Urinary albumin excretion from spot urine samples predict all-cause and stroke mortality in Africans

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.

Association of impaired kidney function with mortality in rural Uganda: results of a general population cohort study

OBJECTIVE

To determine the association between baseline kidney function and subsequent all-cause mortality.

DESIGN AND SETTING

A general population-based cohort study from rural Uganda.

PARTICIPANTS

People aged 18 years and above with measured baseline estimated glomerular filtration rate (eGFR), recruited from survey rounds in 2011-2012 or 2014-2015 and followed up to March 2019.

OUTCOME MEASURE

The primary outcome was all-cause mortality, identified through reports from community health workers and verified by verbal autopsy. The association between baseline eGFR category and mortality was determined using multivariable Cox regression.

RESULTS

Of 5812 participants in both rounds, we included 5678 (97.7%) participants with kidney function and mortality data; the median age was 36 years (IQR 24-50), 60.7% were female, 10.3% were hypertensive, 9.8% were HIV-positive and 1.5% were diabetic. During a median follow-up of 5.0 years (IQR 3.7-6.0) there were 140 deaths. In age-adjusted and sex-adjusted analyses, eGFR <45 mL/min/1.73 m2 at baseline was associated with a 5.97 (95% CI 2.55 to 13.98) increased risk of mortality compared with those with baseline eGFR >90 mL/min/1.73 m2. After inclusion of additional confounders (HIV, body mass index, diabetes, hypertension, alcohol and smoking status) into the model, eGFR <45 mL/min/1.73 m2 at baseline remained strongly associated with mortality (HR 6.12, 95% CI 2.27 to 16.45), although the sample size fell to 3102. Test for trend showed strong evidence (p<0.001) that the rate of mortality increased progressively as the category of baseline kidney function decreased. When very high eGFR was included as a separate category in age-adjusted and sex-adjusted analyses, baseline eGFR ≥120 mL/min/1.73 m2 was associated with increased risk of mortality (HR 2.68, 95% CI 1.47 to 4.87) compared with the reference category of 90-119 mL/min/1.73 m2.

CONCLUSION

In a prospective cohort in rural Uganda we found that impaired baseline kidney function was associated with subsequently increased total mortality. Improved understanding of the determinants of kidney disease and its progression is needed in order to inform interventions for prevention and treatment.

The role of urinary albumin-to-creatinine ratio as a biomarker to predict stroke: A meta-analysis and systemic review

Albuminuria excretion rate, calculated as urinary albumin-to-creatinine ratio (UACR), is used clinically to evaluate albuminuria. There are different attitudes to whether high UACR predicts higher risk of stroke. The aim of this study was to evaluate the relationship between UACR and stroke. Two investigators independently searched MEDLINE, EMBASE, Cochrane Controlled Trials Register Database, Scopus and Google Scholar from January 1966 through June 2021 were screened. In addition, a manual search was conducted using the bibliographies of original papers and review articles on this topic. Two blinded reviewers abstracted the data independently to a predefined form. Among the 10,939 initially identified studies, 7 studies with 159,302 subjects were finally included. It is demonstrated that UACR predicted an increased risk of stroke using cutoff value of either 0.43 (HR, 2.39; 95% CI: 1.24 - 4.61; P <0.01), 10 mg/g (HR, 1.60; 95% CI: 1.30 - 1.97; P < 0.01) or 30 mg/g (HR, 1.84; 95% CI: 1.49 - 2.28; P < 0.01). The overall analysis confirmed that high UACR was associated with an increased rate of stroke (HR, 1.81; 95% CI: 1.52 - 2.17; P < 0.01). Furthermore, High UACR predicted higher risk of stroke in local inhabitants (HR, 1.67; 95% CI: 1.17 – 2.37; P = 0.04), adults (HR, 2.21; 95% CI: 2.07 – 2.36; P < 0.01) or elderly adults (HR, 1.96; 95% CI: 1.56 – 2.46; P < 0.01). Whereas, high UACR was unable to predict stroke in patients with either T2DM (HR, 2.25; 95% CI: 0.55 – 9.17; P = 0.26) or hypertension (HR, 0.95; 95% CI: 0.28 – 3.22; P = 0.93). Another subgroup analysis revealed that high UACR was associated with increased risk of ischemic stroke (HR, 1.60; 95% CI: 1.43 - 1.80; P < 0.01), as well as hemorrhagic stroke (HR, 1.76; 95% CI: 1.22 - 1.45; P < 0.01). In conclusion, UACR is associated with an increased risk of hemorrhagic and ischemic stroke. UACR may be used as an indicator to predict stroke in non-diabetic and non-hypertensive subjects.

