Skip to main content

Table 1 Characteristics of the included studies for the meta-analysis of insulin sensitivity

From: Acute caffeine ingestion reduces insulin sensitivity in healthy subjects: a systematic review and meta-analysis

Author Year Study design Subjects (n/m:f) Subject characteristics (Age, body mass index [kg/m2], other information) Duration of caffeine abstention Caffeine dose Mode of administration Placebo Insulin sensitivity assessment method
Battram 2006 Randomized
Double-blind
Crossover
11
11:0
23.3 ± 0.6 y
Healthy, non-smokers
Body weight: 76.4 ± 1.9 kg
Percent body fatness 15.6 ± 2.3
7 days 4.45 mg/kg caffeine
Orally
Dextrose
OGTT
aMatsuda & DeFronzo
Equation [39]
Greenberg 2010 Randomized
Single-blind
Crossover
11
11:0
23.5 ± 5.7 y
23.6 ± 4.2 kg/m2
1 week prior: maintain stable diet, exercise, and alcohol intake
No caffeinated drinks, foods, or medications
No smoking
No alcohol or exercise 48 h prior
48 h 6 mg/kg caffeine
Orally
Caffeine vs warm water
Caffeinated coffee vs decaffeinated coffee
OGTT
Matsuda & DeFronzo
Equation [39]
Keijzers 2002 Randomized
Double-blind
Crossover
12
6:6
20–28 y
Nonsmoking
21.9 ± 2.7 kg/m2 (lean)
72 h 3 mg/kg caffeine
Intravenously
NaCl 0.9%
Hyperinsulinemic- euglycemic
glucose
clamp
Moisey 2008 Randomized
Single-blind
Crossover
10
10:0
23.3 ± 1.1 y
25.3 ± 1.05 kg/m2
Non-smokers, healthy
48 h 5 mg/kg caffeinated coffe
Orally
Decaffeinated coffee
OGTT
Belfiore formula [39]
Moisey 2010 Randomized
Double-blind
Crossover
10
10:0
23.3 ± 1 y
23.4 ± 0.8 kg/m2
Non-smokers, healthy
3/10 Non-caffeine users
48 h 5 mg/kg caffeinated coffee
Orally
Decaffeinated coffee
OGTT
Matsuda & DeFronzo
Equation [39]
Petrie 2004 Randomized
Double-blind
Crossover
9
9:0
19–34 y
No history of disease (diabetes mellitus)
No drug or alcohol abuse
Sedentary
34.0 ± 1.0 kg/m2 (obese)
48 h 5 mg/kg caffeine
Orally
Dextrose
OGTT
Matsuda & DeFronzo
Equation [39]
Thong 2002 Randomized
Double-blind
Crossover
7
7:0
24 ± 1 y
23 cpe ± 1 kg/m2 Lean
48 h 5 mg/kg caffeine
Orally
5 mg/kg dextrose
OGTT
Matsuda & DeFronzo
Equation [39]
  1. aMatsuda and DeFronzo equation \( ISI=\frac{10000}{\surd FPG\times FPI\Big)\times \left(\overline{G}\times \overline{I}\right)} \) where FPG is fasting plasma glucose, FPI is fasting plasma insulin, \( \overline{G} \) is mean plasma glucose concentration during OGTT, and Ī is mean plasma insulin concentration during OGTT