Different associations between serum urate and diabetic complications in men and postmenopausal women

Association between serum uric acid levels and diabetic peripheral neuropathy in type 2 diabetes: a systematic review and meta-analysis

Background

The evidence supporting a connection between elevated serum uric acid (SUA) levels and diabetic peripheral neuropathy (DPN) is controversial. The present study performed a comprehensive evaluation of this correlation by conducting a systematic review and meta-analysis of relevant research.

Method

PubMed, Web of Science (WOS), Embase, and the Cochrane Library were searched for published literature from the establishment of each database to January 8, 2024. In total, 5 cohort studies and 15 cross-sectional studies were included, and 2 researchers independently screened and extracted relevant data. R 4.3.0 was used to evaluate the included literature. The present meta-analysis evaluated the relationship between SUA levels and the risk of DPN in type 2 diabetes (T2DM) by calculating the ratio of means (RoM) and 95% confidence intervals (CIs) using the method reported by JO Friedrich, and it also analyzed continuous outcome measures using standardized mean differences (SMDs) and 95% CIs to compare SUA levels between DPN and non-DPN groups. Funnel plot and Egger's test were used to assess publication bias. Sensitivity analysis was conducted by sequentially removing each study one-by-one.

Results

The meta-analysis included 20 studies, with 12,952 T2DM patients with DPN and 16,246 T2DM patients without DPN. There was a significant correlation between SUA levels and the risk of developing DPN [odds ratio (OR) = 1.23; 95% CI: 1.07-1.41; p = 0.001]. Additionally, individuals with DPN had higher levels of SUA compared to those without DPN (SMD = 0.4; 95% CI: -0.11-0.91; p < 0.01).

Conclusion

T2DM patients with DPN have significantly elevated SUA levels, which correlate with a heightened risk of peripheral neuropathy. Hyperuricemia (HUA) may be a risk indicator for assessing the risk of developing DPN in T2DM patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42024500373.

Lower Serum Uric Acid Levels May Lower the Incidence of Diabetic Chronic Complications in U.S. Adults Aged 40 and Over

Previous studies have generally reported the association between serum uric acid (SUA) and diabetic complications, but large-scale research exploring the above association in U.S. adults with diabetes is limited. To explore the association between SUA and chronic complications of diabetes among U.S. patients aged ≥40, we used data from the National Health and Nutrition Examination Survey 1999−2008. SUA was divided into three levels: T1 (SUA ≥ 420 μmol/L), T2 (300 ≤ SUA < 420 μmol/L), and T3 (SUA < 300 μmol/L). Binary logistic regression and restricted cubic spline analysis were applied to evaluate the association between SUA and chronic complications of diabetes. A trend test was performed as the SUA increased substantially. After full-adjusted confounding factors, patients in the T3 group had a lower risk of diabetic kidney disease, cardiovascular disease, and peripheral neuropathy compared with the T1 group, with a OR (95% CIs) of 0.33 (0.21−0.52), 0.56 (0.36−0.87), and 0.49 (0.27−0.89), respectively. The restricted cubic spline showed a significant positive relationship between SUA and cardiovascular disease and diabetic kidney disease in diabetes patients, but not peripheral neuropathy. Maintaining a SUA of less than 300 μmol/L might be protective against the risk of cardiovascular disease, diabetic kidney disease, and peripheral neuropathy other than diabetic retinopathy compared with a SUA of more than 420 μmol/L in U.S. diabetes patients aged 40 and over.

Diabetes Mellitus Type 2 Patients with Abdominal Obesity Are Prone to Osteodysfunction: A Cross-Sectional Study

Introduction

The interaction between diabetes, obesity, and bone metabolism was drawing increasing public attention. However, the osteometabolic changes in diabetes mellitus type 2 (T2DM) patients with abdominal obesity have not been fully revealed. This study is aimed at investigating the association between abdominal obesity indices and bone turnover markers among T2DM participants.

Methods

4351 subjects were involved in the METAL study. Abdominal obesity indices included neck, waist, and hip circumference, visceral adiposity index (VAI), lipid accumulation product (LAP), waist-to-hip ratio (WHR), and Chinese visceral adiposity index (CVAI). They were applied to elucidate the nexus between β-C-terminal telopeptide (β-CTX), osteocalcin (OC), and intact N-terminal propeptide of type I collagen (P1NP).

