The effects of niacin and a single bout of aerobic exercise on glucose, insulin, and C-peptide profiles in postmenopausal women
The purpose of this investigation was to determine the effects of niacin and a single bout of aerobic exercise on glucose, insulin, and C-peptide profiles in postmenopausal women. Seventeen sedentary, women (57 ± 6 years) served as participants. A rest and exercise (treadmill walking at 60% HRR, expending 400 kcal) trial without niacin was performed first followed by a with niacin trial (1000 mg/day for 4 weeks). Fasting blood samples were collected for three consecutive days for all trials. The 24 hour time point results found niacin significantly increased glucose from 95.03 mg/dL to 105.07 mg/dL; insulin from 16.98 μU/mL to 27.48 μU/mL; and C-peptide from 1.65 ng/mL to 2.41 ng/mL. Exercise alone or combined with niacin showed no significant change in values. Given the adverse effects of niacin, the use of niacin in postmenopausal women should be conducted with caution and under medical supervision until further investigations are conducted.