model was used to pool the effect estimates. Twenty-two studies (16 before-after and 6 randomized controlled trials) were found and included in the meta-analysis. The analysis of controlled clinical trials revealed that PSA change from baseline [weighted mean difference (WMD)=-1.66 ng/ml, 95% CI: -0.69, 0.36, p=0.543)], PSA response proportion (RP=1.18, 95% CI: 0.97, 1.45, p=0.104) and mortality rate (risk ratio (RR)=1.05, 95% CI: 0.81-1.36; p=0.713) were not significantly different between vitamin D supplementation and placebo groups. Single arm trials revealed that vitamin D supplementation had a modest effect on PSA response proportion: 19% of those enrolled had at least a 50% reduction in PSA by the end of treatment (95% CI: 7% to 31%; p=0.002). Although before-after studies showed that vitamin D increases the PSA response proportion, it does not seem that patients with prostate cancer benefit from high dose vitamin D supplementation and it should not be recommended for the treatment.

Identifying patient-important outcomes in medication-assisted treatment for opioid use disorder patients: a systematic review protocol

INTRODUCTION

Illicit opioid use has become a national crisis in Canada, with over 65 000 people seeking treatment for opioid use disorder (OUD) in Ontario and British Columbia alone. Medication-assisted treatment (MAT) is a common treatment for OUD. There is substantial variability in treatment outcomes used to evaluate effectiveness of MAT, making it difficult to establish clinically and scientifically relevant treatment effect. Furthermore, patients are often excluded from the process of determining these outcomes. The primary objective of this review is to examine outcomes currently used to measure MAT effectiveness and to identify patient-relevant outcomes to enhance effectiveness of treatment options. This review refers to patient-important outcomes as those outcomes patients consider important to or markers of treatment success.

METHODS AND ANALYSIS

MEDLINE, EMBASE, PsycINFO, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Cochrane Library, Cochrane Clinical Trials Registry, National Institutes for Health Clinical Trials Registry and WHO International Clinical Trials Registry Platform databases will be searched. We will search databases from inception to the date the search is ran. Studies of interest include those evaluating the effectiveness of MAT for patients with OUD, with or without consultation with patients regarding what they consider to be important as an indicator of treatment success. Results will be analysed using thematic analysis and qualitative analysis where possible. This will result in comprehensive synthesis of all outcomes and measures found related to OUD treatment effectiveness.

ETHICS AND DISSEMINATION

We are collaborating with Canadian Addiction Treatment Centres which provide MAT to patients with OUD who will participate in disseminating study results. Dissemination strategies will involve sharing study results through workshops, presentations, peer-reviewed publications, study reports, community presentations and resources in primary care settings.

PROSPERO REGISTRATION NUMBER

CRD42018095553.

Food sources of fructose-containing sugars and glycaemic control: systematic review and meta-analysis of controlled intervention studies

OBJECTIVE

To assess the effect of different food sources of fructose-containing sugars on glycaemic control at different levels of energy control.

DESIGN

Systematic review and meta-analysis of controlled intervention studies.

DATA SOURCES

Medine, Embase, and the Cochrane Library up to 25 April 2018.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Controlled intervention studies of at least seven days' duration and assessing the effect of different food sources of fructose-containing sugars on glycaemic control in people with and without diabetes were included. Four study designs were prespecified on the basis of energy control: substitution studies (sugars in energy matched comparisons with other macronutrients), addition studies (excess energy from sugars added to diets), subtraction studies (energy from sugars subtracted from diets), and ad libitum studies (sugars freely replaced by other macronutrients without control for energy). Outcomes were glycated haemoglobin (HbA1c), fasting blood glucose, and fasting blood glucose insulin.

DATA EXTRACTION AND SYNTHESIS

Four independent reviewers extracted relevant data and assessed risk of bias. Data were pooled by random effects models and overall certainty of the evidence assessed by the GRADE approach (grading of recommendations assessment, development, and evaluation).

RESULTS

155 study comparisons (n=5086) were included. Total fructose-containing sugars had no harmful effect on any outcome in substitution or subtraction studies, with a decrease seen in HbA1c in substitution studies (mean difference -0.22% (95% confidence interval to -0.35% to -0.08%), -25.9 mmol/mol (-27.3 to -24.4)), but a harmful effect was seen on fasting insulin in addition studies (4.68 pmol/L (1.40 to 7.96)) and ad libitum studies (7.24 pmol/L (0.47 to 14.00)). There was interaction by food source, with specific food sources showing beneficial effects (fruit and fruit juice) or harmful effects (sweetened milk and mixed sources) in substitution studies and harmful effects (sugars-sweetened beverages and fruit juice) in addition studies on at least one outcome. Most of the evidence was low quality.

CONCLUSIONS

Energy control and food source appear to mediate the effect of fructose-containing sugars on glycaemic control. Although most food sources of these sugars (especially fruit) do not have a harmful effect in energy matched substitutions with other macronutrients, several food sources of fructose-containing sugars (especially sugars-sweetened beverages) adding excess energy to diets have harmful effects. However, certainty in these estimates is low, and more high quality randomised controlled trials are needed.

STUDY REGISTRATION

Clinicaltrials.gov (NCT02716870).

Nuts as a replacement for carbohydrates in the diabetic diet: a reanalysis of a randomised controlled trial

AIMS/HYPOTHESIS

In line with current advice, we assessed the effect of replacing carbohydrate consumption with mixed nut consumption, as a source of unsaturated fat, on cardiovascular risk factors and HbA_1c in type 2 diabetes. The data presented here are from a paper that was retracted at the authors' request ( https://doi.org/10.2337/dc16-rt02 ) owing to lack of adjustment for repeated measures in the same individual. Our aim, therefore, was to fix the error and add new complementary data of interest, including information on clotting factors and LDL particle size.

