Long-term kidney and systemic effects of calorie restriction in overweight or obese type 2 diabetic patients (C.Re.S.O. 2 randomized controlled trial)

Intermittent fasting versus continuous caloric restriction for glycemic control and weight loss in type 2 diabetes: A traditional review

Type 2 Diabetes Mellitus (T2DM) represents a major global health issue, with its incidence anticipated to increase markedly in the forthcoming decades. Efficient non-pharmacological therapies, especially dietary approaches, are essential for regulating glycemic control and facilitating weight reduction. Intermittent Fasting (IF) and Continuous Caloric Restriction (CCR) are two well researched methodologies, but their relative effectiveness and enduring advantages continue to be topics of active discussion. This review systematically assesses and contrasts the impacts of intermittent fasting (IF) and continuous calorie restriction (CCR) on glycemic regulation and weight reduction in persons with type 2 diabetes mellitus (T2DM), highlighting their short-term and long-term effects, safety profiles, and adherence rates. A thorough literature analysis was performed utilizing PubMed and Google Scholar, concentrating on papers published from 2000 to 2024. The review encompassed randomized controlled trials and observational studies that investigated the effects of intermittent fasting (IF) and continuous calorie restriction (CCR) on glycemic indicators (HbA1c, fasting glucose) and body weight. IF shown substantial short-term advantages, encompassing marked decreases in HbA1c levels, fasting glucose, and body weight. Mechanistic discoveries emphasized better insulin sensitivity, augmented fat metabolism, and autophagy as key aspects. In contrast, CCR was linked to enduring metabolic enhancements, including decreased visceral fat and improved insulin sensitivity. Nevertheless, both dietary approaches demonstrated constraints.

Obesity and Metabolic Health in CKD

Obesity is a worldwide epidemic with a future projected growth of 40% over 10 years. Obesity increases the risk of diabetes, hypertension, and cardiovascular disease, and it also leads to higher risk of CKD, through both direct and indirect mechanisms. Although obesity is a feature of overnutrition and is associated with poor outcomes in the general population, obese individuals with CKD often display complex metabolic patterns such as sarcopenic obesity, and obesity can be associated with better survival in individuals with advanced CKD. Weight loss interventions are proven to improve glycemic control and cardiovascular risk factors, and successful weight loss is associated with improved albuminuria in patients with preexisting CKD. The long-term effects of weight loss interventions on kidney function and on survival in patients with CKD are less well studied, and hence, such interventions should be individualized.

Effects of Different Caloric Restriction Patterns on Blood Pressure and Other Cardiovascular Risk Factors: A Systematic Review and Network Meta-Analysis of Randomized Trials

CONTEXT

All types of caloric restriction are preventive against cardiovascular risk factors, but the best restriction method and most affected factors have not been identified.

OBJECTIVE

The objective of this study was to explore the effects of different caloric restriction methods on various cardiovascular risk factors by horizontally comparing program advantages and disadvantages via network meta-analysis.

DATA SOURCES

The PubMed, Web of Science, Cochrane Library, and Embase literature databases were searched (October 2013 to October 2023).

DATA EXTRACTION

Eligible randomized controlled trials involving participants who underwent caloric restriction and systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), and high-density lipoprotein (HDL) cholesterol level measurements were included.

DATA ANALYSIS

Thirty-six of 13 208 records (0.27%) were included. Two researchers reviewed the articles, extracted data, and assessed article quality.

RESULTS

Alternate-day fasting (ADF) reduced SBP (4.88 mmHg; CI, 2.06-7.15) and DBP (5.10 mmHg; CI, 2.44-7.76). Time-restricted eating reduced SBP (2.46 mmHg; CI, 0.16-4.76) but not DBP. Continuous energy restriction (CER) significantly reduced BMI (1.11 kg/m2; CI = 0.16, 2.06) and waist circumference (3.28 cm; CI, 0.62-5.94).

CONCLUSIONS

This meta-analysis confirmed the preventive effect of CER and ADF on various cardiovascular risk factors. Additionally, CER is more likely to reduce obesity, and ADF is more likely to reduce blood pressure (BP). Based on this meta-analysis, CER is recommended to control obesity only for people who are obese and do not have elevated BP or other abnormal indicators. Additionally, ADF for early control or prevention is recommended for patients who have abnormal BP or other cardiovascular risk factors.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023455889.

