Table 1.

Characteristics of the first morning urine in the low and high drinkers (Adjusted mean values with their standard errors; medians and quartiles)

	Low drinkers (n 39)	High drinkers (n 32)	P
	Adjusted mean	se	Median	Q1–Q3	Adjusted mean	se	Median	Q1–Q3	Group effect	Sex effect
Normal distribution: mixed ANOVA linear model
Volume (litres)	0·233	0·020			0·301	0·024			0·035	NS
USG	1·021	0·001			1·016	0·001			0·020	NS
Osmolality (mOsm/kg)	794	40			590	47			0·001	NS
Na (mmol/l)	116·8	6·5			76·8	7·7			< 0·001	NS
K (mmol/l)	42·6	3·5			31·7	4·1			0·046	NS
Phosphate (mmol/l)	37·0	2·6			27·6	3·0			0·022	NS
Creatinine (mmol/l)	17·5	1·0			12·5	1·2			0·003	NS
Uric acid (mmol/l)	3·4	0·2			2·5	0·3			0·007	NS
Urea (mmol/l)	432·6	24·6			332·0	29·0			0·010	NS
Mg (mmol/l)	3·8	0·4			3·7	0·4			NS	NS
pH	6·0	0·1			5·9	0·1			NS	NS
Tiselius CRI	1·31	0·16			1·42	0·20			NS	NS
Normality assumption rejected: non-parametric Wilcoxon rank-sum test
Citrate (μmol/l)			1918	1081–2953			1304	709–2067	0·026
Ca (mmol/l)			4·3	2·6–6·4			2·7	1·7–4·8	0·051
Colour(20,21)			3·0	2·0–4·0			2·5	2·0–3·0	NS
Cortisol (nmol/l)			46·9	24·8–71·7			35·9	19·3–52·4	NS
Aldosterone (nmol/l)			27	13–41			23	11–38	NS
Oxalate (μmol/l)			266	177–432			261	183–438	NS

USG, urine specific gravity; CRI, Crystallization Risk Index.