HNF1A variant, energy-reduced diets and insulin resistance improvement during weight loss: The POUNDS Lost trial and DIRECT

Using Metabolic Testing to Personalize Behavioral Obesity Treatment

Background

There are large individual differences in weight loss and maintenance. Metabolic testing can provide phenotypical information that can be used to personalize treatment so that people remain in negative energy balance during weight loss and remain in energy balance during maintenance. Behavioral testing can assess the reinforcing value and change in the temporal window related to the personalized diet and exercise program to motivate people to maintain engagement in healthier eating and activity programs.

Objective

Provide an expository overview of how metabolic testing can be used to personalize weight control. Ideas about incorporating behavioral economic concepts are also included.

Methods

A broad overview of how resting metabolic rate, thermic effect of food and respiratory quotient can be used to improve weight control. Also discussed are behavioral economic principles that can maximize adherence to diet and activity protocols.

Results

Research suggests that measuring metabolic rate can be used to set calorie goals for weight loss and maintenance, thermic effect of food to increase energy expenditure, and respiratory quotient to guide macronutrient composition of the diet and maximize fat loss. Developing programs that foster a strong motivation to eat healthier and be active can maximize treatment success.

Conclusion

Incorporating metabolic measures can personalize behavioral weight loss programs, and the use of behavioral economic principles can increase the probability of adherence and long-term success in weight control.

Combined effects of genetic background and diet on mouse metabolism and gene expression

In humans, dietary patterns impact weight and metabolism differentially across individuals. To uncover genetic determinants for differential dietary effects, we subjected four genetically diverse mouse strains to humanized diets (American, Mediterranean, vegetarian, and vegan) with similar macronutrient composition, and performed body weight, metabolic parameter, and RNA-seq analysis. We observed pronounced diet- and strain-dependent effects on weight, and triglyceride and insulin levels. Differences in fat mass, adipose tissue, and skeletal muscle glucose uptake, and gene expression changes in most tissues were strain-dependent. In visceral adipose tissue, ∼400 genes responded to diet in a strain-dependent manner, many of them in metabolite transport and lipid metabolism pathways and several previously identified to modify diet effects in humans. Thus, genetic background profoundly impacts metabolism, though chosen dietary patterns modify the strong genetic effects. This study paves the way for future mechanistic investigations into strain-diet interactions in mice and translation to precision nutrition in humans.

Toward Precision Weight-Loss Dietary Interventions: Findings from the POUNDS Lost Trial

The POUNDS Lost trial is a 2-year clinical trial testing the effects of dietary interventions on weight loss. This study included 811 adults with overweight or obesity who were randomized to one of four diets that contained either 15% or 25% protein and 20% or 40% fat in a 2 × 2 factorial design. By 2 years, participants on average lost from 2.9 to 3.6 kg in body weight in the four intervention arms, while no significant difference was observed across the intervention arms. In POUNDS Lost, we performed a series of ancillary studies to detect intrinsic factors particular to genomic, epigenomic, and metabolomic markers that may modulate changes in weight and other cardiometabolic traits in response to the weight-loss dietary interventions. Genomic variants identified from genome-wide association studies (GWASs) on obesity, type 2 diabetes, glucose and lipid metabolisms, gut microbiome, and dietary intakes have been found to interact with dietary macronutrients (fat, protein, and carbohydrates) in relation to weight loss and changes of body composition and cardiometabolic traits. In addition, we recently investigated epigenomic modifications, particularly blood DNA methylation and circulating microRNAs (miRNAs). We reported DNA methylation levels at NFATC2IP, CPT1A, TXNIP, and LINC00319 were related to weight loss or changes of glucose, lipids, and blood pressure; we also reported thrifty miRNA expression as a significant epigenomic marker related to changes in insulin sensitivity and adiposity. Our studies have also highlighted the importance of temporal changes in novel metabolomic signatures for gut microbiota, bile acids, and amino acids as predictors for achievement of successful weight loss outcomes. Moreover, our studies indicate that biochemical, behavioral, and psychosocial factors such as physical activity, sleep disturbance, and appetite may also modulate metabolic changes during dietary interventions. This review summarized our major findings in the POUNDS Lost trial, which provided preliminary evidence supporting the development of precision diet interventions for obesity management.

