The effect of diet-induced weight loss on circulating homocysteine levels in people with obesity and type 2 diabetes

BACKGROUND/AIMS

Having type 2 diabetes (T2D) in combination with being overweight results in an additional increase in cardiovascular disease (CVD) risk. In addition, T2D and obesity are associated with increased levels of total homocysteine (tHcy), possibly contributing to the CVD risk. Weight loss dieting has positive effects on several CVD risk factors, but whether it affects tHcy remains unclear. Therefore, the aim of this study was to determine the effect of a calorie restricted diet on tHcy in overweight people with T2D.

METHODS

In this post-hoc analysis of the POWER study, adults with T2D and a BMI greater than 27 kg/m² were included from the outpatient diabetes clinic of the Erasmus Medical Center, Rotterdam. The patients were subjected to a very low-calorie diet with fortified meal replacements for 20 weeks. Before and after this intervention, blood samples were collected to measure tHcy and other CVD risk factors like glycaemic and lipid parameters.

RESULTS

161 overweight participants with T2D were included, with a mean age of 54 years (range 26-74), mean weight of 104.6 ± 19.9 kg and mean HbA1c of 62.7 ± 14.3 mmol/mol. At baseline, men displayed higher tHcy than women, and tHcy level was positively correlated with body weight and triglyceride levels, while it was negatively correlated with renal function and HDL cholesterol. During the intervention, bodyweight was reduced by a mean of 9.7% (from 104.6 ± 19.9 to 94.5 ± 18.1 kg p < 0.001), and all measured glycaemic and lipid blood parameters improved significantly. However, tHcy remained unchanged (from 12.1 ± 4.1 to 12.1 ± 4.2 umol/L, p = 0.880). The change in tHcy during the intervention was negatively associated with the change in weight and BMI (p = 0.01 and p = 0.008, respectively). People who lost < 10 kg (n = 92) had a mean tHcy change of -0.47 umol/L, while people who lost more than ≥ 10 kg (n = 69) had a mean tHcy change of 0.60 umol/L (p = 0.021).

CONCLUSION

In conclusion, our data show that a calorie restricted diet does not affect tHcy in people with T2D and obesity, despite the use of meal replacements fortified with folic acid and vitamin B12. Our data showed a negative correlation between change in tHcy levels and weight loss, suggesting that people who lost more weight (> 10 kg) showed an increase in tHcy. Future studies should explore the potential increase in tHcy induced by weight loss dieting and target the question if tHcy reduction strategies during weight loss could be clinically beneficial.

Effects of a calorie-restricted dietary intervention on weight loss and gut microbiota diversity in obese patients with sleep deprivation

OBJECTIVES

This study aimed to investigate the effects of a calorie-restricted dietary (CRD) intervention on weight and gut microbiota diversity in obese patients with sleep deprivation (SD).

METHODS

Twenty obese patients were divided into a sleep deprivation group (SD group, n = 10) and a nonsleep deprivation group (NSD group, n = 10), both of which underwent a CRD intervention for 12 weeks. Measurement of anthropometric parameters, biochemical examinations and gut microbiota detection were performed at baseline and at the end of week 12. Mi Smart Bands 1 (Standard Option) were used to monitor sleep and exercise.

RESULTS

(1) The CRD intervention improved body weight (BW), waist circumference (WC), blood pressure (BP), basal metabolic rate (BMR), body fat content (BFC), and insulin resistance index (HOMA-IR) in all obese patients. (2) In the NSD group, BW, BFC, VFA (visceral fat area), BMR and total cholesterol (TC) were significantly reduced after the CRD intervention (P < 0.05). (3) The alpha diversity of the gut microbiota remained unchanged after the intervention in the two groups. (4) There was a negative correlation between Mollicutes and BMR in the NSD group.

CONCLUSIONS

The effects of a CRD intervention weaken on weight loss and the metabolism of blood lipids may be weakened by SD. The abundance of Mollicutes bacteria may be related to weight loss after a CRD intervention in obese patients.

LEVEL OF EVIDENCE

III, prospective cohort study.

Efficacy of progressive versus severe energy restriction on body composition and strength in concurrent trained women

PURPOSE

This study evaluated the concurrent training (CT) effect in combination with either progressive energy restriction (PER) or severe energy restriction (SER) on body composition and strength-related variables in resistance-trained women.

METHODS

Fourteen women (29.5 ± 3.8 years; 23.8 ± 2.8 kg·m^-2) were randomly assigned to a PER (n = 7) or SER (n = 7) group. Participants performed an 8-week CT program. Pre- and post-intervention measures of fat mass (FM) and fat-free mass (FFM) were assessed by dual-energy X-ray absorptiometry and strength-related variables were assessed through 1-repetition maximum (in the squat and bench press) and countermovement jump.

