Table 3.

Details of clinical trials investigating effects of Sildenafil on energy expenditure/BAT activity.

Author	Agent	Study Design	Dose	Population	Duration	Measurement of energy expenditure	Effect on energy expenditure	Key findings
Li et al. (31)	Sildenafil	Randomized, double blinded, placebo controlled, parallel group trial	100 mg/day sildenafil in fractionated dose (25 mg at 8AM plus 25mg at 4PM plus 50mg at 10PM) VS identical placebo	16 newly diagnosed Chinese male overweight subjects, age 20-30	7 days	Measurement of EE not specified.	↑	Increase from baseline in RMR [1465 ± 196 kcal/day (pre) vs 1642 ± 166 kcal/day (post), P<0.01]. No significant changes in weight.
Zemel et al. (32)	NS-0200 (combination of leucine, metformin and sildenafil)	Randomized, placebo controlled, double blinded, phase 2 multicenter study	Placebo, Low dose NS-0200 (1.1g leucine/0.5g metformin/0.5mg sildenafil) and high dose NS-0200 (1.1g leucine/0.5g metformin/1mg sildenafil)	91 subjects, age 18-75, BMI 25-40, stable health and body weight for the preceding 12 weeks, MRI-PDFF>/= 15%, ALT>/= 30U/L for men and 19U/L for women.	16 weeks	Measurement of EE not specified	Not specified.	NS-0200 dose responsively reduced weight by 2.4kg in the study cohort.

EE, energy expenditure; RMR, resting metabolic rate.