Ramadan Intermittent Fasting Affects Adipokines and Leptin/Adiponectin Ratio in Type 2 Diabetes Mellitus and Their First-Degree Relatives

The effectiveness of fasting regimens on serum levels of some major weight regulating hormones: a GRADE-assessed systematic review and meta-analysis in randomized controlled trial

A current investigation was performed to review and summarize the results of randomized clinical trials (RCTs) studies that have assessed the effectiveness of fasting regimens (FRs) including intermittent fasting (IF), time-restricted feeding (TRF), alternate day fasting (ADF) and fasting-mimicking diet (FMD) on some weight regulation hormones included; leptin, adiponectin, ghrelin, and resistin in healthy, overweight and obese adults recently. Four databases have been reviewed until June 2024 using keywords related to the subject of the study. Overall, 16 documents were considered in this study. Based on Pooled effect sizes, the FRs marginal significantly increased the level of adiponectin (weighted mean differences (WMD): 0.41 µg/ml, 95% confidence interval (CI): - 0.07 to 0.89, P: 0.09) and also significantly decreased the level of leptin (WMD: - 2.65 ng/ml, 95% CI: - 3.86 to - 1.44, p < 0.001) and ghrelin (WMD: - 0.57 ng/ml, 95% CI: - 1.01 to - 0.03, P: 0.01). There was no significant effect of this regimen approach on resistin levels. In general, according to this evaluation, FRs have a beneficial impact on weight-regulating hormone levels, still the long-term effects of these dietary approaches should also be evaluated in future studies.

Effects of Ramadan intermittent fasting on hormones regulating appetite in healthy individuals: A systematic review and meta-analysis

BACKGROUND AND AIMS

This systematic review and meta-analysis aimed to examine the effect of Ramadan intermittent fasting on appetite-regulating hormones including leptin, ghrelin, insulin, gastrin, glucagon-like peptide-1, peptide YY, and cholecystokinin.

METHODS

We searched the MEDLINE, Embase, Cochrane Library, CINAHL, Google Scholar, and Web of Science databases to identify relevant research on appetite-regulating hormones during Ramadan intermittent fasting, published until the end of March 2024.

RESULTS

Data from 16 eligible studies comprising 664 participants (341, 51.4 % male) with a mean ± standard deviation age of 33.9 ± 10.8 years were included. The meta-analysis included 12 studies with complete leptin data, showing no significant effect of Ramadan intermittent fasting on leptin concentrations (standardised mean difference - SMD = -0.11 μg/mL, 95 % CI: -0.36 to 0.14). Analysis of three studies with complete ghrelin data demonstrated a significant increase in ghrelin concentrations following Ramadan intermittent fasting (SMD = 0.31 pg/mL, 95 % CI: 0.03 to 0.60). Six studies examining insulin concentrations pre- and post-fasting revealed no significant effect on insulin concentrations (SMD = -0.24 μU/mL, 95 % CI: -0.54 to 0.02). Similarly, analysis of three studies with complete gastrin data showed no significant effect of intermittent fasting on gastrin concentrations (SMD = 0.23 pg/mL, 95 % CI: -0.71 to 0.99).

CONCLUSION

Ramadan intermittent fasting significantly increases ghrelin concentrations while showing no significant effects on leptin, insulin, and gastrin. While ghrelin findings were consistent across studies, the high heterogeneity in leptin studies suggests further research to better understand the effects of Ramadan intermittent fasting on appetite-regulating hormones.

A detective story of intermittent fasting effect on immunity

Intermittent fasting (IF) refers to periodic fasting routines, that caloric intake is minimized not by meal portion size reduction but by intermittently eliminating ingestion of one or several consecutive meals. IF can instigate comprehensive and multifaceted alterations in energy metabolism, these metabolic channels may aboundingly function as primordial mechanisms that interface with the immune system, instigating intricate immune transformations. This review delivers a comprehensive understanding of IF, paying particular attention to its influence on the immune system, thus seeking to bridge these two research domains. We explore how IF effects lipid metabolism, hormonal levels, circadian rhythm, autophagy, oxidative stress, gut microbiota, and intestinal barrier integrity, and conjecture about the mechanisms orchestrating the intersect between these factors and the immune system. Moreover, the review includes research findings on the implications of IF on the immune system and patients burdened with autoimmune diseases.

Effect of intermittent fasting on lipid biokinetics in obese and overweight patients with type 2 diabetes mellitus: prospective observational study

BACKGROUND

Intermittent fasting (IF) is a commonly used dietary practice that alternates between periods of unrestricted dietary consumption and abstinence from caloric intake. IF reduces caloric intake along with metabolic switch from utilization of glucose to fatty acids and ketones and resulting in reduction in adiposity and subsequently insulin resistance. Thus, it has been hypothesized that IF regimens can improve body composition in obese and overweight individuals.

