Of the 947 referred patients, only 864 of them had complete data set and analyzed further for various characteristics. The proportion of males (57.8%) was higher than females (42.2%). Table 1 shows baseline anthropometric and biochemical parameters of individuals based on serum levels of 25(OH) Vit. D. The deficient group had the highest percentage (44.7%), while insufficient and normal levels of 25(OH) Vit. D levels were recorded in 38.8% and 13.7% of participants, respectively. Moreover, 29.3% of participants had BMI < 25, 48.1% were overweight, and 22.6% were obese.
Table 1
Clinical anthropometric measures, indices and measure indicators adjusted for gender and VitD status
Gender
|
Males (499, 57.8%)
|
Females (365, 42.2%)
|
characteristic
|
Normal
( vit D ≥ 30 )
|
Insufficient
( 30 > vit D > 15 )
|
Deficient
( vit D ≤ 15 )
|
P value
|
Normal
( vit D ≥ 30 )
|
Insufficient
( 30 > vit D > 15 )
|
Deficient
( vit D ≤ 15 )
|
P value
|
Age (years )
|
62.62 ± 10.88
|
57.91 ± 11.92
|
57.90 ± 11.917
|
0.008* #
|
57.73 ± 11.97
|
54.09 ± 12.60
|
50.41 ± 14.33
|
0.001*#
|
Anthropometric measures
|
BMI (kg/\({m}^{2}\))
|
27.22 ± 6.48
|
28.25 ± 5.78
|
28.05 ± 7.50
|
0.361
|
32.72 ± 7.96
|
34.45 ± 8.42
|
37.13 ± 10.68
|
0.015*#
|
WC (cm)
|
99.65 ± 17.75
|
101.67 ± 15.74
|
110.76 ± 22.75
|
0.192
|
108.25 ± 13.43
|
112.06 ± 14.22
|
122.28 ± 16.33
|
<0.001*
|
HC (cm)
|
143.50 ± 21.92
|
142.15 ± 16.16
|
140.15 ± 11.91
|
0.898
|
140.13 ± 27.17
|
136.81 ± 9.59
|
139.44 ± 11.88
|
0.552
|
WHtR
|
0.59 ± 0.09
|
0.60 ± 0.08
|
0.64 ± 0.12
|
0.002 *#
|
0.69 ± 0.08
|
0.71 ± 0.08
|
0.76 ± 0.10
|
< 0.001 *#
|
WHR
|
1.01 ± 0.10
|
0.98 ± 0.04
|
1.03 ± 0.06
|
0.161
|
0.87 ± 0.11
|
0.89 ± 0.06
|
0.91 ± 0.09
|
0.167
|
Past history
|
Hypertension (%)
|
9.8%
|
44.5%
|
45.6%
|
0.703
|
23.5%
|
36.6%
|
39.9%
|
0.127
|
Smoking (%)
|
52.2%
|
67%
|
71.2%
|
0.139
|
2.8%
|
3%
|
12.5%
|
0.137
|
Supplement intake (%)
|
4.2%
|
1.9%
|
0.4%
|
< 0.001*#
|
16.7%
|
1.6%
|
1.9%
|
< 0.001*#
|
Biochemistry measures
|
FBS (mg/dl)
|
110.40 ± 35.11
|
110.30 ± 34.48
|
119.55 ± 43.27
|
0.391
|
116.76 ± 52.22
|
107.96 ± 33.64
|
133.07 ± 61.13
|
0.453
|
HbA1c
|
5.79 ± 0.39
|
5.57 ± 0.46
|
5.76 ± 0.53
|
0.066
|
5.70 ± 0.28
|
5.66 ± 0.42
|
5.86 ± 0.71
|
0.872
|
hsCRP
|
0.47 ± 1.40
|
0.39 ± 0.63
|
0.54 ± 0.83
|
0.831
|
0.32 ± 0.31
|
0.26 ± 0.32
|
0.34 ± 0.22
|
0.548
|
Fasting insulin (IU/L )
|
13.34 ± 17.88
|
13.00 ± 11.62
|
14.70 ± 13.73
|
0.733
|
15.02 ± 8.01
|
12.98 ± 10.04
|
15.97 ± 9.73
|
0.325
|
Serum Cr (mg/dl)
|
0.99 ± 0.25
|
0.91 ± 0.18
|
0.95 ± 0.20
|
0.240
|
0.78 ± 0.22
|
0.79 ± 0.21
|
0.70 ± 0.22
|
0.624
|
TG (mg/dl)
|
135.48 ± 66.72
|
143.27 ± 77.34
|
152.10 ± 77.32
|
0.243
|
133.37 ± 56.27
|
153.48 ± 69.63
|
161.66 ± 77.45
|
0.013*
|
Tch (mg/dl)
|