Results

Abdominal obesity indices were strongly negatively associated with β-CTX and OC. Among males, five indices were negatively correlated with β-CTX (BMI, WC, LAP, WHR, and CVAI) and OC (BMI, NC, WC, WHR, and CVAI). There were no significant associations with P1NP. Among females, all eight indices were negatively associated with β-CTX. Seven indices were negatively related to OC (BMI, NC, WC, HC, LAP, WHR, and CVAI). The VAI was negatively correlated with P1NP.

Conclusions

The present study demonstrated that in T2DM, abdominal obesity had an obviously negative correlation with bone metabolism. Abdominal obesity indices were significantly negatively associated with skeletal destruction (β-CTX) and formation (OC). In routine clinical practice, these easily obtained indices could be used as a preliminary screening method and relevant factors for osteodysfunction incidence risk at no additional cost and may be of particular value for postmenopausal women in T2DM populations.

Association Between Uric Acid to HDL Cholesterol Ratio and Diabetic Complications in Men and Postmenopausal Women

AIM

Previous studies have implicated the uric acid to high-density lipoprotein cholesterol (HDL-C) ratio (UHR) was associated with type 2 diabetes. However, the association between UHR and diabetes-related vascular damages is still unclear.

METHODS

The total of 4551 patients with type 2 diabetes from the cross-sectional Environmental Pollutant Exposure and Metabolic Diseases in Shanghai study (METAL study) were enrolled. UHR was calculated as uric acid to HDL-C ratio. Cardiovascular disease (CVD) was defined as previously diagnosed with stroke, coronary heart disease, or peripheral arterial disease. Chronic kidney disease (CKD) was defined as estimated glomerular filtration rate ≤60 mL/min/1.73 m² and/or urinary albumin to creatinine ratio ≥30 mg/g. Fundus image was examined by trained individuals and degree of diabetic retinopathy (DR) was evaluated.

RESULTS

UHR was positively correlated with CVD (OR = 1.28, 95% CI: 1.02-1.61) and CKD (OR = 1.78, 95% CI: 1.39-2.27) after adjusting for all confounders. No association was found between UHR and DR. In stratified analyses, UHR was predominantly correlated with CVD in diabetic patients with age older than 65 (OR = 1.41, 95% CI: 1.08-1.85), female (OR = 1.43, 95% CI: 1.06-1.94) and BMI≥24kg/m² (OR = 1.57, 95% CI: 1.17-2.11). A 1-SD increment of UHR was also positively associated with CVD (OR 1.26, 95% CI 1.03, 1.15) and CKD (OR 1.28, 95% CI 1.20,1.39). UHR was positively associated with CKD in all subgroups analysis. No significant interaction effect was observed between UHR and all subgroup variables in CVD and CKD risk.

CONCLUSION

Our study reported a positive association between the UHR and diabetic-related vascular complications in men and postmenopausal women. The relationship between the UHR and DR seems to be uncertain and requires further investigation. And no significant interaction effect was observed between the UHR and all subgroup variables in CVD and CKD risk.

Association of Serum Uric Acid With Retinal Capillary Plexus

BACKGROUND

To determine the association between serum uric acid (SUA) and the retinal capillary plexus (RCP) using optical coherence tomography angiography (OCTA).

METHODS

This cross-sectional study evaluated data from August 2019 to January 2020 from participants recruited from the Jidong community (Tangshan, Hebei, China). All participants completed detailed anthropometrical measurements, laboratory tests and comprehensive ophthalmic examinations. We assessed the vessel density in RCP using OCTA. We used multivariable analysis to evaluate the sex-specific association between SUA and RCP after adjusting for confounders.

RESULTS

A total of 2730 participants were included in this study. The mean age of the participants was 44.0 ± 11.6 years, and 1463 (53.6%) were women. The multivariable βs and 95% confidence intervals (CIs) of superficial RCP vessel density in the second through fourth SUA quartiles compared with the lowest SUA quartiles were -0.27 (-0.56 - 0.03), -0.30 (-0.60 - 0.01), and -0.46 (-0.78 - -0.14) (P for trend = 0.007) in men.

CONCLUSIONS

Higher SUA levels were significantly associated with lower RCP vessel density in men. Our findings provide evidence for the detrimental effect of high SUA levels on the retinal microvasculature and imply the importance of modulating SUA to prevent the microvascular alternation especially for men.

Low-level lead exposure promotes hepatic gluconeogenesis and contributes to the elevation of fasting glucose level

BACKGROUND

Lead (Pb) is considered an endocrine-disrupting chemical. However, few studies have investigated the effects of low-level Pb exposure on plasma glucose levels. Herein, we aimed to investigate whether low-level Pb exposure causes elevated plasma glucose levels and the possible mechanisms involved.

