Alteration of BDNF, SPARC, FGF-21, and GDF-15 circulating levels after 1 year of anti-obesity treatments and their association with 1-year weight loss

PURPOSE

Emerging evidence revealed that brain-derived neurotrophic factor (BDNF), secreted protein acidic and rich in cysteine (SPARC), fibroblast growth factor 21(FGF-21) and growth differentiation factor 15 (GDF-15) are involved in energy metabolism and body weight regulation. Our study aimed at examining their association with BMI, their alterations after anti-obesity treatments, and their association with 1-year weight loss.

METHODS

A prospective observational study of 171 participants with overweight and obesity and 46 lean controls was established. All participants received lifestyle educational intervention (LEI) with or without anti-obesity treatments (LEI + bariatric/metabolic surgery, n = 41; LEI + topiramate, n = 46; LEI + liraglutide, n = 31; LEI + orlistat, n = 12; and LEI alone, n = 41). Anthropometric and metabolic parameters, insulin sensitivity, C-reactive protein (CRP), fasting plasma levels of BDNF, SPARC, GDF-15, and FGF-21 were measured at baseline and 1 year.

RESULTS

Multiple linear regression showed that fasting levels of SPARC, FGF-21, and GDF-15 were significantly associated with baseline BMI after adjustment for age and sex. At 1 year, the average weight loss was 4.8% in the entire cohort with a significant improvement in glycemia, insulin sensitivity, and CRP. Multiple linear regression adjusted for age, sex, baseline BMI, type of treatment, and presence of T2DM revealed that the decrease in log10FGF-21 and log10GDF-15 at 1 year from baseline was significantly associated with a greater percentage of weight loss at 1 year.

CONCLUSIONS

This study highlights the association of SPARC, FGF-21, and GDF-15 levels with BMI. Decreased circulating levels of GDF-15 and FGF-21 were associated with greater weight loss at 1 year, regardless of the types of anti-obesity modalities.

Effects of a novel rice-based diabetes-specific formula on postprandial glucose and gastrointestinal hormones: a double-blinded multi-arm randomized crossover trial

Introduction

We developed a novel rice-based medical food for diabetes (MFDM) powder formula, using locally available ingredients in Thailand, which can potentially improve patient access to diabetes-specific formula (DSF) by reducing cost and improving availability.

Purpose

The goals of our studies were to 1) measure the glycemic index (GI) and glycemic load (GL) of the MFDM powder formula in healthy individuals, and 2) assess postprandial glucose, insulin, satiety, hunger, and gastrointestinal (GI) hormone responses in adults with prediabetes or early type 2 diabetes after consuming MFDM in comparison with a commercially available standard formula (SF) and a DSF.

Methods

In Study 1, glycemic responses were assessed using the area under the curve (AUC), which was used to calculate GI and GL. Study 2 was a double-blinded multi-arm randomized crossover trial enrolling participants with either prediabetes or type 2 diabetes of ≤6 years. At each study visit, participants consumed either MFDM, SF, or DSF which contained 25 g of carbohydrates. Hunger and satiety were assessed using a visual analog scale (VAS). Glucose, insulin, and GI hormones were assessed using AUC.

Results

All participants tolerated the MFDM well with no adverse events. In Study 1, the measured GI was 39 ± 6 (low GI) and GL was 11 ± 2 (medium GL). In Study 2, glucose and insulin responses were significantly lower after MFDM compared with SF (p-value<0.01 for both), however, those responses were similar between MFDM and DSF. MFDM suppressed hunger, promoted satiety, stimulated active GLP-1, GIP, and PYY, and suppressed active ghrelin although these changes were similar to SF and DSF.

Conclusions

MFDM had a low GI and a low-to-medium GL. In people with prediabetes or early type 2 diabetes, MFDM elicited reduced glucose and insulin responses when compared with SF. Rice-based MFDM may be an option for patients who are at risk for postprandial hyperglycemia.

Clinical Trial Registration

https://www.thaiclinicaltrials.org/show/TCTR20210731001, identifier TCTR20210731001; https://www.thaiclinicaltrials.org/show/TCTR20210730007, identifier TCTR20210730007.

Autosomal dominant diabetes associated with a novel ZYG11A mutation resulting in cell cycle arrest in beta-cells

Diabetes is a genetically heterogeneous disease, for which we are aiming to identify causative genes. Here, we report a missense mutation (c.T1424C:p.L475P) in ZYG11A identified by exome sequencing as segregating with hyperglycemia in a Thai family with autosomal dominant diabetes. ZYG11A functions as a target recruitment subunit of an E3 ubiquitin ligase complex that plays an important role in the regulation of cell cycle. We demonstrate an increase in cells arrested at G₂/mitotic phase among beta-cells deficient for ZYG11A or overexpressing L475P-ZYG11A, which is associated with a decreased growth rate. This is the first evidence linking a ZYG11A mutation to hyperglycemia, and suggesting ZYG11A as a cell cycle regulator required for beta-cell growth. Since most family members were either overweight or obese, but only mutation carriers developed hyperglycemia, our data also suggests the ZYG11A mutation as a genetic factor predisposing obese individuals to beta-cell failure in maintenance of glucose homeostasis.