In the context of the triple burden of malnutrition: A systematic review of gene-diet interactions and nutritional status

Genetic background interacts with dietary components to modulate nutritional health status. This study aimed to review the evidence for gene-diet interactions in all forms of malnutrition. A comprehensive systematic literature search was conducted through April 2021 to identify observational and intervention studies reporting the effects of gene-diet interactions in over-nutrition, under-nutrition and micronutrient status. Risk of publication bias was assessed using the Quality Criteria Checklist and a tool specifically designed for gene-diet interaction research. 167 studies from 27 populations were included. The majority of studies investigated single nucleotide polymorphisms (SNPs) in overnutrition (n = 158). Diets rich in whole grains, vegetables, fruits and low in total and saturated fats, such as Mediterranean and DASH diets, showed promising effects for reducing obesity risk among individuals who had higher genetic risk scores for obesity, particularly the risk alleles carriers of FTO rs9939609, rs1121980 and rs1421085. Other SNPs in MC4R, PPARG and APOA5 genes were also commonly studied for interaction with diet on overnutrition though findings were inconclusive. Only limited data were found related to undernutrition (n = 1) and micronutrient status (n = 9). The findings on gene-diet interactions in this review highlight the importance of personalized nutrition, and more research on undernutrition and micronutrient status is warranted.

Fruit and Vegetable Consumption Interacts With HNF1A Variants on the C-Reactive Protein

Epidemiological studies have demonstrated the inverse association between the intake of fruits and vegetables and inflammation. However, the mechanisms by which inflammation-related genes interact with fruit and vegetable intake and the role of these combinations in inflammation remain unclear. Therefore, we assessed the effect of interactions between fruit and vegetable intake and the hepatic nuclear factor 1 alpha (HNF1A) genetic variants on the C-reactive protein (CRP) levels. Baseline data from the Ansan and Ansung Cohort Study of the Korean Genome and Epidemiology Study (KoGES) were used. A total of 7,634 participants (3,700 men and 3,934 women) were included in the analyses. Fruit and vegetable intake was assessed using semi-quantitative food frequency questionnaire data. Genotyping information for HNF1A was extracted from the Affymetrix Genome-Wide Human SNP array 5.0. Inflammation was determined after overnight fasting by measuring CRP levels using automated analyzers. Multivariable logistic regression was used to estimate the adjusted odds ratio (AOR) with a 95% confidence interval (CI). In the fully adjusted model, men and women with the GG genotype of HNF1A rs2393791 and high fruit intake had lower odds of elevated CRP levels compared to those with the AA genotype and low fruit intake (AOR 0.50, 95% CI 0.38–0.67; AOR 0.73, 95% CI 0.55–0.97, respectively). Men and women with the rs2393791 GG genotype and high vegetable intake had lower odds of having elevated CRP levels compared to those with the AA genotype and low fruit intake (AOR 0.57, 95% CI 0.43–0.75; AOR 0.65, 95% CI 0.49–0.86, respectively). Men and women with the GG genotype and high total fruit and vegetable intake had lower odds of having elevated CRP levels. These findings indicate that fruit and vegetable intake interacts with HNF1A genetic polymorphisms, consequently influencing the inflammation levels.

Nutrition for precision health: The time is now

Precision nutrition has emerged as a boiling area of nutrition research, with a particular focus on revealing the individual variability in response to diets that is determined mainly by the complex interactions of dietary factors with the multi-tiered "omics" makeups. Reproducible findings from the observational studies and diet intervention trials have lent preliminary but consistent evidence to support the fundamental role of gene-diet interactions in determining the individual variability in health outcomes including obesity and weight loss. Recent investigations suggest that the abundance and diversity of the gut microbiome may also modify the dietary effects; however, considerable instability in the results from the microbiome research has been noted. In addition, growing studies suggest that a complicated multiomics algorithm would be developed by incorporating the genome, epigenome, metabolome, proteome, and microbiome in predicting the individual variability in response to diets. Moreover, precision nutrition would also scrutinize the role of biological (circadian) rhythm in determining the individual variability of dietary effects. The evidence gathered from precision nutrition research will be the basis for constructing precision health dietary recommendations, which hold great promise to help individuals and their health care providers create precise and effective diet plans for precision health in the future.

