Urinary albumin-to-creatinine ratio within normal range and all-cause or cardiovascular mortality among U.S. adults enrolled in the NHANES during 1999-2015

The relationship between low levels of albuminuria and mortality among adults without major cardiovascular risk factors

AIMS

The determine if elevated levels of albuminuria within the low range (urinary albumin-to-creatinine ratio, UACR <30 mg/g) are linked to cardiovascular death in adults lacking major cardiovascular risk factors.

METHODS

The association between UACR and cardiovascular mortality was investigated among 12,835 participants in the 1999-2014 National Health and Nutrition Examination Survey using Cox proportional hazard models and confounder-adjusted survival curves. We excluded participants with baseline cardiovascular disease, hypertension, diabetes, pre-diabetes, estimated glomerular filtration rate (eGFR) <60ml/min/1.73m2, currently pregnant, and those who had received dialysis in the last year.

RESULTS

Over a median follow-up of 12.3 years, 110 and 621 participants experienced cardiovascular and all-cause mortality. In multivariable-adjusted models, each doubling of UACR was associated with a 36% higher risk of cardiovascular death [HR 1.36 (95% confidence interval (CI) 1.02-1.82)] and a 24% higher risk of all-cause mortality [HR 1.24 (95% CI 1.10-1.39)]. The 15-year adjusted cumulative incidences of cardiovascular mortality were 0.91%, 0.99%, and 2.1% for UACR levels of <4.18 mg/g, 4.18 to <6.91 mg/g, and ≥6.91 mg/g, respectively. The 15-year adjusted cumulative incidences of all-cause mortality were 5.1%, 6.1%, and 7.4% for UACR levels of <4.18 mg/g, 4.18 to <6.91 mg/g, and ≥6.91 mg/g, respectively.

CONCLUSIONS

Adults with elevated levels of albuminuria within the low range (UACR <30 mg/g) and no major cardiovascular risk factors had elevated risks of cardiovascular and all-cause mortality. The risks increased linearly with higher albuminuria levels. This emphasizes a risk gradient across all albuminuria levels, even within the supposedly normal range, adding to the existing evidence.

Association between dietary inflammation index and albuminuria: results from the National Health and Nutrition Examination Survey

Background

The Dietary Inflammation Index (DII) is a tool for evaluating the potential for dietary inflammation, and inflammation is a major cause of exacerbation in chronic kidney disease. Our study aimed to investigate the relationship between DII and albuminuria.

Methods

Data were obtained from the 2005-2018 National Health and Nutrition Examination Survey (NHANES) after excluding pregnant, minors, and missing data of urinary albumin-creatinine ratio (ACR), estimated glomerular filtration rate (eGFR), and DII were enrolled in our study. Albuminuria was defined as ACR > 30 mg/g. DII was calculated and divided into tertiles. After fully adjusted, multivariate logistic regression analysis and subgroup analysis were performed to investigate the association between DII and albuminuria.

Results

A total of 22,607 participants including 2,803 (12.40%) with and 19,804 (87.60%) without albuminuria were enrolled in our study. The albuminuria increased with the increasing DII tertiles (Tertile 1: 10.81%; Tertile 2: 12.41%; Tertile 3:13.97%, P < 0.001). After fully adjusting for covariates, multivariate logistic regression showed that the higher the DII, the greater the odds of albuminuria (OR = 1.19; 95% CI, 1.00-1.41, P < 0.001). Subgroup analysis and interaction test of participants found that the positive correlation between DII and albuminuria was not significantly related to gender, age, BMI, hypertension, diabetes, and eGFR (P for interaction >0.05).

Conclusion

Elevated DII is associated with high odds of albuminuria. Further large-scale prospective studies are still needed to analyze the role of DII in albuminuria.

