[Show abstract][Hide abstract] ABSTRACT: As nutrition-related chronic diseases have become more and more frequent, the importance of dietary prevention has also increased. Dietary fat plays a major role in human nutrition, and modification of fat and/or fatty acid intake could have a preventive potential. The aim of the guideline of the German Nutrition Society (DGE) was to systematically evaluate the evidence for the prevention of the widespread diseases obesity, type 2 diabetes mellitus, dyslipoproteinaemia, hypertension, metabolic syndrome, coronary heart disease (CHD), stroke, and cancer through the intake of fat or fatty acids. The main results can be summarized as follows: it was concluded with convincing evidence that a reduced intake of total and saturated fat as well as a larger intake of polyunsaturated fatty acids (PUFA) at the expense of saturated fatty acids (SFA) reduces the concentration of total and low-density lipoprotein cholesterol in plasma. Furthermore, there is convincing evidence that a high intake of trans fatty acids increases risk of dyslipoproteinaemia and that a high intake of long-chain polyunsaturated n-3 fatty acids reduces the triglyceride concentration in plasma. A high fat intake increases the risk of obesity with probable evidence when total energy intake is not controlled for (ad libitum diet). When energy intake is controlled for, there is probable evidence for no association between fat intake and risk of obesity. A larger intake of PUFA at the expense of SFA reduces risk of CHD with probable evidence. Furthermore, there is probable evidence that a high intake of long-chain polyunsaturated n-3 fatty acids reduces risk of hypertension and CHD. With probable evidence, a high trans fatty acid intake increases risk of CHD. The practical consequences for current dietary recommendations are described at the end of this article.
[Show abstract][Hide abstract] ABSTRACT: Aims/hypothesis:
Studies on weight cycling and the risk of type 2 diabetes have revealed inconsistent results, possibly due to differences in the definition of weight fluctuations. Here, we investigated whether weight cycling during adulthood is related to diabetes risk in a large cohort study, using a complementary approach to define patterns of weight development.
Weight cycling, weight loss and weight gain were defined (1) a priori, using distinct categories, and (2) by functional principal component analysis (FPCA) to capture weight patterns in greater detail. Associations of weight cycling, weight loss and weight gain with the risk of type 2 diabetes were evaluated by Cox regression models.
A priori defined weight cycling was associated with increased diabetes risk, compared with stable weight (HR 1.36 [95% CI 1.09, 1.68]). No significant association between FPCA-derived weight cycling and risk of diabetes was observed after adjustment for concurrent weight patterns (HR 1.19 [95% CI 0.89, 1.60]). Subgroup analyses showed that FPCA-derived weight cycling during net weight gain was associated with a higher risk of diabetes (HR 1.68 [95% CI 1.14, 2.48]). A priori defined weight gain (HR 2.08 [95% CI 1.60, 2.70]) was more clearly related to the risk of diabetes than FPCA-derived weight gain (HR 1.20 [95% CI 0.95, 1.51]), while no significant associations were observed for weight loss.
Overall, weight cycling may not be an independent risk factor for type 2 diabetes when accounting for concurrent patterns of weight development. However, weight cycling may pose a stronger risk of diabetes than non-cycling during net weight gain.
[Show abstract][Hide abstract] ABSTRACT: Beta-cell apoptosis and failure to induce beta-cell regeneration are hallmarks of type 2-like diabetes in mouse models. Here we show that islets from obese, diabetes-susceptible New Zealand Obese (NZO) mice, in contrast to diabetes-resistant C57BL/6J (B6)-ob/ob mice, do not proliferate in response to an in-vivo glucose challenge but lose their beta-cells. Genome-wide RNAseq based transcriptomics indicated an induction of 22 cell cycle-associated genes in B6-ob/ob islets that did not respond in NZO islets. Of all genes differentially expressed in islets of the two strains, seven mapped to the diabesity QTL Nob3, and were hypomorphic in either NZO (Lefty1, Apoa2, Pcp4l1, Mndal, Slamf7, Pydc3) or B6 (Ifi202b). Adenoviral overexpression of Lefty1, Apoa2, and Pcp4l1 in primary islet cells increased proliferation, whereas overexpression of Ifi202b suppressed it. We conclude that the identified genes in synergy with obesity and insulin resistance participate in adaptive islet hyperplasia and prevention from severe diabetes in B6-ob/ob mice.