METHODS

A total of 117 men and postmenopausal women with type 2 diabetes who were taking oral glucose-lowering agents and with HbA_1c between 47.5 and 63.9 mmol/mol (6.5-8.0%) were randomised after stratification by sex and baseline HbA_1c in a parallel design to one of three diets for 3 months: (1) 'full-dose nut diet' (n = 40): a diet with 2.0 MJ (477 kcal) per 8.4 MJ (2000 kcal) energy provided as mixed nuts (75 g/day); (2) 'full-dose muffin diet' (n = 39): a diet with 1.97 MJ (471 kcal) per 8.4 MJ (2000 kcal) energy provided as three whole-wheat muffins (188 g/day), with a similar protein content to the nuts, and the same carbohydrate-derived energy content as the monounsaturated fatty acid-derived energy content in the nuts; or (3) 'half-dose nut diet' (n = 38): a diet with 1.98 MJ (474 kcal) per 8.4 MJ (2000 kcal) energy provided as half portions of both the nuts and muffins. The primary outcome was change in HbA_1c. The study was carried out in a hospital clinical research centre and concluded in 2008. Only the statistician, study physicians and analytical technicians could be blinded to the group assessment.

RESULTS

A total of 108 participants had post-intervention data available for analysis (full-dose nut group, n = 40; full-dose muffin group, n = 35; half-dose nut group, n = 33). Compared with the full-dose muffin diet, the full-dose nut diet provided 9.2% (95% CI 7.1, 11.3) greater total energy intake from monounsaturated fat. The full-dose nut diet (median intake, 75 g/day) also reduced HbA_1c compared with the full-dose muffin diet by -2.0 mmol/mol (95% CI -3.8, -0.3 mmol/mol) (-0.19% [95% CI -0.35%, -0.02%]), (p = 0.026). Estimated cholesterol levels in LDL particles with a diameter <255 ångström [LDL-c_<255Å]) and apolipoprotein B were also significantly decreased after the full-dose nut diet compared with the full-dose muffin diet. According to the dose response, the full-dose nut diet is predicted to reduce HbA_1c (-2.0 mmol/mol [-0.18%]; p = 0.044), cholesterol (-0.25 mmol/l; p = 0.022), LDL-cholesterol (-0.23 mmol/l; p = 0.019), non-HDL-cholesterol (-0.26 mmol/l; p = 0.020), apolipoprotein B (-0.06 g/l, p = 0.013) and LDL-c<_255Å (-0.42 mmol/l; p < 0.001). No serious study-related adverse events occurred, but one participant on the half-dose nut diet was hospitalised for atrial fibrillation after shovelling snow.

CONCLUSIONS/INTERPRETATION

Nut intake as a replacement for carbohydrate consumption improves glycaemic control and lipid risk factors in individuals with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00410722 FUNDING: The study was funded by the International Tree Nut Council Nutrition Research and Education Foundation, the Peanut Institute, Loblaw Companies and the Canada Research Chairs Program of the Government of Canada.

Overweight and obesity management strategies in survivors of paediatric acute lymphoblastic leukaemia: a systematic review protocol

INTRODUCTION

Acute lymphoblastic leukaemia is the most common paediatric cancer. Survivors of childhood acute lymphoblastic leukaemia (SALL) are at risk of obesity and related cardiometabolic diseases including type 2 diabetes, hypertension, stroke and cardiovascular events. Therefore, it is important to address obesity in this population as this may help mitigate future cardiometabolic comorbidities. In this systematic review, we aim to assess current treatment strategies including lifestyle interventions, pharmacotherapy and bariatric surgery to manage overweight and obesity in SALL.

METHODS AND ANALYSIS

We will search the following databases for primary studies: CINAHL, SPORTDiscus, EMBASE, MEDLINE, PsycINFO, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews. In addition, unpublished primary studies will be searched in ClinicalTrials.gov as well as conference proceedings, presentations, abstracts, editorials and ProQuest Dissertations and Theses A&I. Reviewers will perform title, abstract, and full-text screening as well as data abstraction and risk of bias assessment independently with a third reviewer to be consulted to resolve disagreements. Searches will be run and updated through May 1st, 2018. The overall quality of the evidence will be determined using the Grading of Recommendations, Assessment, Development, and Evaluation criteria for each outcome. A meta-analysis will be performed if two studies deploying similar interventions, populations, and design and outcomes are identified.

ETHICS AND DISSEMINATION

As individual patient data will not be included, we do not require ethics approval. This review will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42016051031.

Effect of Plant Protein on Blood Lipids: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

There is a heightened interest in plant‐based diets for cardiovascular disease prevention. Although plant protein is thought to mediate such prevention through modifying blood lipids, the effect of plant protein in specific substitution for animal protein on blood lipids remains unclear. To assess the effect of this substitution on established lipid targets for cardiovascular risk reduction, we conducted a systematic review and meta‐analysis of randomized controlled trials using the Grading of Recommendations Assessment, Development, and Evaluation system.

