Maternal intake of fried foods and risk of gestational diabetes mellitus

Potato Intake and the Risk of Overweight/Obesity, Hypertension, Diabetes, and Cardiovascular Disease: A Systematic Review and Meta-analysis of Observational Studies

CONTEXT

Results from observational studies and meta-analyses examining the relationship between total, fried, and nonfried potato intake and cardiometabolic disease remain conflicted.

OBJECTIVE

The aim was to synthesize existing evidence on the relationships between total potato intake and specific types of potato intake with the risk of overweight/obesity, hypertension, diabetes, gestational diabetes mellitus (GDM), cardiovascular disease (CVD), coronary heart disease (CHD), and stroke.

DATA SOURCES

Systematic searches were conducted in PubMed, Embase, and Web of Science until July 13, 2023.

DATA EXTRACTION

Data extracted from studies included first author, publication year, location, data source, follow-up duration (cohort studies only), demographics, sample size, cases, outcomes, exposure and outcome types, measurements, adjustments, study design, potato intake categories, and adjusted risk estimates (odds ratio, relative risk [RR], hazard ratio) with 95% CIs.

DATA ANALYSIS

Random-effects models were applied to estimate the summary RRs and 95% CIs.

RESULTS

Fifty-one articles (103 studies) were identified in the current meta-analysis. Comparing the highest with the lowest categories of total potato intake, total potato intake was not associated with hypertension (summary RR = 1.07; 95% CI: 0.95, 1.21), diabetes (1.08; 95% CI: 0.96, 1.22), GDM (1.16; 95% CI: 0.86, 1.57), CHD (1.00; 95% CI: 0.99, 1.02), CVD (0.97; 95% CI: 0.91, 1.03), or stroke (0.97; 95% CI: 0.88, 1.06); fried potato intake was not associated with overweight/obesity (1.24; 95% CI: 0.90, 1.70) or GDM (1.03; 95% CI: 0.97, 1.09) but was significantly associated with increased diabetes risk (1.16; 95% CI: 1.04, 1.30); nonfried potato intake was significantly associated with increased diabetes risk (1.05; 95% CI: 1.01, 1.10) but not hypertension (1.06; 95% CI: 0.97, 1.15).

CONCLUSION

Total potato intake was not associated with an increased risk of hypertension, diabetes, GDM, or cardiometabolic disease, but both fried and nonfried potato intake may increase the risk of diabetes but not other cardiometabolic diseases. Future cohort studies are needed to explore the association between different types of potato intake and cardiometabolic disease. In addition, the limited number of studies on total potato intake and overweight/obesity/heart failure, fried potato intake and CHD/stroke/heart failure, and nonfried potato intake and overweight/obesity/GDM/CHD/CVD/heart failure prevented us from conducting an analysis.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. RD42023454244.

Data Mining of Infertility and Factors Influencing Its Development: A Finding From a Prospective Cohort Study of RaNCD in Iran

Background and Aims

Infertility, as defined by the World Health Organization, is the inability to conceive after 12 months of regular, unprotected intercourse. This study aimed to identify factors influencing infertility by applying data mining techniques, specifically rule-mining methods, to analyze diverse patient data and uncover relevant insights. This approach involves a thorough analysis of patients' clinical characteristics, dietary habits, and overall conditions to identify complex patterns and relationships that may contribute to infertility.

Methods

In this study, we examined the impact of lifestyle factors on infertility using machine learning and data mining techniques, specifically Association Rules. The study included a total of 4437 women who participated in the Ravansar Non-Communicable Disease Cohort study. Among the remaining participants, 434 were infertile. We utilized 38 variables to generate the relevant association rules.

Results

As a result, the analysis reveals that 97% of infertile women are likely to cook for more than 2 h and engage in standing activities. Additionally, 94% of infertile women are likely to have central obesity. Infertile women also have a 73% chance of reusing cooking oil and a 74% chance of consuming fried food at least once a week. The likelihood of infertility increases to 98% among women who use more than 24 eggs per month and to 97% among those who consume moldy jam or syrup. The evaluation of these associations was further supported by measures of support, confidence, and lift.