[Show abstract][Hide abstract] ABSTRACT: Early life, adiposity rebound, and puberty represent critical growth periods when food choices could have long-term relevance for cancer risk. We aimed to relate dietary patterns during these periods to the growth hormone-insulin-like-growth-factor (GH-IGF) axis, insulin resistance, and body fatness in adulthood. Data from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study participants with outcome data at 18-37 years, and ≥2 dietary records during early life (1-2 yr; n = 128), adiposity rebound (4-6 years, n = 179), or puberty (girls 9-14, boys 10-15 yr; n = 213) were used. Dietary patterns at these ages were derived by 1) reduced rank regression (RRR) to explain variation in adult IGF-I, IGF-binding protein-3 (IGFBP-3), homoeostasis model assessment for insulin resistance (HOMA-IR) and fat-mass index; 2) principal component analysis (PCA). Regarding RRR, the patterns "cake/canned fruit/cheese & eggs" (early life), "sweets & dairy" (adiposity rebound) and "high-fat foods" (pubertal boys) were independently associated with higher adult HOMA-IR. Furthermore, the patterns "favorable carbohydrate sources" (early life), "snack & convenience foods" (adiposity rebound), and "traditional & convenience carbohydrates" (pubertal boys) were related to adult IGFBP-3 (P trend < 0.01). PCA identified "healthy" patterns for all periods, but none was associated with the outcomes (P trend > 0.1). In conclusion, dietary patterns during sensitive growth periods may be of long-term relevance for adult insulin resistance and IGFBP-3.
Nutrition and Cancer 07/2015; 67(6):1-16. DOI:10.1080/01635581.2015.1056313 · 2.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Reduced rank regression (RRR) is an innovative technique to establish dietary patterns related to biochemical risk factors for type 2 diabetes, but has not been applied in sub-Saharan Africa. In a hospital-based case-control study for type 2 diabetes in Kumasi (diabetes cases, 538; controls, 668) dietary intake was assessed by a specific food frequency questionnaire. After random split of our study population, we derived a dietary pattern in the training set using RRR with adiponectin, HDL-cholesterol and triglycerides as responses and 35 food items as predictors. This pattern score was applied to the validation set, and its association with type 2 diabetes was examined by logistic regression. The dietary pattern was characterized by a high consumption of plantain, cassava, and garden egg, and a low intake of rice, juice, vegetable oil, eggs, chocolate drink, sweets, and red meat; the score correlated positively with serum triglycerides and negatively with adiponectin. The multivariate-adjusted odds ratio of type 2 diabetes for the highest quintile compared to the lowest was 4.43 (95% confidence interval: 1.87–10.50, p for trend < 0.001). The identified dietary pattern increases the odds of type 2 diabetes in urban Ghanaians, which is mainly attributed to increased serum triglycerides.
[Show abstract][Hide abstract] ABSTRACT: Aims/hypothesis: Intake of dietary fibre has been associated with a reduced risk of type 2 diabetes, but few European studies have been published on this. We evaluated the association between intake of dietary fibre and type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct study and in a meta-analysis of prospective studies. Methods: During 10.8 years of follow-up, 11,559 participants with type 2 diabetes were identified and a subcohort of 15,258 participants was selected for the case-cohort study. Country-specific HRs were estimated using Prentice-weighted Cox proportional hazards models and were pooled using a random effects meta-analysis. Eighteen other cohort studies were identified for the meta-analysis. Results: In the EPIC-InterAct Study, dietary fibre intake was associated with a lower risk of diabetes (HRQ4 vs Q1 0.82; 95% CI 0.69, 0.97) after adjustment for lifestyle and dietary factors. Similar inverse associations were observed for the intake of cereal fibre and vegetable fibre, but not fruit fibre. The associations were attenuated and no longer statistically significant after adjustment for BMI. In the meta-analysis (19 cohorts), the summary RRs per 10 g/day increase in intake were 0.91 (95% CI 0.87, 0.96) for total fibre, 0.75 (95% CI 0.65, 0.86) for cereal fibre, 0.95 (95% CI 0.87, 1.03) for fruit fibre and 0.93 (95% CI 0.82, 1.05) for vegetable fibre. Conclusions/interpretation: The overall evidence indicates that the intake of total and cereal fibre is inversely related to the risk of type 2 diabetes. The results of the EPIC-InterAct Study suggest that the association may be partially explained by body weight.