Transcriptional control by HNF-1: Emerging evidence showing its role in lipid metabolism and lipid metabolism disorders

The present review focuses on the roles and underlying mechanisms of action of hepatic nuclear factor-1 (HNF-1) in lipid metabolism and the development of lipid metabolism disorders. HNF-1 is a transcriptional regulator that can form homodimers, and the HNF-1α and HNF-1β isomers can form heterodimers. Both homo- and heterodimers recognize and bind to specific cis-acting elements in gene promoters to transactivate transcription and to coordinate the expression of target lipid-related genes, thereby influencing the homeostasis of lipid metabolism. HNF-1 was shown to restrain lipid anabolism, including synthesis, absorption, and storage, by inhibiting the expression of lipogenesis-related genes, such as peroxisome proliferator-activated receptor γ (PPARγ) and sterol regulatory element-binding protein-1/2 (SREBP-1/2). Moreover, HNF-1 enhances the expression of various genes, such as proprotein convertase subtilisin/kexin type 9 (PCSK9), glutathione peroxidase 1 (GPx1), and suppressor of cytokine signaling-3 (SOCS-3) and negatively regulates signal transducer and activator of transcription (STAT) to facilitate lipid catabolism in hepatocytes. HNF-1 reduces hepatocellular lipid decomposition, which alleviates the progression of nonalcoholic fatty liver disease (NAFLD). HNF-1 impairs preadipocyte differentiation to reduce the number of adipocytes, stunting the development of obesity. Furthermore, HNF-1 reduces free cholesterol levels in the plasma to inhibit aortic lipid deposition and lipid plaque formation, relieving dyslipidemia and preventing the development of atherosclerotic cardiovascular disease (ASCVD). In summary, HNF-1 transcriptionally regulates lipid-related genes to manipulate intracorporeal balance of lipid metabolism and to suppress the development of lipid metabolism disorders.

Genome-wide Association Analysis of Proinflammatory Cytokines and Gene-lifestyle Interaction for Invasive Breast Cancer Risk: The WHI dbGaP Study

Immune-related etiologic pathways to influence invasive breast cancer risk may interact with lifestyle factors, but the interrelated molecular genetic pathways are incompletely characterized. We used data from the Women's Health Initiative Database for Genotypes and Phenotypes Study including 16,088 postmenopausal women, a population highly susceptible to inflammation, obesity, and increased risk for breast cancer. With 21,784,812 common autosomal single-nucleotide polymorphisms (SNP), we conducted a genome-wide association (GWA) gene-environment interaction (G × E) analysis in six independent GWA Studies for proinflammatory cytokines [IL6 and C-reactive protein (CRP)] and their gene-lifestyle interactions. Subsequently, we tested for the association of the GWA SNPs with breast cancer risk. In women overall and stratified by obesity status (body mass index, waist circumference, and waist-to-hip ratio) and obesity-related lifestyle factors (exercise and high-fat diet), 88 GWA SNPs in 10 loci were associated with proinflammatory cytokines: 3 associated with IL6 (1 index SNP in MAPK1 and 1 independent SNP in DEC1); 85 with CRP (3 index SNPs in CRPP1, CRP, RP11-419N10.5, HNF1A-AS1, HNF1A, and C1q2orf43; and two independent SNPs in APOE and APOC1). Of those, 27 in HNF1A-AS1, HNF1A, and C1q2orf43 displayed significantly increased risk for breast cancer. We found a number of novel top markers for CRP and IL6, which interacted with obesity factors. A substantial proportion of those SNPs' susceptibility influenced breast cancer risk. Our findings may contribute to better understanding of genetic associations between pro-inflammation and cancer and suggest intervention strategies for women who carry the risk genotypes, reducing breast cancer risk. PREVENTION RELEVANCE: The top GWA-SNPs associated with pro-inflammatory biomarkers have implications for breast carcinogenesis by interacting with obesity factors. Our findings may suggest interventions for women who carry the inflammatory-risk genotypes to reduce breast cancer risk.

Randomized Controlled Lifestyle Intervention (LION) Study for Weight Loss and Maintenance in Adults With Obesity-Design and Methods

Introduction: Due to the increasing prevalence of obesity, approaches for a more effective treatment especially in the long-term perspective are needed. However, studies on weight loss and maintenance show heterogeneous results with large inter-individual variations. Therefore, it is of interest to identify factors that contribute to inter-individual differences and predict the success of long-term weight management.