Conclusion

This study showed that key lifestyle factors linked to infertility, underscoring the role of lifestyle in reproductive health. These findings suggest that targeted interventions and lifestyle changes may help reduce infertility rates. Further research is needed to confirm these associations and investigate the underlying mechanisms.

Dose-response association between animal protein sources and risk of gestational diabetes mellitus: a systematic review and meta-analysis

CONTEXT

There are contradictory findings about the relationship between various animal protein sources and the risk of gestational diabetes mellitus (GDM).

OBJECTIVE

The purpose of our study was to understand better the associations between total protein, animal protein, and animal protein sources and the risk of developing GDM.

DATA SOURCES

A systematic literature search was conducted in PubMed, Scopus, and Web of Science encompassing the literature up until August 2022. A random-effects model was used to combine the data. For estimating the dose-response curves, a one-stage linear mixed-effects meta-analysis was conducted.

DATA EXTRACTION

Data related to the association between animal protein consumption and the risk of GDM in the general population was extracted from prospective cohort studies.

DATA ANALYSIS

It was determined that 17 prospective cohort studies with a total of 49 120 participants met the eligibility criteria. It was concluded with high certainty of evidence that there was a significant association between dietary animal protein intake and GDM risk (1.94, 95% CI 1.42 to 2.65, n = 6). Moreover, a higher intake of total protein, total meat, and red meat was positively and significantly associated with an increased risk of GDM. The pooled relative risks of GDM were 1.50 (95% CI: 1.16, 1.94; n = 3) for a 30 g/d increment in processed meat, 1.68 (95% CI: 1.25, 2.24; n = 2) and 1.94 (95% CI: 1.41, 2.67; n = 4) for a 100 g/d increment in total and red meat, and 1.21 (95% CI: 1.10, 1.33; n = 4) and 1.32 (95% CI: 1.15, 1.52; n = 3) for a 5% increment in total protein and animal protein, respectively. GDM had a positive linear association with total protein, animal protein, total meat consumption, and red meat consumption, based on non-linear dose-response analysis.

CONCLUSION

Overall, consuming more animal protein-rich foods can increase the risk of GDM. The results from the current study need to be validated by other, well-designed prospective studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022352303.

The association between ultra-processed food and common pregnancy adverse outcomes: a dose-response systematic review and meta-analysis

OBJECTIVES

Given the increasing incidence of negative outcomes during pregnancy, our research team conducted a dose-response systematic review and meta-analysis to investigate the relationship between ultra-processed foods (UPFs) consumption and common adverse pregnancy outcomes including gestational diabetes mellitus (GDM), preeclampsia (PE), preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA) infants. UPFs are described as formulations of food substances often modified by chemical processes and then assembled into ready-to-consume hyper-palatable food and drink products using flavors, colors, emulsifiers, and other cosmetic additives. Examples include savory snacks, reconstituted meat products, frozen meals that have already been made, and soft drinks.

METHODS

A comprehensive search was performed using the Scopus, PubMed, and Web of Science databases up to December 2023. We pooled relative risk (RR) and 95% confidence intervals (CI) using a random-effects model.

RESULTS

Our analysis (encompassing 54 studies with 552,686 individuals) revealed a significant association between UPFs intake and increased risks of GDM (RR = 1.19; 95% CI: 1.10, 1.27; I2 = 77.5%; p < 0.001; studies = 44; number of participants = 180,824), PE (RR = 1.28; 95% CI: 1.03, 1.59; I2 = 80.0%; p = 0.025; studies = 12; number of participants = 54,955), while no significant relationships were found for PTB, LBW and SGA infants. Importantly, a 100 g increment in UPFs intake was related to a 27% increase in GDM risk (RR = 1.27; 95% CI: 1.07, 1.51; I2 = 81.0%; p = 0.007; studies = 9; number of participants = 39,812). The non-linear dose-response analysis further indicated a positive, non-linear relationship between UPFs intake and GDM risk Pnonlinearity = 0.034, Pdose-response = 0.034), although no such relationship was observed for PE (Pnonlinearity = 0.696, Pdose-response = 0.812).