Methods and Results

MEDLINE, EMBASE, and the Cochrane Registry were searched through September 9, 2017. We included randomized controlled trials of ≥3 weeks comparing the effect of plant protein in substitution for animal protein on low‐density lipoprotein cholesterol, non–high‐density lipoprotein cholesterol, and apolipoprotein B. Two independent reviewers extracted relevant data and assessed risk of bias. Data were pooled by the generic inverse variance method and expressed as mean differences with 95% confidence intervals. Heterogeneity was assessed (Cochran Q statistic) and quantified (I² statistic). The overall quality (certainty) of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation system. One‐hundred twelve randomized controlled trials met the eligibility criteria. Plant protein in substitution for animal protein decreased low‐density lipoprotein cholesterol by 0.16 mmol/L (95% confidence interval, −0.20 to −0.12 mmol/L; P<0.00001; I²=55%; moderate‐quality evidence), non–high‐density lipoprotein cholesterol by 0.18 mmol/L (95% confidence interval, −0.22 to −0.14 mmol/L; P<0.00001; I²=52%; moderate‐quality evidence), and apolipoprotein B by 0.05 g/L (95% confidence interval, −0.06 to −0.03 g/L; P<0.00001; I²=30%; moderate‐quality evidence).

Conclusions

Substitution of plant protein for animal protein decreases the established lipid targets low‐density lipoprotein cholesterol, non–high‐density lipoprotein cholesterol, and apolipoprotein B. More high‐quality randomized trials are needed to improve our estimates.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02037321.

Does the impact of a plant-based diet during pregnancy on birth weight differ by ethnicity? A dietary pattern analysis from a prospective Canadian birth cohort alliance

OBJECTIVE

Birth weight is an indicator of newborn health and a strong predictor of health outcomes in later life. Significant variation in diet during pregnancy between ethnic groups in high-income countries provides an ideal opportunity to investigate the influence of maternal diet on birth weight.

SETTING

Four multiethnic birth cohorts based in Canada (the NutriGen Alliance).

PARTICIPANTS

3997 full-term mother-infant pairs of diverse ethnic groups who had principal component analysis-derived diet pattern scores-plant-based, Western and health-conscious-and birth weight data.

RESULTS

No associations were identified between the Western and health-conscious diet patterns and birth weight; however, the plant-based dietary pattern was inversely associated with birth weight (β=-67.6 g per 1-unit increase; P<0.001), and an interaction with non-white ethnicity and birth weight was observed. Ethnically stratified analyses demonstrated that among white Europeans, maternal consumption of a plant-based diet associated with lower birth weight (β=-65.9 g per 1-unit increase; P<0.001), increased risk of small-for-gestational age (SGA; OR=1.46; 95% CI 1.08 to 1.54;P=0.005) and reduced risk of large-for-gestational age (LGA; OR=0.71; 95% CI 0.53 to 0.95;P=0.02). Among South Asians, maternal consumption of a plant-based diet associated with a higher birth weight (β=+40.5 g per 1-unit increase; P=0.01), partially explained by cooked vegetable consumption.

CONCLUSIONS

Maternal consumption of a plant-based diet during pregnancy is associated with birth weight. Among white Europeans, a plant-based diet is associated with lower birth weight, reduced odds of an infant born LGA and increased odds of SGA, whereas among South Asians living in Canada, a plant-based diet is associated with increased birth weight.

The effects of various diets on glycemic outcomes during pregnancy: A systematic review and network meta-analysis

Aims

Evidence to support dietary modifications to improve glycemia during pregnancy is limited, and the benefits of diet beyond limiting gestational weight gain is unclear. Therefore, a systematic review and network meta-analysis of randomized trials was conducted to compare the effects of various common diets, stratified by the addition of gestational weight gain advice, on fasting glucose and insulin, hemoglobin A1c (Hb_A1c), and homeostatic model assessment for insulin resistance (HOMA-IR) in pregnant women.

Methods

MEDLINE, EMBASE, Cochrane database, and reference lists of published studies were searched through April 2017. Randomized trials directly comparing two or more diets for ≥2-weeks were eligible. Bayesian network meta-analysis was performed for fasting glucose. Owing to a lack of similar dietary comparisons, a standard pairwise meta-analysis for the other glycemic outcomes was performed. The certainty of the pooled effect estimates was assessed using the GRADE tool.

Results

Twenty-one trials (1,865 participants) were included. In general, when given alongside gestational weight gain advice, fasting glucose improved in most diets compared to diets that gave gestational weight gain advice only. However, fasting glucose increased in high unsaturated or monounsaturated fatty acids diets. In the absence of gestational weight gain advice, fasting glucose improved in DASH-style diets compared to standard of care. Although most were non-significant, similar trends were observed for these same diets for the other glycemic outcomes. Dietary comparisons ranged from moderate to very low in quality of evidence.

Conclusion/Interpretation

Alongside with gestational weight gain advice, most diets, with the exception of a high unsaturated or a high monounsaturated fatty acid diet, demonstrated a fasting glucose improvement compared with gestational weight gain advice only. When gestational weight gain advice was not given, the DASH-style diet appeared optimal on fasting glucose. However, a small number of trials were identified and most dietary comparisons were underpowered to detect differences in glycemic outcomes. Further studies that are high in quality and adequately powered are needed to confirm these findings.

Registration

PROSPERO CRD42015026008

Effect of Current Dietary Recommendations on Weight Loss and Cardiovascular Risk Factors

BACKGROUND

Dietary recommendations emphasize increased consumption of fruit, vegetables, and whole grain cereals for prevention of chronic disease.

OBJECTIVES

This study assessed the effect of dietary advice and/or food provision on body weight and cardiovascular disease risk factors.