METHODS

We conducted a cross-sectional study of 5747 participants from 16 sites in China. The participants underwent measurements of anthropometric factors, blood lead level (BLL) and fasting plasma glucose (FPG). Wistar rats were exposed to 0.05% Pb through drinking water or fed with a high-fat diet (HFD) for 28 weeks. The relevant parameters of glucose homeostasis, hepatic glucose production (HGP) and gene expression levels of hepatic gluconeogenesis enzymes, including phosphoenolpyruvate carboxy kinase (PEPCK), glucose-6-phosphatase (G6PC) and fructose-1,6-bisphosphatase (FBP1), were measured. In addition, gene expression levels of gluconeogenesis enzymes were also measured in HepG2 cells administered with different concentrations of lead acetate for 24 h.

RESULTS

In humans, after adjusting for confounders, the odds of having High_FPG (≥5.6 mmol/L) were significantly increased by 25% in the participants in the fourth BLL quartile (OR 1.25, 95% CI 1.05, 1.49). In the animals exposed to 0.05% Pb, FPG, HGP and hepatic gene expression levels of PEPCK, G6PC and FBP1 were increased. In addition, the mRNA expression levels of PEPCK, G6PC and FBP1 in HepG2 cells were also increased in response to Pb exposure.

CONCLUSIONS

These findings support the possibility that low-level Pb exposure may increase HGP by affecting key enzymes of hepatic gluconeogenesis, eventually resulting in impaired FPG and hyperglycemia.

Gender Differences in Diabetic Kidney Disease: Focus on Hormonal, Genetic and Clinical Factors

Diabetic kidney disease (DKD) is one of the most serious complications of both type 1 (T1DM) and type 2 diabetes mellitus (T2DM). Current guidelines recommend a personalized approach in order to reduce the burden of DM and its complications. Recognizing sex and gender- differences in medicine is considered one of the first steps toward personalized medicine, but the gender issue in DM has been scarcely explored so far. Gender differences have been reported in the incidence and the prevalence of DKD, in its phenotypes and clinical manifestations, as well as in several risk factors, with a different impact in the two genders. Hormonal factors, especially estrogen loss, play a significant role in explaining these differences. Additionally, the impact of sex chromosomes as well as the influence of gene-sex interactions with several susceptibility genes for DKD have been investigated. In spite of the increasing evidence that sex and gender should be included in the evaluation of DKD, several open issues remain uncovered, including the potentially different effects of newly recommended drugs, such as SGLT2i and GLP1Ras. This narrative review explored current evidence on sex/gender differences in DKD, taking into account hormonal, genetic and clinical factors.

Higher Serum Uric Acid Levels Are Associated With an Increased Risk of Vision-Threatening Diabetic Retinopathy in Type 2 Diabetes Patients

Purpose

To investigate the association between serum uric acid (SUA) levels and vision-threatening diabetic retinopathy (VTDR) in patients with type 2 diabetes.

Methods

This cross-sectional study evaluated 3481 patients with type 2 diabetes from four communities in China between 2016 and 2019. VTDR was defined as severe nonproliferative, proliferative diabetic retinopathy, or clinically significant macular edema evaluated by fundus photography and optical coherence tomography. Potential association between SUA and VTDR was examined using multivariable logistic regression. Sub-group analyses based on sex were constructed.

Results

A total of 305 participants had VTDR. Both higher SUA (odds ratio [OR], 1.22 per 100 µmol/L; 95% confidence interval [CI], 1.04–1.44; P = 0.013) and hyperuricemia (OR, 1.47; 95% CI, 1.07–2.04; P = 0.019) were positively associated with VTDR after adjustment for relevant covariates. Compared with those in the lowest SUA quartile, participants in the third (OR, 1.60; 95% CI, 1.07–2.39; P = 0.022) and fourth (OR, 2.05; 95% CI, 1.37–3.08; P = 0.001) sex-specific SUA quartiles showed a significantly increased risk of VTDR after adjustment. No sex-related difference was observed.

Conclusions

Higher SUA levels were associated with an increased risk of VTDR in patients with type 2 diabetes in both sexes, although females seemed to be more sensitive to high SUA than males. Prospective cohort studies are needed to verify SUA as a biomarker for predicting the risk of VTDR. Whether decreased SUA levels could decrease the risk of VTDR also requires further investigation.

