OBJECTIVE: We investigated the effect of caffeine ingestion on insulin sensitivity in sedentary lean men (n = 8) and obese men with (n = 7) and without (n = 8) type 2 diabetes. We also examined whether chronic exercise influences the relationship between caffeine and insulin sensitivity in these individuals. RESEARCH DESIGN AND METHODS: Subjects underwent two hyperinsulinemic-euglycemic clamp procedures, caffeine (5 mg/kg body wt) and placebo, in a double-blind, randomized manner before and after a 3-month aerobic exercise program. Body composition was measured by magnetic resonance imaging. RESULTS: At baseline, caffeine ingestion was associated with a significant reduction (P < 0.05) in insulin sensitivity by a similar magnitude in the lean (33%), obese (33%), and type 2 diabetic (37%) groups in comparison with placebo. After exercise training, caffeine ingestion was still associated with a reduction (P < 0.05) in insulin sensitivity by a similar magnitude in the lean (23%), obese (26%), and type 2 diabetic (36%) groups in comparison with placebo. Exercise was not associated with a significant increase in insulin sensitivity in either the caffeine or placebo trials, independent of group (P > 0.10). CONCLUSIONS: Caffeine consumption is associated with a substantial reduction in insulin-mediated glucose uptake independent of obesity, type 2 diabetes, and chronic exercise.
RCT Entities:
OBJECTIVE: We investigated the effect of caffeine ingestion on insulin sensitivity in sedentary lean men (n = 8) and obesemen with (n = 7) and without (n = 8) type 2 diabetes. We also examined whether chronic exercise influences the relationship between caffeine and insulin sensitivity in these individuals. RESEARCH DESIGN AND METHODS: Subjects underwent two hyperinsulinemic-euglycemic clamp procedures, caffeine (5 mg/kg body wt) and placebo, in a double-blind, randomized manner before and after a 3-month aerobic exercise program. Body composition was measured by magnetic resonance imaging. RESULTS: At baseline, caffeine ingestion was associated with a significant reduction (P < 0.05) in insulin sensitivity by a similar magnitude in the lean (33%), obese (33%), and type 2 diabetic (37%) groups in comparison with placebo. After exercise training, caffeine ingestion was still associated with a reduction (P < 0.05) in insulin sensitivity by a similar magnitude in the lean (23%), obese (26%), and type 2 diabetic (36%) groups in comparison with placebo. Exercise was not associated with a significant increase in insulin sensitivity in either the caffeine or placebo trials, independent of group (P > 0.10). CONCLUSIONS:Caffeine consumption is associated with a substantial reduction in insulin-mediated glucose uptake independent of obesity, type 2 diabetes, and chronic exercise.
Authors: Ilona Mikkola; Sirkka Keinänen-Kiukaanniemi; Jari Jokelainen; Ari Peitso; Pirjo Härkönen; Markku Timonen; Tiina Ikäheimo Journal: Scand J Prim Health Care Date: 2012-06 Impact factor: 2.581
Authors: Tina Landsvig Berentzen; Lars Ängquist; Anna Kotronen; Ronald Borra; Hannele Yki-Järvinen; Patricia Iozzo; Riitta Parkkola; Pirjo Nuutila; Robert Ross; David B Allison; Steven B Heymsfield; Kim Overvad; Thorkild I A Sørensen; Marianne Uhre Jakobsen Journal: PLoS One Date: 2012-02-24 Impact factor: 3.240
Authors: Brenda M Malinauskas; Victor G Aeby; Reginald F Overton; Tracy Carpenter-Aeby; Kimberly Barber-Heidal Journal: Nutr J Date: 2007-10-31 Impact factor: 3.271