CONCLUSION

In summary, both prior to and during pregnancy, chronic and excessive intake of UPFs is associated with an increased risk of GDM and PE. However, further observational studies, particularly among diverse ethnic groups with precise UPFs consumption measurement tools, are imperative for a more comprehensive understanding.

The Role of the Glycemic Index and Glycemic Load in the Dietary Approach of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a common metabolic disorder that often develops during pregnancy, characterized by glucose intolerance and insulin resistance (IR). To ensure the well-being of both the mother and the fetus, the body undergoes multiple metabolic and immunological changes that result in peripheral IR and, under certain hereditary or acquired abnormalities, GDM in predisposed women. The adverse short- and long-term effects of GDM impact both the mother and the fetus. Nutrition seems to play an important role to prevent GDM or improve its evolution. An emphasis has been given to the proportion of carbohydrates (CHO) relative to protein and lipids, as well as dietary patterns, in GDM. The effects of CHO on postprandial glucose concentrations are reflected in the glycemic index (GI) and glycemic load (GL). Diets rich in GI and GL may induce or exacerbate IR, whereas diets low in GI and GL appear to enhance insulin sensitivity and improve glycemic control. These positive outcomes may be attributed to direct interactions with insulin and glucose homeostasis or indirect effects through improved body composition and weight management. This comprehensive narrative review aims to explore the significance of nutrition, with a focus on the critical evaluation of GI and GL in the dietary management of women with GDM.

The Importance of Metabolic and Environmental Factors in the Occurrence of Oxidative Stress during Pregnancy

Metabolic changes in pregnant women begin in the first weeks after conception under the influence of placental hormones that affect the metabolism of all nutrients. An increased concentration of total lipids accompanies pregnancy and an increased accumulation of triglycerides in low-density lipoproteins (LDL) particles. Lipids in small dense LDL particles are more susceptible to oxidative modification than normal-density LDL particles. Unlike LDL high-density lipoproteins (HDL), lipoprotein particles have an atheroprotective role in lipid metabolism. The very growth of the fetus depends on the nutrition of both parents, so obesity is not only in the mother but also in the father. Nutritional programming of the offspring occurs through changes in lipid metabolism and leads to an increased risk for cardiometabolic diseases. Pregnancy is accompanied by an increased need for oxygen in the mitochondria of the placenta and a tendency to develop oxidative stress. Oxidative stress represents a disturbance in the balance of oxidation-reduction processes in the body that occurs due to the excessive production of free oxygen radicals that cellular homeostatic mechanisms are unable to neutralize. When the balance with the antioxidant system is disturbed, which happens when free oxygen radicals are in high concentrations, serious damage to biological molecules occurs, resulting in a series of pathophysiological and pathological changes, including cell death. Therefore, oxidative stress plays a significant role in the pathogenesis of many complications that can occur during pregnancy. The oxidative status of pregnant women is also influenced by socioeconomic living conditions, lifestyle habits, diet, smoking, and exposure to environmental air pollution. During a healthy pregnancy, the altered lipid profile and oxidative stress create an increased risk for premature birth and pregnancy-related diseases, and a predisposition to adult diseases.

Higher Global Diet Quality Score Is Inversely Associated with Risk of Type 2 Diabetes in US Women

BACKGROUND

We have developed a diet quality metric intended for global use. To assess its utility in high-income settings, an evaluation of its ability to predict chronic disease is needed.