Methods and Analysis: The primary outcome of the Lifestyle Intervention (LION) Study is to evaluate the effect of two diets (low carb vs. low fat) and two digital counseling tools (newsletter vs. mobile application) on weight maintenance 12 months after weight loss. The identification of predictive factors (e.g., genetic, epigenetic, physiological, psychological) for the success of weight loss and maintenance is a secondary outcome. Men and women with a body mass index (BMI) between 30.0 and 39.9 kg/m², aged 18–65 years, and without severe diseases are considered eligible. After phenotyping (e.g., anthropometry, resting metabolic rate, meal challenges, blood parameters) participants will follow a formula-based, low-calorie diet (LCD) for 8 weeks. In addition, the intake of 200 g raw or cooked non-starchy vegetables are allowed per day. Subsequently, 252 participants will be randomized into one of the four intervention groups (low carb/app, low carb/newsletter, low fat/app, low fat/newsletter) for the 12-month weight maintenance step. The study will be concluded after another 12 months of follow-up. Results should provide indications for successful weight management and give insights into the personalized treatment of obesity.

Ethics and Dissemination: This study has been granted ethical approval by the local Ethics Review Committee of the School of Medicine, Technical University of Munich (vote: 69/19 S).

Trial Registration Number: This study has been registered within ClinicalTrials.gov (NCT04023942) and the German Clinical Trials Register (DRKS00017819).

Associations between Genotype-Diet Interactions and Weight Loss-A Systematic Review

Studies on the interactions between single nucleotide polymorphisms (SNPs) and macronutrient consumption on weight loss are rare and heterogeneous. This review aimed to conduct a systematic literature search to investigate genotype-diet interactions on weight loss. Four databases were searched with keywords on genetics, nutrition, and weight loss (PROSPERO: CRD42019139571). Articles in languages other than English and trials investigating special groups (e.g., pregnant women, people with severe diseases) were excluded. In total, 20,542 articles were identified, and, after removal of duplicates and further screening steps, 27 articles were included. Eligible articles were based on eight trials with 91 SNPs in 63 genetic loci. All articles examined the interaction between genotype and macronutrients (carbohydrates, fat, protein) on the extent of weight loss. However, in most cases, the interaction results were not significant and represented single findings that lack replication. The publications most frequently analyzed genotype-fat intake interaction on weight loss. Since the majority of interactions were not significant and not replicated, a final evaluation of the genotype-diet interactions on weight loss was not possible. In conclusion, no evidence was found that genotype-diet interaction is a main determinant of obesity treatment success, but this needs to be addressed in future studies.

The "Virtual Digital Twins" Concept in Precision Nutrition

Nutritional and lifestyle changes remain at the core of healthy aging and disease prevention. Accumulating evidence underscores the impact of genetic, metabolic, and host gut microbial factors on individual responses to nutrients, paving the way for the stratification of nutritional guidelines. However, technological advances that incorporate biological, nutritional, lifestyle, and health data at an unprecedented scale and depth conceptualize a future where preventative dietary interventions will exceed stratification and will be highly individualized. We herein discuss how genetic information combined with longitudinal metabolomic, immune, behavioral, and gut microbial parameters, and bioclinical variables could define a digital replica of oneself, a "virtual digital twin," which could serve to guide nutrition in a personalized manner. Such a model may revolutionize the management of obesity and its comorbidities, and provide a pillar for healthy aging.

Genetic susceptibility, lifestyle intervention and glycemic changes among women with prior gestational diabetes

AIMS

Women with prior gestational diabetes mellitus (GDM) or high genetic susceptibility are prone to development of type 2 diabetes. We examined whether a lifestyle intervention modified the genetic effect on changes in glycemic markers among women with prior GDM.

RESEARCH DESIGN AND METHODS

This study included 560 women with prior GDM from a randomized controlled trial, the Tianjin Gestational Diabetes Mellitus Prevention Program, who were assigned into an intervention arm (improved physical activity and healthy dietary intakes) or a control arm. We assessed associations of GDM related genetic variants in/near the CDKAL1 (rs7754840) and MTNR1B (rs10830962) genes with changes in fasting levels of glucose and insulin, β-cell function (HOMA-B) and insulin resistance (HOMA-IR) at 1 year and 2 years after the baseline.