Effectiveness of Calorie Restriction for Weight Loss in Type 2 Diabetes Mellitus: A Systematic Review

The effectiveness of calorie restriction (CR) for weight loss in type 2 diabetes mellitus (T2DM) has not been thoroughly studied. This review aims to evaluate CR's short- and long-term effectiveness for weight loss and its impact on cardiometabolic parameters in T2DM. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, Medline Complete, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Cochrane Library databases were searched to identify studies up to June 7, 2024. Furthermore, a reference search was conducted. Randomized controlled trials involving adults with T2DM examining CR and reporting weight changes were included. The revised Cochrane risk-of-bias tool was used to assess the study's quality. A narrative synthesis was used to analyze the findings. Eleven studies, with 1,554 participants, were included; all had a low risk of bias. The intervention group participants' mean baseline weight and Body Mass Index were 93.3 kg and 32.7 kg/m², respectively. Interventions used included total diet replacement (TDR) and very low- and low-calorie diets lasting 12 weeks to two years. CR with TDR resulted in >12% weight loss. Additionally, CR improved cardiometabolic parameters; glycated hemoglobin (HbA1c) decreased to ≤6.5%; diabetes remission was achieved in 19% to 83%; high-density lipoprotein significantly increased; and triglyceride, systolic, and diastolic blood pressure significantly decreased. In conclusion, CR effectively reduces weight and improves cardiometabolic markers in T2DM. However, large long-term studies addressing CR in T2DM are lacking, which challenges drawing firm conclusions. This highlights the need for further research to address this gap. This review is registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD42024573505.

Intermittent fasting as a dietary intervention with potential sexually dimorphic health benefits

Intermittent fasting (IF) has proven to be a feasible dietary intervention for the wider population. The recent increase in IF clinical trials highlights its potential effects on health, including changes in body composition, cardiometabolic status, and aging. Although IF may have clinical applications in different populations, studies suggest there may be sex-specific responses in parameters such as body composition or glucose and lipid metabolism. Here, the existing literature on IF clinical trials is summarized, the application of IF in both disease prevention and management is discussed, and potential disparities in response to this type of diet between men and women are assessed. Moreover, the potential mechanisms that may be contributing to the sexually dimorphic response, such as age, body composition, tissue distribution, or sex hormones are investigated. This review underscores the need to further study these sex-specific responses to IF to define the most effective time frames and length of fasting periods for men and women. Tailoring IF to specific populations with a personalized approach may help achieve its full potential as a lifestyle intervention with clinical benefits.

Approaches to patients with obesity and CKD: focus on nutrition and surgery

Obesity is recognized as a public health challenge. During the last three decades, the global age-standardized prevalence increased from 8.8% to 18.5% in women and from 4.8% to 14.0% in men, with an absolute current number of 878 million obese subjects. Obesity significantly increases per se the risk of developing disability and chronic diseases, including chronic kidney disease (CKD). Specifically, obesity acts as a major, modifiable cause of CKD onset and progression toward kidney failure; as such, it is considered by the International Society of Nephrology a major health priority. This review analyses the effectiveness, safety and practicability of non-pharmacological anti-obesity interventions in CKD as the different patient phenotypes that may take advantage of personalized approaches.

A late eating midpoint is associated with increased risk of diabetic kidney disease: a cross-sectional study based on NHANES 2013-2020

BACKGROUND

Modifying diet is crucial for diabetes and complication management. Numerous studies have shown that adjusting eating habits to align with the circadian rhythm may positively affect metabolic health. However, eating midpoint, eating duration, and their associations with diabetic kidney disease (DKD) are poorly understood.

METHODS

The National Health and Nutrition Examination Survey (2013-2020) was examined for information on diabetes and dietary habits. From the beginning and ending times of each meal, we calculated the eating midpoint and eating duration. Urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g and/or estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 were the specific diagnostic criteria for DKD.

RESULTS

In total, details of 2194 subjects with diabetes were collected for analysis. The overall population were divided into four subgroups based on the eating midpoint quartiles. The prevalence of DKD varied noticeably (P = 0.037) across the four categories. When comparing subjects in the second and fourth quartiles of eating midpoint to those in the first one, the odds ratios (ORs) of DKD were 1.31 (95% CI, 1.03 to 1.67) and 1.33 (95% CI, 1.05 to 1.70), respectively. And after controlling for potential confounders, the corresponding ORs of DKD in the second and fourth quartiles were 1.42 (95% CI, 1.07 to 1.90) and 1.39 (95% CI, 1.04 to 1.85), respectively.

CONCLUSIONS

A strong correlation was found between an earlier eating midpoint and a reduced incidence of DKD. Eating early in the day may potentially improve renal outcomes in patients with diabetes.

