Urine Creatinine in a General Out-Patient Population: Implications

Ernest Ndukaife Anyabolu

doi:10.11648/j.sjcm.20160506.11

Abstract

Some diseases, environmental pollutants and physiologic states may influence urine creatinine. Urine creatinine is not routinely evaluated in the general out-patient population. The objective of this study was to evaluate urine creatinine and factors that may influence it in subjects attending the general out-patient clinic in a tertiary hospital in Nigeria. This was a cross-sectional study involving subjects consecutively recruited from a general out-patient clinic in Federal Medical Centre, Owerri, Nigeria. Creatinine in spot and 24-hour urine samples and other relevant investigations were performed. Dilute urine or low urine creatinine was defined as 24-hour urine creatinine (24HUCr) <300mg, normal urine creatinine as 24HUCr 300 - 300mg, and concentrated urine or high urine creatinine as 24HUCr >3000mg.The association of variables with urine creatinine and the strength of variables to predict dilute and concentrated urine were determined. The mean spot urine creatinine (SUCr) of the subjects was 148±167mg/dl, minimum value 14.7mg/dl, maximum value 746.7mg/dl and range of values 732.0mg/dl. The mean 24HUCr was 1203±316mg, minimum value 651.0mg, maximum value 2320mg, and range of values 1669.0mg. All the subjects have 2HUCr in the normal range. Spot urine creatinine has significant correlation with body mass index, spot urine protein (SUP), spot urine osmolality, 24-hour urine protein (24HUP), 24HUCr, serum creatinine, serum cholesterol and serum low density lipoprotein cholesterol. In contrast, 24HUCr has significant correlation with 24-hour urine volume, serum creatinine and serum cholesterol. Spot urine protein and 24HUP predicted SUCr, while only serum creatinine predicted 24HUCr. Low and high urine creatinine were absent in subjects attending the general out-patient clinic. Proteinuric renal abnormalities were common in these subjects with normal urine creatinine. There is need for clinicians to routinely conduct urine creatinine and further search for renal damage, dyslipidemia and abnormal weight changes in the general out patients with normal urine creatinine.

Highlights

In normal healthy state, the kidney excretes creatinine at a constant rate that varies with age, gender and weight
There is a paucity of studies on urine creatinine in subjects attending the general out-patient clinics emanating from SubSaharan Africa
This study showed that low and high urine creatinine were absent in the out-patient population as all of them have 24-hour urine creatinine (24HUCr) in the normal range (300 – 3000mg)

Summary

Introduction

The kidney excretes creatinine at a constant rate that varies with age, gender and weight. The amount of creatinine excreted in urine is influenced by both endogenous production as well as by exogenous substances. [7] At the other pole, older age, low BMI, Ernest Ndukaife Anyabolu: Urine Creatinine in a General Out-Patient Population: Implications protein intake, glomerular filtration rate, proteinuria and diabetes were associated with dilute urine. There is a paucity of studies on urine creatinine in subjects attending the general out-patient clinics emanating from SubSaharan Africa. We have embarked on this study to evaluate urine creatinine in these subjects This will help in identifying subjects with dilute and concentrated urine and the factors which influence urine creatinine with a view to instituting interventions that will stem down the attendant adverse outcomes in the general out patients

Objectives

Methods

Conclusion