Table 1.
Mean coefficients of variation () and minimum and maximum CVs for urinary (Ca; mg), citrate (Cit; mg), chloride (Cl; mmoles), creatinine (Cr; mg), potassium (K; mmoles), sodium (Na; mmoles), magnesium (Mg; mg), oxalate (Ox; mg), phosphorus (P; g), ammonium (NH4; mmoles), sulfate (SO4; meq), uric acid (UA; g) and urea nitrogen (UN; mg) within a complete population of 9,024 male and 6,758 female kidney stone patients aged 16–80, and in individuals aged 16–45 and 56–80.
Figure 1.
Mean ranked coefficients of variation (CV) for chloride (Cl), magnesium (Mg), sodium (Na), oxalate (Ox) and phosphorus (P) in a complete population of 6,758 females and 9,024 males submitted to Litholink, Inc.
significant at nominal (Cl, Mg, Na and Ox) and α0.05 False Discovery Rate thresholds selected using backwards stepwise regression (Pacceptance = 0.1).
Table 2.
Effects of gender on ranked coefficients of variation (CV) from paired 24-h urinary measurements of urinary ammonium (NH3), calcium (Ca), chloride (Cl), citrate (Cit), potassium (K), magnesium (Mg), sodium (Na), oxalate (Ox), phosphorus (P), sulfate (SO4), uric acid (UA) and urine urea nitrogen (UN) adjusted for creatinine, urinary volume, age and weight in the complete population of 6,758 females and 9,024 males aged 16–80, and in individuals aged 16–45 and 56–80 in a stepwise backward regression (Pacceptance≤0.1).
Figure 2.
Mean ranked coefficients of variation (CV) for citrate (Cit), chloride (Cl), potassium (K), magnesium (Mg) and phosphorus (P) in 4097 females (F) and 4014 males (M) in an approximate ‘menarche-menstrual’ (MM) period (ages 16–45) and in 1715 females and 3479 males in an approximate ‘postmenopausal’ group (PM) (ages 56–80).
Significance of differences in CV by trait and age group (MM vs. PM) indicated as P<0.05*, P<0.01**.
Table 3.
Effects of sex-by-age category (16–45 years vs. 56–80 years) interaction on ranked coefficients of variation (CV = σ/μ) calculated from original paired 24-h urinary solutes (urinary ammonium (NH3), calcium (Ca), chloride (Cl), citrate (Cit), potassium (K), magnesium (Mg), sodium (Na), oxalate (Ox), phosphorus (P), sulfate (SO4), uric acid (UA), urine urea nitrogen (UN)) collected from 6,758 female and 9,024 male stone-formers aged 16–80 at the False Discovery Rate [Verhoeven, 2005 #22836].