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. 2023 Aug 7;77(11):1071–1083. doi: 10.1038/s41430-023-01318-3

Table 4.

Multivariable logistic regression results (using GEE) for individual nutrient deficiency and related independent variables for Sleeve Gastrectomy and Gastric Bypass participants.

Dependent Variable Independent Variablea Sleeve Gastrectomy Gastric Bypass
Model 1e Model 2f Model 1e Model 2f
Odds ratio (95% CI) p value Odds ratio (95% CI) p value Odds ratio (95% CI) p value Odds ratio (95% CI) p value
Iron deficiency (Ferritin <30 ug/L and Transferrin Saturation <16%)g Preop Ref Ref Ref Ref
1–3 months postop 1.30 (0.64, 2.64) 0.5 1.49 (0.38, 5.87) 0.6 0.73 (0.44, 1.23) 0.2 0.82 (0.32, 2.11) 0.7
6 months postop 1.47 (0.71, 3.07) 0.3 2.05 (0.59, 7.06) 0.3 0.79 (0.39, 1.57) 0.5 1.28 (0.35, 4.70) 0.7
12 months postop 1.66 (0.81, 3.40) 0.2 4.11 (1.04, 16.2) 0.04 0.83 (0.36, 1.88) 0.7 1.17 (0.35, 3.97) 0.8
Oral iron supplement doseb 1.02 (0.74, 1.40) 0.9 0.75 (0.47, 1.21) 0.2
Female 3.52 (0.45, 27.4) 0.2 5.37 (1.06, 27.1) 0.04
CRP >5mg/L 1.90 (1.04, 3.44) 0.04 0.80 (0.32, 2.03) 0.6
Vitamin B12 deficiency and insufficiency (<133 pmol/L) Preop Ref Ref Ref
1–3 months postop 1.08 (0.25, 4.57) 0.9 0.73 (0.11, 4.69) 0.7 0.14 (0.03, 0.62) 0.01
6 months postop 1.75 (0.58, 5.29) 0.3 1.24 (0.26, 5.89) 0.8 0.30 (0.10, 0.94) 0.04
12 months postop 2.07 (0.58, 7.42) 0.3 2.39 (0.46, 12.3) 0.3 0.54 (0.20, 1.44) 0.2
Oral vitamin B12 supplement doseb 1.05 (0.69, 1.60) 0.8
IM vitamin B12 supplementationc 1.16 (0.10, 13.9) 0.9
Metformind 2.78 (0.94, 8.27) 0.07
CRP >5mg/L 1.29 (0.48, 3.43) 0.6
Folate deficiency (<10 nmol/L) Preop Ref Ref Ref Ref
1–3 months postop 0.95 (0.20, 4.65) 1 2.91 (0.39, 21.7) 0.3 0.65 (0.08, 5.45) 0.7 0.76 (0.07, 7.94) 0.8
6 months postop 3.80 (1.14, 12.7) 0.03 12.9 (2.00, 83.7) 0.007 3.30 (1.07, 10.2) 0.04 8.56 (1.64, 44.6) 0.01
12 months postop 1.09 (0.89, 10.7) 0.08 3.68 (0.64, 21.9) 0.1 2.00 (0.28, 14.6) 0.5 7.67 (1.10, 53.7) 0.04
Oral folic acid supplement doseb 0.78 (0.62, 0.98) 0.04 0.93 (0.74, 1.17) 0.5
CRP >5mg/L 1.22 (0.37, 4.00) 0.7 9.46 (2.20, 40.7) 0.003
Vitamin D deficiency and insufficiency (<50 nmol/L) Preop Ref Ref Ref Ref
1–3 months postop 0.15 (0.06, 0.37) <0.001 0.21 (0.07, 0.66) 0.008 0.62 (0.27, 1.41) 0.25 1.93 (0.64, 5.82) 0.2
6 months postop 0.20 (0.09, 0.41) <0.001 0.16 (0.05, 0.56) 0.004 0.57 (0.24, 1.36) 0.21 3.19 (0.88, 11.5) 0.08
12 months postop 0.27 (0.14, 0.54) <0.001 0.21 (0.05, 0.82) 0.02 0.80 (0.33, 1.94) 0.63 5.10 (1.24, 20.9) 0.03