OBJECTIVES

We aimed to prospectively examine the ability of the Global Diet Quality Score (GDQS) to predict the risk of type 2 diabetes in the United States, examine potential differences of association by age, and compare the GDQS with other diet quality scores.

METHODS

Health, lifestyle, and diet information was collected from women (n = 88,520) in the Nurses' Health Study II aged 27-44 y at baseline through repeated questionnaires between 1991 and 2017. The overall GDQS consists of 25 food groups. Points are awarded for higher intake of healthy groups and lower intake of unhealthy groups (maximum of 49 points). Multivariable HRs were computed for confirmed type 2 diabetes using proportional hazards models. We also compared the GDQS with the Minimum Diet Diversity score for Women (MDD-W) and the Alternate Healthy Eating Index-2010 (AHEI-2010).

RESULTS

We ascertained 6305 incident cases of type 2 diabetes during follow-up. We observed a lower risk of diabetes with higher GDQS; the multivariable HR comparing extreme quintiles of the GDQS was 0.83 (95% CI: 0.76, 0.91; P-trend < 0.001). The magnitude of association was similar between women aged <50 y and those aged ≥50 y. An inverse association was observed with lower intake of unhealthy components (HR comparing extreme quintiles of the unhealthy submetric: 0.76; 95% CI: 0.69, 0.84; P-trend < 0.001) but was not with the healthy submetric. The inverse association for each 1-SD increase in the GDQS (HR: 0.93; 95% CI: 0.91, 0.96) was stronger (P < 0.001) than for the MDD-W (HR: 1.00; 95% CI: 0.94, 1.04) but was slightly weaker (P = 0.03) than for the AHEI-2010 (HR: 0.91; 95% CI: 0.88, 0.94).

CONCLUSIONS

A higher GDQS was inversely associated with type 2 diabetes risk in US women of reproductive age or older, mainly from lower intake of unhealthy foods. The GDQS performed nearly as well as the AHEI-2010.

Dietary potato intake and risks of type 2 diabetes and gestational diabetes mellitus

BACKGROUND & AIMS

Evidence regarding associations between potato consumption and type 2 diabetes (T2D) and gestational diabetes mellitus (GDM) risks is accumulating. This study aims to synthesize the evidence by conducting a meta-analysis of available studies.

METHODS

PubMed, Web of Science, EMBASE and Cochrane Library were searched (up to August 2020) to retrieve all eligible studies on the associations of interest. The risk estimates with 95% confidence intervals (CIs) were summarized using random- or fixed-effects model based on heterogeneity. Meta-analyses were performed for East and West regions separately. Dose-response relationship was assessed using data from all intake categories in each study.

RESULTS

A total of 19 studies (13 for T2D; 6 for GDM) were identified, including 21,357 T2D cases among 323,475 participants and 1516 GDM cases among 29,288 pregnancies. Meta-analysis detected a significantly positive association with T2D risk for total potato (RR: 1.19 [1.06, 1.34]), baked/boiled/mashed potato (RR: 1.08 [1.00, 1.16]), and French fries/fried potato (RR: 1.33 [1.03, 1.70]) intakes among Western populations. Dose-response meta-analysis demonstrated a significantly increased T2D risk by 10% (95% CI: 1.07, 1.14; P for trend<0.001), 2% (95% CI: 1.00, 1.04; P for trend = 0.02) and 34% (95% CI: 1.24, 1.46; P for trend<0.001) for each 80 g/day (serving) increment in total potato, unfried potato, and fried potato intakes, respectively. As for GDM, summarized estimates also suggested a higher though non-significant GDM risk for total potato (RR: 1.19 [0.89, 1.58]), and French fries/fried potato (RR: 1.03 [0.97, 1.09]) intakes in Western countries. In the dose-response meta-analysis, a significantly increased GDM risk was revealed for each daily serving (80 g) intakes of total potato (RR: 1.22; 95% CI: 1.06, 1.42; P for trend = 0.007) and unfried potato (RR: 1.26; 95% CI: 1.07, 1.48; P for trend = 0.006).

