A comparison of urinary albumin excretion rate and microalbuminuria in various glucose tolerance subjects

Impaired sensitivity to thyroid hormones is associated with albuminuria in the euthyroid population: results from NHANES

PURPOSE

The relationship between thyroid hormone sensitivity and albuminuria remains unclear. We aimed to investigate the association between thyroid hormone sensitivity and the risk of albuminuria in a euthyroid population.

METHODS

This cross-sectional study included 7634 euthyroid adults collected from the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2012. Central sensitivity to thyroid hormones was evaluated using the thyroid-stimulating hormone index (TSHI), the thyrotrophic thyroxine resistance index (TT4RI), and the thyroid feedback quantile-based index (TFQI). Peripheral sensitivity to thyroid hormones was measured using the free triiodothyronine/free thyroxine (FT3/FT4) ratio. Furthermore, the independent relationship between sensitivity to thyroid hormones and albuminuria was assessed.

RESULTS

The proportion of albuminuria increased with a higher interquartile range of TFQI levels (7.31% vs. 7.89% vs. 7.95% vs. 9.89%, P = 0.024). Furthermore, TFQI was found to be independently associated with the risk of albuminuria after adjusting for confounding factors (OR = 1.28, 95% CI 1.01-1.60, P = 0.037). Subgroup analysis revealed a significant relationship between TFQI and albuminuria, especially among individuals over 60.

CONCLUSIONS

In euthyroid subjects, impaired central sensitivity to thyroid hormones is associated with albuminuria. TFQI holds significant potential as an epidemiological tool for quantifying the impact of impaired central sensitivity on the risk of albuminuria.

Thyroid function and thyroid homeostasis parameters are associated with increased urinary albumin excretion in euthyroid individuals over 60 years old from NHANES

Introduction

The relationship between thyroid function/homeostasis parameters and renal function has been extensively studied. However, the relationship between thyroid function and thyroid homeostasis parameters with albuminuria among elderly individuals remains unclear.

Methods

The population was divided into an albuminuria group and a non-albuminuria group for baseline characteristic difference analysis. Multivariable logistic regression was used to test the association between thyroid function, and thyroid homeostasis parameters and albuminuria. The nonlinear relationship was explored with restricted cubic splines. Meanwhile, we investigated whether the relationship also existed in the diabetes and hypertension subgroups. Receiver operating characteristic (ROC) curves were used to assess the effectiveness of the indices.

Results

FT4 and TFQIFT4 were positively correlated with albuminuria (OR = 1.12; 95% CI = 1.02-1.23, p = 0.02; OR = 1.79; 95% CI = 1.08-2.99, p = 0.03), and FT3/FT4 was negatively correlated with albuminuria (OR = 0.03; 95% CI = 0.00-0.26, p = 0.003). Additionally, the nonlinear relationship between FT3/FT4 as well as TSHI and albuminuria was approximately U-shaped. Similar results were observed in the hypertension subgroup but not in the diabetes subgroup. There was a U-shaped nonlinear relationship between FT3 and albuminuria in the diabetes group. In addition, FT3/FT4 performed better than TFQI, TT4RI, and TSHI in ROC analyses for albuminuria prediction.

Conclusion

FT4, TFQIFT4, and a low FT3/FT4 ratio were risk factors for albuminuria in euthyroid individuals over 60 years old. However, FT3 was more associated with albuminuria in the diabetes subgroup. TSH was not associated with albuminuria in any analysis. In our study, we attempted to provide more reasonable thyroid parameters and basis for evaluating patients with underlying albuminuria. FT3/FT4 may be used as a helpful indicator to predict albuminuria and provide novel ideas for the evaluation and treatment of albuminuria.

The relationship between triglyceride-glucose index and albuminuria in United States adults

Purpose

Triglyceride-glucose (TyG) index is a simple and reliable indicator of metabolic dysfunction. We aimed to investigate a possible relationship between TyG index and albuminuria in the United States adult population.

Methods

This cross-sectional study was conducted among adults with complete TyG index and urinary albumin/urinary creatinine (UACR) from 2011-2018 National Health and Nutrition Examination Survey (NHANES). The independent relationship between TyG index and albuminuria (UACR>30mg/g) was evaluated. TyG index was compared with insulin resistance represented by homeostatic model assessment of insulin resistance (HOMA-IR), and metabolic syndrome. Subgroup analysis was also performed.

Results

A total of 9872 participants were included in this study, and the average TyG index was 8.53 ± 0.01. The proportion of albuminuria gradually increased with the increase of TyG index quartile interval. Elevated TyG index was independently associated with albuminuria, and this association persisted after additional adjustments for HOMA-IR or dichotomous metabolic syndrome. The area under the ROC curve (AUC) of TyG index was larger than that of log (HOMA-IR). Subgroup analysis suggested that the relationship between TyG index and albuminuria is of greater concern in age<60, overweight/obese, diabetic, and metabolic syndrome patients.

Conclusion

The TyG index may be a potential epidemiological tool to quantify the role of metabolic dysfunction, rather than just insulin resistance, in albuminuria in the United States adult population. Further large-scale prospective studies are needed to confirm our findings.

Cardiometabolic index is associated with urinary albumin excretion and renal function in aged person over 60: Data from NHANES 2011-2018

PURPOSE

Cardiometabolic index (CMI) is recently considered to have certain significance in the screening of diabetes, atherosclerosis, and renal dysfunction. Therefore, this study intends to explore the relationship between CMI and the risk of albuminuria.

