Table 2 Clinical characteristics by quartiles of serum neuregulin 4 (Nrg4) levels in obese subjects

Sample size

303

302

304

303

Serum Nrg4, ng/mL

1.95 (1.56–2.23)

2.88 (2.70–3.10)

3.90 (3.59–4.31)

6.62 (5.41–9.13)

< 0.001

Age, years

52.2 ± 7.7

53.4 ± 7.1

53.4 ± 7.1

54.4 ± 7.1

0.570

Gender (male), n (%)

126 (41.6)

84 (27.8)

77 (25.3)

61 (20.1)

< 0.001

BMI, kg/m²

27.5 ± 2.8

27.05 ± 2.7

27.2 ± 2.6

26.7 ± 2.7**

0.104

Resting energy expenditure, kcal/day

1476.6 ± 189.3

1415.4 ± 191.8***

1414.1 ± 165.3***

1384.3 ± 156.0***

0.491

Waist circumference, cm

95.2 ± 7.3

93.4 ± 7.5

93.9 ± 6.9

92.8 ± 7.1**

0.068

Current smokers, n (%)

57 (18.8)

37 (12.3)

35 (11.5)

29 (9.6)

0.005

Systolic BP, mmHg

134.1 ± 17.6

133.0 ± 17.5

134.3 ± 18.3

131.9 ± 16.8

0.286

Diastolic BP, mmHg

79.8 ± 10.3

79.3 ± 10.9

79.6 ± 10.8

78.3 ± 10.5

0.658

Triglycerides, mmol/L

1.6 (1.1–2.3)

1.6 (1.0–2.4)

2.3 (1.1–2.3)

1.5 (1.0–2.2)

0.522

Total cholesterol, mmol/L

5.9 ± 1.1

5.9 ± 1.1

5.9 ± 1.0

5.8 ± 1.1

0.396

LDL-cholesterol, mmol/L

3.7 ± 1.0

3.7 ± 1.0

3.7 ± 0.9

3.6 ± 1.0

0.353

HDL-cholesterol, mmol/L

1.4 ± 0.3

1.4 ± 0.3

1.4 ± 0.3

1.4 ± 0.3

0.302

Fasting glucose, mmol/L

6.3 ± 2.0

6.2 ± 1.9

6.1 ± 1.6

5.9 ± 1.2***

0.009

2-h glucose, mmol/L

9.1 ± 4.3

9.0 ± 4.1

9.0 ± 4.0

8.7 ± 3.6

0.255

HOMA-IR

2.99 (2.09–4.38)

3.08 (2.07–4.26)

2.99 (2.17–4.29)

2.74 (2.05–3.99)

0.229

Body fat mass, kg

24.1 ± 5.4

23.9 ± 5.6

24.4 ± 5.3

23.8 ± 5.1**

0.047

Metabolic syndrome, n (%)

204 (67.3)

205 (67.9)

198 (65.1)

174 (57.4)**

0.006

Raised blood pressure, n (%)

190 (62.7)

181 (59.7)

175 (57.6)

162 (53.3)**

0.021

Raised fasting glucose, n (%)

191 (63.0)

188 (61.8)

174 (57.2)**

164 (54.0)***

< 0.001

Raised triglycerides, n (%)

141 (46.5)

143 (47.2)

144 (47.4)

121 (39.9)

0.446

Reduced HDL-cholesterol, n (%)

76 (25.1)

113 (37.3)***

95 (31.3)

98 (32.3)

0.521