CONCLUSIONS

This study suggests that higher potato intake is associated with higher T2D risk among Western populations. The positive relationship presents a significant dose-response manner. Wisely controlled potato consumption may confer potential glucometabolic benefits.

Relevance of dietary glycemic index, glycemic load and fiber intake before and during pregnancy for the risk of gestational diabetes mellitus and maternal glucose homeostasis

BACKGROUND & AIMS

To date, the prevalence of Gestational diabetes mellitus (GDM) in China was 17.5%. Given the substantial relevance of GDM for medium- and long-term health of both mother and offspring and the paucity of existing data on the link between maternal diet and glucose homeostasis during pregnancy in Asian population, additional studies are needed. To examine the relevance of dietary glycemic index (GI), glycemic load (GL) and fiber intake before and during pregnancy for the development of GDM and glucose homeostasis over the course of pregnancy.

METHODS

Cox proportional hazards analysis and linear mixed effects regressions were performed on data from 9317 women for whom three food frequency questionnaires (pre-pregnancy, 1^st and 2^nd trimesters) and biochemical measures during pregnancy were available. Investigated outcome variables included GDM risk, fasting plasma glucose (FPG), glycated hemoglobin (HbA_1C), and homeostasis model assessment insulin resistance (HOMA-IR) in the 1st, 2nd and 3rd trimesters.

RESULTS

Women in the highest tertile of dietary GI (or GL) before pregnancy, in the 1^st, or the 2^nd trimester respectively had a 12% (15%), 25% (23%) or 29% (25%) higher risk of developing GDM than those in the lowest tertile (all p for trend ≤ 0.02). Women with the highest dietary fiber intake before pregnancy, in the 1st or 2nd trimester had a 11%, 17% or 18% lower GDM risk (all p for trend ≤ 0.03). Moreover, increases in GI or GL and decreases in fiber intake over the course of pregnancy (1^st to 3^rd trimesters) were independently associated with adverse concurrent developments in FPG, HbA_1C and HOMA-IR (p ≤ 0.03).

CONCLUSIONS

Our study indicates that dietary GI, GL and fiber intake before and during pregnancy affects glucose homeostasis of pregnant Chinese women.

Western Dietary Patterns, Foods, and Risk of Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

An increasing number of epidemiological studies suggest that adherence to Western dietary patterns (WDPs) is associated with risk of gestational diabetes mellitus (GDM), but results remain inconsistent. Therefore, we conducted a systematic review and meta-analysis of the effect of WDPs and typical Western dietary foods on GDM. A literature search was performed in PubMed, Embase, Web of Knowledge, and the Cochrane Library up to December 2019. Cohort studies investigating the combined associations of WDPs with incidence of GDM were included. Reviewers were paired, and they independently reviewed and assessed studies, extracted data, and evaluated study quality. Pooled HRs were calculated using random-effects models. Heterogeneity and publication bias tests were also conducted. Twenty-one prospective cohort studies with 191,589 participants, including 12,331 women with GDM, were included in our analysis. The pooled risk ratio (RR) of WDPs was 1.52 (95% CI: 1.21, 1.91), indicating a significant association with GDM risk in Western countries. Potatoes (pooled RR: 1.12; 95% CI: 0.93, 1.35) showed a nonsignificant (P > 0.05) relation to GDM risk. However, consumption of animal meat (pooled RR: 1.35; 95% CI: 1.16, 1.57) and fast food (pooled RR: 1.75; 95% CI: 1.41, 2.19) showed a positive association with the risk of developing GDM. Subgroup analysis demonstrated that the consumption of red meat and processed red meat increased the risk of GDM more than either poultry or fish intake. Our study provides further evidence for understanding the relation between dietary factors and increased GDM risk and contributes to reducing the incidence of GDM through healthy diets.

