The Impact of Vitamin D in Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study in Patients with Morbid Obesity

Figures & data

Table 1 Clinical and Demographic Characteristics of the Population Included (n=1124). Values are Shown as Mean ± Standard Deviation or as Median [95% Confidence Interval]

Age, years	43.3 ± 10.7
Female, %	84.3
Weight, kg	115.6 ± 19.1
Body Mass Index, kg/m^2	43.3 ± 10.7
Waist circumference, cm	122.2 ± 13.6
Hip circumference, cm	131.5 ± 11.2
Diabetes mellitus, %	32.5
Dyslipidaemia, %	45.2
Hypertension, %	62.1
Vitamin D Deficiency (<12ng/mL), %	34.8
Vitamin D Deficiency (<20ng/mL), %	70.8
Vitamin D supplementation, %	6.6
Albumin, g/L	41.3 [39.5, 43.4]
AST, U/L	21.0 [17.0, 28.0]
ALT, U/L	24.0 [17.0, 35.0]
GGT, U/L	26.0 [19.0, 41.0]
ALP, U/L	76.0 [63.0, 92.0]
Total Bilirubin, mg/dL	0.53 [0.42, 0.65]
Direct Bilirubin, mg/dL	0.10 [0.08, 0.13]
BARD, %
1	22.1
2	15.2
3	45.1
4	17.6
FLI	97.4 [94.0, 99.1]

Abbreviations: AST, aspartate transaminase; ALT, alanine transaminase; GGT, gamma-glutamyltransferase; ALP, alkaline phosphatase.

Table 2 Clinical, Demographic and Biochemical Characteristics and Liver Scores of the Population According to Vitamin D Levels (12ng/dL cut-off) (n=1124). Values are Shown as Mean ± Standard Deviation or as Median [95% Confidence Interval]

	Vitamin D ≥12ng/mL n=733	Vitamin D <12ng/mL n=391	P value
Age, years	43.4 ± 10.8	42.9 ± 10.7	0.44
Female, %	86.4	80.3	<0.01
Weight, kg	113.5 ± 18.2	119.7 ± 19.9	<0.01
Body Mass Index, kg/m^2	43.0 ± 5.5	44.8 ± 5.9	<0.01
Waist circumference, cm	120.7 ± 12.8	124.9 ± 14.6	<0.01
Hip circumference, cm	130.8 ± 11.1	132.9 ± 11.3	0.01
Diabetes mellitus, %	30.5	36.3	0.06
Dyslipidaemia, %	44.8	46.1	0.66
Hypertension, %	59.1	67.4	0.01
Vitamin D supplementation, %	6.0	7.8	0.26
Albumin, g/L	41.2 [39.6, 43.3]	41.3 [39.5, 43.5]	0.66
AST, U/L	21.0 [17.0, 28.0]	21.0 [18.0, 28.0]	0.27
ALT, U/L	23.0 [17.0, 34.0]	25.0 [18.0, 36.0]	0.09
GGT, U/L	25.0 [19.0, 39.0]	27.0 [19.0, 44.0]	0.07
ALP, U/L	74.0 [62.0, 90.0]	79.0 [66.0, 94.0]	<0.01
Total Bilirubin, mg/dL	0.5 [0.4, 0.6]	0.5 [0.4, 0.7]	0.64
Direct Bilirubin, mg/dL	0.1 [0.1, 0.1]	0.1 [0.1, 0.1]	1.00
BARD, %			0.01
1	20.3	25.3
2	15.2	15.2
3	48.7	38.4
4	15.7	21.0
FLI	97.2 [93.2, 99.0]	97.9 [95.1, 99.5]	<0.01

Notes: AST, ALT, GGT, total bilirubin and direct bilirubin were log-transformed. Numbers are bolded if statistically significant (p value<0.05).

Abbreviations: AST, aspartate transaminase; ALT, alanine transaminase; GGT, gamma-glutamyltransferase; ALP, alkaline phosphatase.

Table 3 Clinical, Demographic and Biochemical Characteristics and Liver Scores of the Population According to Vitamin D Levels (20ng/dL cut-off) (n=1124). Values are Shown as Mean ± Standard Deviation or as Median [95% Confidence Interval]