METHODS

This is a cross-sectional study involving 2732 elderly people (age ≥ 60). The research data are from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018. Calculate CMI index: Triglyceride (TG) (mmol/L)/ High density lipid-cholesterol (HDLC) (mmol/L) × WHtR.

RESULTS

The CMI level in microalbuminuria group was significantly higher than that in normal albuminuria group (P < 0.05 or P < 0.01), whether in the general population or in diabetes and hypertensive population respectively. The proportion of abnormal microalbuminuria increased gradually with the increase of CMI tertile interval (P < 0.01). Correlation analysis showed that CMI was positively correlated with urinary albumin-creatinine ratio (UACR), blood urea nitrogen (BUN), and serum creatinine (Scr), and negatively correlated with estimated glomerular filtration rate (eGFR). With the occurrence of albuminuria as the dependent variable, weighted logistic regression analysis showed that CMI was an independent risk factor for microalbuminuria. Weighted smooth curve fitting showed that CMI index was linearly related to the risk of microalbuminuria. Subgroup analysis and interaction test showed that they participated in this positive correlation.

CONCLUSIONS

Obviously, CMI is independently associated with microalbuminuria, suggesting that CMI, a simple indicator, can be used for risk assessment of microalbuminuria, especially in diabetes patients.

Elevated One-Hour Post-Load Glucose Is Independently Associated with Albuminuria: A Cross-Sectional Population Study

The purpose of this study was to examine and compare the associations between albuminuria and fasting (FPG), 1 h post-load (1 h PG) and 2 h post-load plasma glucose (2 h PG) in an oral glucose tolerance test (OGTT). A total of 496 people free of known diabetes (mean age 72 years) participated in the examinations including the OGTT with plasma glucose measurements at 0, 1, and 2 h and levels of HbA1c. Albuminuria was determined by the urinary albumin-to-creatinine ratio and was defined as ≥3.0 mg/mmol. Compared with those without albuminuria, participants with albuminuria had significantly higher 1 h PG and 2 h PG levels, but not FPG or HbA1c levels. An elevated 1 h PG increased the estimated odds ratio of albuminuria more than three times in people with prediabetic 1 h PG (8.6–11.5 mmol/L: OR 3.60; 95% CI 1.70–7.64) and diabetic 1 h PG (≥11.6 mmol/L: OR 3.05; 95% CI 1.29–7.23). After adjusting for blood pressure and age, the association of elevated 1 h PG with albuminuria remained significant. Prediabetic or diabetic FPG, 2 h PG, or HbA1c did not have a statistically significant association with albuminuria. These findings suggest that 1 h PG seems to be the best glycemic parameter and is useful in recognizing persons with an elevated risk of early kidney disease due to hyperglycemia.

Prevalence of microvascular and macrovascular complications of diabetes in newly diagnosed type 2 diabetes in low-and-middle-income countries: A systematic review and meta-analysis

There is an excessive burden of diabetes complications in low-resource settings. We conducted a systematic review to determine the nature and frequency of diabetes complications in newly diagnosed with type 2 diabetes. A systematic search was performed using Medline, CINAHL and Global Health online databases from inception to July 2020. Articles reporting prevalence of microvascular or macrovascular complications within six months of type 2 diabetes diagnosis and published in English or French from low- and middle-income countries (LMICs) were eligible for analysis. Data were extracted using a standardized data extraction tool. Descriptive statistics were used to describe the prevalence of micro and macrovascular complications in newly diagnosed type 2 diabetes. Assessment of heterogeneity was conducted using the inconsistency index (I2) and Cochran-Q chi2 statistical tests. Publication bias was assessed by the Funnel plot and Egger test. A total of 3 292 records underwent title or abstract screening and 95 articles underwent full text review. Thirty-three studies describing 13 283 participants (aged 20 years and older) met the inclusion criteria. The eligible studies were from Asia (n = 24), Africa (n = 4), Oceania (n = 2), South America (n = 2) and the Caribbean (n = 1). For microvascular complications, the median prevalence (interquartile range) of retinopathy, nephropathy and neuropathy were 12% (6%-15%), 15% (7%-35%) and 16% (10%25%) respectively. For macrovascular complications, the median prevalence (interquartile range) was 10% (7%-17%) for ischaemic heart disease, 6% (1%-20%) for peripheral arterial disease and 2% (1%-4%) for stroke. There was evidence of substantial heterogeneity between studies for all outcomes (I2 > 90%. We found a high prevalence of complications in newly diagnosed type 2 diabetes in LMICs. Findings suggest that many people live with diabetes and are only diagnosed when they present with complications in LMICs. Research is needed to guide timely and effective identification of people living with diabetes in these settings.

Pathological Hyperinsulinemia and Hyperglycemia in the Impaired Glucose Tolerance Stage Mediate Endothelial Dysfunction Through miR-21, PTEN/AKT/eNOS, and MARK/ET-1 Pathways

BACKGROUND

Impaired glucose tolerance (IGT) is an important prediabetic stage characterized by elevated concentrations of glucose and insulin in the blood. The pathological hyperglycemia and hyperinsulinemia in IGT may regulate the expression of microRNA-21 (miR-21) and affect the downstream insulin signaling pathways, leading to endothelial cell dysfunction and early renal damage.

METHODS

The individual and combined effects of insulin and glucose were investigated using human glomerular endothelial cells (HGECs). The expression levels of miR-21, and PTEN/AKT/eNOS and MAPK/ET-1 pathway proteins in the treated cells were measured. The levels of nitric oxide (NO) and endothelin-1 (ET-1) secreted by the cells were also measured. The role of miR-21 in mediating the regulatory effects of insulin and glucose was assessed by overexpression/inhibition of this miRNA using mimics/inhibitor.