Point-of-care image-based quantitative urinalysis with commercial reagent strips: Design and clinical evaluation

Urinalysis is a useful test as an indicator of health or disease and as such, is a part of routine health screening. Urinalysis can be undertaken in many ways, one of which is reagent strips used in the general evaluation of health and to aid in the diagnosis and monitoring of kidney disease. To be effective, the test must be performed properly, and the results interpreted correctly. However, different light conditions and colour perception can vary between users leading to ambiguous readings. This has led to camera devices being used to capture and generate the estimated biomarker concentrations, but image colour can be affected by variations in illumination and inbuilt image processing. Therefore, a new portable device with embedded image processing techniques is presented in this study to provide quantitative measurements that are invariant to changes in illumination. The device includes a novel calibration process and uses the ratio of RGB values to compensate for variations in illumination across an image and improve the accuracy of quantitative measurements. Results show that the proposed calibration method gives consistent homogeneous illumination across the whole image. Comparisons against other existing methods and clinical results show good performance with a correlation to the clinical values. The proposed device can be used for point-of-care testing to provide reliable results consistent with clinical values.

A cross-sectional study investigating the relationship between urinary albumin creatinine ratio and abdominal aortic calcification in adults

Introduction

The presence of abdominal aortic calcification (AAC) is strongly linked to the development of atherosclerosis and the incidence of morbidity and mortality related to cardiovascular diseases (CVD). Urinary albumin creatinine ratio (UACR) was found related with the increased risk of CVD. The aim of this study is to explore the relationship between the UACR and severe AAC (SAAC).

Methods and Results

This study included a total of 2,379 individuals aged over 40 years, and their information was obtained from the National Health and Nutrition Examination Survey conducted (NHANES) in 2013-2014. The measurement of AAC was conducted through dual-energy x-ray absorptiometry and assessed using the Kauppila scoring system. SAAC was characterized by a Kauppila score of 6 or higher. Multivariate regression models were used to analyze the relationship between UACR level and SAAC, with covariate adjustment. In the completely adapted model, the top third subgroup exhibits increased likelihood of SAAC (odds ratio 1.50; 95%CI: 0.98, 2.29; p = 0.030) in contrast to the bottom third subgroup. The subgroup analyses revealed a more pronounced correlation among the older participants (p-value for interaction = 0.013).

Discussion

In the United States, SAAC was more likely to occur in adults who had a higher probability of UACR. The use of UACR has the potential to be a valuable method for forecasting the likelihood of SAAC.

Strategies to prevent, diagnose and treat kidney disease related to systemic arterial hypertension: a narrative review from the Mexican Group of Experts on Arterial Hypertension

This narrative review highlights strategies proposed by the Mexican Group of Experts on Arterial Hypertension endorsed to prevent, diagnose, and treat chronic kidney disease (CKD) related to systemic arterial hypertension (SAH). Given the growing prevalence of CKD in Mexico and Latin America caused by SAH, there is a need for context-specific approaches to address the effects of SAH, given the diverse population and unique challenges faced by the region. This narrative review provides clinical strategies for healthcare providers on preventing, diagnosing, and treating kidney disease related to SAH, focusing on primary prevention, early detection, evidence-based diagnostic approaches, and selecting pharmacological treatments. Key-strategies are focused on six fundamental areas: 1) Strategies to mitigate kidney disease in SAH, 2) early detection of CKD in SAH, 3) diagnosis and monitoring of SAH, 4) blood pressure targets in patients living with CKD, 5) hypertensive treatment in patients with CKD and 6) diuretics and Non-Steroidal Mineralocorticoid Receptor Inhibitors in Patients with CKD. This review aims to provide relevant strategies for the Mexican and Latin American clinical context, highlight the importance of a multidisciplinary approach to managing SAH, and the role of community-based programs in improving the quality of life for affected individuals. This position paper seeks to contribute to reducing the burden of SAH-related CKD and its complications in Mexico and Latin America.