METHODS

Healthy overweight men (n = 209) and women (n = 710), mean age 44.7 years, body mass index [BMI] 32.4 kg/m², were randomized between November 2005 and August 2009 to receive Health Canada's food guide (control, n = 486) or 1 of 3 interventions: dietary advice consistent with both Dietary Approaches to Stop Hypertension (DASH) and dietary portfolio principles (n = 145); weekly food provision reflecting this advice (n = 148); or food delivery plus advice (n = 140). Interventions lasted 6 months with 12-month follow-up. Semiquantitative food frequency questionnaires and fasting blood, anthropometric and blood pressure measurements were obtained at baseline, 6 months, and 18 months.

RESULTS

Participant retention at 6 and 18 months was 91% and 81%, respectively, after food provision compared to 67% and 57% when no food was provided (p < 0.0001). Test and control treatments showed small reductions in body weight (-0.8 to -1.2 kg), waist circumference (-1.1 to -1.9 cm), and mean arterial pressure (0.0 to -1.1 mm Hg) at 6 months and Framingham coronary heart disease risk score at 18 months (-0.19 to -0.42%), which were significant overall. Outcomes did not differ among test and control groups.

CONCLUSIONS

Provision of foods increased retention but only modestly increased intake of recommended foods. Current dietary recommendations showed small overall benefits in coronary heart disease risk factors. Additional dietary strategies to maximize these benefits are required. (Fruits, Vegetables, and Whole Grains: A Community-based Intervention; NCT00516620).

Relation of total sugars, fructose and sucrose with incident type 2 diabetes: a systematic review and meta-analysis of prospective cohort studies

BACKGROUND

Sugar-sweetened beverages are associated with type 2 diabetes. To assess whether this association holds for the fructose-containing sugars they contain, we conducted a systematic review and meta-analysis of prospective cohort studies.

METHODS

We searched MEDLINE, Embase, CINAHL and the Cochrane Library (through June 2016). We included prospective cohort studies that assessed the relation of fructose-containing sugars with incident type 2 diabetes. Two independent reviewers extracted relevant data and assessed risk of bias. We pooled risk ratios (RRs) using random effects meta-analyses. The overall quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

Fiffeen prospective cohort studies (251 261 unique participants, 16 416 cases) met the eligibility criteria, comparing the highest intake (median 137, 35.2 and 78 g/d) with the lowest intake (median 65, 9.7 and 25.8 g/d) of total sugars, fructose and sucrose, respectively. Although there was no association of total sugars (RR 0.91, 95% confidence interval [CI] 0.76-1.09) or fructose (RR 1.04, 95% CI 0.84-1.29) with type 2 diabetes, sucrose was associated with a decreased risk of type 2 diabetes (RR 0.89, 95% CI 0.80-0.98). Our confidence in the estimates was limited by evidence of serious inconsistency between studies for total sugars and fructose, and serious imprecision in the pooled estimates for all 3 sugar categories.

INTERPRETATION

Current evidence does not allow us to conclude that fructose-containing sugars independent of food form are associated with increased risk of type 2 diabetes. Further research is likely to affect our estimates.

TRIAL REGISTRATION

ClinicalTrials.gov, no. NCT01608620.

The effect of alpha-linolenic acid on glycemic control in individuals with type 2 diabetes: A systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND

Polyunsaturated fats (PUFAs) have been shown to reduce type 2 diabetes (T2DM) risk and improve insulin responsiveness in T2DM subjects, but whether the plant sources of omega-3 PUFA (alpha-linolenic acid [ALA]) have an effect on glycemic control requires further investigation.

METHODS

The parameters of interest were glycated hemoglobin (HbA1c), fasting blood glucose (FBG), fasting blood insulin (FBI), homeostatic model assessment for insulin resistance (HOMA-IR), fructosamine, and glycated albumin. A comprehensive search was conducted with MEDLINE, Embase, CINAHL, and Cochrane. Eligible studies included randomized controlled trials (RCTs) ≥1 month in duration that compared diets enriched in ALA with usual diets on glycemic parameters. For each study, the risk of bias as well as the study quality was assessed. Using the statistical software RevMan (v5.3), data were pooled using the generic inverse method with random effects model, and final results were expressed as mean differences (MD) with 95% confidence intervals (CI). Heterogeneity was assessed by the Cochran Q statistic and quantified by the I statistic.

RESULTS

A total of 8 trials (N = 212) were included in the meta-analysis. Compared to a control diet, a median dose of 4.4 g/day of ALA intake for a median duration of 3 months did not affect HbA1c (%) (MD = -.01; [95%: -.32, .31], P = .96). A median ALA dose of 5.4 g/day did not lower FBG (MD = .07; [95% CI: -.61, .76], P = .84) or FBI (MD = 7.03, [95% CI: -5.84, 19.89], P = .28). Summary effect estimates were generally compromised by considerable and unexplained heterogeneity (I ≥75%). In the subgroup analysis of continuous predictors, a reduction in HbA1c (%) and FBG (mmol/L) was significantly associated with an increased intake of ALA. Further adjustment for Publication Bias using Duval and Tweedie's trim-and-fill analysis provided an adjusted, significant MD of -.25 (95% CI: -.38, -.12; P <.001) for HbA1c (%).

CONCLUSIONS

ALA-enriched diets did not affect HbA1c, FBG, or FBI. The scarce number of existing RCTs and the presence of heterogeneity in our meta-analysis limit the ability to make firm conclusions about ALA in T2DM management. The potential for ALA to have dose-dependent effects warrants further research in this area.