[Show abstract][Hide abstract] ABSTRACT: Background: Biomarker fatty acids (FAs) reflecting de novo lipogenesis (DNL) are strongly linked to the risk of cardiometabolic diseases. Liver fat accumulation could mediate this relation. There is very limited data from human population-based studies that have examined this relation. Objective: The aim of this study was to investigate the relation between specific FAs in the DNL pathway and liver fat accumulation in a large population-based study. Methods: We conducted a cross-sectional analysis of a subsample (n = 1,562) of the EPIC-Potsdam study, which involves 27,548 middle-aged men and women. Baseline blood samples have been analyzed for proportions of 32 FAs in erythrocyte membranes (determined by gas chromatography) and biomarker concentrations in plasma. As indicators for DNL, the DNL-index (16:0/18:2n-6) and proportions of individual blood FAs in the DNL pathway were used. Plasma parameters associated with liver fat content (fetuin-A, ALT, and GGT) and the algorithm-based fatty liver index (FLI) were used to reflect liver fat accumulation. Results: The DNL-index tended to be positively associated with the FLI and was positively associated with GGT activity in men (p for trend: 0.12 and 0.003). Proportions of 14:0 and 16:0 in erythrocytes were positively associated with fetuin-A, whereas 16:1n-7 were positively associated with the FLI and GGT activity (all p for trends in both sexes at least 0.004). Furthermore, the proportion of 16:1n-7 was positively related to fetuin-A in women and ALT activity in men (all p for trend at least 0.03). The proportion of 16:1n-9 showed positive associations with the FLI and GGT activity in men and fetuin-A in both sexes, whereas 18:1n-7 was positively associated with GGT activity in men (all p for trend at least 0.048). Conclusion: Findings from this large epidemiological study suggest that liver fat accumulation could link erythrocyte FAs in the DNL pathway to the risk of cardiometabolic diseases.
PLoS ONE 05/2015; 10(5):e0127368. DOI:10.1371/journal.pone.0127368 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The fatty liver index (FLI) predicts fatty liver by using BMI, waist circumference, γ-glutamyltransferase and triglycerides. We investigated the association between the FLI and the risk of type 2 diabetes and evaluated to what extent single FLI components contribute to the diabetes risk. We analysed a case-cohort study (random sub-cohort: 1922; incident cases: 563) nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study. The proportion of exposure effect (PEE) explained by single FLI components was evaluated and effect decomposition using inverse probability weighting (IPW) was applied. Women and men with a FLI ≥60 compared to those with a FLI <30 had a multivariable-adjusted Hazard Ratio (HR) of 17.6; 95% confidence interval (CI) 11.1-28.0 and HR: 10.9; 95% CI 6.22-19.2, respectively. Adjustment for BMI or waist circumference attenuated this association in men [PEEBMI (95% CI) = 53.8% (43.9%-65.8%); PEEwaist (95% CI) = 54.8% (44.2%-68.8%)]. In women, adjustment for waist circumference attenuated the association to a lesser degree than in men [PEEwaist (95% CI) = 31.1%; (21.9%-43.1%)] while BMI had no appreciable effect [PEEBMI (95% CI) = 11.0% (2.68%-21.0%)]. γ-glutamyltransferase and triglycerides showed only a small attenuation in women [PEEGGT(95% CI) = 3.11% (-0.72%-4.48%); PEETG (95% CI) = 6.36% (3.81%-9.92%)] and in men [PEEGGT = 0%; PEETG (95% CI) = 6.23% (2.03%-11.8%)]. In women, the total effect was decomposed into a direct effect and 4 indirect effects (HRBMI = 1.10; HRwaist = 1.28; HRGGT = 0.97 and HRTG = 1.03). In men, the 4 indirect effects were HRBMI = 1.25; HRwaist = 1.29; HRGGT = 0.97 and HRTG = 0.99. These data suggest that the FLI, as a proxy for fatty liver, is associated with risk of type 2 diabetes. This association is only partly explained by standard estimates of overall and abdominal body fatness, particularly among women.
