A double blind randomized placebo control crossover trial on the effect of dietary nitrate supplementation on exercise tolerance in stable moderate chronic obstructive pulmonary disease

Table 3 Safety phase data for heart rate (HR) on standing (beats per minute) (n = 23 unless otherwise stated)

	Heart rate	Mean difference from 0 hours sitting HR	Compared to 0 hours sitting HR 95% CI*	P value⁺
0 hours sitting	88.2 ± 11.9	n/a	n/a	n/a
0 hours standing^o	94.3 ± 13.0	6.2 ± 8.0	2.8 to 9.7	0.001^{^}
0.5 hours standing	92.4 ± 9.9	3.8 ± 7.5	0.47 to 7.1	0.027^{^}
1 hours standing	92.0 ± 11.9	3.9 ± 10.0	−0.43 to 8.2	0.076
4 hours standing	87.7 ± 11.4	−0.478 ± 13.4	−6.3 to 5.3	0.866

*95% confidence interval; ^{^}significant comparison at the 95% confidence level; ⁺paired sample two tailed t-test; ^on = 22 for the 0 hour standing comparison due to missing data.

ISSN: 1471-2466