Mechanistic insights of soluble uric acid-induced insulin resistance: Insulin signaling and beyond

Elevated triglyceride-glucose index predisposes to the initial episode of peritonitis in chronic peritoneal dialysis patients

OBJECTIVE

The serum triglyceride-glucose (TyG) index is a marker of inflammation. However, the relationship between TyG index and peritoneal dialysis-related peritonitis (PDRP) is unclear. This study aimed to investigate the potential relationship between the baseline TyG index and the initial episode of PDRP.

METHODS

A total of 208 peritoneal dialysis (PD) patients were enrolled from January 1, 2012, to December 31, 2019 and followed up until December 31, 2022. They were divided into 2 groups according to the median TyG. The primary outcome was the occurrence of the initial episode of PDRP while on PD therapy. Kaplan-Meier curves and Cox regression analyses were used to examine the association between them.

RESULTS

Eighty-five initial episodes of PDRP were identified. The risk of PDRP was higher in the high-TyG index group (p = 0.030). Multivariate Cox regression analysis showed a higher risk of PDRP in patients with a high TyG index (HR = 1.800, 95% CI 1.511-2.815, p = 0.010).

CONCLUSION

The baseline serum TyG index was an independent risk factor for the initial episode of PDRP in chronic PD patients.

Higher ratio of serum uric acid to serum creatinine (SUA/SCr) increases the risk of metabolic unhealthy phenotype

BACKGROUND AND AIM

It is very important to understand which factors play roles in switching from a healthy to an unhealthy metabolism. It is unclear if SUA/SCr is an independent risk factor for metabolic unhealthy phenotype. We examined whether SUA/SCr is associated with an increased risk for metabolic unhealthy phenotype in the Chinese population.

METHODS AND RESULTS

As many as 3158 subjects aged 25-75 years who had a metabolic healthy phenotype at baseline were included in the retrospective cohort study. They were assigned to four groups based on the quartile of SUA/SCr. We compared the demographic and clinical characteristics among the four groups. The correlation between SUA/SCr and the risk of metabolic unhealthy phenotype in the overall population and stratified by subgroups was examined by logistic regression analyses. Greater SUA/SCr values were correlated with greater BMI, systolic and diastolic BP, TC, TG, RBC, WBC, HB, ALT, SUA and eGFR. During the two-year follow-up, 632 of the study subjects (20.01%) developed new-onset metabolic unhealthy phenotype from the total of 3158 study subjects. A statistically significant increase in the rates of metabolic unhealthy phenotype was observed with increasing SUA/SCr levels within each group. After multivariate adjustment, the adjusted ORs and 95% CIs were 1.44 (1.03-2.00) and 2.11 (1.52-2.94) in the Q3 group and Q4 group, respectively.

CONCLUSION

SUA/SCr was positively related to the risk of metabolic unhealthy phenotype in the Chinese subjects, suggesting the potential of SUA/SCr to serve as an independent risk predictor in the development of metabolic unhealthy phenotype.

Uric acid levels correlate with disease activity in growth hormone-secreting pituitary adenoma patients

Objective

Few studies reported the effects of growth hormone-secreting pituitary adenoma (GHPA) on uric acid (UA) metabolism and the relationship between growth hormone (GH)/insulin-like growth factor-1 (IGF-1) levels and UA are controversial. This study aimed to evaluate the relationship between IGF-1 and UA in patients with GHPA and to further clarify whether UA levels are associated with GHPA disease activity by follow-up.

Methods

A longitudinal study of 424 GHPA patients presenting to Beijing Tiantan Hospital, Capital Medical University between January 2015 and January 2023 was conducted. Spearman's correlation tests were performed to examine the relationship between IGF-1 and UA at baseline. Univariate and multivariate linear regression analysis was conducted to investigate the independent association between UA and IGF-1. Changes in postoperative IGF-1 and UA levels were followed prospectively, and the differences in UA levels between the biochemical remission and nonremission groups were compared.

Results

At baseline, male patients, the lower the age, the higher the IGF-1 and body mass index (BMI), and the higher the UA levels. IGF-1 was significantly associated with UA after controlling for sex, age, and BMI (r = 0.122, P = 0.012). In adjusted multiple linear regression analysis, IGF-1 was independently associated with UA, and UA levels increased significantly with increasing IGF-1. During postoperative follow-up, UA decreased gradually as IGF-1 levels decreased. At 12 months postoperatively, UA levels were significantly lower in the biochemical remission group than in the nonremission group (P = 0.038).