PLoS ONE 04/2015; 10(4):e0124749. DOI:10.1371/journal.pone.0124749 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective. A proportion of type 2 diabetes cases arise from normal-weight individuals who can therefore be considered to be "metabolically unhealthy normal-weight" (MUH-NW). It remains unclear which factors account for this access risk. Our aims were to identify risk factors for type 2 diabetes in normal-weight individuals and to compare the strengths of their associations with type 2 diabetes to that observed in overweight and obese participants. Methods. A case-cohort, including 2027 sub-cohort participants and 706 incident type 2 cases, was designed within the population-based European Prospective Investigation into Cancer and Nutrition Potsdam study. Adjusted means and relative frequencies of anthropometric, lifestyle and biochemical risk factors were calculated in groups stratified by BMI and incident diabetes status. Cox regressions were applied to evaluate associations between these variables and diabetes risk stratified by BMI category. Results. MUH-NW individuals were characterized by known diabetes risk factors, e.g. They were significantlymore likely to bemale, formersmokers, hypertensive, and less physically active compared to normal-weight individuals without incident diabetes. Higher waist circumference (women: 75.5 vs. 73.1 cm; men: 88.0 vs. 85.1 cm), higher HbA1c (6.1 vs. 5.3%), higher triglycerides (1.47 vs. 1.11 mmol/l), and higher levels of high sensitive C-reactive protein (0.81 vs. 0.51 mg/l) as well as lower levels of HDL-cholesterol (1.28 vs. 1.49 mmol/l) and adiponectin (6.32 vs. 8.25 μg/ml) characterized this phenotype. Stronger associations with diabetes among normal-weight participants compared to overweight and obese (p for interaction < 0.05) were observed for height, waist circumference, former smoking, and hypertension.
[Show abstract][Hide abstract] ABSTRACT: The Net Reclassification Improvement (NRI) has become a popular metric for evaluating improvement in disease prediction models through the past years. The concept is relatively straightforward but usage and interpretation has been different across studies. While no thresholds exist for evaluating the degree of improvement, many studies have relied solely on the significance of the NRI estimate. However, recent studies recommend that statistical testing with the NRI should be avoided. We propose using confidence ellipses around the estimated values of event and non-event NRIs which might provide the best measure of variability around the point estimates. Our developments are illustrated using practical examples from EPIC-Potsdam study.
European Journal of Epidemiology 02/2015; 30(4). DOI:10.1007/s10654-015-0001-1 · 5.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fasting glucose and insulin are intermediate traits for type 2 diabetes. Here we explore the role of coding variation on these traits by analysis of variants on the HumanExome BeadChip in 60,564 non-diabetic individuals and in 16,491 T2D cases and 81,877 controls. We identify a novel association of a low-frequency nonsynonymous SNV in GLP1R (A316T; rs10305492; MAF=1.4%) with lower FG (β=-0.09±0.01 mmol l(-1), P=3.4 × 10(-12)), T2D risk (OR[95%CI]=0.86[0.76-0.96], P=0.010), early insulin secretion (β=-0.07±0.035 pmolinsulin mmolglucose(-1), P=0.048), but higher 2-h glucose (β=0.16±0.05 mmol l(-1), P=4.3 × 10(-4)). We identify a gene-based association with FG at G6PC2 (pSKAT=6.8 × 10(-6)) driven by four rare protein-coding SNVs (H177Y, Y207S, R283X and S324P). We identify rs651007 (MAF=20%) in the first intron of ABO at the putative promoter of an antisense lncRNA, associating with higher FG (β=0.02±0.004 mmol l(-1), P=1.3 × 10(-8)). Our approach identifies novel coding variant associations and extends the allelic spectrum of variation underlying diabetes-related quantitative traits and T2D susceptibility.