RESULTS

We found significant interactions between CDKAL1 variant rs7754840 and lifestyle intervention on changes in fasting insulin and HOMA-IR at 1 year (P for interactions = 0.008 and 0.006, respectively). The GDM-increasing C allele was associated with a 0.07-unit greater increase in fasting insulin (P = 0.048) and HOMA-IR (P = 0.045) in the control group, while opposite-directional associations were observed in the intervention group; women with the C allele seemed to decrease more in these glycemic markers than the non-C-carriers (both P ≤ 0.06). The interactions between the CDKAL1 genetic variant and lifestyle intervention on changes in fasting insulin (P = 0.035) and HOMA-IR (P = 0.024) remained significant over the 2-year period, even though the effects of lifestyle intervention were attenuated at 2-year. The MTNR1B variant rs10830962 did not show interaction with lifestyle intervention on changes in the glycemic markers.

CONCLUSIONS

Healthy lifestyle intervention may be beneficial for women with the GDM predisposing CDKAL1 genetic variant in improvement of insulin resistance.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01554358. URL OF REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT01554358.

Hypoglycaemic effect of catalpol in a mouse model of high-fat diet-induced prediabetes

Type 2 diabetes mellitus is a major health problem and a societal burden. Individuals with prediabetes are at increased risk of type 2 diabetes mellitus. Catalpol, an iridoid glycoside, has been reported to exert a hypoglycaemic effect in db/db mice, but its effect on the progression of prediabetes is unclear. In this study, we established a mouse model of prediabetes and examined the hypoglycaemic effect, and the mechanism of any such effect, of catalpol. Catalpol (200 mg/(kg·day)) had no effect on glucose tolerance or the serum lipid level in a mouse model of impaired glucose tolerance-stage prediabetes. However, catalpol (200 mg/(kg·day)) increased insulin sensitivity and decreased the fasting glucose level in a mouse model of impaired fasting glucose/impaired glucose tolerance-stage prediabetes. Moreover, catalpol increased the mitochondrial membrane potential (1.52-fold) and adenosine triphosphate content (1.87-fold) in skeletal muscle and improved skeletal muscle function. These effects were mediated by activation of the insulin receptor-1/glucose transporter type 4 (IRS-1/GLUT4) signalling pathway in skeletal muscle. Our findings will facilitate the development of a novel approach to suppressing the progression of diabetes at an early stage. Novelty Catalpol prevents the progression of prediabetes in a mouse model of prediabetes. Catalpol improves insulin sensitivity in skeletal muscle. The effects of catalpol are mediated by activation of the IRS-1/GLUT4 signalling pathway.

Lessons Learned from the POUNDS Lost Study: Genetic, Metabolic, and Behavioral Factors Affecting Changes in Body Weight, Body Composition, and Cardiometabolic Risk

PURPOSE OF REVIEW

This paper reviews the genetic and non-genetic factors that provided predictions of, or were associated with, weight loss and other metabolic changes in the POUNDS Lost clinical trial of weight loss. This trial randomized 811 individuals who were overweight or obese to one of four diets that contained either 15% or 25% protein and 20% or 40% fat in a 2 × 2 factorial design. A standard behavioral weight loss program was available for all participants who were followed for 2 years with an 80% completion rate.

RECENT FINDINGS

Nineteen genes and five genetic risk scores were used along with demographic, behavioral, endocrine, and metabolic measurements. Genetic variations in most of the genes were associated with weight loss, but this association often varied with the dietary assignment. A number of demographic and behavioral factors, including attendance at behavioral sessions and food cravings were predictive of weight changes. A high baseline level of free triiodothyronine or free thyroxine predicted the magnitude of weight loss. Several perfluoroakyl compounds predicted more rapid weight regain. Genetic evidence from POUNDS Lost provides guidance toward selection of a personalized weight loss diet and improvement in metabolic profile. There is still room for additional research into the predictors of weight loss.

Lifestyle intervention modifies the effect of the MC4R genotype on changes in insulin resistance among women with prior gestational diabetes: Tianjin Gestational Diabetes Mellitus Prevention Program

BACKGROUND

A history of gestational diabetes mellitus (GDM) has been related to an elevated risk of type 2 diabetes. The melanocortin-4 receptor (MC4R) genotype has been related to glycemic changes in women with prior GDM.

