Association of Triglyceride Glucose Index with Prevalence and Incidence of Diabetic Retinopathy in a Singaporean Population

Interconnections between diabetic corneal neuropathy and diabetic retinopathy: diagnostic and therapeutic implications

Diabetic corneal neuropathy and diabetic retinopathy are ocular complications occurring in the context of diabetes mellitus. Diabetic corneal neuropathy refers to the progressive damage of corneal nerves. Diabetic retinopathy has traditionally been considered as damage to the retinal microvasculature. However, growing evidence suggests that diabetic retinopathy is a complex neurovascular disorder resulting from dysfunction of the neurovascular unit, which includes both the retinal vascular structures and neural tissues. Diabetic retinopathy is one of the leading causes of blindness and is frequently screened for as part of diabetic ocular screening. However, diabetic corneal neuropathy is commonly overlooked and underdiagnosed, leading to severe ocular surface impairment. Several studies have found that these two conditions tend to occur together, and they share similarities in their pathogenesis pathways, being triggered by a status of chronic hyperglycemia. This review aims to discuss the interconnection between diabetic corneal neuropathy and diabetic retinopathy, whether diabetic corneal neuropathy precedes diabetic retinopathy, as well as the relation between the stage of diabetic retinopathy and the severity of corneal neuropathy. We also endeavor to explore the relevance of a corneal screening in diabetic eyes and the possibility of using corneal nerve measurements to monitor the progression of diabetic retinopathy.

Association Between Triglyceride-Glucose Index and Diabetic Retinopathy: A Meta-Analysis

The objective of this study was to assess the relationship between the triglyceride-glucose (TyG) index, a recently proposed marker of insulin resistance, and the occurrence of diabetic retinopathy (DR), a complication associated with cardiovascular risk. This systematic review and meta-analysis aimed to evaluate the association between the TyG index and DR. To achieve the objective of the meta-analysis, an extensive search was conducted on databases such as PubMed, Embase, and Web of Science to identify observational studies with longitudinal follow-up. Random-effects models were employed to combine the findings, taking into account the potential influence of heterogeneity. Twelve observational studies from 11 reports were included in the meta-analysis, which involved 16 259 patients with type 2 diabetes (T2D). Among them, 4302 (26.5%) were diagnosed as DR. Pooled results showed that a higher TyG index was associated with a higher risk of DR [odds ratio (OR) for the fourth versus the first quartile of TyG index: 1.91, 95% confidence interval (CI): 1.44 to 2.53, p<0.001; I2=72%]. Meta-analysis of TyG index analyzed in continuous variable showed consistent results (OR for per 1 unit increment of TyG index: 1.41, 95% CI: 1.08 to 1.86, p=0.01; I2=82%). Subgroup analysis showed that adjustment of HbA1c or the duration of diabetes did not significantly affect the results (p for subgroup difference all>0.05). In conclusion, a high TyG index was associated with the risk of DR in T2D patients.

Role of Triglyceride-Glucose Index in Type 2 Diabetes Mellitus and Its Complications

Insulin resistance (IR) is the major mechanism in the pathogenesis of type 2 diabetes mellitus (T2DM). Early identification of IR is of great significance for preventing the onset of T2DM and delaying the progression of the disease. Previous studies have shown that triglyceride-glucose (TyG) index can be used as an effective surrogate marker for IR. There is a significant correlation between TyG index and T2DM and its common complications. In addition, the predictive efficacy of TyG index is better than that of other IR surrogate indicators. TyG index may not only become an important marker to identify people at high risk of T2DM and its complications, but is also expected to become a strong predictor of the prognosis of these diseases. However, there are still some challenges in the widespread application of TyG index in clinical practice. In the future, more high-quality studies are needed to clarify the assessment methods of TyG index for the prognosis of T2DM and its complications. Further investigations of the relationship between TyG index and T2DM and its complications will be expected to provide new ideas and methods for the prevention and treatment of T2DM and its complications.

