OBJECTIVE: 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.
In this study of 12,835 adults without major cardiovascular risk factors (such as hypertension, cardiovascular disease, diabetes, pre-diabetes, or chronic kidney disease), we investigated the association between higher albuminuria levels within the low range (urine albumin-to-creatinine ratio (UACR) <30 mg/g) and both cardiovascular and all-cause mortality. Our findings revealed a linear increase in excess risk for both outcomes with rising albuminuria among relatively healthy adults. Each doubling of albuminuria was associated with a 36% higher risk of cardiovascular death (HR 1.36, 95% CI 1.02-1.82) and a 24% higher risk of all-cause mortality (HR 1.24, 95% CI 1.10-1.39). Each 10 mg/g increase in albuminuria was associated with 66% higher risk of cardiovascular mortality (HR 1.66, 95% CI 1.20, 2.28) and 41% higher risk of all-cause mortality (HR 1.41, 95% CI 1.17-1.68). These results challenge the assumption that UACR values below 30 mg/g are non-prognostic in adults without major cardiovascular risk factors.

UNASSIGNED: Albuminuria is associated with cardiovascular events among adults with underlying cardiovascular disease and diabetes, even at low levels of urinary albumin excretion. We hypothesized that low levels of albuminuria in the \'normal\' range (urinary albumin-to-creatine ratio (UACR) <30 mg/g) are associated with cardiovascular death among apparently healthy adults.
UNASSIGNED: We studied adults who participated in the 1999-2014 National Health and Nutrition Examination Survey. We excluded participants with baseline cardiovascular disease, hypertension, diabetes, estimated glomerular filtration rate (eGFR) <60ml/min/1.73m2, those who were currently pregnant, and those who had received dialysis in the last year. After excluding these conditions, only 5.0% of the remaining population had UACR ≥30 mg/g (N=873) and were excluded. The final sample size was 16,247. We assessed the relationship between UACR and cardiovascular and all-cause mortality using multivariable-adjusted Cox proportional hazards models. Models were adjusted for age, sex, race or ethnicity, smoking status, systolic blood pressure, hemoglobin A1c, total cholesterol, health insurance, food insecurity, serum albumin, body mass index, use of statins, and eGFR.
UNASSIGNED: Mean age was 38.9 years (SD 13.6) and 53.7% were women. The median length of follow-up was 12.2 years. In multivariable-adjusted models, each doubling of UACR (within the <30 mg/g range) was associated with a 36% higher risk of cardiovascular death [HR 1.36 (95% confidence interval (CI) 1.11-1.65)] and a 28% higher risk of all-cause mortality [HR 1.28 (95%CI 1.17-1.41)]. The highest tertile of UACR (7.1-29.9 mg/g) was associated with an 87% higher risk of cardiovascular death [HR 1.87 (95%CI 1.20-2.92)] and 59% higher risk of all-cause mortality [HR 1.59 (95%CI 1.28-1.96)], compared with the lowest tertile (< 4.3 mg/g).
UNASSIGNED: In a nationally representative sample of relatively healthy community-dwelling adults, higher levels of albuminuria in the conventionally \"normal\" range <30 mg/g in healthy individuals are associated with greater mortality. Overall, our findings contribute to the growing body of evidence on the existence of a risk gradient across all levels of albuminuria, even in the so-called normal range.

A urine albumin/creatinine ratio (UACR) <30 mg/g is considered to be normal, while increased risk of incident hypertension and cardiovascular disease mortality in subjects with high normal UACR level had been observed. However, a mild elevated but normal UACR level was associated with the risk of initiating chronic kidney disease (CKD) is uncertain. We investigated whether higher normal UACR is associated with the risk of developing CKD. A total of 4821 subjects with type 2 diabetes mellitus (T2DM), an estimated glomerular filtration rate >60 ml/min/1.73 m2 and UACR <30 mg/g enrolled in a diabetes disease management program between 2006 and 2020 were studied. The optimal cutoff point for baseline UACR as a predictor for progression to CKD according to the 2012 KDIGO definition was calculated using receiving operating characteristic curve analysis. After a mean of 4.9 years follow-up, the CKD risk progression increased in parallel with the quartiles of baseline UACR <30 mg/g (p for trend <0.0001). UACR cutoff points of 8.44 mg/g overall, 10.59 mg/g in males and 8.15 mg/g in females were associated with the risk of CKD progression. In multivariate Cox regression analysis, the hazard ratios for the association between UACR (>8.44 mg/g, >10.9 mg/g, >8.15 mg/g in overall, male, and female patients, respectively) and the risk of CKD progression were significant. This study demonstrated that a cutoff UACR value of >10 mg/g could significantly predict the cumulative incidence and progression of CKD in patients with T2DM.

