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Table 1 Characteristics of whole sample, and split by type-2 diabetes and non-type-2 diabetes group [continuous variables: mean (± standard deviation); categorical variables: frequency (% of total)]

From: Assessment of CYP1A2 enzyme activity in relation to type-2 diabetes and habitual caffeine intake

Variable

Whole sample (n = 203)

Type-2 diabetes cases (n = 57)

Non-type-2 diabetes controls (n = 146)

p-value between groups

Age (years)

59.3 (±15.9)

63.9 (±9.9)

57.4 (±17.4)

0.008

Male Gender (%)

87 (42.9 %)

38 (66.7 %)

49 (33.6 %)

<0.001

Body Mass Index (BMI; kg/m2)a

25.1 (±4.5)

28.6 (±5.3)

23.7 (±3.3)

<0.001

Overweight/Obese BMI (%)b

84 (41.8 %)

42 (73.7 %)

42 (29.2 %)

<0.001

Smoking (% yes)

21 (10.3 %)

9 (15.8 %)

12 (8.2 %)

0.127

Alcohol Intake (% yes)c

78 (38.4 %)

16 (28.1 %)

62 (42.5 %)

0.077

Long-Term Medication (% yes)

129 (63.5 %)

55 (96.5 %)

74 (50.7 %)

<0.001

Oral Medication for Diabetes (% yes)

42 (20.7 %)

42 (73.7 %)

0 (0 %)

<0.001

Insulin Injections for Diabetes (% yes)

19 (9.4 %)

19 (33.3 %)

0 (0 %)

<0.001

Contraceptive Pill (% yes)

9 (4.4 %)

0 (0 %)

9 (6.2 %)

0.064

Total Habitual Caffeine Intake (mg/day)d

295.8 (±158.1)

365.2 (±191.3)

268.7 (±134.4)

<0.001

Caffeine from Coffee (mg/day)d, e

240.3 (±162.2)

306.9 (±195.7)

214.3 (±139.4)

0.001

Higher Habitual Caffeine Intake (% yes)f

64 (31.5 %)

28 (49.1 %)

36 (24.7 %)

0.001

Salivary Caffeine Concentration (μmol/l)d

11.0 (±7.7)

11.9 (±8.2)

10.6 (±7.6)

0.259

Salivary Paraxanthine Concentration (μmol/l)d

5.2 (±3.4)

6.0 (±3.4)

4.9 (±3.4)

0.024

Time between saliva sample and final caffeine portion (h)

6.7 (±2.6)

5.8 (±2.6)

7.1 (±2.5)

0.001

Gene Cytochrome P450-1A2 (CYP1A2)g

Allele Frequency (%)

A

276 (69.0 %)

83 (74.1 %)

193 (67.0 %)

0.186

C

124 (31.0 %)

29 (25.9 %)

95 (33.0 %)

Genotype Frequency (%)

    

0.036

 

A/A

97 (48.5 %)

34 (60.7 %)

63 (43.8 %)

0.040

C/A

82 (41.0 %)

15 (26.8 %)

67 (46.5 %)

0.011

C/C

21 (10.5 %)

7 (12.5 %)

14 (9.7 %)

0.610

Enzyme Inducibility (%)

High

97 (48.5 %)

34 (60.7 %)

63 (43.8 %)

0.040

Less

103 (51.5 %)

22 (39.3 %)

81 (56.3 %)

  1. Abbreviations T2D type-2 diabetes, Non-T2D non-type-2 diabetes, Data for continuous variables are means (± standard deviation) of raw data. P-values (2-tailed) were calculated using independent samples t-tests, comparing T2D and Non-T2D groups, on raw data. If raw data was abnormally distributed, the data was transformed to achieve a normal distribution before the t-test was applied (method of transformation noted in legend). Data for categorical variables are frequencies (%). P-values (exact; 2-tailed) were calculated using Fisher’s exact test
  2. aRaw data transformation: Log10; T2D (n = 57); Non-T2D (n = 144). bOverweight/Obese BMI >24.9 vs. Underweight/Healthy BMI ≤24.9; T2D (n = 57); Non-T2D (n = 144). cConsume 3 or more alcoholic drinks per week. dRaw data transformation: Square root. eIncludes caffeine from decaffeinated coffee (4.5 mg/cup). fHigher habitual caffeine intake (> Swiss average of 288 mg/day) vs. Lower/Normal habitual caffeine intake (≤ Swiss average). gSNP ID: rs762551. T2D (n = 56); Non-T2D (n = 144). Highly inducible = genotype A/A. Less inducible = genotypes A/C and C/C
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Nutrition & Metabolism

ISSN: 1743-7075

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