Triglyceride-glucose index is strongly associated with all-cause mortality in elderly females with diabetic foot ulcers: A 9-year follow-up study

This study aims to explore the association between the triglyceride-glucose (TyG) index and all-cause mortality in patients with diabetic foot ulcers (DFUs) through an ambispective cohort study. A total of 555 inpatients with DFUs were qualified to participate in the trial study from 2013 to 2022. Throughout a median 63-month period, all subjects were followed up every 6 months. According to the three quantiles of the TyG index, participants were divided into three groups: low-level (≤8.75, n = 185), moderate-level (8.76-9.33, n = 185) and high-level (≥9.34, n = 185). The association between the TyG index and all-cause mortality in patients with DFUs was then assessed. During the follow-up period, out of 555 patients with DFUs, 116 died (20.9%). After adjusting for confounding factors, the TyG index was positively associated with all-cause mortality in patients with DFUs (HR = 1.733; 95% CI = 1.341-2.241; p < 0.001). Compared with the low-level TyG index, the moderate-level TyG index (HR = 1.685; 95% CI = 1.011-2.810; p = 0.045) and the high-level TyG index (HR = 2.769; 95% CI = 1.678-4.568; p < 0.001) were positively correlated with all-cause mortality in patients with DFUs. Additionally, in subgroup analysis, both females (HR = 1.905; 95% CI = 1.250-2.904; p = 0.003), males (HR = 1.729; 95% CI = 1.240-2.409; p = 0.001), younger (<65 years old) (HR = 1.467; 95% CI = 1.008-2.135; p = 0.046) and elderly (≥ 65) (HR = 1.933; 95% CI = 1.339-2.791; p < 0.001) showed a positive correlation between TyG index and all-cause mortality rate in patients with DFUs. Furthermore, in the high-level TyG index group compared, males (HR = 2.699; 95% CI = 1.457-4.998) and participants aged <65 years (HR = 2.031; 95% CI = 0.972-4.242), with the TyG index level increase by 1.0, the risk for all-cause mortality increased 3.277-fold in females (HR = 4.277; 95% CI = 1.645-11.124) and 1.909-fold in elderly aged ≥65 years (HR = 2.909; 95% CI = 1.486-5.695), respectively. Kaplan-Meier survival curve analysis showed that the higher the TyG index level, the higher risk of all-cause mortality in patients with DFUs (log-rank, all p < 0.001). Briefly, this study implies a strong positive correlation between the TyG index and all-cause mortality in patients with DFUs, especially in older women. Therefore, special attention should be paid to elderly females with DFUs because they have a higher TyG index level and risk of all-cause mortality than other populations in daily clinical practice.

Association between the triglyceride glucose index and diabetic retinopathy in type 2 diabetes: a meta-analysis

The triglyceride-glucose (TyG) index is an accessible and reliable surrogate indicator of insulin resistance and is strongly associated with diabetes. However, its relationship with diabetic retinopathy (DR) remains controversial. This meta-analysis aimed to assess the relationship between the TyG index and the prevalence of DR. Initial studies were searched from PubMed, Embase, Web of Science, and China National Knowledge Infrastructure (CNKI) electronic databases. The retrieval time range was from the establishment of the database to June 2023. Pooled estimates were derived using a random-effects model and reported as odds ratio (OR) with 95% confidence intervals (CIs). Two researchers independently assessed the methodological quality of the included studies. The Newcastle-Ottawa Quality Scale (NOS) was utilized to assess cohort studies or case-control studies. The Agency for Healthcare Research and Quality (AHRQ) methodology checklist was applied to assess cross-sectional studies. Ten observational studies encompassing 13716 patients with type 2 diabetes were included in the meta-analysis. The results showed that a higher TyG index increased the risk of DR compared with a low TyG index (OR: 2.34, 95% CI: 1.31-4.19, P < 0.05). When the index was analyzed as a continuous variable, consistent results were observed (OR: 1.48, 95% CI: 1.12-1.97, P < 0.005). There was no significant effect on the results of the sensitivity analyses excluding one study at a time (P all < 0.05). A higher TyG index may be associated with an increased prevalence of DR in patients with type 2 diabetes. However, high-quality cohort or case-control studies are needed to further substantiate this evidence.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023432747.