*4.2.5 Spot urine and daily urine protein excretion were predictors of spot urine creatinine in non-HIV subjects*

This study demonstrated that spot urine protein and 24-hour urine protein were predictors of spot urine creatinine. This was slightly similar to a study that found protein intake associated with urine creatinine [26]. We observed that these two variables were not associated with 24-hour urine creatinine. Protein in urine predicting spot urine creatinine, with 24-hour urine creatinine within the normal range, indicated that the subjects studied might have proteinuria even in the presence of normal renal filtration function.

Spot urine osmolality was associated with spot urine creatinine but did not predict it, in this study. The precise relationship between urine creatinine and urine osmolality has not been fully elucidated, even though the utility of the hypothetical ratios for estimation of daily urine protein excretion involving creatinine and osmolality has been established [27, 28].

### *4.2.6 Inverse correlation between spot urine creatinine and daily urine creatinine excretion in non-HIV subjects*

There was an inverse correlation between spot urine creatinine and 24-hour urine creatinine observed in this study. This implied that as spot urine creatinine increased, 24-hour urine creatinine declined and vice versa. Studies were sparse on the link between spot urine creatinine and 24-hour urine creatinine.

### *4.2.7 Association between serum creatinine and spot urine creatinine in non-HIV subjects*

The study showed that serum creatinine was associated with spot urine creatinine. Serum creatinine in normal state is maintained at a reasonably constant level as excess creatinine produced by the body or taken exogenously is excreted in urine. This produces variability in the amount of creatinine in urine excreted by an individual and between different individuals [29]. However, elevated serum creatinine would be observed in impaired renal function, associated with reduced urine creatinine [30]. Expectedly, serum creatinine was a predictor of 24-hour urine creatinine in this study.

#### *4.2.8 Spot urine creatinine associated with HDL and LDL in non-HIV subjects*

Serum cholesterol and serum low-density lipoprotein cholesterol were associated with spot urine creatinine, as observed in our study. Lipid abnormalities have been described in renal disease associated with reduced urine creatinine excretion [31, 32]. This might suggest that our study subjects might have renal impairment.

### *4.2.9 Daily urine creatinine excretion associated with daily urine volume in non-HIV subjects*

We noted that 24-hour urine volume was associated with 24-hour urine creatinine in this study. A related study reported an association between 24-hour urine volume and creatinine clearance [33]. In contrast, our study did not find any association between 24-hour urine creatinine and creatinine clearance. Nonetheless, urine volume tends to decrease with decreasing creatinine clearance, and 24-hour urine creatinine is a function of creatinine clearance. This probably would explain the association between 24-hour urine volume and 24-hour urine creatinine observed in this study.