The relationship between advanced glycation end products and gestational diabetes: A systematic review and meta-analysis

INTRODUCTION

Gestational Diabetes Mellitus (GDM) is a condition in which women without history of diabetes experience hyperglycemia during pregnancy, especially at the second and third trimesters. In women who have had GDM, an elevated body mass index (BMI) may have a substantial impact for persistent hyperglycemia in their lives after gestation. Beyond hyperglycemia, increased local oxidative stress directly promotes the formation of Advanced Glycation End-products (AGEs). Hence, this systematic review and meta-analysis was aimed to determine the relationship between the level of AGEs and/or related metabolic biomarkers with GDM.

METHODS

Literature search was carried out through visiting electronic databases, indexing services, and directories including PubMed/MEDLINE (Ovid®), EMBASE (Ovid®), google scholar and WorldCat to retrieve studies without time limit. Following screening and eligibility evaluation, relevant data were extracted from included studies and analyzed using Rev-Man 5.3 and STATA 15.0. Inverse variance method with random effects pooling model was used for the analysis of outcome measures at 95% confidence interval. Hedge's adjusted g statistics was applied to calculate the standardized mean difference (SMD) to consider the small sample bias. Besides, meta-regression, meta-influence, and publication bias analyses were conducted. The protocol has been registered on PROSPERO with ID: CRD42020173867.

RESULTS

A total of 16 original studies were included for the systematic review and meta-analysis. Compared with women with pregnant controls, the level of AGE was significantly higher in women with GDM (SMD [95% CI] = 2.26 [1.50‒3.02], Z = 5.83, P < 0.00001; I2 = 97%, P< 0.0001). The BMI was also significantly higher in women with GDM (SMD [95% CI] = 0.97 [0.33‒1.62], Z = 2.98, P = 0.003) compared to controls. Regarding specific and related metabolic biomarkers, there was higher level of HOMA-IR (SMD [95% CI] = 0.39 [0.22-0.55], Z = 4.65, P < 0.0001, after sensitivity analysis) and HbA1c (SMD [95% CI] = 0.58 [0.03‒1.12], Z = 2.07, P = 0.04, after sensitivity analysis) in gestational diabetic women. Subgroup analyses indicated that studies conducted in Asia and Europe, at third trimester of pregnancy and blood/plasma AGE samples showed a significant difference in AGE level among women with GDM compared to pregnant controls. What is more, meta-regression with the sample size (regression coefficient (Q) = -0.0092, P = 0.207) and year of publication (Q = 0.0035, P = 0.984) suggested that the covariates had no significant effect on the heterogeneity.

CONCLUSION

The study indicated that there was a strong relationship between AGE and GDM. Besides, the BMI and other specific biomarkers showed a significant difference between the two groups indicating the high risk of developing long-standing type 2 diabetes and its complications in gestational diabetic women. Early detection of these biomarkers may play a pivotal role in controlling postpartum diabetic complications.

Effects of Maternal Dietary Patterns during Pregnancy on Early Childhood Growth Trajectories and Obesity Risk: The CANDLE Study

We investigated the associations between maternal dietary patterns during pregnancy and early childhood growth trajectories and overweight/obesity risk in offspring. Maternal diet was assessed using a food frequency questionnaire during the second trimester, and dietary patterns were derived by reduced rank regression. The associations between maternal dietary pattern scores and body mass index (BMI) trajectories from birth to age four (rising-high, moderate, and low BMI trajectories) as well as overweight/obesity risk at age four were analyzed (n = 1257). Two maternal dietary patterns were identified. The fast food pattern included a higher intake of fried chicken and fish, fruit juices, mayonnaise, and sugar-sweetened beverages, while the processed food pattern included a higher intake of dairy, salad dressing, processed meat, and cold breakfast cereal. Women with greater adherence to the fast food pattern were more likely to have children in the rising-high BMI trajectory group [OR (95% CI) = 1.32 (1.07-1.62); p = 0.008] or having overweight/obesity at age four [OR (95% CI) = 1.31 (1.11-1.54); p = 0.001]. The processed food pattern was not associated with these outcomes. The maternal dietary pattern during pregnancy represented by fried foods and sugar-sweetened beverages may contribute to rapid early childhood growth and increased risk for obesity in offspring.