Oral vitamin D supplement doseb 1.03 (0.88, 1.21) 0.7 0.74 (0.65, 0.85) <0.001
CRP >5mg/L 1.32 (0.60, 3.00) 0.5 1.83 (0.75, 4.49) 0.2
HbA1c (%) 0.91 (0.68, 1.22) 0.5 0.96 (0.69, 1.33) 0.8
Vitamin B1 deficiency (<0.9 nmol/g Hb) Preop Ref Ref Ref Ref
1–3 months postop 0.64 (0.27, 1.48) 0.3 1.87 (0.69, 5.07) 0.2 0.25 (0.10, 0.63) 0.003 8.27 (2.67, 25.6) <0.001
6 months postop 1.00 (0.41, 2.41) 1 1.52 (0.42, 5.59) 0.5 0.52 (0.18, 1.49) 0.2 6.27 (1.86, 21.1) 0.003
12 months postop 6.60 (1.18, 36.9) 0.03 0.24 (0.05, 1.22) 0.09 1.54 (0.30, 8.27) 0.6 2.04 (0.30, 13.9) 0.5
Oral vitamin B1 supplement doseb 0.49 (0.27, 0.88) 0.02 0.45 (0.29, 0.70) <0.001
CRP >10mg/L 0.17 (0.05, 0.59) 0.005 1.78 (0.73, 4.36) 0.2
Vitamin A deficiency (<1.1 umol/L) Preop Ref Ref
1–3 months postop 6.31 (2.02, 19.8) 0.002 5.25 (0.93, 29.5) 0.06
6 months postop 3.56 (1.24, 10.2) 0.02 2.99 (0.53, 16.8) 0.2
12 months postop 0.78 (0.12, 5.02) 0.8 0.79 (0.10, 6.43) 0.8
Oral vitamin A supplement doseb 1.11 (0.91, 1.37) 0.3
CRP >10mg/L 3.25 (1.04, 10.2) 0.04
Plasma Glutathione Peroxidase deficiency (<370 U/L) Preop Ref Ref
1–3 months postop 2.38 (1.35, 4.18) 0.003 1.74 (0.64, 4.79) 0.3
6 months postop 1.83 (1.03, 3.24) 0.04 1.43 (0.40, 5.08) 0.6
12 months postop 0.54 (0.28, 1.03) 0.06 0.38 (0.11, 1.32) 0.1
Oral selenium supplement doseb 0.92 (0.75, 1.13) 0.4
CRP >5mg/L 2.27 (1.16, 4.44) 0.02
Hba1c (%) 0.51 (0.37, 0.71) <0.001
Red Cell Glutathione Peroxidase deficiency (<25 U/g Hb) Preop Ref Ref
1–3 months postop 1.01 (0.50, 2.01) 1 1.09 (0.25, 4.66) 0.9
6 months postop 1.14 (0.43, 3.04) 0.8 1.13 (0.15, 8.80) 0.9
12 months postop 2.07 (0.79, 5.38) 0.1 2.27 (0.30, 17.3) 0.4
Oral selenium supplement doseb 1.14 (0.85, 1.53) 0.4
CRP >5mg/L 1.73 (0.33, 9.14) 0.5
HbA1c (%) 1.20 (0.89, 1.64) 0.2

ref reference category.

aUsing the Generalised Estimated Equation, comparing the indpendent variables to preoperative nutrient deficiency prevalence as the reference category.

bOral supplementation dose is loge(supplementation dose/day +1) as is not normally distributed and contains zero values.

cPatient received any dose of IM vitamin B12 supplementation prior to their blood test at that timepoint.

dOn any dose of metformin at time of blood test.

eModel 1: multivariable model with only time as the independent variable.

fModel 2: multivariable model with time, supplementation, inflammation (measured using C-reactive protein (CRP) cut offs to define inflammation) and metformin for vitamin B12 as independent variables.

gCases that used IV iron excluded from analysis.