RESULTS

Significant reductions in FM were observed in PER and SER (Δ = - 1.7 ± 0.4 kg; P =  < 0.001; ES = - 0.39 and Δ = - 1.2 ± 0.6 kg; P = 0.002; ES = - 0.20, respectively). After correcting FFM for fat-free adipose tissue (FFAT), no significant differences for this variable were found either in PER (Δ = - 0.3 ± 0.1; P = 0.071; ES = - 0.06) or in SER (Δ = - 0.2 ± 0.1; P = 0.578; ES = - 0.04). There were no significant changes in the strength-related variables. No between-group differences were found in any of the variables.

CONCLUSION

A PER has similar effects to a SER on body composition and strength in resistance-trained women performing a CT program. Given that PER is more flexible and thus may enhance dietary adherence, it might be a better alternative for FM reduction compared to SER.

Eating, diet, and nutrition for the treatment of non-alcoholic fatty liver disease

Nutrition and dietary interventions are a central component in the pathophysiology, but also a cornerstone in the management of patients with non-alcoholic fatty liver disease (NAFLD). Summarizing our rapidly advancing understanding of how our diet influences our metabolism and focusing on specific effects on the liver, we provide a comprehensive overview of dietary concepts to counteract the increasing burden of NAFLD. Specifically, we emphasize the importance of dietary calorie restriction independently of the macronutrient composition together with adherence to a Mediterranean diet low in added fructose and processed meat that seems to exert favorable effects beyond calorie restriction. Also, we discuss intermittent fasting as a type of diet specifically tailored to decrease liver fat content and increase ketogenesis, awaiting future study results in NAFLD. Finally, personalized dietary recommendations could be powerful tools to increase the effectiveness of dietary interventions in patients with NAFLD considering the genetic background and the microbiome, among others.

Changes of Insulin Resistance and Adipokines Following Supplementation with Glycyrrhiza Glabra L. Extract in Combination with a Low-Calorie Diet in Overweight and Obese Subjects: a Randomized Double Blind Clinical Trial

Purpose: Adipose tissue is a highly active endocrine organ which plays a key role in energy homeostasis. The aim of this study was to determine the effects of dried licorice extract along with a calorie restricted diet on body composition, insulin resistance and adipokines in overweight and obese subjects.

Methods: Sixty-four overweight and obese volunteers (27 men, 37 women) were recruited into this double-blind, placebo-controlled, randomized, clinical trial. Participants were randomly allocated to the Licorice (n=32) or the placebo group (n=32), and each group received a low-calorie diet with either 1.5 g/day of Licorice extract or placebo for 8 weeks. Biochemical parameters, anthropometric indices, body composition and dietary intake were measured at baseline and at the end of the study.

Results: A total of 58 subjects completed the trial. No side effects were observed following licorice supplementation. At the end of the study, waist circumference, fat mass, serum levels of vaspin, zinc-α2 glycoprotein, insulin and HOMA-IR were significantly decreased in the intervention group, but only the reduction in serum vaspin levels in the licorice group was significant when compared to the placebo group (p<0.01).

Conclusion: Supplementation with dried licorice extract plus a low-calorie diet can increase vaspin levels in obese subjects. However, the anti-obesity effects of the intervention were not stronger than a low-calorie diet alone in the management of obesity.

Long-term food restriction prevents aging-associated sphingolipid turnover dysregulation in the brain

Abnormalities of sphingolipid turnover in the brain during normal aging and age-related neurological disorders were associated with the neurons loss and cognitive malfunction. Calorie restriction (CR) prevented age-related deficits in hippocampal long-term potentiation and improved cognitive function at old age. In the paper we investigated the ceramide and sphingomyelin (SM) levels in the brain regions, which are critical for learning and memory of 3- and 24-month-old rats, as well as the correction of sphingolipid turnover in the brain of old rats, by means of the CR diet and modulators of SM turnover. Using the [methyl-(14)C-choline]SM, the neutral, but not the acid SMase activity has been observed to increase in both the hippocampus and brain cortex of 24-month-old rats with respect to 3-month-old animals. Age-dependent changes of neutral SMase activities were associated with ceramide accumulation and SM level drop in the brain structures studied. Treatment of the rats with the CR diet or N-acetylcysteine (NAC) or α-tocopherol acetate, but not an inhibitor of acid SMase imipramine, reduced the ceramide content and neutral SMase activity in the hippocampus of 24-month-old animals with respect to control rats of the same age. These results suggest that redox-sensitive neutral SMase plays important role in SM turnover dysregulation in both the hippocampus and neocortex at old age and that the CR diet can prevent the age-dependent accumulation of ceramide mainly via neutral SMase targeting.