RESULTS

High (>16.7 mmol/L) concentration of glucose upregulated the expression of miR-21, leading to the activation and inhibition of the PTEN/AKT/eNOS and MAPK/ET-1 pathways, and upregulation of NO and downregulation of ET-1 secretion, respectively. High (>25 ng/mL) concentration of insulin downregulated the expression of miR-21, and lead to the activation of the MAPK/ET-1 and inhibition of the PTEN/AKT/eNOS pathway, thereby upregulating the expression of ET-1 and downregulating the secretion of NO. MiR-21 was observed to play a key role by directly controlling the activation of the insulin signaling pathways when the cells were cotreated with different concentrations of insulin and glucose. The expression of miR-21 was found to be dependent on the relative concentration of insulin and glucose. Under simulated conditions of the IGT stage (8.3 mmol/L glucose + 50 ng/mL insulin), the inhibitory effect of high insulin concentration on miR-21 expression in the cells attenuated the activation by high glucose concentration, resulting in the downregulation of miR-21, upregulation of ET-1 and downregulation of NO secretion.

CONCLUSION

Taken together, these results indicate that high insulin and glucose concentrations regulate the secretory function of glomerular endothelial cells in opposite ways by regulating the expression of miRNA-21. Pathological concentrations of insulin and glucose in the IGT stage may lead to a decrease in miR-21 expression, thereby disordering the secretion of vasoactive factors, resulting in renal tubule ischemia.

Insulin: Trigger and Target of Renal Functions

Kidney function in metabolism is often underestimated. Although the word “clearance” is associated to “degradation”, at nephron level, proper balance between what is truly degraded and what is redirected to de novo utilization is crucial for the maintenance of electrolytic and acid–basic balance and energy conservation. Insulin is probably one of the best examples of how diverse and heterogeneous kidney response can be. Kidney has a primary role in the degradation of insulin released in the bloodstream, but it is also incredibly susceptible to insulin action throughout the nephron. Fluctuations in insulin levels during fast and fed state add another layer of complexity in the understanding of kidney fine-tuning. This review aims at revisiting renal insulin actions and clearance and to address the association of kidney dysmetabolism with hyperinsulinemia and insulin resistance, both highly prevalent phenomena in modern society.

Renal cortical stiffness is markedly increased in pre-diabetes mellitus and associated with albuminuria

INTRODUCTION

We aimed to investigate changes in renal cortical stiffness (CS) in Type 2 diabetes mellitus (DM) and pre-DM patients compared to subjects with normal glucose metabolism (NGM), as well as the usefulness of renal CS to determine the presence of nephropathy.

METHODS

This study included 125 individuals with NGM, pre-DM and Type 2 DM. Routine laboratory data was obtained, and micro- and macrovascular involvement were investigated. Urinary albumin-creatinine ratio (UACR) was measured for urinary albuminuria detection. In addition to routine renal ultrasonography, CS was measured using renal elastography.

RESULTS

Among the included patients, 42, 40 and 43 patients had NGM, pre-DM and Type 2 DM, respectively, with prevalence of nephropathy of 5%, 15% and 33%, respectively. Carotid and aortic intima-media thickness (IMT), renal width, and CS were found to be higher in the pre-DM and Type 2 DM groups than the NGM group. Aortic IMT, renal width and UACR levels were independently associated with CS. Patients with nephropathy were found to have a higher CS value than those without nephropathy (8.72 ± 1.67 kPa vs. 10.60 ± 1.74 kPa, p = 0.001). In receiver operating characteristic curve analysis, when the cut-off value for CS was taken as 9.2 kPa, renal CS predicted the possibility of nephropathy with 78.9% sensitivity and 71.4% specificity.

CONCLUSION

CS values are significantly higher in patients with impaired glucose metabolism. We recommend CS measurement as part of routine screening of nephropathy in patients with pre-DM and newly diagnosed Type 2 DM.

Hyperinsulinemia contributes to impaired-glucose-tolerance-induced renal injury via mir-7977/SIRT3 signaling

Background:

Increasing evidence indicates that impaired glucose tolerance (IGT) is independently associated with chronic kidney disease, but the characteristics and underlying mechanisms remain largely unknown.

Methods:

Here, the cross-sectional study was performed to study the characteristics of IGT-induced renal injury (IGT-RI). Furthermore, urine microRNA profile was evaluated and microRNAs involved in tubular injury were determined by in-vitro experiments.

Results:

It was found that 12.1% of IGT patients had microalbuminuria, which we termed “IGT-RI.” Overall, 100% of patients with IGT-RI exhibited reabsorption dysfunction and 58.3% had structural damage in the renal tubules. Two-hour postprandial insulin, retinol-binding protein, and N-acetyl-β-glucosaminidase were significantly associated with microalbuminuria and they were independent risk factors for IGT-RI. The expression of mir-7977 was altered in IGT-RI patients and may be involved in cellular response to oxidative stress. In proximal tubule epithelial cells in vitro, a high level of insulin increased the expression of mir-7977 and decreased that of sirtuin 3 (SIRT3), leading to oxidative stress. Overexpression of mir-7977 further decreased SIRT3 expression, whereas inhibition of mir-7977 had the opposite effect. Furthermore, mir-7977 can bind to the 3′-untranslated region of SIRT3 mRNA and inhibit its expression. Moreover, inhibition of SIRT3 reduced the expression of cubilin and the endocytosis of albumin.