Association of fried food consumption with all cause, cardiovascular, and cancer mortality: prospective cohort study

OBJECTIVE

To examine the prospective association of total and individual fried food consumption with all cause and cause specific mortality in women in the United States.

DESIGN

Prospective cohort study.

SETTING

Women's Health Initiative conducted in 40 clinical centers in the US.

PARTICIPANTS

106 966 postmenopausal women aged 50-79 at study entry who were enrolled between September 1993 and 1998 in the Women's Health Initiative and followed until February 2017.

MAIN OUTCOME MEASURES

All cause mortality, cardiovascular mortality, and cancer mortality.

RESULTS

31 558 deaths occurred during 1 914 691 person years of follow-up. For total fried food consumption, when comparing at least one serving per day with no consumption, the multivariable adjusted hazard ratio was 1.08 (95% confidence interval 1.01 to 1.16) for all cause mortality and 1.08 (0.96 to 1.22) for cardiovascular mortality. When comparing at least one serving per week of fried chicken with no consumption, the hazard ratio was 1.13 (1.07 to 1.19) for all cause mortality and 1.12 (1.02 to 1.23) for cardiovascular mortality. For fried fish/shellfish, the corresponding hazard ratios were 1.07 (1.03 to 1.12) for all cause mortality and 1.13 (1.04 to 1.22) for cardiovascular mortality. Total or individual fried food consumption was not generally associated with cancer mortality.

CONCLUSIONS

Frequent consumption of fried foods, especially fried chicken and fried fish/shellfish, was associated with a higher risk of all cause and cardiovascular mortality in women in the US.

Breakfast Skipping Is Associated with Increased Risk of Type 2 Diabetes among Adults: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

Background

Epidemiologic studies have indicated that breakfast skipping is associated with risk of type 2 diabetes. However, the shape of the dose-response relation and the influence of adiposity on this association have not been reported.

Objective

We investigated the association between breakfast skipping and risk of type 2 diabetes by considering the influence of the body mass index (BMI).

Methods

In this systematic review and meta-analysis, PubMed and Web of Science were searched up to August 2017. Prospective cohort studies on breakfast skipping and risk of type 2 diabetes in adults were included. Summary RRs and 95% CIs, without and with adjustment for BMI, were estimated with the use of a random-effects model in pairwise and dose-response meta-analyses.

Results

In total 6 studies, based on 96,175 participants and 4935 cases, were included. The summary RR for type 2 diabetes comparing ever with never skipping breakfast was 1.33 (95% CI: 1.22, 1.46, n = 6 studies) without adjustment for BMI, and 1.22 (95% CI: 1.12, 1.34, n = 4 studies) after adjustment for BMI. Nonlinear dose-response meta-analysis indicated that risk of type 2 diabetes increased with every additional day of breakfast skipping, but the curve reached a plateau at 4-5 d/wk, showing an increased risk of 55% (summary RR: 1.55; 95% CI: 1.41, 1.71). No further increase in risk of type 2 diabetes was observed after 5 d of breakfast skipping/wk (P for nonlinearity = 0.08).

Conclusions

This meta-analysis provides evidence that breakfast skipping is associated with an increased risk of type 2 diabetes, and the association is partly mediated by BMI.

Glycated proteins in nutrition: Friend or foe?