Conclusions

In patients with GHPA, UA levels are associated with disease activity. Changes in UA levels should be taken into account in the comprehensive treatment of GHPA, patients presenting with HUA should be given lifestyle guidance and appropriate urate-lowering treatment according to their condition to better improve their prognosis.

Association between serum uric acid and triglyceride-glucose index in children and adolescents with short stature

The aim of this study was to explore the relationship between serum uric acid (SUA) and the triglyceride-glucose (TyG) index, which is a more effective indicator of insulin resistance. The study participants included 1700 children and adolescents with short stature who were recruited at the Affiliated Hospital of Jining Medical University in China between March 2013 and April 2021. A positive association between SUA levels and the TyG index was detected by univariate analysis (p < 0.001). Furthermore, a nonlinear relationship was detected between SUA and the TyG index, whose point was 6.55 mg/dL. There was a positive association between SUA and the TyG index when the SUA level was greater than 6.55 mg/dL (β 0.17, 95% CI: 0.07, 0.27; P < 0.001). However, we did not observe a significant relationship between SUA and the TyG index when the SUA level was less than 6.55 mg/dL (β 0.02, 95% CI: - 0.01, 0.05; P = 0.091). In addition, a stratified analysis was performed to appraise changes in this relationship for different sexes. The relationship between SUA and the TyG index in males and females is consistent with that in the general population, showing a nonlinear relationship. However, the inflection points of SUA level were significantly higher in males than in females, and the inflection points were approximately 6.72 and 5.88 mg/dL, respectively. This study revealed a nonlinear relationship between SUA and the TyG index in children with short stature. The nonlinear relationship remained in gender stratification analysis, but the inflection point of SUA level was higher in men. Further studies are needed to establish a causal relationship between SUA levels and the TyG index in children with short stature.

The Association of Surrogates of Insulin Resistance with Hyperuricemia among Middle-Aged and Older Individuals: A Population-Based Nationwide Cohort Study

The triglyceride-glucose (TyG) index, triglyceride-to-high-density-lipoprotein-cholesterol (TG/HDL-C) ratio, metabolic score for insulin resistance (METS-IR) and TyG with body mass index (TyG-BMI) have been proposed as indicators of insulin resistance (IR). This study aimed to explore the association between these IR surrogates and their longitudinal variation with the development of hyperuricemia in a middle-aged and older Chinese population. Data from the China Health and Retirement Longitudinal Study (CHARLS) was used to identify 5269 participants aged ≥45 years. Logistic regression was used to assess the effect of IR surrogates and their variations on the risk of hyperuricemia. After four years of follow-up, 517 (9.81%) participants developed incident hyperuricemia. Increased baseline values of TyG, TG/HDL, METS-IR, and TyG-BMI were all significantly associated with higher risks of hyperuricemia. Compared to individuals with maintained low levels of IR surrogates, those with low-to-high and maintained high variation patterns had a significantly higher risk of hyperuricemia. These four IR surrogates have comparable predictive ability for hyperuricemia. This study provides evidence of the associations between IR and hyperuricemia. Early intervention among middle-aged and elderly Chinese individuals with high IR levels may effectively reduce the burden of hyperuricemia.

Extraction, Purification, Structural Characteristics, Health Benefits, and Application of the Polysaccharides from Lonicera japonica Thunb.: A Review

Lonicera japonica Thunb. is a widely distributed plant with ornamental, economic, edible, and medicinal values. L. japonica is a phytoantibiotic with broad-spectrum antibacterial activity and a potent therapeutic effect on various infectious diseases. The anti-diabetic, anti-Alzheimer's disease, anti-depression, antioxidative, immunoregulatory, anti-tumor, anti-inflammatory, anti-allergic, anti-gout, and anti-alcohol-addiction effects of L. japonica can also be explained by bioactive polysaccharides isolated from this plant. Several researchers have determined the molecular weight, chemical structure, and monosaccharide composition and ratio of L. japonica polysaccharides by water extraction and alcohol precipitation, enzyme-assisted extraction (EAE) and chromatography. This article searched in the Chinese Pharmacopoeia, Flora of China, Web of Science, PubMed, and CNKI databases within the last 12 years, using "Lonicera. japonica polysaccharides", "Lonicera. japonica Thunb. polysaccharides", and "Honeysuckle polysaccharides" as the key word, systematically reviewed the extraction and purification methods, structural characteristics, structure-activity relationship, and health benefits of L. japonica polysaccharides to provide insights for future studies. Further, we elaborated on the potential applications of L. japonica polysaccharides in the food, medicine, and daily chemical industry, such as using L. japonica as raw material to make lozenges, soy sauce and toothpaste, etc. This review will be a useful reference for the further optimization of functional products developed from L. japonica polysaccharides.