Ethnic and diet-related differences in the healthy infant microbiome

Background

The infant gut is rapidly colonized by microorganisms soon after birth, and the composition of the microbiota is dynamic in the first year of life. Although a stable microbiome may not be established until 1 to 3 years after birth, the infant gut microbiota appears to be an important predictor of health outcomes in later life.

Methods

We obtained stool at one year of age from 173 white Caucasian and 182 South Asian infants from two Canadian birth cohorts to gain insight into how maternal and early infancy exposures influence the development of the gut microbiota. We investigated whether the infant gut microbiota differed by ethnicity (referring to groups of people who have certain racial, cultural, religious, or other traits in common) and by breastfeeding status, while accounting for variations in maternal and infant exposures (such as maternal antibiotic use, gestational diabetes, vegetarianism, infant milk diet, time of introduction of solid food, infant birth weight, and weight gain in the first year).

Results

We demonstrate that ethnicity and infant feeding practices independently influence the infant gut microbiome at 1 year, and that ethnic differences can be mapped to alpha diversity as well as a higher abundance of lactic acid bacteria in South Asians and a higher abundance of genera within the order Clostridiales in white Caucasians.

Conclusions

The infant gut microbiome is influenced by ethnicity and breastfeeding in the first year of life. Ethnic differences in the gut microbiome may reflect maternal/infant dietary differences and whether these differences are associated with future cardiometabolic outcomes can only be determined after prospective follow-up.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-017-0421-5) contains supplementary material, which is available to authorized users.

Adiposity in childhood brain tumors: A report from the Canadian Study of Determinants of Endometabolic Health in Children (CanDECIDE Study)

Children with brain tumors (CBT) are at high risk of cardiovascular diseases and type 2 diabetes compared to the general population. Recently, adiposity has been reported to be more informative for cardiometabolic risk stratification than body mass index (BMI) in the general population. The goal of this study is to describe the adiposity phenotype in CBT, and to establish adiposity determinants. We recruited CBT (n = 56) and non-cancer controls (n = 106). Percent body fat (%FM), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were measured to determine total and central adiposity, respectively. Regression analyses were used to evaluate adiposity determinants. CBT had higher total and central adiposity compared to non-cancer controls despite having similar BMI measurements. Those with tumors at the supratentorial region had increased total and central adiposity, while those who received radiotherapy had increased total adiposity. In conclusion, CBT have increased total and central adiposity in the presence of similar BMI levels when compared to non-cancer controls. Adiposity, especially central adiposity, is a potential cardiometabolic risk factor present relatively early in life in CBT. Defining interventions to target adiposity may improve long-term outcomes by preventing cardiometabolic disorders in CBT.

Cross-sectional associations between dietary intake and carotid intima media thickness in type 2 diabetes: baseline data from a randomised trial

OBJECTIVE

To assess associations between dietary intake and carotid intima media thickness (CIMT) by carotid ultrasound (CUS), a surrogate marker of cardiovascular disease (CVD) risk, in those with type 2 diabetes.

DESIGN

Cross-sectional analysis of baseline data from 325 participants from three randomised controlled trials collected in the same way.

SETTING

Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Canada.

PARTICIPANTS

325 participants with type 2 diabetes, taking oral antidiabetic agents, with an HbA1c between 6.5% and 8.0% at screening, without a recent cardiovascular event.

MAIN OUTCOME MEASURES

CIMT by CUS and associations with dietary intake from 7-day food records, as well as anthropometric measures and fasting serum samples.

RESULTS

CIMT was significantly inversely associated with dietary pulse intake (β=-0.019, p=0.009), available carbohydrate (β=-0.004, p=0.008), glycaemic load (β=-0.001, p=0.007) and starch (β=-0.126, p=0.010), and directly associated with total (β=0.004, p=0.028) and saturated (β=0.012, p=0.006) fat intake in multivariate regression models adjusted for age, smoking, previous CVD event, blood pressure medication, antidiabetic medication and ultrasonographer.

CONCLUSIONS

Lower CIMT was significantly associated with greater consumption of dietary pulses and carbohydrates and lower total and saturated fat intake, suggesting a potential role for diet in CVD risk management in type 2 diabetes. Randomised controlled trials are anticipated to explore these associations further.

TRIAL REGISTRATION NUMBER

NCT01063374.

Evaluating overweight and obesity prevalence in survivors of childhood brain tumors: a systematic review protocol

BACKGROUND

Overweight and obesity are well-known risk factors for cardiometabolic diseases including hypertension, myocardial infarction, stroke, and type 2 diabetes in the general population. Survivors of childhood brain tumors (SCBT) are at risk of premature mortality, and recent evidence suggests that these cardiometabolic diseases are potential emerging determinants of survival and quality of life. Therefore, the rates of overweight and obesity in this population need to be examined to assess their impact on outcomes. The objective of this systematic review is to examine the prevalence of overweight and obesity in SCBT. The secondary aim of this review is to evaluate whether SCBT have higher adiposity compared to the general population.

METHODS

Searches will be conducted in MEDLINE, CINAHL, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, PubMed, and Database of Abstracts of Reviews of Effect. For gray literature, we will search ProQuest Dissertations and Theses A&I and Web of Science. Two reviewers will independently screen all articles against predetermined eligibility criteria and complete data abstraction, risk of bias, and quality assessments. The primary outcome includes the prevalence of overweight or obesity. The secondary outcomes involve waist-to-hip ratio, waist-to-height ratio, body fat percentage, and skinfold thickness. Meta-analysis will be performed when two or more studies with similar design, populations, and outcomes are available.