Lead exposure and its association with cardiovascular disease and diabetic kidney disease in middle-aged and elderly diabetic patients

AIMS

Previous studies have suggested that a high blood lead level (BLL) is associated with cardiovascular outcomes and impaired renal function in the general population; however, studies investigating the effect of a high BLL on diabetic vascular complications have been limited. We aimed to investigate whether a higher BLL is associated with cardiovascular disease (CVD) and diabetic kidney disease (DKD).

METHODS

We analyzed 4234 individuals out of 4813 diabetic participants enrolled from seven communities in China in 2018 in this cross-sectional study. Macrovascular measurements, including assessment of common carotid artery (CCA) plaques and their diameters, were performed with ultrasound. CVD was defined as a composite measure including a previous diagnosis of coronary heart disease, myocardial infarction, or stroke. The definition of DKD was an albumin to creatinine ratio (ACR) ≥30 mg/g or an estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 m². Linear and logistic regression analyses were used to measure the associations.

RESULTS

The median age and BLL of the participants were 67 years (interquartile range, 62-72 years) and 26 μg/L (interquartile range, 18-36 μg/L). Compared with the first quartile, the odds ratio (OR) (95% CI) of CCA plaques ranging from none to bilateral in the ordinal logistic regression analysis associated with BLL was 1.53 (1.29, 1.82) in the fourth BLL quartile (P for trend <0.01), and the odds of having CVD was significantly increased by 44% for participants in the fourth quartile (1.44 (1.17, 1.76)) (P for trend <0.01). The odds of DKD in the fourth BLL quartile increased by 36% (1.36 (1.06, 1.74)) compared with that in the first quartile (P for trend <0.05). These associations were adjusted for potential confounders.

CONCLUSIONS

A high BLL may be a potential risk factor for CVD and DKD in middle-aged and elderly diabetic adults.

Associations between abdominal obesity indices and diabetic complications: Chinese visceral adiposity index and neck circumference

Background and aims

Obesity, especially abdominal obesity, has been considered a risk factor for diabetic complications. Many abdominal obesity indices have been established, including neck circumference (NC), waist-to-hip ratio (WHR), lipid accumulation product (LAP), visceral adiposity index (VAI) and the Chinese visceral adiposity index (CVAI). However, studies investigating the associations between these indices and diabetic complications are limited. The objective of this study was to investigate the associations of the abdominal obesity indices with cardiovascular and cerebrovascular disease (CVD), diabetic kidney disease (DKD) and diabetic retinopathy (DR).

Methods

A total of 4658 diabetic participants were enrolled from seven communities in Shanghai, China, in 2018. Participants completed questionnaires and underwent blood pressure, glucose, lipid profile, and urine albumin/creatinine ratio measurements; fundus photographs; and anthropometric parameters, including height, weight, waist circumference (WC), NC and hip circumference (HC).

Results

In men, a one standard deviation (SD) increase in CVAI level was significantly associated with a greater prevalence of CVD (OR 1.35; 95% CI 1.13, 1.62) and DKD (OR 1.38; 95% CI 1.12, 1.70) (both P < 0.05). In women, a one SD increase in CVAI level was significantly associated with a greater prevalence of CVD (OR 1.32; 95% CI 1.04, 1.69) and DKD (OR 2.50; 95% CI 1.81, 3.47) (both P < 0.05). A one SD increase in NC was significantly associated with a greater prevalence of CCA plaque in both men (OR 1.26; 95% CI 1.10, 1.44) and women (OR 1.20; 95% CI 1.07, 1.35). These associations were all adjusted for potential confounding factors.

Conclusions

CVAI was most strongly associated with the prevalence of CVD and DKD among the abdominal obesity indices, and NC was unique associated with the prevalence of CCA plaque in Chinese adults with diabetes.

Trial registration ChiCTR1800017573, www.chictr.org.cn. Registered 04 August 2018.

The unique association between the level of peripheral blood monocytes and the prevalence of diabetic retinopathy: a cross-sectional study

OBJECTIVE

The attraction and influx of monocytes into the retina has been considered a critical step in the development of diabetic retinopathy (DR). However, large population studies about the association between peripheral blood monocyte levels, an inexpensive and easily measurable laboratory index, and DR are limited. Thus, we aimed to investigate the association between peripheral blood monocyte levels and DR.