Urinary Albumin-to-Creatinine Ratio in Normal Range, Cardiovascular Health, and All-Cause Mortality

Importance

Although cumulative evidence suggests that elevated urinary albumin-to-creatinine ratio (UACR) in the normal range (<30 mg/g) may be associated with an increased risk of mortality, few studies have investigated whether cardiovascular health (CVH) modifies the harmful outcomes of high-normal UACR.

Objective

To investigate associations of traditionally normal UACR and CVH with all-cause mortality.

Design, Setting, and Participants

This cohort study used National Health and Nutrition Examination Survey data from 2005 through 2018 and linked mortality information until 2019. Data were analyzed from March 1 through October 31, 2023. The study included adult participants aged 20 to 79 years with a normal UACR (<30 mg/g) based on Kidney Disease: Improving Global Outcomes criteria.

Exposures

The UACR was treated as a continuous variable and categorized into tertiles delineated as low (<4.67 mg/g), medium (4.67-7.67 mg/g), and high (7.68 to <30 mg/g). Cardiovascular health was assessed using Life's Essential 8 scores and grouped as poor (0-49 points), moderate (50-79 points), and ideal (80-100 points).

Main Outcomes and Measures

Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% CIs for associations of UACR with all-cause mortality in total participants and as stratified by CVH groups.

Results

The study included 23 697 participants (mean [SD] age, 45.58 [15.44] years; 11 806 women [49.7%] and 11 891 men [50.3%]). During the median 7.8 years (range, 4.5-11.1 years) of follow-up, 1403 deaths were recorded. Near-linear associations were observed for continuous UACR and CVH with all-cause mortality. Compared with the low UACR group, high UACR in the normal range showed an increased mortality risk in the moderate and poor CVH groups (CVH [50-79]: HR, 1.54 [95% CI, 1.26-1.89]; CVH [0-49]: HR, 1.56 [95% CI, 1.10-2.20]), with a significant multiplicative interaction of UACR and CVH (P < .001).

Conclusions and Relevance

The findings suggest that high UACR within the normal range is associated with a significantly increased risk of all-cause mortality, with the association more pronounced in adults with poor CVH status. These findings highlight the importance of risk management for early kidney dysfunction, particularly among individuals with poor CVH.

Associations Between Albuminuria and Mortality Among US Adults by Demographic and Comorbidity Factors

Background Albuminuria is a known marker of mortality risk. Whether the association between albuminuria and mortality differs by demographic and comorbidity factors remains unclear. Therefore, we sought to determine whether albuminuria is differentially associated with mortality. Methods and Results This study included 49 640 participants from the National Health and Nutrition Examination Survey (1999-2018). All-cause mortality through 2019 was linked from the National Death Index. Multivariable-adjusted Poisson regression models were used to determine whether levels of urine albumin-to-creatinine ratio (ACR) were associated with mortality. Models were adjusted for demographic, socioeconomic, behavioral, and clinical factors. Mean age in the population was 46 years, with 51.3% female, and 30.3% with an ACR ≥10 mg/g. Over a median follow-up of 9.5 years, 6813 deaths occurred. Compared with ACR <10, ACR ≥300 was associated with increased risk of mortality by 132% overall (95% CI, 2.01-2.68), 124% among men (95% CI, 1.84-2.73), 158% among women (95% CI, 2.14-3.11), 130% among non-Hispanic White adults (95% CI: 1.89-2.79), 135% among non-Hispanic Black adults (95% CI, 1.82-3.04), and 114% among Hispanic adults (95% CI, 1.55-2.94). Compared with ACR <10, ACR ≥300 was associated with increased risk of mortality by 148% among individuals with neither hypertension nor hypercholesterolemia (95% CI, 1.69-3.64), 128% among individuals with hypertension alone (95% CI, 1.86-2.79), and 166% among individuals with both hypertension and hypercholesterolemia (95% CI, 2.18-3.26). Conclusions We found strong associations between albuminuria and mortality risk, even at mildly increased levels of albuminuria. Associations persisted across categories of sex, race or ethnicity, and comorbid conditions, with subtle differences.

