By definition, the ACR is dependent on albumin and creatinine excretion rates. The influence of age and sex on 24 h

urinary creatinine is well established. For example, one large population-based Belgian study of over 4000 people (26–60 years) demonstrated significantly lower creatinine excretion in females and significant negative correlation of 24 h urinary creatinine excretion with age.11 Therefore, increases in ACR with age can be explained Small molecule library high throughput in part by the age related changes in AER and 24 h urinary creatinine excretion observed in both males and females. Normal ageing is characterized by a progressive decline in skeletal muscle mass and increase in body fat composition. Other age related factors that may influence ACR include the decline in skeletal muscle mass between the 20–80 years of age, which has been estimated to range from 22% to 40%,84,85 a decrease in the proportion of muscle in lean body mass85 and a lower meat intake in older subjects.81 Bakker71 has proposed the use of age-specific cut off values for ACR to help restrict the number of people selected for follow up with timed urine collections. In this large study (n > 2300) an increase in the ACR cut-off for each decade, from age group <50

to >70 years, was required to maintain equivalent sensitivities and specificities in each age subgroup. However, the use of both gender and age-specific cut off values for ACR may be confusing and impractical. The clinical importance of an age-related increase in ACR is an increased false positive rate in older patients (e.g. decreased specificity). Using the recommended cut off values, the age-related increase in false positive rates Sirolimus datasheet for spot ACR was approximately 30% for patients of either sex over 65 years limits.79 Table A4 presents a summary of studies (including those discussed above) that

provide evidence in relation to the use of AER and ACR PTK6 for the screening and diagnosis of albuminuria. Included in the table is a summary of the key components of the cross sectional studies relevant to assessment of diagnostic accuracy. Where reported the sensitivity and specificity is shown along with the key conclusions made by the authors. It should be noted that only a few of the studies provided PPV and NPV values. Estimation of GFR (eGFR) based on serum creatinine is a pragmatic, clinically relevant approach to assessing kidney function in people with type 2 diabetes (Level III – Diagnostic Accuracy). The CG and the MDRD formulas for the estimation of GFR were developed predominantly in individuals without diabetes. Studies involving people with type 2 diabetes, are summarized in Table A5 and are generally consistent with the findings for the large number of studies in non diabetes populations.46 Nonetheless, the study by Walser86 questioned the acceptability of the CG and MDRD equations for monitoring kidney function in individuals with type 2 diabetes.