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

Do not forget the kidney in graves' disease

PURPOSE

To investigate the prevalence of microalbuminuria and factors associated with microalbuminuria in Graves' Disease (GD).

METHODS

This cross-sectional and single-center study included 99 patients with GD and 47 healthy controls (HC). Exclusion criteria such as active infection, uncontrolled diabetes, and chronic kidney disease were applied to the participants. The participants' clinical findings, comorbidities, drug use, laboratory tests, and thyroid antibody levels were recorded. Spot urine samples were collected and stored at - 80 ℃ to analyze the presence of microalbuminuria.

RESULTS

The prevalence of microalbuminuria in patients with GD was 12.1%. The median microalbumin/creatinine ratio in spot urine (UACR) in patients with GD (9.49 mg/g [5.09-18.10]) was higher than in the HC group (7.99 mg/g [3.48-12.88], p = 0.033). UACR was correlated with thyroid-stimulating hormone receptor antibody (TRAb), thyroid-stimulating hormone (TSH), and free triiodothyronine (FT3) levels (p = 0.020, p = 0.006, p = 0.009 respectively). In the regression analysis, only the relationship between TRAb level and UACR remained (p = 0.040).

CONCLUSION

This study demonstrates an increased prevalence of microalbuminuria in patients with GD. There was a significant correlation between microalbuminuria and TRAb level in patients with GD. This relationship suggests that one of the underlying mechanisms of microalbuminuria seen in patients with GD may be autoimmunity.

Association of microalbuminuria with left ventricular dysfunction in Nigerian normotensive type 2 diabetes patients

BACKGROUND

Diabetes mellitus (DM) is a risk factor for left ventricular (LV) dysfunction, and microalbuminuria is frequently associated with DM. This study aimed to compare LV function among normotensive type 2 diabetes (T2DM) patients with normoalbuminuria, those with microalbuminuria, and healthy controls.

METHODS

This was a cross-sectional study conducted at the diabetes and cardiology clinics of the University of Uyo Teaching Hospital, Uyo, Akwa-Ibom State, Nigeria, from January 2013 to March 2014. Microalbuminuria was tested for using Micral test strips, and echocardiography-derived indices of LV function were compared among the three groups.

RESULTS

Sixty-three normoalbuminuric, 71 microalbuminuric T2DM patients and 59 healthy controls were recruited. Mean age of participants was 50 ± 8 years and the three groups were age and gender matched (p = 0.23, p = 0.36, respectively). LV diastolic dysfunction (LVDD) showed a stepwise increase from the healthy controls to the normoalbuminuric to the microalbuminuric T2DM patients (16.9 vs 61.9 vs 78.9%, respectively) (p < 0.001), while E/A ratio and fractional shortening showed a significant stepwise decrease (both p < 0.001). LV systolic dysfunction was rare among the three groups. Microalbuminuria showed a strong direct association with LVDD (OR 3.58, 95% CI: 1.99-6.82, p < 0.001). Age remained independently associated with LVDD (OR 1.10, 95% CI: 1.03-1.17, p = 0.003).

CONCLUSION

LV diastolic function was altered in Nigerian normotensive T2DM patients, and the presence of microalbuminuria with DM had additional effects on this abnormality. Early screening for DM and microalbuminuria could identify individuals with high cardiovascular risk and possibly abnormal LV function.

Urine Albumin-Creatinine Ratio Versus Albumin Excretion for Albuminuria Staging: A Prospective Longitudinal Cohort Study

BACKGROUND

New guidelines advocate the use of albumin-creatinine ratio (ACR) in a urine sample instead of 24-hour urinary albumin excretion (UAE) for staging albuminuria. Concern has been expressed that this may result in misclassification for reasons including interindividual differences in urinary creatinine excretion.

STUDY DESIGN

Prospective longitudinal cohort study.

SETTING & PARTICIPANTS

We examined 7,623 participants of the PREVEND and RENAAL studies for reclassified when using ACR instead of 24-hour UAE, the characteristics of reclassified participants, and their outcomes. Albuminuria was categorized into 3 ACR and UAE categories: <30, 30 to 300, and >300mg/g or mg/24 h, respectively.

PREDICTORS

Baseline ACR and 24-hour UAE.

OUTCOMES

Cardiovascular (CV) morbidity and mortality and all-cause mortality.

RESULTS

When using ACR in the early morning void instead of 24-hour UAE, 88% of participants were classified in corresponding albuminuria categories. 307 (4.0%) participants were reclassified to a higher, and 603 (7.9%), to a lower category. Participants who were reclassified to a higher ACR category in general had a worse CV risk profile compared with nonreclassified participants, whereas the reverse was true for participants reclassified to a lower ACR category. Similarly, Cox proportional hazards regression analyses showed that reclassification to a higher ACR category was associated with a tendency for increased risk for CV morbidity and mortality and all-cause mortality, whereas reclassification to a lower ACR category was associated with a tendency for lower risk. Net reclassification improvement, adjusted for age, sex, and duration of follow-up, was 0.107 (P=0.002) for CV events and 0.089 (P<0.001) for all-cause mortality.

LIMITATIONS

Early morning void urine collection instead of spot urine collection.

CONCLUSIONS

Our results indicate that there is high agreement between early morning void ACR and 24-hour UAE categories. Reclassification is therefore limited, but when present, is generally indicative of the presence of CV risk factors and prognosis.

Why 24-h Urine Albumin Excretion Rate Method Still is Used for Screening of Diabetic Nephropathy in Isfahan Laboratories?

BACKGROUND

The first step in diagnosis of diabetic nephropathy is measurement of albumin in a spot urine sample. The aim of this study was assessment of the accuracy of urinary albumin to creatinine ratio (UACR) in random urine specimens (RUS) for microalbuminuria and macroalbuminuria screening in Iranian diabetic patients.

METHODS

A total of 200 diabetic patients participated to our study. 24 h timed urine specimens followed by RUS were collected. 24-h urine albumin excretion (24-h urinary albumin excretion (UAE)) and UACR in RUS were measured. Data were analyzed by Pearson's correlation, receiver operating characteristic (ROC) curve and McNemar test.

RESULTS

A total of 165 patients finalized the study. Pearson's correlation of coefficient for 24-h UAE versus UACR was 0.64. The area under ROC curve for UACR was 0.83 in microalbuminuria and 0.91 in macroalbuminuria. The cutoff point of 30 mg/g in UACR method had 86% sensitivity and 60% specificity for microalbuminuria screening and cut-off point of 300 mg/g had 75% sensitivity and 99% specificity for macroalbuminuria screening respectively.

CONCLUSIONS

UACR in RUS showed acceptable performance as a screening test for diagnosis of both micro and macroalbuminuria in Iranian diabetic patients.