DISCUSSION

This review will summarize current data on the prevalence of overweight and obesity in SCBT. This will help the development of an understanding of the scale of overweight and obesity in this population and guide the design of interventions that will improve outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016051035.

Harmonization of Food-Frequency Questionnaires and Dietary Pattern Analysis in 4 Ethnically Diverse Birth Cohorts

BACKGROUND

Canada is an ethnically diverse nation, which introduces challenges for health care providers tasked with providing evidence-based dietary advice.

OBJECTIVES

We aimed to harmonize food-frequency questionnaires (FFQs) across 4 birth cohorts of ethnically diverse pregnant women to derive robust dietary patterns to investigate maternal and newborn outcomes.

METHODS

The NutriGen Alliance comprises 4 prospective birth cohorts and includes 4880 Canadian mother-infant pairs of predominantly white European [CHILD (Canadian Healthy Infant Longitudinal Development) and FAMILY (Family Atherosclerosis Monitoring In earLY life)], South Asian [START (SouTh Asian birth cohoRT)-Canada], or Aboriginal [ABC (Aboriginal Birth Cohort)] origins. CHILD used a multiethnic FFQ based on a previously validated instrument designed by the Fred Hutchinson Cancer Research Center, whereas FAMILY, START, and ABC used questionnaires specifically designed for use in white European, South Asian, and Aboriginal people, respectively. The serving sizes and consumption frequencies of individual food items within the 4 FFQs were harmonized and aggregated into 36 common food groups. Principal components analysis was used to identify dietary patterns that were internally validated against self-reported vegetarian status and externally validated against a modified Alternative Healthy Eating Index (mAHEI).

RESULTS

Three maternal dietary patterns were identified-"plant-based," "Western," and "health-conscious"-which collectively explained 29% of the total variability in eating habits observed in the NutriGen Alliance. These patterns were strongly associated with self-reported vegetarian status (OR: 3.85; 95% CI: 3.47, 4.29; r² = 0.30, P < 0.001; for a plant-based diet), and average adherence to the plant-based diet was higher in participants in the fourth quartile of the mAHEI than in the first quartile (mean difference: 46.1%; r² = 0.81, P < 0.001).

CONCLUSION

Dietary data collected by using FFQs from ethnically diverse pregnant women can be harmonized to identify common dietary patterns to investigate associations between maternal dietary intake and health outcomes.

Fructose intake and risk of gout and hyperuricemia: a systematic review and meta-analysis of prospective cohort studies

BACKGROUND

The prevalence of hyperuricemia and gout has increased in recent decades. The role of dietary fructose in the development of these conditions remains unclear.

OBJECTIVE

To conduct a systematic review and meta-analysis of prospective cohort studies investigating the association fructose consumption with incident gout and hyperuricemia.

DESIGN

MEDLINE, EMBASE and the Cochrane Library were searched (through September 2015). We included prospective cohort studies that assessed fructose consumption and incident gout or hyperuricemia. 2 independent reviewers extracted relevant data and assessed study quality using the Newcastle-Ottawa Scale. We pooled natural-log transformed risk ratios (RRs) using the generic inverse variance method. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I² statistic). The overall quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

2 studies involving 125 299 participants and 1533 cases of incident gout assessed the association between fructose consumption and incident gout over an average of 17 years of follow-up. No eligible studies assessed incident hyperuricemia as an outcome. Fructose consumption was associated with an increase in the risk of gout (RR=1.62, 95% CI 1.28 to 2.03, p<0.0001) with no evidence of interstudy heterogeneity (I²=0%, p=0.33) when comparing the highest (>11.8% to >11.9% total energy) and lowest (<6.9% to <7.5% total energy) quantiles of consumption.

LIMITATIONS

Despite a dose-response gradient, the overall quality of evidence as assessed by GRADE was low, due to indirectness. There were only two prospective cohort studies involving predominantly white health professionals that assessed incident gout, and none assessed hyperuricemia.

CONCLUSIONS

Fructose consumption was associated with an increased risk of developing gout in predominantly white health professionals. More prospective studies are necessary to understand better the role of fructose and its food sources in the development of gout and hyperuricemia.

PROTOCOL REGISTRATION NUMBER

NCT01608620.

Low-glycaemic index diet to improve glycaemic control and cardiovascular disease in type 2 diabetes: design and methods for a randomised, controlled, clinical trial

INTRODUCTION

Type 2 diabetes (T2DM) produces macrovascular and microvascular damage, significantly increasing the risk of cardiovascular disease (CVD), renal failure and blindness. As rates of T2DM rise, the need for effective dietary and other lifestyle changes to improve diabetes management become more urgent. Low-glycaemic index (GI) diets may improve glycaemic control in diabetes in the short term; however, there is a lack of evidence on the long-term adherence to low-GI diets, as well as on the association with surrogate markers of CVD beyond traditional risk factors. Recently, advances have been made in measures of subclinical arterial disease through the use of MRI, which, along with standard measures from carotid ultrasound (CUS) scanning, have been associated with CVD events. We therefore designed a randomised, controlled, clinical trial to assess whether low-GI dietary advice can significantly improve surrogate markers of CVD and long-term glycaemic control in T2DM.

METHODS AND ANALYSIS

169 otherwise healthy individuals with T2DM were recruited to receive intensive counselling on a low-GI or high-cereal fibre diet for 3 years. To assess macrovascular disease, MRI and CUS are used, and to assess microvascular disease, retinal photography and 24-hour urinary collections are taken at baseline and years 1 and 3. Risk factors for CVD are assessed every 3 months.

