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Table 1 Baseline characteristics by the levels of serum concentration of vitamin B12, a cohort study in China, 2012–2019

From: Association between serum vitamin B12 and risk of all-cause mortality in elderly adults: a prospective cohort study

 

Serum concentration of vitamin B12

 

Variables

Low level (≤ 203 ng/mL)

Middle level (203–740 ng/mL)

High level (> 740 ng/mL)

P value

No. of participants

210

1670

206

 

No. of death

105

740

98

 

Age at baseline, Mean ± SD, years

90.74 ± 10.54

87.57 ± 11.28

86.11 ± 11.14

< 0.0001 a b

Categories, n(%)

    

< 80 years

39 (18.57)

455 (27.25)

60 (29.13)

 

80–89 years

54 (25.71)

438 (26.23)

64 (31.07)

 

90–99 years

57 (27.14)

409 (24.49)

51 (24.76)

 

≥ 100 years

60 (28.57)

368 (22.04)

31 (15.05)

 

Male, n(%)

87 (41.43)

732 (43.83)

89 (43.20)

0.6908

Ethnicity (Han), n(%)

168 (98.82)

1308 (98.42)

149 (98.03)

0.8653

Married, n(%)

143 (68.75)

1020 (62.50)

123 (62.76)

0.4669

Residence, n(%)

   

0.0969

City

7 (3.33)

56 (3.35)

12 (5.83)

 

Town

16 (7.62)

245 (14.67)

27 (13.11)

 

Rural area

187 (89.05)

1369 (81.98)

167 (81.07)

 

Occupation, n(%)

   

0.7919

Farmer or manual

174 (92.55)

1247 (88.25)

128 (87.07)

 

Clerical

9 (4.79)

77 (5.45)

10 (6.80)

 

Professional

2 (1.06)

43 (3.04)

5 (3.40)

 

Others

3 (1.60)

46 (3.26)

4 (2.72)

 

Education, n(%)

   

0.6738

Illiterate

149 (73.40)

1073 (65.71)

121 (60.20)

 

Primary school

45 (22.17)

429 (26.27)

61 (30.35)

 

Middle school or above

9 (4.43)

131 (8.02)

19 (9.45)

 

Smoking status, n(%)

   

0.8888

Never

162 (78.26)

1255 (76.57)

146 (73.74)

 

Ever smoker

16 (7.73)

133 (8.11)

23 (11.62)

 

Current smoker

29 (14.01)

251 (15.31)

29 (14.65)

 

Drinking status, n(%)

   

0.8806

Never

167 (81.07)

1289 (78.89)

146 (75.26)

 

Ever drinker

9 (4.37)

89 (5.45)

20 (10.31)

 

Current drinker

30 (14.56)

256 (15.67)

28 (14.43)

 

Exercise status, n(%)

   

0.7463

Never

172 (83.50)

1322 (82.42)

163 (83.59)

 

Ever exerciser

2 (0.97)

42 (2.62)

4 (2.05)

 

Current exerciser

32 (15.53)

240 (14.96)

28 (14.36)

 

Access to medical service, yes, n(%)

193 (93.24)

1577 (95.75)

188 (95.43)

0.4252

Vitamin supplementation use, n(%)

31 (14.90)

200 (12.14)

25 (12.63)

0.5460

ADL score, Mean ± SD

5.22 ± 1.66

5.42 ± 1.42

5.23 ± 1.69

0.0591

MMSE score, Mean ± SD

18.22 ± 10.37

21.49 ± 9.46

21.29 ± 10.17

< 0.0001 a b

Physical performance score, median(IQR)

4.50 (3.00–5.00)

5.00 (3.50-5.00)

4.75 (3.50-5.00)

0.0293 a

Food diversity score, Mean ± SD

4.05 ± 1.86

4.35 ± 1.89

4.39 ± 1.82

0.0853

Social activity score, Mean ± SD

1.91 ± 1.55

2.37 ± 1.68

2.52 ± 1.76

0.0003 a b

Chronic disease score, Mean ± SD

0.98 ± 1.86

0.87 ± 1.57

0.87 ± 1.23

0.8614

Hemoglobin, median(IQR), g/L

121 (109–134)

123 (111–136)

123 (111–134)

0.1517

Total cholesterol, median(IQR), mmol/L

3.89 (3.41–4.60)

4.49 (3.91–5.16)

4.69 (4.09–5.53)

< 0.0001 a b c

Triglyceride, median(IQR), mmol/L

0.82 (0.60–1.14)

0.91 (0.67–1.28)

0.86 (0.60–1.23)

0.0069 a

Systolic BP, Mean ± SD, mm Hg

140.01 ± 22.66

143.60 ± 25.01

139.47 ± 22.87

0.0167 c

Diastolic BP, Mean ± SD, mm Hg

79.39 ± 13.55

80.16 ± 13.57

77.66 ± 11.45

0.0360 c

Glucose, median(IQR), mmol/L

4.79 (4.15–6.16)

4.68 (4.04–5.48)

4.79 (3.96–5.48)

0.1471

eGFR, median(IQR), mL/min/1.73 m2

67.05 (53.87–78.47)

67.89 (54.43–79.42)

68.17 (55.38–80.34)

0.5890

  1. Abbreviations: ADL: activities of daily living; BP: blood pressure; eGFR: estimated glomerular filtration rate; IQR, interquartile range; MMSE: Mini-Mental State Examination; SD standard deviation.
  2. P value: analysis of variance for continuous variables; ordinal Chi-square test for categorical variables. a Statistical significance between low level group and middle level group; b Low level group and high level group; c Middle level group and high level group