Advanced glycation end products (AGEs) are formed in in vivo, and accumulate in tissues and body fluids during ageing. Endogenous AGE-modified proteins show altered structure and function, and may interact with receptor for AGEs (RAGE) resulting in production of reactive oxygen species, inflammatory, atherogenic and diabetogenic responses. AGEs are also formed in thermally processed foods. Studies in rodents document that dietary AGEs are partially absorbed into circulation, and accumulate in different tissues. Knowledge on the health effects of high dietary intake of AGEs is incomplete and contradictory. In this overview we discuss the data from experimental and clinical studies, either those supporting the assumption that restriction of dietary AGEs associated with health benefits, or data suggesting that dietary intake of AGEs associates with positive health outcomes. We polemicize whether the effects of exaggerated intake or restriction of highly thermally processed foods might be straightforward interpreted as the effects of AGEs-rich vs. AGEs-restricted diets. We also underline the lack of studies, and thus a poor knowledge, on the effects of different single chemically defined AGEs administration, concurrent intake of different dietary AGEs, of load with dietary AGEs corresponding to the habitual diet in humans, and on those of dietary AGEs in vulnerable populations, such as infants and particularly elderly.

The effects of a maternal advanced glycation end product-rich diet on somatic features, reflex ontogeny and metabolic parameters of offspring mice

Maternal exposure to a Western type diet during pregnancy might predispose the offspring to manifestation of metabolic and behavioral disturbances in later life. The Western type diet contains large amounts of advanced glycation end products (AGEs). In humans and experimental rodents, the intake of an AGE-rich diet (AGE-RD) negatively affected glucose homeostasis, and initiated the production of reactive oxygen species. Rats consuming the AGE-RD presented changes in behavior. It remains unclear whether maternal intake of the AGE-RD might affect developmental plasticity in offspring. We examined early somatic (weight, incisor eruption, ear unfolding, and eye opening) and neuromotor development, oxidative status, insulin sensitivity (HOMA index) and locomotor activity assessed in PhenoTyper cages in the offspring of mice fed during pregnancy with either the AGE-RD (25% bread crusts/75% control chow) or control chow. Until weaning, the somatic development of offspring did not differ between the two dietary groups. The AGE-RD offspring manifested physiological reflexes (auditory startle, eye lid, ear twitch and righting reflexes) earlier. As young adults, the male offspring of the AGE-RD dams were heavier and less insulin sensitive compared with their control counterparts. The AGE-RD offspring showed higher locomotor activity during the active phase. Our data indicate that the maternal AGE-RD during pregnancy might accelerate the maturation of reflexes in offspring, predispose the male progeny to weight gain and affect their glucose homeostasis. These effects manifest without the direct consumption of the AGE-RD by offspring. Further work is needed to determine the mechanisms by which the maternal AGE-RD affects neurobehavioral pathways in offspring, as well as sex differences in adverse metabolic responses.

Dietary Protein Intake, Meat Consumption, and Dairy Consumption in the Year Preceding Pregnancy and During Pregnancy and Their Associations With the Risk of Gestational Diabetes Mellitus: A Prospective Cohort Study in Southwest China

Background: Gestational diabetes mellitus (GDM) has become a public health problem in China. Objective: To examine the association of dietary protein intake before and during pregnancy with the risk of GDM. Design: Dietary intake before pregnancy and during the first and second trimesters of pregnancy was assessed using food frequency questionnaires in a prospective cohort of pregnant women. To screen GDM, participants underwent an OGTT test during 24-28 weeks of gestation. Cox proportional hazards were used to estimate RRs and 95% CIs for the associations between tertiles of dietary protein and the source of protein intake in different time windows with GDM status. Results: Higher intake of total protein [RR (95% CI): 1.92 (1.10-3.14), p for trend = 0.04] or animal protein [1.67 (1.19-2.93), p for trend = 0.03] in mid-pregnancy was associated with higher risk of GDM. Vegetable protein intake before or during pregnancy was not related to GDM risk (p for trend > 0.05). Moreover, in the mid-pregnancy, participants with higher meat consumption or dairy consumption had a higher risk of GDM. Conclusion: Our study indicated that higher dietary intakes of total protein and animal protein in mid-pregnancy were associated with an increased risk of GDM among pregnant Chinese women.