Conclusions:

In conclusion, IGT-RI mainly manifests as tubular injury, especially reabsorption dysfunction. Compensatory hyperinsulinemia may be involved. A high level of insulin can activate mir-7977/SIRT3 signaling, resulting in tubular injury by inducing oxidative stress as well as reabsorption dysfunction by inhibiting the expression of cubilin, ultimately contributing to IGT-RI.

Association of Prediabetes With CKD Progression and Adverse Cardiovascular Outcomes: An Analysis of the CRIC Study

PURPOSE

Despite our understanding of diabetes as an established risk factor for progressive kidney disease and cardiac complications, the prognostic significance of prediabetes in patients with chronic kidney disease (CKD) remains largely unknown.

METHODS

Participants of the Chronic Renal Insufficiency Cohort (CRIC) were categorized as having normoglycemia, prediabetes, or diabetes according to fasting plasma glucose, glycated hemoglobin A1c (HbA1c), and treatment with antidiabetic drugs at baseline. Unadjusted and adjusted proportional hazards models were fit to estimate the association of prediabetes and diabetes (versus normoglycemia) with: (1) composite renal outcome (end-stage renal disease, 50% decline in estimated glomerular filtration rate to ≤ 15 mL/min/1.73 m2, or doubling of urine protein-to-creatinine ratio to ≥ 0.22 g/g creatinine); (2) composite cardiovascular (CV) outcome (congestive heart failure, myocardial infarction or stroke); and (3) all-cause mortality.

RESULTS

Of the 3701 individuals analyzed, 945 were normoglycemic, 847 had prediabetes and 1909 had diabetes. The median follow-up was 7.5 years. Prediabetes was not associated with the composite renal outcome (adjusted hazard ratio [aHR] 1.13; 95% confidence interval [CI], 0.96-1.32; P = 0.14), but was associated with proteinuria progression (aHR 1.23; 95% CI, 1.03-1.47; P = 0.02). Prediabetes was associated with a higher risk of the composite CV outcome (aHR 1.38; 95% CI, 1.05-1.82; P = 0.02) and a trend towards all-cause mortality (aHR 1.28; 95% CI, 0.99-1.66; P = 0.07). Participants with diabetes had an increased risk of the composite renal outcome, the composite CV outcome, and all-cause mortality.

CONCLUSIONS

In individuals with CKD, prediabetes was not associated with composite renal outcome, but was associated with an increased risk of proteinuria progression and adverse CV outcomes.

Impaired Fasting Glucose and Chronic Kidney Disease, Albuminuria, or Worsening Kidney Function: a Secondary Analysis of the SPRINT

PURPOSE

Diabetes mellitus is a risk factor for the development and progression of chronic kidney disease (CKD). However, the association of prediabetes with adverse kidney outcomes is uncertain.

METHODS

We performed a secondary analysis of the Systolic Blood Pressure Intervention Trial (SPRINT), including 9,361 participants without diabetes at baseline. We categorized participants according to fasting glucose as having impaired fasting glucose (≥100 mg/dL [(≥5.6 mmol/L]) or normoglycemia (<100 mg/dL [(<5.6 mmol/L]). Unadjusted and adjusted proportional hazards models were fit to estimate the association of impaired fasting glucose (versus normoglycemia) with a composite outcome of worsening kidney function (≥30% decrease in eGFR to <60 ml/min/1.73 m2 in participants without baseline CKD; ≥50% decrease in eGFR or need of long-term dialysis/kidney transplantation in participants with CKD) or incident albuminuria (doubling of urinary albumin to creatinine ratio from <10 mg/g to >10 mg/g). These outcomes were also evaluated separately, and according to CKD status at baseline.

RESULTS

The mean age was 67.9 ± 9.4 years, 35.5% were female, and 31.4% were black. The median follow-up was 3.3 years and 41.8% had impaired fasting glucose. Impaired fasting glucose was not associated with higher rates of the composite outcome (HR 0.97; 95%CI 0.81-1.16), worsening kidney function (HR 1.02; 95%CI 0.75-1.37), or albuminuria (HR 0.98; 95%CI 0.78-1.23). Similarly, there was no association of impaired fasting glucose with outcomes according to baseline CKD status.

CONCLUSIONS

Impaired fasting glucose at baseline was not associated with the development of worsening kidney function or albuminuria in participants of SPRINT.

Hyperinsulinemia Can Cause Kidney Disease in the IGT Stage of OLETF Rats via the INS/IRS-1/PI3-K/Akt Signaling Pathway

AIMS

We investigated the changes of renal structure and its function in normal glucose tolerance (NGT), impaired glucose tolerance (IGT), diabetes mellitus (DM), and diabetic kidney disease (DKD) stages in OLETF rats and explored the role of the INS/IRS-1/PI3-K/Akt signaling pathway.

METHODS

OLETF rats were assigned into four groups on the basis of OGTT results and 24 h urinary microalbumin: NGT, IGT, DM, and DKD groups. The changes of renal structure and function and the corresponding pathological changes were observed. The absorption of albumin and the expression of megalin, cubilin, IRS-1, PI3-K, and Akt in NRK-52E cells were measured after being stimulated by different concentrations of insulin.