UNASSIGNED: Albuminuria is a well-known risk factor for end-stage kidney disease, all-cause mortality, and cardiovascular mortality, even when the albumin-to-creatinine ratio is <30 mg/g. However, the association between transiently observed trace albuminuria and these major adverse outcomes has not yet been reported. This study aimed to examine the effect of transient albuminuria on these major adverse outcomes using the National Health Insurance Service data in Korea.
UNASSIGNED: The National Health Insurance Service-National Sample Cohort from Korea, followed from 2002 to 2015, consisted of 1,025,340 individuals, accounting for 2.2% of the total Korean population. We analyzed the effect of transient albuminuria on all-cause death, cardiovascular death, and incident chronic kidney disease (CKD) and compared it with the group without albuminuria. Among 1,025,340 individuals, 121,876 and 2,815 had transient albuminuria and no albuminuria, respectively. Adjusted hazard ratios of the transient albuminuria group for cardiovascular death and incident CKD were 1.76 (1.01-3.08) and 1.28 (1.15-1.43), respectively. There were significant differences in all-cause death, cardiovascular death, and incident CKD between the two groups after propensity score matching (p = 0.0037, p = 0.015, and p < 0.0001, respectively). Propensity score matching with bootstrapping showed that the hazard ratios of the transient albuminuria group for all-cause death and cardiovascular death were 1.39 (1.01-1.92) and 2.18 (1.08-5.98), respectively.
UNASSIGNED: In this nationwide, large-scale, retrospective cohort study, transient albuminuria was associated with all-cause death, cardiovascular death, and incident CKD, suggesting that transient albuminuria could be a risk marker for adverse outcomes in the future, and that its own subclinical phenotype could play an important role during the course of CKD.

Individuals with metabolic syndrome have elevated risks of micro- and macro-albuminuria as well as chronic kidney disease (CKD).
To assess the influence of metabolic abnormalities on the presence of low-grade albuminuria (below the threshold for microalbuminuria). Design, participants, and main outcome measures: This community-based cohort study included 3,935 eligible individuals aged 40 years or older. The presence of low-grade albuminuria was detected in those without micro- or macro-albuminuria and analyzed according to the highest quartile of the baseline urinary albumin-to-creatinine ratio (ACR ≥11.13 mg/g). CKD was defined by an estimated glomerular filtration rate <60 mL/min/1.73 m2 or the new presence of albuminuria (ACR ≥30 mg/g).
Overall, 577 (14.7%) participants developed low-grade albuminuria and 164 (4.2%) participants developed CKD during a mean follow-up period of 3.6 years. Compared with participants without metabolic syndrome, those with metabolic syndrome had greater risks of low-grade albuminuria [adjusted odd ratio (OR) and 95% confidence interval (95% CI): 1.30 (1.05-1.61)] and CKD [1.71 (1.20-2.44)]. Moreover, the incidence rates of low-grade albuminuria and CKD increased as the number of metabolic syndrome components increased (P for trend <0.0001).
The presence of metabolic syndrome is associated with increased incidence rates of low-grade albuminuria and CKD the middle-aged and elderly Chinese populations.