AIM

To assess the effect of IF on lipid biokinetics in obese and overweight patients with type 2 diabetes (T2D).

PATIENTS AND METHODS

Thirty overweight or obese T2D patients were recruited from the diabetes outpatient clinics at the Specialized Medical Hospital, Mansoura University. Patients were subjected to time restricted fasting for 16 h (from dawn to sunset) during Ramadan. Anthropometric data were measured for participants before and 3 weeks after Ramadan fasting. Fasting plasma glucose (FPG), HbA1c, lipid profile, leptin, beta hydroxybutyrate (βHB) and high sensitive CRP levels were measured 1 week before and 3 weeks after Ramadan fasting.

RESULTS

30 diabetic patients were recruited with a mean age of 54.3 ± 7.2 years. 24 (80%) were females. Obesity was diagnosed in 27 cases (90%). The median diabetes duration was 10 years. The study showed a statistically significant decrease in post-fasting body weight (BW), Body mass index (BMI), waist circumference (WC) & hip circumference (HC). There was a statistically significant decrease of post-fasting low density lipoprotein (LDL-C), Total cholesterol (TC), and leptin. The study also showed a statistically significant increase of post-fasting high density lipoprotein (HDL-C) and βHB. No significant change was found in post-fasting levels of HbA1c, FPG, triglycerides (TG) or high sensitive CRP. Post-fasting leptin was positively correlated with post-fasting BW, BMI, WC, and HC. Post-fasting βHB was positively correlated with post-fasting TG, HbA1c, and LDL-C. Leptin levels change (pre vs post fasting) was positively correlated with the change in LDL-C levels.

CONCLUSION

IF reduced leptin and increased β-hydroxybutyrate levels. IF is an effective tool for losing weight and visceral fat and improving lipid profile in obese and overweight patients with T2D.

The effects of short-term caloric restriction on cardiometabolic health in overweight/obese men and women: A single-arm trial

Overweight and obesity (Ow/Ob) is a risk factor for cardiometabolic disease. Caloric restriction (CR) have been investigated but little is known about the acute effects of CR and often such diets are not standardized. Thus, we aimed to assess the impact of a new standardized 3-day CR diet (590 kcal/d intake) on cardiometabolic health in weight-stable Ow/Ob individuals. In a single-arm design, 15 Ow/Ob men and women were assessed pre-post a 3-day standardized CR diet; specifically, body weight/composition (%body fat, visceral fat score (Vfs), blood pressure (BP), and vascular stiffness (VS), resting energy expenditure (REE), substrate utilization (respiratory quotient, RQ), and blood glucose/lipid profile). CR lowered body weight (93.1 ± 15.2 to 90.67 ± 14.4 kg, p < 0.001, d = 1.9), %fat (37.2 ± 7.5 to 35.8 ± 7.5%, p = 0.002, d = 1.1), and Vfs (13.1 ± 4.5 to 12.2 ± 3.9 a.u., p = 0.002, d = 1.1), but not body water (46.3 ± 3.6 to 46.0 ± 3.6%, p = 0.29). CR lowered VS (29.8 ± 17.5 to 21.5 ± 14.5%, p = 0.05, d = 0.6), but not BP (p > 0.05). Blood glucose (86 ± 7 to 84 ± 11 mg/dL, p = 0.33) and lipids (total cholesterol (196 ± 49 to 203 ± 54 mg/dL, p = 0.16) and TC/HDL (4.9 ± 2.4 to 6.1 ± 4.7, p = 0.13)) were unchanged. RQ decreased with CR (0.84 ± 0.01 to 0.76 ± 0.00, p < 0.001, d = 1.9), though REE was unchanged (p = 0.83). The 3-day CR diet significantly improved fat metabolism, body weight and composition, and vascular stiffness.

Dysregulation of adipokines levels among healthy first-degree relatives of type 2 diabetes patients

Background

Leptin, adiponectin and its ratio (L/A), as well as adipocyte fatty acid binding protein (A-FABP) have shown association to type 2 diabetes and atherosclerosis. Since first degree relatives (FDR) of type 2 diabetes are known to have higher risks of developing aforementioned diseases, this study aimed to see differences in adipokines profiles between FDR of type 2 diabetes and non-FDR counterpart.

Methods

Age, sex and body mass index (BMI)-matched normotensive-normoglycemic subjects, aged 19-39 years with BMI<30 kg/m2, were included in this cross-sectional study. Serum adiponectin, leptin, and A-FABP levels were measured by sandwich ELISA while HOMA-IR was calculated from fasting blood glucose and insulin levels.