RESULTS

In the IGT group, the index which reflects the function of renal tubule-like N-acetyl-β-glucosaminidase, neutrophil gelatinase-associated lipocalin, retinol-binding protein, and cystatin C was higher than those in the control group and the NGT group (P < 0.05). Significant renal structure damages, especially in renal tubules, were observed in the IGT group. In the presence of insulin at a high concentration, the IRS-1/PI3-K/Akt signaling pathway in renal tubular epithelial cells was inhibited, and the expression of megalin and cubilin was significantly downregulated which was accompanied by a minimum uptake of albumin.

CONCLUSIONS

In contrast to DKD, the renal structural damage and functional changes in the IGT stage, in which we propose the term "IGT kidney disease," mainly manifest as renal tubular injury. Insulin resistance and compensatory hyperinsulinemia may be involved in its pathogenesis.

Prediabetes is associated with microalbuminuria, reduced kidney function and chronic kidney disease in the general population: The KORA (Cooperative Health Research in the Augsburg Region) F4-Study

BACKGROUND AND AIMS

We investigated the associations of serum fasting (FG) and 2-h postload (2HG) glucose from an oral glucose tolerance test (OGTT), glycated hemoglobin (HbA1c), fasting insulin and the homeostasis model assessment-insulin resistance index (HOMA-IR) with urinary albumin-to-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR).

METHODS AND RESULTS

We performed cross-sectional analyses of 2713 subjects (1429 women; 52.7%) without known type 2 diabetes, aged 31-82 years, from the KORA (Cooperative Health Research in the Augsburg Region) F4-Study. FG, 2HG, HbA1c, fasting insulin, HOMA-IR and glucose tolerance categories were analyzed for association with ACR and eGFR in multivariable adjusted linear and median regression models, and with isolated microalbuminuria (i-MA), isolated reduced kidney function (i-RKF) and chronic kidney disease (CKD, defined as MA and/or RKF) in multivariable adjusted logistic regression models. Among the 2713 study participants, 28% revealed prediabetes (isolated impaired fasting glucose [i-IFG], isolated glucose tolerance [i-IGT] or both by American Diabetes Association definition), 4.2% had unknown type 2 diabetes, 6.5% had i-MA, 3.1% i-RKF and 10.9% CKD. In multivariable adjusted analysis, all continuous variables (FG, 2HG, HbA1c, fasting insulin and HOMA-IR) were associated with i-MA, i-RKF and CKD. The odds ratios (ORs) for i-MA and CKD were 1.54 (95% confidence interval: 1.02-2.33) and 1.58 (1.10-2.25) for individuals with i-IFG. Moreover, the OR for i-RKF was 2.57 (1.31-5.06) for individuals with IFG + IGT.

CONCLUSION

Our findings suggest that prediabetes might have harmful effects on the kidney.

Comparison of Urine Albumin-to-Creatinine Ratio (ACR) Between ACR Strip Test and Quantitative Test in Prediabetes and Diabetes

BACKGROUND

Albuminuria is generally known as a sensitive marker of renal and cardiovascular dysfunction. It can be used to help predict the occurrence of nephropathy and cardiovascular disorders in diabetes. Individuals with prediabetes have a tendency to develop macrovascular and microvascular pathology, resulting in an increased risk of retinopathy, cardiovascular diseases, and chronic renal diseases. We evaluated the clinical value of a strip test for measuring the urinary albumin-to-creatinine ratio (ACR) in prediabetes and diabetes.

METHODS

Spot urine samples were obtained from 226 prediabetic and 275 diabetic subjects during regular health checkups. Urinary ACR was measured by using strip and laboratory quantitative tests.

RESULTS

The positive rates of albuminuria measured by using the ACR strip test were 15.5% (microalbuminuria, 14.6%; macroalbuminuria, 0.9%) and 30.5% (microalbuminuria, 25.1%; macroalbuminuria, 5.5%) in prediabetes and diabetes, respectively. In the prediabetic population, the sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of the ACR strip method were 92.0%, 94.0%, 65.7%, 99.0%, and 93.8%, respectively; the corresponding values in the diabetic population were 80.0%, 91.6%, 81.0%, 91.1%, and 88.0%, respectively. The median [interquartile range] ACR values in the strip tests for measurement ranges of <30, 30-300, and >300 mg/g were 9.4 [6.3-15.4], 46.9 [26.5-87.7], and 368.8 [296.2-575.2] mg/g, respectively, using the laboratory method.

CONCLUSIONS

The ACR strip test showed high sensitivity, specificity, and negative predictive value, suggesting that the test can be used to screen for albuminuria in cases of prediabetes and diabetes.

Impact of glucose load in an oral glucose tolerance test on urinary albumin excretion varies with 2-h glucose levels

BACKGROUND

The aim of the present study was to investigate whether an oral glucose load can induce an increase in urinary albumin excretion (UAE).

METHODS

One hundred and thirty subjects without macroalbuminuria or increased fasting serum glucose (≥7.0 mmol/L) were included in the study. At 0600 hours, subjects were asked to empty their bladder and drink 300 mL water. At 0800 hours, venous blood and 2-h urine were collected for fasting examination. Subjects were then asked to drink 300 mL solution containing 75 g glucose and, at 1000 hours, samples were collected again for post-challenge examination. Concentrations of serum glucose, urinary glucose, albumin, N-acetyl-β-D-glucosaminidase and retinol-binding protein were measured.

