The validity of random urine specimen albumin measurement as a screening test for diabetic nephropathy

A Comparative Study of Clinical Utility of Spot Urine Samples with 24-h Urine Albumin Excretion for Screening of Microalbuminuria in Type 2 Diabetic Patients

Twenty-four hour urinary albumin excretion (UAE) is considered as gold standard method for albuminuria measurement, but collection of 24-h urine is inconvenient. The aim of present study was to evaluate whether albumin: creatinine ratio (ACR) and urinary albumin concentration (UAC) in different spot urine samples correlate or not with 24-h UAE for screening of microalbuminuria in type 2 diabetic patients. We collected first morning void (FMV), random urine sample (RUS) and 24-h urine, separately on consecutive days from 104 type 2 diabetic patients. ACR and UAC in each spot urine sample compared with 24-h UAE with regard to Pearson correlation coefficient. Pearson's correlation of albumin: creatinine ratio (ACR) with 24-h UAE was (r = 0.802 and 0.623) in first morning void (FMV) and random urine sample (RUS), respectively. Pearson's correlation coefficient of urinary albumin concentration (UAC) compared with 24-h UAE was (r = 0.943 and 0.920), in FMV and RUS, respectively, P < 0.01. Results revealed that values in first morning void (FMV) were better correlated with 24-h urinary albumin excretion (UAE), than the values in random urine sample (RUS). We conclude that the first morning void (FMV) may be able to replace 24-h urine collection, preferably urinary albumin concentration (UAC) in the initial screening of microalbuminuria in diabetic patients.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (doi:10.1007/s12291-011-0136-0) contains supplementary material, which is available to authorized users.

Antidiabetic effects of Corni Fructus extract in streptozotocin-induced diabetic rats

PURPOSE

Diabetes is the leading cause of end-stage renal failure. The present study was undertaken to characterize the effects of Corni Fructus on diabetic nephropathy in streptozotocin-induced diabetic rats and their mechanisms.

MATERIALS AND METHODS

Streptozotocin-diabetic rats were orally administrated with Corni Fructus at a dose of 100, 200 or 400 mg/kg body mass for 40 days.

RESULTS

Corni Fructus-treated diabetic rats showed significant decreases of blood glucose, urinary protein levels and water consumption. Corni Fructus also reduced serum total cholesterol, total triglyceride and low-density lipoprotein cholesterol levels, and showed a tendency of enhancing high-density lipoprotein cholesterol level. Levels of serum albumin and creatinine in diabetic rats were also significantly reduced by Corni Fructus administration at a dose of 200 and 400 mg/kg body mass compared with non-treated diabetic rats. Corni Fructus increased catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidose (GSH-px) activities in the kidneys of diabetic rats. Furthermore, Corni Fructus treatment enhanced renal peroxisome proliferator-activated receptor-γ (PPARγ) expression in diabetic rats.

CONCLUSION

These results demonstrated that Corni Fructus may have the potential to protect the animals from diabetic nephropathy by amelioration of oxidative stress and stimulation of PPARγ expression.

Risk factors and prevalence of diabetic peripheral neuropathy: A study of type 2 diabetic outpatients in Bangladesh

Aims/Hypothesis:

The purpose of the study is to estimate the prevalence and risk factors for diabetic peripheral neuropathy (DPN) in type 2 diabetic outpatients at the BIRDEM hospital, Bangladesh.

Materials and Methods:

Type 2 diabetic outpatients, diagnosed 5-11 years prior to the investigation were randomly selected for the study. DPN was assessed using the Neuropathy Symptom Score (NSS) and Neuropathy Disability Score (NDS). Data about demographics, blood pressure, height, weight, waist and hip circumference, and random blood and urine samples were collected.

Results:

Two hundred and ninety four (139 men, 155 women) type 2 diabetic outpatients were studied. The overall DPN prevalence was 19.7 %; male (20.9%), female (18.7 %). The prevalence increased with age (from 11.1% in the 23-40 year-old group to 32.3% in the 60-80 year-old group) and duration of diabetes (from 14.1% in patients with five years to 29.2% in patients with 9-11 years duration). Age > 60 years (OR 4.2, 95% CI 1.4-12.3), low/normal WHR (OR 3.8, 95% CI 1.6-9.3), income < 800 TK (OR 3.1, 95% CI 1.1-9.3) and insulin treatment (OR 2.0, 95% CI 1.0-4.0) were independent, significant risk factors. Longer duration of diabetes (OR1.2 95% CI 1.0-1.4), and higher HbA1c (OR1.1, 95% CI 1.0-1.3) were marginally independent, significant risk factors for DPN.

Conclusions/Interpretations:

We observed a DPN prevalence of 19.7%. Higher age, low socioeconomic status, treatment with insulin, longer duration of diabetes and poor glycemic control were risk factors for DPN.