Urinary albumin-to-creatinine ratio and the risk of first stroke in Chinese hypertensive patients treated with angiotensin-converting enzyme inhibitors

We aimed to evaluate the relationship of the albumin-to-creatinine ratio (ACR) with the risk of first stroke and examine possible effect modifiers in hypertensive patients. A total of 11,632 hypertensive participants with urinary ACR measurements and without a history of stroke from the China Stroke Primary Prevention Trial (CSPPT) were included in this analysis. The primary outcome was first stroke. Over a median follow-up of 4.4 years, 728 first strokes were identified, of which 633 were ischemic, 89 were hemorrhagic, and 6 were uncertain types. Overall, there was a significant positive association between natural log-transformed ACR and the risk of first stroke (HR, 1.11; 95% CI: 1.03-1.20) and first ischemic stroke (HR, 1.12; 95% CI: 1.03-1.22). Consistently, participants with ACR ≥ 10 mg/g had a significantly higher risk of first stroke (HR, 1.26; 95% CI: 1.06-1.50) and first ischemic stroke (HR, 1.33; 95% CI: 1.10-1.59) than those with ACR < 10 mg/g. Moreover, the association of ACR with first stroke was significantly stronger in participants with higher total homocysteine (tHcy) levels (<10 versus ≥ 10 μmol/L; P for interaction = 0.044). However, there was no significant association between ACR and first hemorrhagic stroke (per natural log [ACR] increment: HR, 1.02; 95% CI: 0.82-1.27). In summary, hypertensive patients with ACR ≥ 10 mg/g had a significantly increased risk of first stroke or first ischemic stroke. This positive association was more pronounced among participants with higher tHcy levels.

Cystatin C and Urine Albumin to Creatinine Ratio Predict 5-Year Mortality and Cardiovascular Events in People Living With HIV

BACKGROUND

Identifying people with HIV (PWH) at risk for chronic kidney disease, cardiovascular events, and death is crucial. We evaluated biomarkers to predict all-cause mortality and cardiovascular events, and measured glomerular filtration rate (mGFR) slope.

METHODS

Biomarkers were measured at enrollment. Baseline and 5-year mGFR were measured by plasma iohexol clearance. Outcomes were a composite criterion of all-cause mortality and/or cardiovascular events, and mGFR slope.

RESULTS

Of 168 subjects, 146 (87.4%) had undetectable HIV load. Median follow-up was 59.1 months (interquartile range, 56.2-62.1). At baseline, mean age was 49.5 years (± 9.8) and mean mGFR 98.9 mL/min/1.73m2 (± 20.6). Seventeen deaths and 10 cardiovascular events occurred during 5-year follow-up. Baseline mGFR was not associated with mortality/cardiovascular events. In multivariable analysis, cystatin C (hazard ratio [HR], 5.978; 95% confidence interval [CI], 2.774-12.88; P < .0001) and urine albumin to creatinine ratio (uACR) at inclusion (HR, 1.002; 95% CI, 1.001-1.004; P < .001) were associated with mortality/cardiovascular events. Area under receiver operating curve of cystatin C was 0.67 (95% CI, .55-.79) for mortality/cardiovascular event prediction. Biomarkers were not associated with GFR slope.

CONCLUSIONS

uACR and cystatin C predict all-cause mortality and/or cardiovascular events in PWH independently of mGFR.

Urinary albumin-to-creatinine ratio is inversely related to nitric oxide synthesis in young black adults: the African-PREDICT study

Hypertension is common in black populations and is known to be associated with low nitric oxide (NO) bioavailability. We compared plasma and urinary NO-related markers and plasma creatine kinase (CK) levels between young healthy black and white adults along with the associations of these markers with the urinary albumin-to-creatinine ratio (uACR), which is a surrogate marker of endothelial and kidney function. We included 1105 participants (20-30 years). We measured the uACR, plasma CK, plasma and urinary arginine, homoarginine, asymmetric (ADMA) and symmetric dimethylarginine (SDMA), urinary ornithine/citrulline, nitrate and nitrite, and malondialdehyde (MDA). In addition, the urinary nitrate-to-nitrite ratio (U_NOxR) was calculated and used as a measure of circulating NO bioavailability. The uACR was comparable between the groups, yet the black group had lower urinary nitrate (by -15%) and U_NOxR values (by -18%) (both p ≤ 0.001), higher plasma (by +9.6%) and urinary (by +5.9%) arginine (both p ≤ 0.004), higher plasma (by +13%) and urinary (by +3.7%) ADMA (both p ≤ 0.033), and higher CK (by +9.5%) and MDA (by +19%) (both p < 0.001) compared with white adults. Plasma and urinary homoarginine were similar between the groups. In the multiple regression analysis, we confirmed the inverse associations of the uACR with both plasma (adj. R² = 0.066; β = -0.209; p = 0.005) and urinary (adj. R² = 0.066; β = -0.149; p = 0.010) homoarginine and with the U_NOxR (adj. R² = 0.060; β = -0.122; p = 0.031) in the black group only. The overall less favorable NO profile and higher CK and MDA levels in the black cohort along with the adverse associations with the uACR may reflect the vulnerability of this cohort to the early development of hypertension.

