Table 3

Risk factors for type 2 diabetes by coffee treatment group at Week 8a

Adjusted means at Week 8

value (95% CI)

Caffeinated Coffee

Decaffeinated Coffee

No Coffee


Glucose (mmol/L)

Fasting

4.97 (4.58, 5.40)

5.07 (4.60, 5.58)

4.78 (4.37, 5.22)

2-hour

5.48 (4.66, 6.30)

6.67 (5.72, 7.62)

5.88 (4.98, 6.78)

Area under the curve

13.07 (11.93, 14.20)

14.32 (13.00, 15.64)

13.85 (12.62, 15.08)

Insulin (pmol/L)

Fastingb

47.53 (35.29, 64.03)

62.84 (44.69, 88.37)

48.81 (35.28, 67.54)

2-hourb

255.15 (197.46, 329.70)

369.50 (275.80, 495.05)

312.99 (236.37, 414.46)

Area under the curve

617.99 (464.14, 771.83)

771.03 (594.83, 947.23)

697.47 (530.22, 864.72)

CISI (mmol/L-1 * pmol/L-1)b

17.02 (13.25, 21.86)

12.38 (9.26, 16.53)

16.75 (12.78, 21.94)

Insulin30 min/Glucose30 minb

113.78 (80.96, 159.91)

118.24 (79.65, 175.53)

78.77 (54.70, 113.43)

HOMA-IRb

1.74 (1.23, 2.46)

2.33 (1.55, 3.49)

1.69 (1.16, 2.46)

Adiponectin (μg/mL)

8.90 (8.10, 9.71)c

8.37 (7.44, 9.30)

7.46 (6.58, 8.34)

C-Reactive protein (mg/L)b

1.63 (1.07, 2.47)

1.21 (0.76, 1.91)

1.24 (0.80, 1.92)

Interleukin-6 (pg/mL)b

1.95 (1.50, 2.54)c

1.67 (1.25, 2.22)

1.22 (0.93, 1.59)

Fetuin-A (μg/mL)b

261.52 (228.83, 298.84)

233.71 (201.54, 270.99)c

291.07 (212.94, 333.94)

HDL-cholesterol (mmol/L)

1.44 (1.36, 1.53)

1.39 (1.29, 1.49)

1.49 (1.40, 1.59)

LDL-cholesterol (mmol/L)

2.67 (2.46, 2.87)

2.50 (2.27, 2.73)

2.72 (2.50, 2.94)

Triglycerides (mmol/L)b

0.93 (0.78, 1.11)

0.99 (0.81, 1.22)

0.99 (0.81, 1.20)

Systolic blood pressure (mmHg)

120.57 (115.46, 125.67)

116.23 (110.39, 122.07)

119.37 (113.80 124.95)

Diastolic blood pressure (mmHg)

72.82 (69.70, 75.95)

66.69 (63.10, 70.27)c

72.42 (68.99, 75.84)

Heart rate (beats per minute)

67.77 (64.27, 71.26)

67.39 (63.36, 71.41)

67.63 (63.82, 71.45)


Adjusted means and associated 95% CIs were determined from analysis of covariance procedures. All models included treatment as a main effect, and baseline value and change in weight as covariates.

CI, confidence interval; CISI, composite insulin sensitivity index. HOMA, homeostasis model assessment; IR, insulin resistance; HDL, high density lipoprotein; LDL, low density lipoprotein.

a Results for the Week 8 analysis were based on last-observation-carried-forward method for imputation of missing values. One observation carried forward from Week 4 visit, except fetuin-A not measured at Week 4. The Week 8 analysis was based on 41 participants, except for analysis of glucose tolerance measurements (n = 40) where one participant had a missing value for fasting glucose.

b Original values were log transformed due to significant departures from normality, then back transformed to yield the geometric means and associated confidence intervals.

c Significant difference compared to No Coffee (p < 0.05).

Wedick et al. Nutrition Journal 2011 10:93   doi:10.1186/1475-2891-10-93

Open Data