BACKGROUND: Data are limited with regard to the association between low-grade albuminuria (below the threshold of microalbuminuria) and high cardiovascular risk in normoalbuminuric Chinese adults free of cardiovascular disease (CVD).
METHODS: A total of 32 650 participants aged over 40 years from seven regional centers in China were included in this study. The single-void first morning urine sample was collected to measure the urinary albumin to creatinine ratio (UACR) and the data were divided into sex-specific quartiles. The Framingham Risk Score (FRS) was used to identify participants at high risk of developing coronary heart disease (CHD) over the next 10 years and the association between low-grade albuminuria and high 10-year Framingham risk for CHD (FRS ≥20%) was investigated.
RESULTS: Among males and females, the prevalence of cardiometabolic risk factors (diabetes, hypertension, and dyslipidemia) increased markedly with the elevation of UACR quartiles. Logistic regression analysis showed that the odds ratios (ORs) for high 10-year risk of CHD increased significantly from the second quartile in males (UACR: 4.78 ~ 7.53 mg/g, OR = 1.21, 95% confidence interval [CI]: 1.05-1.40) and the third quartile in females (UACR: 9.13 ~ 15.04 mg/g, OR = 3.07, 95% CI: 1.75-5.40). Stratified analysis showed that in males, the association was especially pronounced in elderly, overweight/obese participants and those without diabetes and hypertension whereas in females, the association was especially pronounced in elderly, overweight/obese participants and those without diabetes and with hypertension.
CONCLUSIONS: Low-grade albuminuria was significantly associated with high 10-year cardiovascular risk among CVD-free and normoalbuminuric Chinese adults.
背景: 在无心血管疾病(CVD)且尿蛋白正常的中国成年人群中, 关于低度白蛋白尿(低于微量白蛋白尿阈值)与心血管高危风险的相关性研究数据有限。 方法: 本研究共纳入来自中国7个中心的32650名40岁以上社区人群。收集晨尿测尿微量白蛋白与肌酐的比值(UACR), 分别在男性和女性中进行数据分析, 并根据UACR水平将各性别人群分成四分位。采用Framingham风险评分(FRS)计算参与者未来10年罹患冠心病(CHD)的风险, FRS ≥ 20%者被定义为未来10年患冠心病的风险为高危。建立Logistic回归模型, 分析低度白蛋白尿与未来10年冠心病高危风险的相关性。 结果: 在男性和女性中, 冠心病高危因素如糖尿病、高血压和血脂异常的患病率随着UACR水平的升高而显著增加。Logistic回归分析显示, 从男性UACR第二分位(UACR: 4.78 ~ 7.53 mg/g, OR = 1.21, 95% [CI]: 1.05-1.40)、女性第三分位(UACR:9.13 ~ 15.04 mg/g, OR = 3.07, 95% CI: 1.75-5.40)开始, 随着UACR的升高, 未来10年冠心病高危风险的比值比(OR)明显增加。分层分析显示, 在老年、超重或肥胖、无糖尿病和无高血压的男性以及老年、超重或肥胖、无糖尿病和有高血压的女性中, 这种相关性最为显著。 结论: 在无心血管疾病病史且尿蛋白正常的中国成年人群中, 低度白蛋白尿与未来10年冠心病高危风险显著相关。.

Low-grade albuminuria, as an early marker of endothelial dysfunction and kidney damage, has been recognized as a risk factor for metabolic disorders. Epidemiological studies manifesting the association of low-grade albuminuria with the risk of incident NAFLD and fibrosis were not available. We aimed to investigate the association of low-grade albuminuria with incident NAFLD and fibrosis by glycaemia status.
A prospective population-based study was performed in 3308 participants without NAFLD at recruitment. Baseline urinary albumin excretion was obtained by a first-voided early morning spot urine sample. At follow-up visit, incident NAFLD was diagnosed by hepatic ultrasound after excluding alcohol abuse and other cause of hepatic diseases. Fatty liver index (FLI) was employed to reflect liver fat content. Liver fibrosis was evaluated by NAFLD fibrosis score (NFS), fibrosis-4 score (FIB-4) and Hepamet fibrosis score (HFS) respectively.
After 4.3 years of follow-up, 622 (18.8%) were detected as incident NAFLD. Participants with low-grade albuminuria imposed a 40.4% [1.404 (1.112-1.772)] greater risk on incident NAFLD, and 52.0% [1.520 (1.141-2.026)], 87.4% [1.874 (1.291-2.720)] and 40.4% [1.404 (1.038-1.898)] higher risks on newly onset higher values of FLI, NFS and FIB-4 respectively. The effect of low-grade albuminuria was stronger in the subgroup of non-diabetic population.
Low-grade albuminuria was independently associated with incident NAFLD and a higher probability of fibrosis, especially among non-diabetic individuals.

