Relationship Between Plasma Growth Differentiation Factor 15 Levels and Complications of Type 2 Diabetes Mellitus: A Cross-sectional Study

Crumbling Pathogenesis and Biomarkers for Diabetic Peripheral Neuropathy

Background: Diabetic sensorimotor polyneuropathy (DSP) is a common chronic diabetic complication. Traditionally, DSP was once considered irreversible with a typical loss of axon. However, the superimpose of acquired demyelination on axonal loss in DSP patients has been observed, implying that DSP may be preventable or reversible, particularly within a subgroup of patients exhibiting early-stage acquired demyelination, underscoring the critical importance of identifying early prognostic markers. Methods: We systemically review the literature on the roles of biomarkers in predicting DSP and monitoring the progress. The underlying mechanisms of biomarkers were also discussed. Results: The pathogenesis of DSP is multifaceted, with various pathological mechanisms contributing to its development. Key mechanisms include aberrant glucose metabolism and induction of oxidative stress and inflammation. Several pathological processes, such as disrupted glucose metabolism, nerve damage, impaired microcirculation, genetic variants, and microRNA dysregulation, lead to molecular and protein changes that may be detectable in blood and other biological compartments, thus serving as potential biomarkers for DSP progression. However, the utility of a biomarker depends on its predictive accuracy, practicality, and ease of measurement. Conclusions: Most biomarkers for predicting DSP have demonstrated suboptimal predictive value, and many lack established accuracy in forecasting DSP progression. Consequently, the diagnostic utility of any single biomarker remains limited. A comprehensive combination of biomarkers from various categories may hold incredible promise for accurate detection. As artificial intelligence (AI) techniques, especially machine learning, rapidly advance, these technologies may offer significant potential for developing diagnostic platforms to integrate and interpret complex biomarker data for DSP.

The value of growth differentiation factor 15 as a biomarker for peripheral artery disease in diabetes patients

BACKGROUND

Growth differentiation factor 15 (GDF15) is significantly correlated with glycolipid metabolic disorders. Increased GDF15 levels are associated with obesity, insulin resistance, and diabetes as well as a poorer diabetes progression and prognosis. This is a prospective cohort study investigated the association between circulating GDF15 and diabetic peripheral artery disease.

METHODS

A total of 174 diabetic patients aged 20-80 were enrolled. Plasma GDF15 levels were measured using ELISA. Peripheral Artery Disease (PAD) was evaluated with the Ankle brachial index (ABI) and the Cardio-ankle vascular index (CAVI).

RESULTS

We found that diabetic patients with higher serum GDF15 levels (mean: 2521.5 pg/mL) had a higher incidence of peripheral artery disease. Multivariate logistic regression analysis indicated that patients with high serum GDF15 levels were at an increased risk of developing peripheral artery disease. High GDF15 levels were associated with ABI < 0.9 (right and left mean 19.5% p = 0.80, OR:1.13; 95%CI: [0.44-2.90]). Increased age (p = 0.025 OR:1.02; 95% CI [0.13-0.87]), family history (p = 0.001 OR:1.37; 95%CI: [0.37-5.05]), heart failure (p = 0.002 OR:4.96; 95%CI: [1.76-13.97]), sodium-glucose linked transporter 2 (SGLT 2) inhibitor use (p = 0.026), estimated glomerular filtration rate (eGFR) (p = < 0.001), and uric acid (p = < 0.001) was also positively associated with high GDF15 levels. Urine albumin-to-creatinine ratio (UACR) (p = < 0.010) was associated with higher GDF15 levels after one year of follow up.

CONCLUSIONS

Elevated GDF15 was significantly associated with worsening metabolic parameters and an increased risk of peripheral artery disease. Thus, it may be a stronger predictor of these outcomes in people with diabetes.

The role of GDF15 in attenuating noise-induced hidden hearing loss by alleviating oxidative stress

Noise-induced hidden hearing loss (HHL) is a newly uncovered form of hearing impairment that causes hidden damage to the cochlea. Patients with HHL do not have significant abnormalities in their hearing thresholds, but they experience impaired speech recognition in noisy environments. However, the mechanisms underlying HHL remain unclear. In this study, we developed single-cell transcriptome profiles of the cochlea of mice with HHL, detailing changes in individual cell types. Our study revealed a transient threshold shift, reduced auditory brainstem response wave I amplitude, and decreased number of ribbon synapses in HHL mice. Our findings suggest elevated oxidative stress and GDF15 expression in cochlear hair cells of HHL mice. Notably, the upregulation of GDF15 attenuated oxidative stress and auditory impairment in the cochlea of HHL mice. This suggests that a therapeutic strategy targeting GDF15 may be efficacious against HHL.