ETHICS AND DISSEMINATION

The study protocol and consent form have been approved by the research ethics board of St. Michael's Hospital. If the study shows a benefit, these data will support the use of low-GI and/or high-fibre foods in the management of T2DM and its complications.

TRIAL REGISTRATION NUMBER

NCT01063374; Pre-results.

Association Between Artificially Sweetened Beverage Consumption During Pregnancy and Infant Body Mass Index

IMPORTANCE

The consumption of artificial sweeteners has increased substantially in recent decades, including among pregnant women. Animal studies suggest that exposure to artificial sweeteners in utero may predispose offspring to develop obesity; however, to our knowledge, this has never been studied in humans.

OBJECTIVE

To determine whether maternal consumption of artificially sweetened beverages during pregnancy is associated with infant body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]).

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included 3033 mother-infant dyads from the Canadian Healthy Infant Longitudinal Development (CHILD) Study, a population-based birth cohort that recruited healthy pregnant women from 2009 to 2012. Women completed dietary assessments during pregnancy, and their infants' BMI was measured at 1 year of age (n = 2686; 89% follow-up). Statistical analysis for this study used data collected after the first year of follow-up, which was completed in October 2013. The data analysis was conducted in August 2015.

EXPOSURES

Maternal consumption of artificially sweetened beverages and sugar-sweetened beverages during pregnancy, determined by a food frequency questionnaire.

MAIN OUTCOMES AND MEASURES

Infant BMI z score and risk of overweight at 1 year of age, determined from objective anthropometric measurements and defined according to World Health Organization reference standards.

RESULTS

The mean (SD) age of the 3033 pregnant women was 32.4 (4.7) years, and their mean (SD) BMI was 24.8 (5.4). The mean (SD) infant BMI z score at 1 year of age was 0.19 (1.05), and 5.1% of infants were overweight. More than a quarter of women (29.5%) consumed artificially sweetened beverages during pregnancy, including 5.1% who reported daily consumption. Compared with no consumption, daily consumption of artificially sweetened beverages was associated with a 0.20-unit increase in infant BMI z score (adjusted 95% CI, 0.02-0.38) and a 2-fold higher risk of infant overweight at 1 year of age (adjusted odds ratio, 2.19; 95% CI, 1.23-3.88). These effects were not explained by maternal BMI, diet quality, total energy intake, or other obesity risk factors. There were no comparable associations for sugar-sweetened beverages.

CONCLUSIONS AND RELEVANCE

To our knowledge, we provide the first human evidence that maternal consumption of artificial sweeteners during pregnancy may influence infant BMI. Given the current epidemic of childhood obesity and widespread use of artificial sweeteners, further research is warranted to confirm our findings and investigate the underlying biological mechanisms, with the ultimate goal of informing evidence-based dietary recommendations for pregnant women.

Probiotic supplementation can positively affect anxiety and depressive symptoms: a systematic review of randomized controlled trials

Gastrointestinal microbiota, consisting of microbial communities in the gastrointestinal tract, play an important role in digestive, metabolic, and immune functioning. Preclinical studies on rodents have linked behavioral and neurochemical changes in the central nervous system with deficits or alterations in these bacterial communities. Moreover, probiotic supplementation in rodents has been shown to markedly change behavior, with correlated changes in central neurochemistry. While such studies have documented behavioral and mood-related supplementation effects, the significance of these effects in humans, especially in relation to anxiety and depression symptoms, are relatively unknown. Thus, the purpose of this paper was to systematically evaluate current literature on the impact of probiotic supplementation on anxiety and depression symptoms in humans. To this end, multiple databases, including Medline, PsycINFO, PubMed, Scopus, and Web of Science were searched for randomized controlled trials published between January 1990 and January 2016. Search results led to a total of 10 randomized controlled trials (4 in clinically diagnosed and 6 in non-clinical samples) that provided limited support for the use of some probiotics in reducing human anxiety and depression. Despite methodological limitations of the included trials and the complex nature of gut-brain interactions, results suggest the detection of apparent psychological benefits from probiotic supplementation. Nevertheless a better understanding of developmental, modulatory, and metagenomic influences on the GI microbiota, specifically as they relate to mood and mental health, represent strong priorities for future research in this area.

The effectiveness of interventions to treat obesity in survivors of childhood brain tumors: a systematic review protocol

BACKGROUND

Pediatric brain tumors are the most common solid tumors in children. Advances in understanding the hallmarks of cancer biology and novel therapies have led to an increasing number of survivors of childhood brain tumors (SCBT). However, these survivors are at an increased risk of obesity and cardiometabolic disorders that affect their quality of life and lifespan. It is important to define effective strategies to treat and prevent obesity in this population. This systematic review aims to investigate the effectiveness of lifestyle interventions, pharmacotherapy, and bariatric surgery on treating obesity in SCBT.

METHODS

Searches will be conducted in PubMed, MEDLINE, EMBASE, PsycINFO, SPORTDiscus, CINAHL, Cochrane Database of Systematic Review, Cochrane Central Register of Controlled Trials (CENTRAL), and Database of Abstracts of Reviews of Effect (DARE). In addition, ClinicalTrials.gov and ProQuest Dissertations and Theses A&I will be searched to identify relevant gray literature. The reference lists of eligible articles will be searched for additional studies. All screening, quality assessment, and data abstraction will be done independently by two reviewers. We will perform meta-analysis if there are sufficient studies.