Recent advances in understanding hypertension development in sub-Saharan Africa

Consistent reports indicate that hypertension is a particularly common finding in black populations. Hypertension occurs at younger ages and is often more severe in terms of blood pressure levels and organ damage than in whites, resulting in a higher incidence of cardiovascular disease and mortality. This review provides an outline of recent advances in the pathophysiological understanding of blood pressure elevation and the consequences thereof in black populations in Africa. This is set against the backdrop of populations undergoing demanding and rapid demographic transition, where infection with the human immunodeficiency virus predominates, and where under and over-nutrition coexist. Collectively, recent findings from Africa illustrate an increased lifetime risk to hypertension from foetal life onwards. From young ages black populations display early endothelial dysfunction, increased vascular tone and reactivity, microvascular structural adaptions as well as increased aortic stiffness resulting in elevated central and brachial blood pressures during the day and night, when compared to whites. Together with knowledge on the contributions of sympathetic activation and abnormal renal sodium handling, these pathophysiological adaptations result in subclinical and clinical organ damage at younger ages. This overall enhanced understanding on the determinants of blood pressure elevation in blacks encourages (a) novel approaches to assess and manage hypertension in Africa better, (b) further scientific discovery to develop more effective prevention and treatment strategies and

Low baseline urine creatinine excretion rate predicts poor outcomes among critically ill acute stroke patients

Urinary creatinine excretion rate (CER) is an established marker of muscle mass. Low CER has been linked to poor coronary artery disease outcomes, but a link between CER and acute stroke prognosis has not been previously explored. We prospectively collected data from patients with acute stroke (ischemic or hemorrhagic) within 24 hours from symptom onset in a Neurological and Neurosurgery Intensive Care Unit in Taiwan. Baseline CER (mg/d) was calculated by urine creatinine concentration in morning spot urine multiplies 24-hour urine volume on the second day of admission. Patients were divided into 3 tertiles with highest, middle, and lowest CER. Primary endpoint was poor outcome defined as modified Rankin Scale 3-6 at 6 months. Among 156 critically ill acute stroke patients meeting study entry criteria, average age was 67.9 years, and 83 (53.2%) patients had ischemic stroke. Patients with lowest CER (vs. highest CER) had a high risk of poor outcome at 6-month after adjustment (odds ratio 4.96, 95% confidence interval 1.22 to 20.15, p value = 0.025). In conclusion, low baseline CER, a marker of muscle mass, was independently associated with poor 6-month outcome among critically ill acute stroke patients. We speculate that preservation of muscle mass through exercise or protein-energy supplement might be helpful for improving prognosis in severe stroke patients.

Several Conventional Risk Markers Suggesting Presence of Albuminuria Are Weak Among Rural Africans With Hypertension

The objective of this cross-sectional study was to investigate risk markers indicating the presence of albuminuria in patients with hypertension in rural sub-Saharan Africa (SSA). Urine albumin-creatinine ratio, glycated hemoglobin (HbA1c ), blood pressure, anthropometry, and other patient characteristics including medications were assessed. We identified 160 patients with hypertension, of whom 68 (42.5%) were co-diagnosed with diabetes mellitus (DM). Among the included participants, 57 (35.6%) had albuminuria (microalbuminuria [n=43] and macroalbuminuria [n=14]). A backward multivariate logistic regression model identified age (per 10-year increment) (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.03-1.95), HbA1c >53 compared with <48 mmol/mol (OR, 3.81; 95% CI, 1.74-8.35), and treatment with dihydropyridine calcium channel blockers (OR, 2.59; 95% CI, 1.09-6.16) as the variables significantly associated with albuminuria. Only dysregulated DM and age were the conventional risk markers that seemed to suggest albuminuria among patients with hypertension in rural SSA.