RESULTS

Based on the results of the oral glucose tolerance test, subjects were divided into three groups: (i) normal glucose tolerance (NGT; n = 55); (ii) impaired glucose tolerance (IGT; n = 39); and (iii) newly diagnosed diabetes mellitus (NDM; n = 36). In the NDM group, post-challenge urinary excretion of glucose and albumin was 14- and 1.6-fold greater than fasting values, respectively. In the IGT and NGT groups, although post-challenge urinary glucose excretion was 2.6- and 1.6-fold greater than fasting values, UAE did not increase. There was a positive correlation between post-challenge serum glucose and the UAE rate (UAER; r = 0.24, P < 0.01) and the UAER increment (ΔUAER; r = 0.19, P < 0.05), as well as between the serum glucose increment and post-challenge UAER (r = 0.23, P < 0.01) and ΔUAER (r = 0.18, P < 0.05). Post-challenge serum glucose levels were independently correlated with logarithmically converted post-challenge UAER (β = 0.322, P = 0.008).

CONCLUSIONS

Oral glucose load can induce a significant increase in UAE in NDM subjects. The main mechanism may be glomerular hyperfiltration.

Postpartum microalbuminuria after gestational diabetes: the impact of current glucose tolerance status

CONTEXT

It has been reported that women with a history of gestational diabetes mellitus (GDM) have an increased risk of microalbuminuria compared with that of their peers. Because previous GDM predicts an increased risk of prediabetes, which itself is associated with microalbuminuria, we hypothesized that current glucose intolerance may confound any association between GDM and microalbuminuria.

OBJECTIVE

The purpose of this study was to evaluate the relative impact of gestational and current dysglycemia on postpartum microalbuminuria in a cohort of women reflecting the full spectrum of gestational glucose tolerance from normal to mildly abnormal to GDM.

DESIGN/SETTING/PARTICIPANTS

In this prospective observational cohort study, 320 women underwent a glucose challenge test (GCT) and an oral glucose tolerance test (OGTT) in pregnancy, which identified 100 women with GDM, 58 with gestational impaired glucose tolerance, 90 with an abnormal GCT but a normal OGTT, and 72 with a normal GCT and OGTT. At 3 years postpartum, they underwent measurement of urine microalbumin and a repeat OGTT that identified 63 women with glucose intolerance (prediabetes/diabetes).

RESULTS

The postpartum urine microalbumin to creatinine ratio did not differ among the 4 gestational glucose tolerance groups (P = .23). Furthermore, on logistic regression analysis, GDM did not independently predict an elevated urine microalbumin to creatinine ratio of ≥1.5 g/mol of creatinine (odds ratio, 0.43; 95% confidence interval, 0.17-1.11), after adjustment for age, ethnicity, family history of diabetes, body mass index, blood pressure, estimated glomerular filtration rate, and current glucose intolerance. In contrast, current glucose intolerance independently predicted a urine microalbumin to creatinine ratio of ≥1.5 (odds ratio, 3.4; 95% confidence interval, 1.4-8.2, P = .005).

CONCLUSION

Current glucose intolerance, rather than previous GDM, may be associated with an increased risk of microalbuminuria in the early postpartum years.

Prediabetes is not independently associated with microalbuminuria in Korean general population: the Korea National Health and Nutrition Examination Survey 2011-2012 (KNHANES V-2,3)

We investigated the association between microalbuminuria and prediabetes in Korean population using data from the KNHANES 2011-2012. Prevalence of microalbuminuria was significantly increased in prediabetes group. However, the odds ratio became insignificant after adjustment for blood pressure, and the prevalence of microalbuminuria was not increased in prediabetic subjects without hypertension.

Microalbuminuria as a risk predictor in diabetes: the continuing saga

OBJECTIVE The rationale for this study was to review the data on microalbuminuria (MA), an amount of albumin in the urine of 30-299 mg/day, in patients with diabetes in the context of cardiovascular risk and development of kidney disease. The objective was to review the pathophysiology of MA in patients with diabetes and review the data from trials regarding MA in the context of risk for cardiovascular events or kidney disease progression. RESEARCH DESIGN AND METHODS Data sources were all PubMed-referenced articles in English-language peer-reviewed journals since 1964. Studies selected had to have a minimum 1-year follow-up and be either a randomized trial linking MA to cardiovascular or kidney disease outcome, a meta-analysis/systematic review, or a large observational cohort study. RESULTS The data suggest that MA is a risk marker for cardiovascular events and possibly for kidney disease development. Its presence alone, however, does not indicate established kidney disease, especially if the estimated glomerular filtration rate is >60 mL/min/1.73 m(2). An increase in MA, when blood pressure and other risk factors are controlled, portends a poor prognosis for kidney outcomes over time. Early in the course of diabetes, aggressive risk factor management focused on glycemic and blood pressure goals is important to delay kidney disease development and reduce cardiovascular risk. CONCLUSIONS MA is a marker of cardiovascular disease risk and should be monitored per guidelines once or twice a year for progression to macroalbuminuria and kidney disease development, especially if plasma glucose, lipids, and blood pressure are at guideline goals.

Correlation between prediabetes conditions and microalbuminuria

Background

Impaired fasting glucose (IFG), and impaired glucose tolerance (IGT) are two prediabetes conditions which have some correlation with macrovascular disorders. The risk of microvascular complications in these groups is not clear.

Objectives

The prevalence of albuminuria in subjects with IFG and IGT was evaluated in the present study.

Patients and Methods

In this study three groups of subjects were entered (45 subjects in each group): IFG, IGT, and normal glucose tolerance as control. The urine albumin-creatinine ratio was studied in morning spot urine samples to detect microalbuminuria. The subjects were followed up for two years, and blood sugar and urine albumin and glycosylated hemoglobin (HbA1C) were measured every 6 months.