Predictors of subclinical atherosclerosis and microalbuminuria in middle-aged women: a cross-sectional study

BACKGROUND

Cardiovascular disease is of increasing concern in women. The aim was to assess the role of clinical and anthropometric measures in the development of subclinical atherosclerosis.

METHODS

A cross-sectional study in 203 Europid females to determine the prevalence of abnormal carotid intima-media thickness (CIMT) and associated clinical parameters.

RESULTS

The study population had a mean age of the 38.3±5.4 years, a median Body Mass Index of 29.25 (IQR 25.06-36.11) kg/m2 and median waist index (WI) of 1.15 (IQR 1.06-1.34). Increased CIMT was present in 169 (83.25%) participants. Linear regression analysis revealed WI to be the sole predictor of increased CIMT (β=24.387, P<0.001). Post-hoc ROC analysis revealed a WI of 1.12 has 62% sensitivity and 53% specificity for predicting increased CIMT (AUC 0.63, 95% CI 0.55-0.72, P=0.016). The median urinary albumin-creatinine ratio (ACR) was 4.4 mg/g, and the prevalence of microalbuminuria was 8.9%; serum triglycerides were the only independent predictor of ACR.

CONCLUSIONS

Atherosclerosis, as detected by abnormal CIMT, is very prevalent in middle-aged women. Waist index is the major predictor of subclinical atherosclerosis in a contemporary premenopausal female population. A WI of 1.12 exhibits relatively good sensitivity and specificity in predicting the presence of atherosclerosis in this patient population.

Positive associations between different circulating trans fatty acids (TFAs) and urinary albumin excretion among adults in the U.S.: a population-based study

BACKGROUND

It is well established that the consumption of trans-fatty acids (TFAs) can increase the incidence of total mortality, cardiovascular disease, cancer, and diabetes. However, there are still no demographic studies on the effects of circulating TFA isoforms on the albumin-creatinine ratio (ACR), an early marker of chronic kidney disease. Our goal was to explore the possible relationships between TFAs and ACR.

METHODS

In this study, complete TFAs and urinary ACR data were collected from the National Health and Nutrition Examination Survey (NHANES) (2009-2010 and 1999-2000 cycles). The independent linear relationships between different circulating TFA isoforms and the ACR were examined by performing multivariable linear regression models. Machine learning was used to analyze the contribution of the different TFA isoforms to the ACR. To assess the nonlinearity of the relationship, smooth curve fitting and an analysis of threshold effect were performed, and a stratified analysis was conducted to identify possible susceptible populations.

RESULTS

Our analysis included a total of 3785 individuals. Elaidic acid, linolelaidic acid, and sum TFAs were shown to be positively associated with the ACR after full adjustment by weighted multivariable regression analysis. In the subgroup analysis, the positive associations were maintained in participants with hypertension and without diabetes. In the XGBoost model of the ACR, Sum TFAs were found to be the most crucial factor. In addition, smooth curve fitting showed that there was a nonlinear relationship between the different TFAs and the ACR, and there was a saturation point.

CONCLUSIONS

Our study demonstrated that TFA isoforms were positively and independently correlated with urinary albumin excretion, especially in participants with hypertension and without diabetes. This suggested that reducing trans fatty acid intake may reduce the risk of renal events.

Association of different obesity patterns with hypertension in US male adults: a cross-sectional study