METHODS

A total of 3223 participants out of 3277 adults with diabetes were enrolled from seven communities in China in this cross-sectional survey. Participants underwent several medical examinations, including the measurement of anthropometric factors, blood pressure, routinely analyzed leukocyte characteristics, glucose, lipid profiles, urine albumin/creatinine ratio and fundus photographs.

RESULTS

The prevalence of DR among the participants in the highest quartile of peripheral blood monocyte levels significantly decreased by 41% (OR 0.59; 95% CI 0.43, 0.81) compared with the participants in the first quartile (P for trend < 0.05). However, there were no associations between the monocyte level and the prevalence of cardiovascular and cerebrovascular diseases (CVD) and diabetic kidney disease (DKD) (both P for trend > 0.05). Associations between leukocyte, neutrophil and lymphocyte levels and DR were also not found (all P for trend > 0.05). These associations were all fully adjusted for age, sex, education status, duration of diabetes history, current smoking, BMI, HbA1c, dyslipidemia, systolic blood pressure and insulin therapy.

CONCLUSION

Decreased peripheral blood monocyte levels were associated with increased odds of DR after adjusting for potential confounders in diabetic adults. However, causation remains to be demonstrated.

Associations between the Neutrophil-to-Lymphocyte Ratio and Diabetic Complications in Adults with Diabetes: A Cross-Sectional Study

OBJECTIVE

The neutrophil-to-lymphocyte ratio (NLR) is an inexpensive and easily measurable laboratory index indicating systemic inflammation, while the application of many other inflammatory markers has been limited in daily clinical practice. However, large population studies about investigating the associations of the NLR level with diabetic complications including cardiovascular and cerebrovascular diseases (CVD), diabetic kidney disease (DKD), and diabetic retinopathy (DR) in the same population were limited. The aim of our study is to evaluate the associations between the NLR level and the prevalence of CVD, DKD, and DR in adults with diabetes simultaneously.

METHODS

A cross-sectional survey of 4,813 diabetic adults was conducted in seven communities in China. Persons underwent several medical examinations, including the measurement of anthropometric factors, blood pressure, routinely analyzed leukocyte characteristics, glucose, lipid profiles, urine albumin/creatinine ratio, and fundus photographs.

RESULTS

Compared with the first quartile of the NLR level, the odds of having CVD was significantly increased by 21% for participants in the highest quartile (OR 1.21; 95% CI 1.00, 1.47) (P for trend < 0.05). Similarly, the prevalence of DKD among participants in the highest quartile of the NLR level was significantly increased by 150% (OR 2.50; 95% CI 1.95, 3.19) (P for trend < 0.05). However, no association was found between the NLR level and the prevalence of DR (P for trend > 0.05). These associations were all fully adjusted.

CONCLUSIONS

A higher NLR level was associated with an increased prevalence of CVD and DKD, other than DR, in diabetic adults.

Associations between different bilirubin subtypes and diabetic microvascular complications in middle-aged and elderly individuals

AIMS

Some studies have reported associations between bilirubin and diabetic microvascular complications. However, these studies focused only on total bilirubin (TBIL) without distinguishing different bilirubin subtypes. In this study, we aimed to investigate the associations of TBIL, direct bilirubin (DBIL) and indirect bilirubin (IBIL) levels with albuminuria/creatinine ratio (ACR) and the prevalence of diabetic retinopathy (DR) among diabetic adults.

METHODS

We analyzed 4368 individuals out of 4813 diabetic participants enrolled from seven communities in 2018 in a cross-sectional study. Participants underwent several checkups, including the measurement of anthropometric parameters, blood pressure, glucose, lipid profile, TBIL, DBIL, IBIL and ACR. DR was detected by high-quality fundus photographs and was remotely read by ophthalmologists.

RESULTS

Compared with the first quartile of DBIL, participants in the fourth quartile had a lower prevalence of high ACR (odds ratio (OR) 0.76; 95% confidence interval (CI) 0.59, 0.99) (p for trend < 0.05). Neither TBIL nor IBIL was associated with the prevalence of high ACR. In DR, higher DBIL and TBIL by one standard deviation was associated with a 19% (OR 0.81; 95% CI 0.69, 0.94) and a 12% (OR 0.88; 95% CI 0.78, 0.99) lower frequency of DR, respectively (both p for trend < 0.05). However, IBIL was not associated with the prevalence of DR. These associations were adjusted for potential confounding factors.

CONCLUSION

DBIL had a stronger association with high ACR and DR than TBIL or IBIL did in diabetic adults. The effect of DBIL on diabetic complications should be noted and investigated in further studies.