Results

The prevalence rate of microalbuminuria was 15.5% in the prediabetic groups, while no one had microalbuminuria in the control group (P = 0.005). The prevalence of microalbuminuria in patients with IFG or IGT was not significantly different (17.8% vs. 13.3%) (P = 0.4). Fourteen subjects (4 in IFG group and 10 in IGT group) developed diabetes mellitus within a 2-year follow-up period (P = 0.1). Thirty six percent of subjects with albuminuria, and twelve percent of subjects without albuminuria progressed to diabetes mellitus during a 2-year follow-up (P = 0.02, odd ratio = 4.1; CI95%, 1.13-15.1).

Conclusions

The risk of microalbuminuria in prediabetic subjects is high, and probably prediabetic subjects are at higher risk of progression to diabetes mellitus. We suggest periodically evaluation of albuminuria in prediabetic patients after the diagnosis.

Impaired glucose tolerance and metabolic syndrome in idiopathic polyneuropathy: the role of pain and depression

Chronic idiopathic axonal polyneuropathy (CIAP) is referred to as axonal neuropathy after an adequate workup fails to determine a cause. A subgroup of patients with CIAP has impaired glucose tolerance (IGT). These patients have been considered by some investigators to have a neuropathy as a result of IGT and/or metabolic syndrome (MetS). Patients with CIAP usually suffer from chronic pain and associated depression, both of which have been proposed to cause insulin resistance (IR) by such mechanisms as a sustained increase in the corticosteroids and catecholamines, and chronic low grade inflammation. In a pilot study of 14 patients with CIAP+IGT and eight normal controls, we found a correlation between the number of features of the MetS with scores of pain and depression. There was no increase in the frequency of retinopathy and nephropathy in these patients, contrary to what would have been expected if chronic hyperglycemia was the cause of the neuropathy. We hypothesize that neuropathy has an unclear cause in the majority of patients with CIAP+IGT/MetS--and IGT/MetS are a result of comorbidities of CIAP, including chronic pain and depression.

Determinants of urinary albumin excretion within the normal range in patients with type 2 diabetes: the Randomised Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) study

AIMS/HYPOTHESIS

In contrast to microalbuminuric type 2 diabetic patients, the factors correlated with urinary albumin excretion are less well known in normoalbuminuric patients. This may be important because even within the normoalbuminuric range, higher rates of albuminuria are known to be associated with higher renal and cardiovascular risk.

METHODS

At the time of screening for the Randomised Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) Study, the urinary albumin/creatinine ratio (UACR) was 0.44 mg/mmol in 4,449 type 2 diabetic patients. The independent correlates of UACR were analysed.

RESULTS

Independent correlates of UACR during baseline were (in descending order): night-time systolic BP (r(s) = 0.19); HbA(1c) (r(s) = 0.18); mean 24 h systolic BP (r(s) = 0.16); fasting blood glucose (r(s) = 0.16); night-time diastolic BP (r(s) = 0.12); office systolic BP, sitting (r(s) = 0.11), standing (r(s) = 0.10); estimated GFR (r(s) = 0.10); heart rate, sitting (r(s) = 0.10); haemoglobin (r(s) = -0.10); triacylglycerol (r(s) = 0.09); and uric acid (r(s) = -0.08; all p <or= 0.001). Significantly higher albumin excretion rates were found for the following categorical variables: higher waist circumference (more marked in men); presence of the metabolic syndrome; smoking (difference more marked in males); female sex; antihypertensive treatment; use of amlodipine; insulin treatment; family history of diabetes; and family history of cardiovascular disease (more marked in women).

CONCLUSIONS/INTERPRETATION

Although observational correlations do not prove causality, in normoalbuminuric type 2 diabetic patients the albumin excretion rate is correlated with many factors that are potentially susceptible to intervention.

TRIAL REGISTRATION

ClinicalTrials.gov ID no.: NCT00185159

FUNDING

This study was sponsored by Daichii-Sankyo.

Is there a clear threshold for fasting plasma glucose that differentiates between those with and without neuropathy and chronic kidney disease?: the Singapore Prospective Study Program

Recent studies suggest that no distinct glycemic threshold consistently differentiates individuals with or without retinopathy. The authors sought to determine whether the same was true for other microvascular complications. They studied 5,094 participants with fasting plasma glucose values and concurrent microvascular complications from 4 previous cross-sectional surveys carried out in Singapore (1982-1998) who attended a follow-up examination in 2004-2007. Peripheral neuropathy was diagnosed based on abnormal responses to a 10-g monofilament or neurothesiometer test. Chronic kidney disease was defined in various ways by using albuminuria (urine albumin:creatinine ratio >30 microg/mg) and estimated glomerular filtration rate, alone and in combination. Prevalence of peripheral neuropathy was 7.5%. For chronic kidney disease, prevalence of albuminuria only was 10.5%, estimated glomerular filtration rate of <60 mL/minute per 1.73 m(2) only was 4.1%, and both was 2.1%. Prevalence of peripheral neuropathy and chronic kidney disease gradually increased in relation to fasting plasma glucose, beginning at levels below the existing diagnostic threshold for diabetes mellitus of 7.0 mmol/L (126 mg/dL). For chronic kidney disease, these associations persisted after adjustment for age, gender, ethnic group, and hypertension. Current diagnostic thresholds for diabetes mellitus have limited sensitivity for identifying individuals with these microvascular complications. Ascertaining these individuals may require development and application of novel screening strategies.