Obesity is an important risk factor for hypertension. We aimed to investigate the association between different obesity patterns and hypertension risk in a large male population in the US. Male participants from the National Health and Nutrition Examination Survey (NHANES) (2007-2018) were enrolled in this cross-sectional study. Social demographic information, lifestyle factors, anthropometric measurements and biochemical measurements were collected. Three obesity patterns were classified according to the body mass index (BMI) and waist circumference (WC), including overweight and general obesity, abdominal obesity, and compound obesity. We adopted multivariate logistic regression to investigate the associations between hypertension and different obesity patterns after adjusting for cofounding factors. Subgroup analysis, stratified by age, smoking, drinking and estimated glomerular filtration rate (eGFR), was also conducted to explore the associations between obesity patterns and hypertension risk among different populations. Moreover, the association between WC and hypertension among male individuals was also explored using restricted cubic spline (RCS) analysis. Receiver operating characteristic (ROC) was used to evaluate the discriminatory power of WC for screening hypertension risk. 13,859 male participants from NHANES survey (2007-2018) were enrolled. Comparing with the normal-weight group, the odds ratios (ORs) [95% confidence interval (CI)] for hypertension in individuals with overweight and general obesity, abdominal obesity and compound obesity were 1.41 [1.17-1.70], 1.97 [1.53-2.54] and 3.28 [2.70-3.99], respectively. Subgroup analysis showed that the effect of different obesity patterns on hypertension risk was highly stable among individuals with different clinical conditions. In addition, WC had a positive correlation with the risk of hypertension (OR: 1.43; 95% CI 1.37-1.52; P < 0.001) in fully adjusted multivariate logistic regression model. RCS analysis showed that the association between WC and hypertension risk was in a nonlinear pattern, and WC had a good discriminatory power for hypertension in ROC analysis. Different patterns of obesity have a great impact on the risk of hypertension among male individuals. Increment of WC significantly increased the hypertension risk. More attention should be paid to the prevention of obesity, especially abdominal obesity and compound obesity in male individuals.

Molecularly imprinted polymer dual electrochemical sensor for the one-step determination of albuminuria to creatinine ratio (ACR)

The urinary albumin to creatinine ratio (ACR) is a convenient and accurate biomarker of chronic kidney disease (CKD). An electrochemical sensor for the quantification of ACR was developed based on a dual screen-printed carbon electrode (SPdCE). The SPdCE was modified with carboxylated multiwalled carbon nanotubes (f-MWCNTs) and redox probes of polymethylene blue (PMB) for creatinine and ferrocene (Fc) for albumin. The modified working electrodes were then molecularly imprinted with coated with polymerized poly-o-phenylenediamine (PoPD) to form surfaces that could be separately imprinted with creatinine and albumin template molecules. The seeded polymer layers were polymerized with a second coating of PoPD and the templates were removed to form two different molecularly imprinted polymer (MIP) layers. The dual sensor presented recognition sites for creatinine and albumin on different working electrodes, enabling the measurement of each analyte in one potential scan of square wave voltammetry (SWV). The proposed sensor produced linear ranges of 5.0-100 ng mL^-1 and 100-2500 ng mL^-1 for creatinine, and 5.0-100 ng mL^-1 for albumin. LODs were 1.5 ± 0.2 ng mL^-1 and 1.5 ± 0.3 ng mL^-1, respectively. The dual MIP sensor was highly selective and stable for seven weeks at room temperature. The ACRs obtained using the proposed sensor compared well (P > 0.05) with the results from immunoturbidimetric and enzymatic methods.

Optimal threshold of urinary albumin-to-creatinine ratio (UACR) for predicting long-term cardiovascular and noncardiovascular mortality

PURPOSE

Traditional cutoff values of urinary albumin-to-creatinine ratio (UACR) for predicting mortality have recently been challenged. In this study, we investigated the optimal threshold of UACR for predicting long-term cardiovascular and non-cardiovascular mortality in the general population.

METHODS

Data for 25,302 adults were extracted from the National Health and Nutrition Examination Survey (2005-2014). Receiver operating characteristic (ROC) curve analysis was performed to assess the predictive value of UACR for cardiovascular and non-cardiovascular mortality. A Cox regression model was established to examine the association between UACR and cardiovascular and non-cardiovascular mortality. X-tile was used to estimate the optimal cutoff of UACR.