Results

Of 116 subjects recruited, there were significant difference of insulin level (6.00 vs 5.00 μIU/mL, P = 0.029) and HOMA-IR (1.27 vs 1.10, P = 0.028). Adiponectin, leptin, L/A ratio, and A-FABP levels were not statistically different between FDR and non-FDR groups. Stratified by BMI, non-obese FDR had higher L/A ratio (0.83 vs 0.49, P = 0.020) compared to those of corresponding non-FDR. In multivariate analysis, after adjusting for age, sex, waist circumference, BMI, and metabolic profiles (HbA1C, HOMA-IR, LDL-C, HDL-C, and triglyceride levels), FDR status became significantly associated with adiponectin level, and in non-obese subgroup, remained its significance with L/A ratio.

Conclusion

The FDR status was independently associated with adiponectin level. Furthermore, higher L/A ratio was more pronounced in non-obese FDR than those of non-FDR subjects, suggesting that FDR status may already contribute to the development of adipokines dysregulation before obesity occurs.

Effects of Intermittent Fasting on Regulation of Metabolic Homeostasis: A Systematic Review and Meta-Analysis in Health and Metabolic-Related Disorders

Intermittent fasting (IF) is an emerging dietetic intervention that has been associated with improved metabolic parameters. Nowadays, the most common IF protocols are Alternate-Day Fasting (ADF) and Time-Restricted Fasting (TRF), but in this review and meta-analysis we have also considered Religious Fasting (RF), which is similar to TRF but against the circadian rhythm. The available studies usually include the analysis of a single specific IF protocol on different metabolic outcomes. Herein, we decided to go further and to conduct a systematic review and meta-analysis on the advantages of different IF protocols for metabolic homeostasis in individuals with different metabolic status, such as with obesity, diabetes mellitus type 2 (T2D) and metabolic syndrome (MetS). Systematic searches (PubMed, Scopus, Trip Database, Web of Knowledge and Embase, published before June 2022) of original articles in peer-review scientific journals focusing on IF and body composition outcomes were performed. Sixty-four reports met the eligibility criteria for the qualitative analysis and forty-seven for the quantitative analysis. Herein, we showed that ADF protocols promoted the major beneficial effects in the improvement of dysregulated metabolic conditions in comparison with TRF and RF protocols. Furthermore, obese and MetS individuals are the most benefited with the introduction of these interventions, through the improvement of adiposity, lipid homeostasis and blood pressure. For T2D individuals, IF impact was more limited, but associated with their major metabolic dysfunctions-insulin homeostasis. Importantly, through the integrated analysis of distinct metabolic-related diseases, we showed that IF seems to differently impact metabolic homeostasis depending on an individual's basal health status and type of metabolic disease.

The impact of Ramadan intermittent fasting on anthropometric measurements and body composition: Evidence from LORANS study and a meta-analysis

Background

Although the effect of Ramadan intermittent fasting (RIF) on anthropometry and body composition has been questioned, none of the previous studies tried to explain the reported changes in these parameters. Also, systematic reviews that investigated the topic were limited to healthy individuals or a specific disease group.

Methods

The London Ramadan Study (LORANS) is an observational study on health effects of RIF. We measured weight, waist circumference (WC), hip circumference (HC), body mass index (BMI), waist-to-hip ratio (WHR), basal metabolic rate (BMR), fat percentage (FP), free-fat mass (FFM), extremities predicted muscle mass, total body water (TBW), trunk FM, trunk FFM and trunk predicted muscle mass before and immediately after Ramadan. Using mixed-effects regression models, we investigated the effect of RIF with adjustment for potential confounders. We also conducted a meta-analysis of the results of LORANS with other studies that investigated the effect of RIF on anthropometry and body composition. The review protocol is registered with PROSPERO registry (CRD42020186532).

Results

We recruited 146 participants (Mean ± SD age = 43.3 ± 15 years). Immediately after Ramadan, compared with before Ramadan, the mean difference was-1.6 kg (P<0.01) in weight,-1.95cm (P<0.01) in WC,-2.86cm (P <0.01) in HC, -0.60 kg/m2 (P < 0.01) in BMI and -1.24 kg (P < 0.01) in FM. In the systematic review and meta-analysis, after screening 2,150 titles and abstracts, 66 studies comprising 7,611 participants were included. In the general population, RIF was followed by a reduction of 1.12 Kg in body weight (-1.89- -0.36, I2 = 0), 0.74 kg/m2 reduction in BMI (-0.96- -0.53, I2 = 0), 1.54cm reduction in WC (-2.37- -0.71, I2 = 0) and 1.76cm reduction in HC (-2.69- -0.83, I2 = 0). The effect of fasting on anthropometric and body composition parameters starts to manifest in the second week of Ramadan and starts to diminish 3 weeks after Ramadan.

Conclusion

RIF is associated with a reduction in body weight, BMI, WC, HC, FM, FP and TBW. Most of these reductions are partially attributed to reduced FM and TBW. The reductions in these parameters appear to reverse after Ramadan.