OBJECTIVE

The objective of this study was to analyze whether lifestyle intervention modified the association between the MC4R genotype and changes in insulin sensitivity among women with prior GDM.

METHODS

We genotyped MC4R rs6567160 and measured glucose and insulin in fasting plasma samples at baseline and during the first 2 follow-up visits in 1128 women with prior GDM. They were randomly assigned to either a 4-y lifestyle intervention involving both diet and physical activity or a control group from a randomized clinical trial, the Tianjin Gestational Diabetes Mellitus Prevention Program. We analyzed the interaction between the MC4R genotype and lifestyle intervention on changes in insulin resistance.

RESULTS

From baseline to 1.28 y, the MC4R genotype was related to changes in fasting insulin, HOMA-IR, and homeostasis model assessment of β cell function (HOMA-B) in the intervention group. Each risk allele (C) of rs6567160 was associated with a 0.08-unit greater decrease in log(insulin), log(HOMA-IR), and log(HOMA-B) (P = 0.02, 0.04, and 0.04, respectively), whereas in the control group, each C allele tended to be associated with a greater increase in HOMA-IR (P = 0.09). We found significant interactions between the MC4R genotype and lifestyle intervention on 1.28-y changes in fasting insulin and HOMA-IR (P = 0.006 and 0.008, respectively), and such interaction remained significant when we analyzed the trajectory of changes in insulin and HOMA-IR from baseline to 2.55 y (both P = 0.03).

CONCLUSIONS

The exploratory results from the first 2 follow-up visits indicate that women with prior GDM carrying a diabetes-increasing MC4R genotype (CC or TC) may obtain better improvement than the TT genotype in insulin resistance through lifestyle intervention. This trial was registered at clinicaltrials.gov as NCT01554358.

Gene-Environment Interactions on Body Fat Distribution

The prevalence of obesity has been increasing markedly in the U.S. and worldwide in the past decades; and notably, the obese populations are signified by not only the overall elevated adiposity but also particularly harmful accumulation of body fat in the central region of the body, namely, abdominal obesity. The profound shift from “traditional” to “obesogenic” environments, principally featured by the abundance of palatable, energy-dense diet, reduced physical activity, and prolonged sedentary time, promotes the obesity epidemics and detrimental body fat distribution. Recent advances in genomics studies shed light on the genetic basis of obesity and body fat distribution. In addition, growing evidence from investigations in large cohorts and clinical trials has lent support to interactions between genetic variations and environmental factors, e.g., diet and lifestyle factors, in relation to obesity and body fat distribution. This review summarizes the recent discoveries from observational studies and randomized clinical trials on the gene–environment interactions on obesity and body fat distribution.

Dietary Fatty Acids and the Metabolic Syndrome: A Personalized Nutrition Approach

Dietary fatty acids are present in a wide variety of foods and appear in different forms and lengths. The different fatty acids are known to have various effects on metabolic health. The metabolic syndrome (MetS) is a constellation of risk factors of chronic diseases. The etiology of the MetS is represented by a complex interplay of genetic and environmental factors. Dietary fatty acids can be important contributors of the evolution or in prevention of the MetS; however, great interindividual variability exists in the response to fatty acids. The identification of genetic variants interacting with fatty acids might explain this heterogeneity in metabolic responses. This chapter reviews the mechanisms underlying the interactions between the different components of the MetS, dietary fatty acids and genes. Challenges surrounding the implementation of personalized nutrition are also covered.

Impact of Genes and Environment on Obesity and Cardiovascular Disease

Obesity and abdominal obesity have been closely related to cardiovascular outcomes, and recent evidence has indicated that environmental and genetic factors act in concert in determining the risks of these conditions. Improving adherence to healthy lifestyle habits and healthy dietary patterns can at least partly counteract genetic variations related to risks of obesity and cardiovascular disease (CVD). Other factors, such as epigenetic alterations, may also modulate a relationship between genetic susceptibility and these disorders. In this review, we highlight data from recent studies on gene and environmental risk factors for obesity and CVD, and describe how these findings might inform understanding of the complex roles of interactions between genes and environmental factors in the development of obesity and CVD.