RESULTS

The UACR had acceptable predictive value for both cardiovascular (AUC (95% CI) for 1-year, 3-year and 5-year mortality, respectively: 0.769 (0.711-0.828), 0.764 (0.722-0.805) and 0.763 (0.730-0.795)) and non-cardiovascular (AUC (95% CI) for 1-year, 3-year and 5-year mortality, respectively: 0.772 (0.681-0.764), 0.708 (0.686-0.731) and 0.708 (0.690-0.725)) mortality. The optimal cutoff values were 16 and 30 mg/g for predicting long-term cardiovascular and non-cardiovascular mortality, respectively. Both cutoffs of UACR had acceptable specificity (0.785-0.891) in predicting long-term mortality, while the new proposed cutoff (16 mg/g) had higher sensitivity. The adjusted hazard ratios of cardiovascular and non-cardiovascular mortality for the high-risk group were 2.50 (95% CI 1.96-3.18, P < 0.001) and 1.92 (95% CI 1.70-2.17, P < 0.001), respectively.

CONCLUSIONS

Compared to the traditional cutoff value (30 mg/g), a UACR cutoff of 16 mg/g may be more sensitive for identifying patients at high risk for cardiovascular mortality in the general population.

Sex modifies the association between urinary albumin-to-creatinine ratio and diabetes among adults in the United States (NHANES 2011-2018)

BACKGROUND

Studies on the association between urinary albumin-to-creatinine ratio (uACR) and diabetes are limited. We aimed to examine the association between uACR and diabetes among adults in the United States, with particular interest in sex differences.

METHODS

Overall, 5307 participants were included in this study. The exposure variable was uACR, where uACR = urine albumin/urine creatinine. The primary outcome of this study was diabetes, defined as self-reported physician diagnosis of diabetes, fasting plasma glucose concentration ≥ 7.0 mmol/L, or use of glucose-lowering drugs.

RESULTS

The average age of the participants in this study was 46.37 ± 17.38 years, 818 (15.41%) had diabetes and the median uACR was 7 mg/g (interquartile range, 4-12 mg/g). There was a significant positive association between uACR and diabetes (per natural log [uACR] increment: OR, 1.81; 95% CI 1.39-2.34). A multivariate logistic regression model demonstrated that per unit increment in LguACR, the diabetes prevalence increased 2.26-fold among male participants (OR 2.26, 95% CI 1.59-3.21). However, in female participants, we observed that uACR was not related to the prevalence of diabetes (odds ratio [OR], 1.28; 95% CI 0.82-2.01). Our findings showed that there was an interaction between sex and uACR (P for interaction = 0.049).

CONCLUSIONS

A higher uACR is significantly associated with an increased prevalence of diabetes, and sex can modify the relationship between them.

Development and validation of a novel nomogram to predict overall survival of patients with moderate to severe chronic kidney disease

Introduction

The risk of death significantly increased from stage 3 chronic kidney disease (CKD) onward. We aimed to construct a novel nomogram to predict the overall survival (OS) of patients afflicted with CKD from stage 3–5.

Methods

A total of 882 patients with stage 3–5 CKD were enrolled from the NHANES 2001–2004 survey. Data sets from the 2003–2004 survey population were used to develop a nomogram that would predict the risk of OS. The 2001–2002 survey population was used to validate the nomogram. Least absolute shrinkage and selection operator (Lasso) regression was conducted to screen the significant predictors relative to all-cause death. The multivariate Cox regression based on the screened factors was applied to effectively construct the nomogram. The performance of the nomogram was evaluated according to the C-index, the area under the receiver operating characteristic curve (AUC), and the calibration curve with 1000 bootstraps resample. Kaplan–Meier’s curves were used for testing the discrimination of the prediction model.

Results

Five variables (age, urinary albumin-to-creatinine ratio (UACR), potassium, cystatin C (Cys C), and homocysteine) were screened by the Lasso regression. The nomogram was constructed using these factors, as well as the CKD stage. The included factors (age, CKD stage, UACR, potassium, Cys C, and homocysteine) were all significantly related to the death of CKD patients, according to the multivariate Cox regression analysis. The internal validation showed that this nomogram demonstrates good discrimination and calibration (adjusted C-index: 0.70; AUC of 3-, 5-, and 10-year OS were 0.75, 0.78, and 0.77, respectively). External validation also demonstrated exceedingly similar results (C-index: 0.72, 95% CI: 0.69–0.76; AUC of 3-, 5-, and 10-year OS were 0.76, 0.79, and 0.80, respectively).