DISCUSSION

This review will summarize evidence for the effectiveness of interventions used to reduce obesity risk in SCBT. This has significant implications for SCBT, as it can identify gaps in knowledge and provide insights into the development of new interventions to manage obesity in survivors, which may improve their outcomes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015025909.

Effects of dietary pulse consumption on body weight: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Obesity is a risk factor for developing several diseases, and although dietary pulses (nonoil seeds of legumes such as beans, lentils, chickpeas, and dry peas) are well positioned to aid in weight control, the effects of dietary pulses on weight loss are unclear.

OBJECTIVE

We summarized and quantified the effects of dietary pulse consumption on body weight, waist circumference, and body fat by conducting a systematic review and meta-analysis of randomized controlled trials.

DESIGN

We searched the databases MEDLINE, Embase, CINAHL, and the Cochrane Library through 11 May 2015 for randomized controlled trials of ≥3 wk of duration that compared the effects of diets containing whole dietary pulses with those of comparator diets without a dietary pulse intervention. Study quality was assessed by means of the Heyland Methodologic Quality Score, and risk of bias was assessed with the Cochrane Risk of Bias tool. Data were pooled with the use of generic inverse-variance random-effects models.

RESULTS

Findings from 21 trials (n = 940 participants) were included in the meta-analysis. The pooled analysis showed an overall significant weight reduction of -0.34 kg (95% CI: -0.63, -0.04 kg; P = 0.03) in diets containing dietary pulses (median intake of 132 g/d or ∼1 serving/d) compared with diets without a dietary pulse intervention over a median duration of 6 wk. Significant weight loss was observed in matched negative-energy-balance (weight loss) diets (P = 0.02) and in neutral-energy-balance (weight-maintaining) diets (P = 0.03), and there was low evidence of between-study heterogeneity. Findings from 6 included trials also suggested that dietary pulse consumption may reduce body fat percentage.

CONCLUSIONS

The inclusion of dietary pulses in a diet may be a beneficial weight-loss strategy because it leads to a modest weight-loss effect even when diets are not intended to be calorically restricted. Future studies are needed to determine the effects of dietary pulses on long-term weight-loss sustainability. This protocol was registered at clinicaltrials.gov as NCT01594567.

Best (but oft-forgotten) practices: sensitivity analyses in randomized controlled trials

A randomized controlled clinical trial is the best way to minimize bias in ascertaining treatment effects, but the credibility of the results of a trial depends on the validity of the methods used to analyze the data, and the conditions under which such methods produce valid answers. A sensitivity analysis is a method to determine the robustness of trial findings by examining the extent to which results are affected by changes in methods, models, values of unmeasured variables, or assumptions. The goal of a sensitivity analysis is to identify results that are most dependent on questionable or unsupported assumptions. In this article, we briefly review the current use of sensitivity analyses in a random sample of published nutrition literature and provide a guide on the use of sensitivity analyses in randomized trials as to when to consider them, what to consider when planning them, and different methods of implementing them. We propose an 8-step strategy for improving the approach to conducting and reporting sensitivity analyses in nutrition-based trials.

Effect of Replacing Animal Protein with Plant Protein on Glycemic Control in Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Previous research on the effect of replacing sources of animal protein with plant protein on glycemic control has been inconsistent. We therefore conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the effect of this replacement on glycemic control in individuals with diabetes. We searched MEDLINE, EMBASE, and Cochrane databases through 26 August 2015. We included RCTs ≥ 3-weeks comparing the effect of replacing animal with plant protein on HbA1c, fasting glucose (FG), and fasting insulin (FI). Two independent reviewers extracted relevant data, assessed study quality and risk of bias. Data were pooled by the generic inverse variance method and expressed as mean differences (MD) with 95% confidence intervals (CIs). Heterogeneity was assessed (Cochran Q-statistic) and quantified (I²-statistic). Thirteen RCTs (n = 280) met the eligibility criteria. Diets emphasizing a replacement of animal with plant protein at a median level of ~35% of total protein per day significantly lowered HbA1c (MD = -0.15%; 95%-CI: -0.26, -0.05%), FG (MD = -0.53 mmol/L; 95%-CI: -0.92, -0.13 mmol/L) and FI (MD = -10.09 pmol/L; 95%-CI: -17.31, -2.86 pmol/L) compared with control arms. Overall, the results indicate that replacing sources of animal with plant protein leads to modest improvements in glycemic control in individuals with diabetes. Owing to uncertainties in our analyses there is a need for larger, longer, higher quality trials.

TRIAL REGISTRATION

ClinicalTrials.gov registration number: NCT02037321.

Food Consumption and its Impact on Cardiovascular Disease: Importance of Solutions Focused on the Globalized Food System: A Report From the Workshop Convened by the World Heart Federation

Major scholars in the field, on the basis of a 3-day consensus, created an in-depth review of current knowledge on the role of diet in cardiovascular disease (CVD), the changing global food system and global dietary patterns, and potential policy solutions. Evidence from different countries and age/race/ethnicity/socioeconomic groups suggesting the health effects studies of foods, macronutrients, and dietary patterns on CVD appear to be far more consistent though regional knowledge gaps is highlighted. Large gaps in knowledge about the association of macronutrients to CVD in low- and middle-income countries particularly linked with dietary patterns are reviewed. Our understanding of foods and macronutrients in relationship to CVD is broadly clear; however, major gaps exist both in dietary pattern research and ways to change diets and food systems. On the basis of the current evidence, the traditional Mediterranean-type diet, including plant foods and emphasis on plant protein sources provides a well-tested healthy dietary pattern to reduce CVD.