First morning voids are more reliable than spot urine samples to assess microalbuminuria

Measurement of urinary albumin excretion (UAE) in a 24-h collection is the gold standard method to determine the presence of microalbuminuria. We sought to compare more practical alternatives--measurement of urinary albumin concentration (UAC) or albumin:creatinine ratio (ACR)--in a first morning void or in a spot urine sample with this gold standard. We asked 241 participants of a prospective cohort study to make three 24-h urine collections, a first morning void, and a spot urine sample. Regression analysis showed that the ACR in a first morning void best agreed with 24-h UAE. The prevalence of microalbuminuria determined by data from a first morning void (7.5%, whether by UAC or ACR) nearly equaled the prevalence of microalbuminuria determined by 24-h UAE (10.0%), whereas the prevalence was higher when determined by spot urine samples (25.4% for UAC and 22.4% for ACR; both P < 0.001 versus 24-h UAE). The intraindividual coefficients of variation of the ACR in a first morning void and 24-h UAE were similar (19%). Intraindividual coefficients of variations of all other measurements of albuminuria were significantly greater. In conclusion, measurement of albuminuria in a first morning void, preferably as the ACR, is more reliable than a spot urine sample to diagnose and monitor microalbuminuria.

Clinical Use and Pathogenetic Basis of Laboratory Tests for the Evaluation of Primary Arterial Hypertension

This review focuses on the laboratory biochemical tests that are useful in the diagnostic approach to the hypertensive patient. A "minimal" diagnostic laboratory work-up, including a small number of tests that are simple and relatively inexpensive, is first described. Because these tests provide basic information on the presence of major cardiovascular (CV) risk factors and target organ damage, and might give some clues to the presence of a secondary form of hypertension (HT), they should be performed on all patients presenting with HT. Other tests that are aimed at assessing the overall CV risk, a major determinant of prognosis that dictates the therapeutic strategy in the individual HT patient, are then discussed. They allow identification of major CV risk factors and associated clinical conditions which, if present, lead to a substantial change of therapeutic strategy. The role of C-reactive protein as a marker of atherosclerosis and its predictive value for CV events are also discussed. Finally, a section is devoted to tests that are currently confined to research purposes, such as markers of endothelial function including endothelin-1, homocysteine and genetic analysis.

Evaluation of measures of urinary albumin excretion in epidemiologic studies

Twenty-four-hour urinary albumin excretion (UAE) is considered the gold standard for determining albumin level in epidemiologic studies, but this measure is inconvenient and often unavailable. Simpler alternatives include the albumin:creatinine ratio (ACR) and urinary albumin concentration (UAC) obtained from a single sample. The authors assessed the strengths and weaknesses of ACR and UAC as alternatives to UAE using albumin measurements from two 24-hour urine samples collected in 1996-1999 from 4,678 participants aged 40-59 years in the International Study of Macronutrients and Blood Pressure (17 population samples from four countries). The authors compared ACR and UAC with regard to correlations with UAE, daily within-person variability, and associations with known predictors of UAE. Rank-order correlations of ACR with UAE were 0.949 and 0.942 for men and women, respectively, versus 0.881 and 0.816 for UAC. Mean within-person coefficients of variation were 34.0-40.0% for the three measures, with the smallest values being observed for UAC. Average correlations with blood pressure were similar for UAE, ACR, and UAC, but the correlation with body mass index was lower for ACR (0.118 for ACR and 0.188 for UAC vs. 0.211 for UAE) because of high correlation between body mass index and creatinine level. Thus, UAC and ACR are acceptable alternatives to the more complex UAE, and the simpler UAC may be preferable to ACR in some respects.

Microalbuminuria and stroke in a British population: the European Prospective Investigation into Cancer in Norfolk (EPIC-Norfolk) population study

OBJECTIVES

To examine the relationship between microalbuminuria and incident stroke in the general population.

DESIGN

Population-based prospective cohort study.

SETTING

Participants were recruited in a primary care setting from 35 participating general practice units in Norfolk, UK.

SUBJECTS AND MAIN OUTCOME MEASURES

The study population consisted of 23,630 individuals aged 40-79 years recruited between 1993 and 1997 for the EPIC-Norfolk Study and followed up for an average of 7.2 years. Random spot urine specimens were collected at baseline and albumin-to-creatinine ratio measured. Participants were categorized into normoalbuminuria, microalbuminuria and macroalbuminuria groups. During follow-up, the main end point was stroke incidence (fatal and nonfatal), ascertained from the UK Office for National Statistics and from the National Health Service Health District database of all hospital admissions.

RESULTS

A total of 246 stroke events occurred during follow-up [crude incidence rate of stroke, 1.5 per 1000 person years (pyrs)]. The age-adjusted incidence of stroke increased significantly across categories of baseline albuminuria (0.9, 1.1 and 1.4/1000 pyrs for tertiles of normoalbuminuria, 2.6/1000 pyrs for microalbuminuria, and 6/1000 pyrs for macroalbuminuria in the total population, P < 0.001 for trend). In all women and men, the multivariate hazard ratio [95% confidence interval (CI)] for stroke associated with microalbuminuria was 1.49 (1.13-2.14) and macroalbuminuria 2.43 (1.11-6.26). After stratifying by stroke subtype, microalbuminuria was only independently predictive of ischaemic stroke, with hazard ratio (95% CI) of 2.01 (1.29-3.31).

CONCLUSION

Microalbuminuria is independently associated with approximately 50% increased risk of stroke in the general population. Microalbuminuria may be useful in identifying those at increased risk of stroke in the general population.