Conclusions

This study effectively constructed a novel nomogram that incorporates CKD stage, age, UACR, potassium, Cys C, and homocysteine, which can be conveniently used to facilitate the individualized prediction of survival probability in patients with stage 3–5 CKD. It displays valuable potential for clinical application.

Discordance between the triglyceride glucose index and HOMA-IR in incident albuminuria: a cohort study from China

Background

To date, there have no study comparing the associations between TyG index and HOMA-IR on the risk of incident albuminuria. Accordingly, the objective of the present study is to use discordance analysis to evaluate the diverse associations between TyG index and HOMA-IR on the risk of incident albuminuria.

Methods

A community-based prospective cohort study was performed with 2446 Chinese adults. We categorized participants into 4 concordance or discordance groups. Discordance was defined as a TyG index equal to or greater than the upper quartile and HOMA-IR less than the upper quartile, or vice versa.

Results

During a median follow-up period of 3.9 years, 203 of 2446 participants developed incident albuminuria (8.3%). In the multivariable logistic analyses, the high TyG index tertile group was associated with a 1.71-fold (95% confidence interval (CI) 1.07–2.72) higher risk of incident albuminuria, comparing with the low tertile group. Participants in TyG (+) & HOMA-IR (−) group had a greater risk of incident albuminuria compared with those in TyG (−) & HOMA-IR (−) group after multivariate adjustment. Subgroup analyses showed that low HOMA-IR and discordantly high TyG index was closely related to a highest risk of incident albuminuria in cardiovascular metabolic disorder subjects.

Conclusions

Participants with a discordantly high TyG index had a significantly greater risk of incident albuminuria, especially in metabolic dysfunction subjects. The TyG index might be a better predictor of early stage of chronic kidney disease than HOMA-IR for subjects with metabolic abnormality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01602-w.

The retinopathy-derived HbA1c threshold of 6.5% for type 2 diabetes also captures the risk of diabetic nephropathy in NHANES

AIM

To determine if an HbA1c diagnostic threshold of less than 6.5% (<48 mmol/mol) could be identified based on a urinary albumin-creatinine ratio (UACR) of 30 mg/g or higher in subjects not known to have diabetes.

METHODS

A UACR was measured for 20 158 participants in the 2011-2018 nationally representative cross-sectional National Health and Nutrition Examination Surveys (NHANES; cycles 7-10 inclusive).

RESULTS

There was a significant trend for an increasing risk with a UACR of 30 mg/g or higher across increasing HbA1c categories (P < .0001). This trend was mainly attributable to the high prevalence of raised UACR in the 7.0% or higher HbA1c subgroup of subjects not previously diagnosed with diabetes. None of the odds ratios in the lower HbA1c subgroups versus the HbA1c subgroup of less than 5.0% reached significance. There were racial/ethnic differences in UACR risk (P < .0001), with White and Black subjects exhibiting little increased risk (vs. HbA1c <5.0%) until they reached an HbA1c of 7.0%, while Asian and Hispanic subjects showed some increased, but non-significant, risks at lower HbA1c levels. Maximizing the area under receiver operating characteristic curves from logistic regressions predicted an ideal HbA1c threshold of 5.8%, but there was little variation in area from 5.5% to 7.0%.

CONCLUSION

A clinically useful diagnostic threshold below 6.5% for HbA1c for elevated UACR risk was not identified, with an increased risk only obvious at an HbA1c of 7.0% or higher. Thus, the retinopathy-derived HbA1c threshold of 6.5% also captures the risk of diabetic nephropathy in NHANES.