*4.2.3 Only normal levels of urine creatinine in non-HIV subjects*

In this study there was an absence of low and high urine creatinine in subjects attending the outpatient clinic. This disagrees with the prevalence of 8.1% of low urine creatinine and 3.1% of high urine creatinine reported by Barr et al. [14]. Their study was conducted in a US general population in contrast with ours that was done in a general outpatient clinic population in Nigeria. This difference in study design might have accounted for the observed differences between the two studies. Additionally, our study subjects were patients who might have presented to hospital for one illness or the other that might impact on urine creatinine.

## *4.2.4 Spot urine creatinine associated with BMI in non-HIV subjects*

Our study showed that BMI was associated with spot urine creatinine but not with 24-hour urine creatinine. This observation is similar to that reported in two studies [14, 24]. Two studies further demonstrated that body mass index was a predictor of spot urine creatinine [24, 25], in contrast with our study which showed that body mass index did not predict spot urine creatinine and 24-hour urine creatinine. Urine creatinine, a function of body mass index, a measure of lean body mass, depends on muscle mass.