The impact of weight loss on renal function in individuals with obesity and type 2 diabetes: a comprehensive review

Obesity and Type 2 Diabetes (T2D) are two highly prevalent diseases that exhibit a complex interplay between them. Obesity serves as a primary risk factor for the development of T2D, and conversely, individuals with T2D often exhibit comorbid obesity. Renal dysfunction emerges as a critical consequence of the convergence of obesity and Type 2 Diabetes, contributing significantly to the overall burden of complications associated with these conditions. Recognizing the profound implications of renal dysfunction in individuals contending with both obesity and Type 2 Diabetes, interventions targeting weight loss have gained prominence as potential therapeutic avenues. Weight loss not only addresses the primary risk factor of obesity but also holds the promise of mitigating the progression of Type 2 Diabetes and its associated renal complications. This comprehensive review aims to explore the impact of weight loss on renal function in individuals contending with the convergence of obesity and T2D.

Unraveling the epigenetic code: human kidney DNA methylation and chromatin dynamics in renal disease development

Epigenetic changes may fill a critical gap in our understanding of kidney disease development, as they not only reflect metabolic changes but are also preserved and transmitted during cell division. We conducted a genome-wide cytosine methylation analysis of 399 human kidney samples, along with single-nuclear open chromatin analysis on over 60,000 cells from 14 subjects, including controls, and diabetes and hypertension attributed chronic kidney disease (CKD) patients. We identified and validated differentially methylated positions associated with disease states, and discovered that nearly 30% of these alterations were influenced by underlying genetic variations, including variants known to be associated with kidney disease in genome-wide association studies. We also identified regions showing both methylation and open chromatin changes. These changes in methylation and open chromatin significantly associated gene expression changes, most notably those playing role in metabolism and expressed in proximal tubules. Our study further demonstrated that methylation risk scores (MRS) can improve disease state annotation and prediction of kidney disease development. Collectively, our results suggest a causal relationship between epigenetic changes and kidney disease pathogenesis, thereby providing potential pathways for the development of novel risk stratification methods.

Interactions between the principal risk factors for reduction of the eGFR in unvaccinated COVID‑19 survivors: Normal pre-COVID‑19 eGFR, not having diabetes and being hospitalized

There are contradictory results regarding changes in estimated glomerular filtration rate (eGFR) in coronavirus disease 2019 (COVID-19) survivors. An analysis of eGFR changes and clinical characteristics associated with those changes was conducted among COVID-19 survivors. eGFR values were compared at different time points (before and 4-, 8- and 12-months after COVID-19 infection). A multivariate generalized linear mixed model (GENLINMIXED procedure) with a binary logistic regression link was used to determine factors associated with eGFR reduction of ≥10 ml/min/1.73 m2. Being hospitalized (RR=2.90, 95% CI=1.10-7.68, P=0.032), treated with Ivermectin (RR=14.02, 95% CI=4.11-47.80, P<0.001) or anticoagulants (RR=6.51, 95% CI=2.69-15.73, P<0.001) are risk factors for a reduced eGFR. Having a low eGFR (<90 ml/min/1.73 m2) before COVID-19 infection, having B-positive blood type, diabetes, taking vitamin C during the acute phase of COVID-19 or suffering from chronic COVID-19 symptoms, were identified as protective factors. Analysis involving a two-way interaction (A x B, where A and B are factors) demonstrated that the combination of patients with a normal eGFR value before COVID-19 infection without diabetes (RR=58.60, 95% CI=11.62-295.38, P<0.001), or a normal eGFR value with being hospitalized for COVID-19 (RR=38.07, 95% CI=8.68-167.00, P<0.001), increased the probability of a reduced eGFR. The changes in eGFR in COVID-19 survivors varied depending on patient characteristics. Furthermore, the principal risk factors for post-COVID-19 eGFR reduction were analyzed in separate models.

Effects of Obesity and Calorie Restriction on Cancer Development

The risk of malignant tumor development is increasing in the world. Obesity is an established risk factor for various malignancies. There are many metabolic alterations associated with obesity which promote cancerogenesis. Excessive body weight leads to increased levels of estrogens, chronic inflammation and hypoxia, which can play an important role in the development of malignancies. It is proved that calorie restriction can improve the state of patients with various diseases. Decreased calorie uptake influences lipid, carbohydrate and protein metabolism, hormone levels and cell processes. Many investigations have been devoted to the effects of calorie restriction on cancer development in vitro and in vivo. It was revealed that fasting can regulate the activity of the signal cascades including AMP-activated protein kinase (AMPK), mitogen-activated protein kinase (MAPK), p53, mTOR, insulin/ insulin-like growth factor 1 (IGF1) and JAK-STAT. Up- or down-regulation of the pathways results in the decrease of cancer cell proliferation, migration and survival and the increase of apoptosis and effects of chemotherapy. The aim of this review is to discuss the connection between obesity and cancer development and the mechanisms of calorie restriction influence on cancerogenesis that stress the importance of further research of calorie restriction effects for the inclusion of this approach in clinical practice.