Aggravation of albuminuria by metabolic syndrome in type 2 diabetic Asian subjects

AIMS

We investigated the relationship of urinary albumin excretion (UAE) to metabolic syndrome and type 2 diabetes in Asian.

METHODS

A total of 446 subjects (187 without diabetes and 259 with type 2 diabetes) were enrolled in this study. The components of metabolic syndrome, high sensitivity C-reactive protein (hs-CRP) and UAE were assessed. Based on metabolic syndrome and diabetes status, participants were categorized into one of the following groups: neither metabolic syndrome nor diabetes (MS-DM-), metabolic syndrome without diabetes (MS+DM-), diabetes without metabolic syndrome (MS-DM+) and both metabolic syndrome and diabetes (MS+DM+).

RESULTS

The UAE in the MS+DM- group was higher than that in the MS-DM- group (P<0.001) and lower than that in the MS+DM+ group (P<0.001), but not significantly different from that in the MS-DM+ group (P=0.349). The trend of increasing UAE in these four groups was independent of hs-CRP.

CONCLUSION

UAE was lowest in subjects with neither metabolic syndrome nor diabetes and highest in subjects with both metabolic syndrome and type 2 diabetes; however, there was no significant difference between the metabolic syndrome alone group and the type 2 diabetes alone group.

Microalbuminuria and the metabolic syndrome and its components in the Chinese population

BACKGROUND

Microalbuminuria and the metabolic syndrome (MetS) have both been linked to chronic kidney disease and cardiovascular disease. This study investigated the association between urinary albumin-to-creatinine ratio (ACR) and MetS and its components.

MATERIALS AND METHODS

A total of 2311 subjects aged 40 years and over were recruited in 2004 in a metropolitan city in Taiwan. The biochemical indices, such as fasting glucose levels, urinary albumin, urinary creatinine and anthropometric indices, were measured. We defined microalbuminuria as a urinary ACR ranging from 30 to 300 mg g(-1) creatinine. MetS was defined using the American Heart Association and the National Heart, Lung and Blood Institute (AHA/NHLBI) and the International Diabetes Federation (IDF) definitions. The relationship between MetS and microalbuminuria was examined using multiple logistical regression analysis.

RESULTS

Subjects with microalbuminuria had higher age, body mass index (BMI), waist circumference, blood pressure, fasting plasma glucose, triglycerides, total cholesterol (TCHOL)/high-density lipoprotein cholesterol (HDL-C) ratio, prevalence of diabetes mellitus and hypertension and lower HDL-C than subjects with normoalbuminuria. After adjusting for age and BMI, microalbuminuria was associated with the individual components of MetS, except in central obesity in women and elevated fasting glucose in men. After adjusting for age, BMI, smoking and alcohol consumption status, multiple logistical regressions revealed that microalbuminuria is strongly associated with MetS in both genders and according to both definitions. The odds ratio of having MetS using the AHA/NHLBI and IDF definition was 1.76 (1.16-2.67) and 1.73 (1.06-2.83) in men and 2.19 (1.38-3.50) and 2.09 (1.24-3.51) in women, respectively.

CONCLUSIONS

Microalbuminuria was strongly associated with MetS and its components. There is an increased likelihood of having MetS if subjects have microalbuminuria.

Identifying patients at risk for microalbuminuria via interaction of the components of the metabolic syndrome: a cross-sectional analytic study

BACKGROUND AND OBJECTIVES

The objective of this study was to investigate correlates of risk for having microalbuminuria in individuals with one or more cardiovascular risk factors.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The study involved 1919 individuals who attended general practice settings, were aged 55 to 75 yr, and did not have a history of cardiovascular events or diabetes but had one or more cardiovascular risk factors. A tree-based regression technique and multivariate analysis were used to identify distinct, homogeneous subgroups of patients with different likelihood of having microalbuminuria; interaction between correlates of microalbuminuria and risk for microalbuminuria was also investigated.

RESULTS

The prevalence of microalbuminuria was 5.9%. Patients who did not have hypertension and had postload glycemia < 140 mg/dl showed the lowest prevalence of microalbuminuria (1.9%) and represented the reference class. The likelihood of microalbuminuria was seven times higher in men with hypertension and homeostatic model assessment levels in the upper tertile and four times higher in women with the same characteristics. Individuals with hypertension and lower homeostatic model assessment levels and normotensive individuals with postload glycemia > or = 140 mg/dl had a more than three-fold increased likelihood of having microalbuminuria. Treatment with statins was associated with a 54% reduction in the likelihood of having microalbuminuria, whereas levels of triglycerides > 150 mg/dl and fibrinogen levels in the upper tertile were associated with a significantly higher risk for microalbuminuria.

CONCLUSIONS

The likelihood of having microalbuminuria in a population-based study of elderly individuals is strongly related to the interaction between the components of the metabolic syndrome, particularly hypertension, insulin resistance, and impaired glucose tolerance.

Microalbuminuria

Microalbuminuria, originally described more than 3 decades ago as a predictor of nephropathy in patients who had type 1 diabetes mellitus and associated with higher cardiovascular risk, is now linked with increased risk for cardiovascular events rather than progression to end-stage kidney disease. This article reviews the role of microalbuminuria in the context of atherosclerotic vascular disease. It presents the methods for microalbuminuria assessment in clinical practice, its relations with other cardiovascular risk factors, and the pathophysiologic associations between microalbuminuria and vascular damage. In addition, this article discusses the prognostic significance of microalbuminuria for cardiovascular disease as well as existing therapeutic interventions for reducing urine albumin excretion in patients who are at high cardiovascular risk.