Research Article

Effects of 16-Week Consumption of Caffeinated and Decaffeinated Instant Coffee on Glucose Metabolism in a Randomized Controlled Trial

Table 1

Anthropometric measures, glucose metabolism parameters, and serum adiponectin and C-reactive protein at baseline.

Parameter (unit)Caffeinated coffee ( )Decaffeinated coffee ( )No coffee ( ) value*

Body weight (kg)77 (70–84)75 (71–80)79 (78–83)0.22
Waist circumference (cm)93 (89–99)91 (88–95)95 (90–97)0.46
Plasma glucose (mmol/L)
 Fasting6.0 (5.3–6.2)6.1 (5.3–7.4)5.8 (5.4–6.3)0.68
 2-hour8.5 (7.3–9.9)10.1 (7.7–12.8)9.2 (7.4–12.9)0.35
 AUC18.3 (15.9–20.1)20.6 (17.5–23.7)20.8 (18.5–23.2)0.16
Plasma insulin (pmol/L)
 Fasting57 (38–66)34 (27–71)58 (52–66)0.53
 2-hour551 (347–868)314 (187–565)472 (312–854)0.24
 AUC999 (676–1289)570 (376–978)881 (629–1057)0.13
Composite ISI3.6 (2.3–4.6)4.8 (2.4–7.9)3.4 (2.1–5.0)0.38
HOMA-IR2.0 (1.3–2.5)1.2 (0.9–3.3)2.0 (1.8–2.9)0.51
Total adiponectin ( g/mL)4.9 (4.1–8.2)5.8 (5.6–6.3)4.8 (3.9–6.5)0.66
HMW adiponectin ( g/mL)2.6 (1.5–4.9)3.1 (2.2–4.4)2.2 (1.7–3.6)0.73
C-reactive protein (mg/L)0.49 (0.26–0.85)0.23 (0.19–0.83)0.42 (0.29–0.72)0.24

AUC: area under the curve; HMW: high-molecular weight; HOMA-IR: homeostasis model assessment of insulin resistance; ISI: insulin sensitivity index.
Values are medians and interquartile ranges (25th and 75th percentiles) in parentheses.
*Overall difference based on Kruskal-Wallis test.
Hour was used for the time scale in the oral glucose tolerance test.