Mechanisms of ageing: growth hormone, dietary restriction, and metformin

Tackling the mechanisms underlying ageing is desirable to help to extend the duration and improve the quality of life. Life extension has been achieved in animal models by suppressing the growth hormone-insulin-like growth factor 1 (IGF-1) axis and also via dietary restriction. Metformin has become the focus of increased interest as a possible anti-ageing drug. There is some overlap in the postulated mechanisms of how these three approaches could produce anti-ageing effects, with convergence on common downstream pathways. In this Review, we draw on evidence from both animal models and human studies to assess the effects of suppression of the growth hormone-IGF-1 axis, dietary restriction, and metformin on ageing.

Comparative efficacy of different eating patterns in the management of type 2 diabetes and prediabetes: An arm-based Bayesian network meta-analysis

AIMS/INTRODUCTION

Diet therapy is a vital approach to manage type 2 diabetes and prediabetes. However, the comparative efficacy of different eating patterns is not clear enough. We aimed to compare the efficacy of various eating patterns for glycemic control, anthropometrics, and serum lipid profiles in the management of type 2 diabetes and prediabetes.

MATERIALS AND METHODS

We conducted a network meta-analysis using arm-based Bayesian methods and random effect models, and drew the conclusions using the partially contextualized framework. We searched twelve databases and yielded 9,534 related references, where 107 studies were eligible, comprising 8,909 participants.

RESULTS

Eleven diets were evaluated for 14 outcomes. Caloric restriction was ranked as the best pattern for weight loss (SUCRA 86.8%) and waist circumference (82.2%), low-carbohydrate diets for body mass index (81.6%), and high-density lipoprotein (84.0%), and low-glycemic-index diets for total cholesterol (87.5%) and low-density lipoprotein (86.6%). Other interventions showed some superiorities, but were imprecise due to insufficient participants and needed further investigation. The attrition rates of interventions were similar. Meta-regression suggested that macronutrients, energy intake, and weight may modify outcomes differently. The evidence was of moderate-to-low quality, and 38.2% of the evidence items met the minimal clinically important differences.

CONCLUSIONS

The selection and development of dietary strategies for diabetic/prediabetic patients should depend on their holistic conditions, i.e., serum lipid profiles, glucometabolic patterns, weight, and blood pressure. It is recommended to identify the most critical and urgent metabolic indicator to control for one specific patient, and then choose the most appropriate eating pattern accordingly.

Obstacles and opportunities in managing coexisting obesity and CKD: Report of a scientific workshop cosponsored by the National Kidney Foundation and The Obesity Society

The National Kidney Foundation (NKF) and The Obesity Society (TOS) cosponsored a multispecialty international workshop in April 2021 to advance the understanding and management of obesity in adults with chronic kidney disease (CKD). The underlying rationale for the workshop was the accumulating evidence that obesity is a major contributor to CKD and adverse outcomes in individuals with CKD, and that effective treatment of obesity, including lifestyle intervention, weight loss medications, and metabolic surgery, can have beneficial effects. The attendees included a range of experts in the areas of kidney disease, obesity medicine, endocrinology, diabetes, bariatric/metabolic surgery, endoscopy, transplant surgery, and nutrition, as well as patients with obesity and CKD. The group identified strategies to increase patient and provider engagement in obesity management, outlined a collaborative action plan to engage nephrologists and obesity medicine experts in obesity management, and identified research opportunities to address gaps in knowledge about the interaction between obesity and kidney disease. The workshop's conclusions help lay the groundwork for development of an effective, scientifically based, and multidisciplinary approach to the management of obesity in people with CKD.

Obstacles and Opportunities in Managing Coexisting Obesity and CKD: Report of a Scientific Workshop Cosponsored by the National Kidney Foundation and The Obesity Society

The National Kidney Foundation (NKF) and The Obesity Society (TOS) cosponsored a multispecialty international workshop in April 2021 to advance the understanding and management of obesity in adults with chronic kidney disease (CKD). The underlying rationale for the workshop was the accumulating evidence that obesity is a major contributor to CKD and adverse outcomes in individuals with CKD, and that effective treatment of obesity, including lifestyle intervention, weight loss medications, and metabolic surgery, can have beneficial effects. The attendees included a range of experts in the areas of kidney disease, obesity medicine, endocrinology, diabetes, bariatric/metabolic surgery, endoscopy, transplant surgery, and nutrition, as well as patients with obesity and CKD. The group identified strategies to increase patient and provider engagement in obesity management, outlined a collaborative action plan to engage nephrologists and obesity medicine experts in obesity management, and identified research opportunities to address gaps in knowledge about the interaction between obesity and kidney disease. The workshop's conclusions help lay the groundwork for development of an effective, scientifically based, and multidisciplinary approach to the management of obesity in people with CKD.