	Vitamin D ≥20ng/mL n=328	Vitamin D <20ng/mL n=796	P value
Age, years	43.3 ± 10.8	43.2 ± 10.7	0.96
Female, %	86.3	83.4	0.23
Weight, kg	113.4 ± 19.0	116.5 ± 19.1	0.01
Body Mass Index, kg/m^2	43.0 ± 5.9	43.9 ± 5.6	0.01
Waist circumference, cm	120.7 ± 13.3	122.7 ± 13.7	0.049
Hip circumference, cm	131.4 ± 11.1	131.6 ± 11.2	0.80
Diabetes mellitus, %	30.6	33.3	0.41
Dyslipidaemia, %	42.7	46.3	0.28
Hypertension, %	58.0	63.7	0.10
Vitamin D supplementation, %	6.3	6.8	0.76
Albumin, g/L	41.1 [39.3, 43.4]	41.3 [39.5, 43.4]	0.30
AST, U/L	20.0 [16.0, 28.0]	22.0 [18.0, 28.0]	0.01
ALT, U/L	22.0 [16.0, 31.0]	25.0 [18.0, 36.0]	<0.01
GGT, U/L	25.0 [19.0, 39.0]	27.0 [19.0, 41.0]	0.18
ALP, U/L	73.0 [62.0, 87.0]	77.0 [64.0, 93.0]	0.02
Total Bilirubin, mg/dL	0.5 [0.4, 0.7]	0.5 [0.4, 0.7]	0.82
Direct Bilirubin, mg/dL	0.1 [0.1, 0.1]	0.1 [0.1, 0.1]	0.67
BARD, %			0.50
1	20.7	22.6
2	13.5	16.0
3	48.7	43.5
4	17.1	17.8
FLI	97.1 [93.1, 99.0]	97.5 [94.1, 99.2]	0.08

Notes: AST, ALT, GGT, total bilirubin and direct bilirubin were log-transformed. Numbers are bolded if statistically significant (p value<0.05).

Abbreviations: AST, aspartate transaminase; ALT, alanine transaminase; GGT, gamma-glutamyltransferase; ALP, alkaline phosphatase.

Table 4 Association of Vitamin D Levels with FLI and BARD Scores

	Vitamin D
	OR (SE)	P value
BARD
Unadjusted	1.06 (0.07)	0.43
Model 1^a	1.01 (0.07)	0.87
Model 2^b	1.02 (0.07)	0.74
Model 3^c	1.05 (0.08)	0.55
FLI
Unadjusted	0.77 (0.07)	<0.01
Model 1^a	0.79 (0.07)	0.01
Model 2^b	0.91 (0.10)	0.41
Model 3^c	0.94 (0.12)	0.65

Notes: The values are shown as odds ratio and standard error obtained from ordered logistic regression models. An increase in one unit of vitamin D represents 10ng/mL ^aAdjusted to sex and age; ^bAdjusted to sex, age and BMI; ^cAdjusted to sex, age, BMI, dyslipidaemia and diabetes. Numbers are bolded if statistically significant (p value<0.05).

Table 5 Linear Association of Vitamin D Levels with Liver Function Tests

	Vitamin D
	β (95% CI)	P value
Albumin
Unadjusted	−0.15 (−0.49, 0.19)	0.39
Model 1^a	−0.07 (−0.40, 0.25)	0.66
Model 2^b	−0.15 (−0.48, 0.18)	0.38
Model 3^c	−0.09 (−0.45, 0.27)	0.62
AST
Unadjusted	−0.01 (−0.03, 0.02)	0.58
Model 1^a	0.001 (−0.03, 0.03)	0.95
Model 2^b	0.004 (−0.02, 0.03)	0.77
Model 3^c	0.01 (−0.02, 0.04)	0.51
ALT
Unadjusted	−0.03 (−0.07, 0.01)	0.11
Model 1^a	−0.02 (−0.05, 0.02)	0.40
Model 2^b	−0.01 (−0.05, 0.02)	0.54
Model 3^c	−0.004 (−0.04, 0.03)	0.84
GGT
Unadjusted	−0.03 (−0.07, 0.01)	0.16
Model 1^a	−0.02 (−0.06, 0.02)	0.42
Model 2^b	−0.01 (−0.05, 0.03)	0.58
Model 3^c	−0.001 (−0.05, 0.04)	0.97
ALP
Unadjusted	−0.03 (−0.06, −0.01)	<0.01
Model 1^a	−0.04 (−0.06, −0.01)	<0.01
Model 2^b	−0.03 (−0.05, −0.01)	<0.01
Model 3^c	−0.04 (−0.06, −0.01)	<0.01
Total Bilirubin
Unadjusted	−0.01 (−0.05, 0.03)	0.55
Model 1^a	−0.01 (−0.05, 0.03)	0.60
Model 2^b	−0.01 (−0.05, 0.03)	0.64
Model 3^c	−0.01 (−0.05, 0.04)	0.76
Direct Bilirubin
Unadjusted	0.01 (−0.04, 0.05)	0.80
Model 1^a	0.01 (−0.03, 0.05)	0.68
Model 2^b	0.01 (−0.03, 0.06)	0.56
Model 3^c	0.03 (−0.01, 0.08)	0.18

Notes: ^aAdjusted to sex and age; ^bAdjusted to sex, age and BMI; ^cAdjusted to sex, age, BMI, diabetes and dyslipidaemia. Numbers are bolded if statistically significant (p value<0.05). The values shown are linear regression coefficients (β) and 95% confidence intervals, estimated by multiple linear regression. An increase in one unit of vitamin D represents 10ng/mL.

Abbreviations: AST, aspartate transaminase; ALT, alanine transaminase; GGT, gamma-glutamyltransferase; ALP, alkaline phosphatase.