Growth Differentiation Factor 15 and Matrix Metalloproteinase 3 in Plasma as Biomarkers for Neuropathy and Nephropathy in Type 1 Diabetes

Diabetic neuropathy and nephropathy are common complications of type 1 diabetes (T1D). The symptoms are often elusive in the early stages, and available diagnostic methods can be improved using biomarkers. Matrix metalloproteinase 3 (MMP-3) has been identified in the kidneys and is thought to be involved in diabetic nephropathy. Growth differentiation factor 15 (GDF-15) has been suggested to have positive effects in diabetes, but is otherwise associated with adverse effects such as cardiovascular risk, declined kidney function, and neurodegeneration. This study aims to investigate plasma MMP-3 and GDF-15 as systemic biomarkers for diabetic neuropathy and nephropathy in T1D. The study involves patients with childhood-onset T1D (n = 48, age 38 ± 4 years) and a healthy control group (n = 30, age 38 ± 5 years). Neurophysiology tests, evaluations of albuminuria, and measurements of routine biochemical markers were conducted. The neuropathy impairment assessment (NIA) scoring system, where factors such as loss of sensation and weakened reflexes are evaluated, was used to screen for symptoms of neuropathy. MMP-3 and GDF-15 concentrations were determined in heparinized plasma using ELISA kits. In total, 9 patients (19%) had albuminuria, and 25 (52%) had diabetic neuropathy. No significant differences were found in MMP-3 concentrations between the groups. GDF-15 levels were higher in T1D, with median and interquartile range (IQR) of 358 (242) pg/mL in T1D and 295 (59) in controls (p < 0.001). In the merged patient group, a positive correlation was found between MMP-3 and plasma creatinine, a negative correlation was found between MMP-3 and estimated glomerular filtration rate (eGFR; rho = -0.358, p = 0.012), and there was a positive correlation between GDF-15 and NIA (rho = 0.723, p < 0.001) and high-sensitive C-reactive protein (rho = 0.395, p = 0.005). MMP-3 was increased in macroalbuminuria and correlated positively with NIA only in the nine T1D patients with albuminuria (rho = 0.836, p = 0.005). The present study indicates that high MMP-3 is associated with low eGFR, high plasma creatinine, and macroalbuminuria, and that GDF-15 can be a biomarker for diabetic neuropathy in T1D. MMP-3 may be useful as biomarker for neuropathy in T1D with albuminuria.

Molecular mechanism and intervention measures of microvascular complications in diabetes

Objective

In this article, the epidemiology, molecular mechanism of occurrence and development, risk factors, and treatment of diabetic microvascular complications such as diabetic nephropathy, diabetic retinopathy, and diabetic peripheral neuropathy were discussed, providing the theoretical basis for more accurate elucidation of the pathogenesis and treatment of diabetic microvascular complications.

Methods

The electronic database of PubMed was searched, and retrieved papers were screened for eligibility by two independent reviewers. Data were extracted using a standardized data extraction form and the quality of included papers was assessed.

Results

Thirty-eight articles were included. Diabetes nephropathy, diabetes peripheral neuropathy, and diabetes retinopathy are the most common and serious microvascular complications of diabetes in clinical patients. Renin-angiotensin system blockers, beta drugs, statins, antivascular endothelial growth factor drugs, and antioxidants can inhibit the occurrence of microvascular complications in diabetes.

Conclusions

However, there has been no breakthrough in the treatment of diabetic microvascular complications. Therefore, prevention of diabetic microvascular complications is more important than treatment.

Duration-specific association between plasma IGFBP7 levels and diabetic complications in patients with type 2 diabetes mellitus

OBJECTIVE

Insulin-like growth factor binding protein 7 (IGFBP7) has a strong affinity to insulin. This study aimed to evaluate the relationship between IGFBP7 and complications among type 2 diabetes mellitus (T2DM) patients.

DESIGN

A total of 1449 T2DM patients were selected from a cross-sectional study for disease management registered in the National Basic Public Health Service in Changshu, China, and further tested for their plasma IGFBP7 levels. Logistic regressions and Spearman's rank correlation analyses were used to explore the associations of IGFBP7 with diabetic complications and clinical characteristics, respectively.

RESULTS

Among the 1449 included T2DM patients, 403 (27.81%) had complications. In patients with shorter duration (less than five years), the base 10 logarithms of IGFBP7 concentration were associated with T2DM complications, with an adjusted odds ratio (OR) of 2.41 [95% confidence interval (95%CI) = 1.06-5.48]; while in patients with longer duration (more than five years), plasma IGFBP7 levels were not associated with T2DM complications. Furthermore, in T2DM patients with shorter duration, those with two or more types of complications were more likely to have higher levels of IGFBP7.

CONCLUSION

IGFBP7 is positively associated with the risk of complication in T2DM patients with shorter duration.