[Show abstract][Hide abstract] ABSTRACT: Background/objectives:
Diets high in saturated and trans fat and low in unsaturated fat may increase type 2 diabetes (T2D) risk, but studies on foods high in fat per unit weight are sparse. We assessed whether the intake of vegetable oil, butter, margarine, nuts and seeds and cakes and cookies is related to incident T2D.
A case-cohort study was conducted, nested within eight countries of the European Prospective Investigation into Cancer (EPIC), with 12,403 incident T2D cases and a subcohort of 16,835 people, identified from a cohort of 340,234 people. Diet was assessed at baseline (1991-1999) by country-specific questionnaires. Country-specific hazard ratios (HRs) across four categories of fatty foods (nonconsumers and tertiles among consumers) were combined with random-effects meta-analysis.
After adjustment not including body mass index (BMI), nonconsumers of butter, nuts and seeds and cakes and cookies were at higher T2D risk compared with the middle tertile of consumption. Among consumers, cakes and cookies were inversely related to T2D (HRs across increasing tertiles 1.14, 1.00 and 0.92, respectively; P-trend <0.0001). All these associations attenuated upon adjustment for BMI, except the higher risk of nonconsumers of cakes and cookies (HR 1.57). Higher consumption of margarine became positively associated after BMI adjustment (HRs across increasing consumption tertiles: 0.93, 1.00 and 1.12; P-trend 0.03). Within consumers, vegetable oil, butter and nuts and seeds were unrelated to T2D.
Fatty foods were generally not associated with T2D, apart from weak positive association for margarine. The higher risk among nonconsumers of cakes and cookies needs further explanation.
European Journal of Clinical Nutrition 11/2014; 69(4). DOI:10.1038/ejcn.2014.249 · 2.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To address major societal challenges and enhance cooperation in research across Europe, the European Commission has initiated and facilitated 'joint programming'. Joint programming is a process by which Member States engage in defining, developing and implementing a common strategic research agenda, based on a shared vision of how to address major societal challenges that no Member State is capable of resolving independently. Setting up a Joint Programming Initiative (JPI) should also contribute to avoiding unnecessary overlap and repetition of research, and enable and enhance the development and use of standardised research methods, procedures and data management. The Determinants of Diet and Physical Activity (DEDIPAC) Knowledge Hub (KH) is the first act of the European JPI 'A Healthy Diet for a Healthy Life'. The objective of DEDIPAC is to contribute to improving understanding of the determinants of dietary, physical activity and sedentary behaviours. DEDIPAC KH is a multi-disciplinary consortium of 46 consortia and organisations supported by joint programming grants from 12 countries across Europe. The work is divided into three thematic areas: (I) assessment and harmonisation of methods for future research, surveillance and monitoring, and for evaluation of interventions and policies; (II) determinants of dietary, physical activity and sedentary behaviours across the life course and in vulnerable groups; and (III) evaluation and benchmarking of public health and policy interventions aimed at improving dietary, physical activity and sedentary behaviours. In the first three years, DEDIPAC KH will organise, develop, share and harmonise expertise, methods, measures, data and other infrastructure. This should further European research and improve the broad multi-disciplinary approach needed to study the interactions between multilevel determinants in influencing dietary, physical activity and sedentary behaviours. Insights will be translated into more effective interventions and policies for the promotion of healthier behaviours and more effective monitoring and evaluation of the impacts of such interventions.
International Journal of Behavioral Nutrition and Physical Activity 11/2014; 11(1). DOI:10.1186/s12966-014-0143-7 · 4.11 Impact Factor