Women with a higher number of pregnancies have a higher risk of developing cardiovascular diseases. Subtle fluctuations in albumin excretion could be related to pathophysiologic changes in the vascular system. We aimed to investigate the possible association of parity with low-grade albuminuria.
We conducted a community-based study in 6495 women aged 40 years or older. Low-grade albuminuria was defined according to the highest quartile of urine albumin-to-creatinine ratio in participants free of micro- or macro-albuminuria.
Parous women with a higher number of pregnancies had increased age, body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), fasting plasma glucose (FPG), and fasting insulin, as well as decreased high-density lipoprotein cholesterol (HDL-C), estimated glomerular filtration rate (eGFR) levels, and proportion of menopause. The prevalence of low-grade albuminuria in parous women gradually increased with parity number. Compared with women with one childbirth, those with more than two childbirths were independently associated with a higher prevalent low-grade albuminuria (odds ratios [ORs] 1.41, 95% confidence interval [CI], 1.09-1.81) after multiple adjustments. In subgroup analysis after multiple adjustments, significant relation between parity number and prevalent low-grade albuminuria was detected in subjects age 55 years or older.
Number of parity is associated with prevalent low-grade albuminuria in middle-aged and elderly Chinese women without micro- or macro-albuminuria.

BACKGROUND: Microalbuminuria is a risk factor for cardiovascular morbidity and mortality in hypertensive patients. However, the relationship between low-grade albuminuria, a higher level of albuminuria below microalbuminuria threshold, and hypertension-related organ damage is unclear. Left ventricular (LV) hypertrophy (LVH) is well recognized to be a subclinical organ damage of hypertension, and LV diastolic dysfunction is also reported to be an early functional cardiac change of hypertension that predicts heart failure. The present study aimed to investigate the association of low-grade albuminuria with LVH and LV diastolic dysfunction in hypertensive patients.
METHODS: This cross-sectional observational clinical study was retrospectively performed in 870 hypertensive patients admitted to our hospital. Urinary albumin to creatinine ratio (UACR) was calculated to assess the levels of albuminuria: macroalbuminuria (≥300 mg/g), microalbuminuria (≥30 mg/g, but <300 mg/g), and normal albuminuria (<30 mg/g). Low-grade albuminuria was defined as sex-specific highest tertile within normal albuminuria (8.1-29.6 mg/g in males and 11.8-28.9 mg/g in females). LVH and LV diastolic dysfunction were identified as recommended by American Society of Echocardiography.
RESULTS: Of the 870 patients, 765 (87.9%) had normal albuminuria, 77 (8.9%) had microalbuminuria, and 28 (3.2%) had macroalbuminuria. Percentage of LVH and LV diastolic dysfunction was increased with ascending UACR. UACR was independently associated with LVH and LV diastolic dysfunction, even in patients with normal albuminuria. Multivariable logistic regression showed that the patients with the highest tertile within normal albuminuria had nearly 80% increase in LVH and nearly 60% increase in LV diastolic dysfunction (adjusted OR for LVH 1.788, 95% CI 1.181-2.708, p = 0.006; adjusted OR for LV diastolic dysfunction 1.567, 95% CI 1.036-2.397, p = 0.034). After further stratification analyses in patients with normal albuminuria, it was shown that this independent association persisted in female patients, those who were younger than 70 years old, and those with duration of hypertension <15 years.
CONCLUSIONS: Low-grade albuminuria was associated with LVH and LV diastolic dysfunction in hypertensive patients, especially in patients younger than 70 years old, and those with duration of hypertension <15 years.

The presence of low-grade albuminuria (LGA) suggested that the pathophysiology of vascular dysfunction has been initiated. Clear evidence supports a role for osteocalcin in energy metabolism and a great incidence of pathological cardiovascular changes. The observational community-based study aims to examine the association of osteocalcin with LGA, which may provide new insight into potential involvement of osteocalcin in cardiovascular diseases.
A total of 1951 adults [58.37 (53.34-63.13) years, 41.3% men] from Shanghai were enrolled. LGA was defined as a urinary albumin-to-creatinine ratio (UACR) < 30 mg/g. Serum osteocalcin was measured using an electrochemiluminescence immunoassay.
Serum osteocalcin level in men decreased with increasing UACR after adjusting for potential covariates (p = 0.045); however, the adjusted association disappeared in women (p = 0.258). Linear regression analysis showed that osteocalcin was a negative variable of UACR in men (standardized β = -0.074, p = 0.030), particularly prominent in non-hyperglycemic, non-hypertensive men, even regardless of estimated glomerular filtration rate (eGFR) (60 ≤ eGFR <90 mL/min/1.73 m2, standardized β =-0.422, p = 0.004; ≥ 90 mL/min/1.73 m2, standardized β = -0.167, p = 0.037).
After controlling for confounders, serum osteocalcin level was independently associated with LGA in men, which suggested that osteocalcin was closely related with atherosclerosis and vascular dysfunction.