Table 2. Variation in calculated hourly percentage excretions of urinary lactulose and mannitol with duration of collection period and consequent change in the lactulose:mannitol ratio (LMR) based on data from 40 healthy female participants.

Duration#(hr)	Mean hourly Mannitol		Mean hourly Lactulose
	Placebo	Aspirin	Placebo	Aspirin
2	1.81 (±0.10)	1.97 (±0.14) *	0.10 (±0.01) †	0.15 (±0.02)* †
4	1.73 (±0.08)	1.68 (±0.10) *	0.09 (±0.01) †	0.16 (±0.02)* †
	LMR
	Placebo	Aspirin
2
Ratio Range	0.053–0.058	0.071–0.081*
4
Ratio Range	0.049–0.054	0.091–0.099*

Data are the mean ±SE.

#Duration: 2 h = (1/2 h–2 h)/2; 4 h = (1/2 h–4 h)/4.

*P<0.001∶2 h versus 4 h; ^†P<0.001: placebo versus aspirin.