165.76 ± 47.26
|
175.80 ± 46.50
|
181.54 ± 46.03
|
0.235
|
193.45 ± 44.54
|
195.53 ± 41.85
|
197.05 ± 46.10
|
0.693
|
LDL (mg/dl)
|
97.59 ± 35.15
|
105.34 ± 37.23
|
104.61 ± 37.32
|
0.185
|
114.97 ± 39.47
|
121.97 ± 36.55
|
118.17 ± 41.24
|
0.381
|
HDL (mg/dl)
|
39.41 ± 8.25
|
40.19 ± 12.66
|
38.32 ± 10.24
|
0.878
|
46.02 ± 12.50
|
45.77 ± 13.46
|
41.62 ± 8.28
|
0.100
|
Hb (mg/dl)
|
14.72 ± 2.00
|
15.24 ± 1.42
|
15.35 ± 1.35
|
0.219
|
13.69 ± 1.35
|
13.62 ± 1.36
|
13.37 ± 1.15
|
0640
|
Anthropometric indices
|
LAP
|
56.57 ± 40.29
|
63.70 ± 59.04
|
84.76 ± 70.90
|
0.128
|
80.70 ± 41.14
|
95.46 ± 55.95
|
118.10 ± 67.81
|
0.009*
|
BAI
|
43.36 ± 7.90
|
43.29 ± 5.85
|
42.08 ± 6.37
|
0.911
|
54.27 ± 14.18
|
50.08 ± 4.66
|
50.81 ± 6.14
|
0.056
|
VAI
|
1.97 ± 0.93
|
2.35 ± 1.42
|
2.54 ± 2.06
|
0.060
|
2.91 ± 1.90
|
3.19 ± 1.78
|
3.16 ± 1.71
|
0.382
|
BRI
|
5.40 ± 2.29
|
5.57 ± 2.11
|
6.82 ± 3.27
|
0.237
|
7.98 ± 2.36
|
8.39 ± 2.14
|
9.97 ± 3.12
|
0.004*
|
BSI
|
0.08 ± 0.00
|
0.08 ± 0.00
|
0.08 ± 0.00
|
0.151
|
0.08 ± 0.00
|
0.08 ± 0.02
|
0.07 ± 0.00
|
0.784
|
*significant for comparison of deficient versus normal groups, #significant for comparison of insufficient versus normal groups, $ significant for comparison of deficient versus insufficient groups |
Out of newly developed indices, mean differences of LAP (p value = 0.009) and BRI (p value = 0.004) were significant among females according to the serum level of 25(OH) Vit. D, but no significant differences were detected among males. Considering ancient indices, BMI, WC, and WHtR (p value = 0.015, < 0.001 and 0.001, respectively) showed significant mean differences in the female group, while only WHtR (p value = 0.002) showed the mentioned effect among males.
After adjustment for sex, Pearson correlation of 25(OH) Vit. D with anthropometric indices showed inversly significant relationships with WC ( r = -0.188, p = 0.005 ), WHtR ( r = -0.171, p = 0.017 ), LAP ( r = -0.169, p = 0.014 ), and BRI ( r = -0.165, p = 0.015) in the male group. Almost the same pattern was observed in the female group, where 25(OH) Vit. D levels were inversely correlated with WC (r = -0.277, p < 0.0001), LAP (r = -0.185, p = 0.004), and BRI (r = -0.246, p < 0.0001) in the female group. Nonetheless, the correlation between 25(OH) Vit. D and BMI was inversely significant only in women (r = 0.165, p = 0.002) and was not seen in the male group (r = -0.034, p = 0.456) and was depicted in Fig. 1 (Scatter plots are shown in).
On the other hand, the area under the curve analysis, BSI represented the best AUC [AUC (95% CI) = 0.56(0.52–0.76)] for both gender [AUC (95% CI) = 0.63(0.47–0.88)], though it showed only a sufficient power in discriminating Vit. D-deficient as compared to normal persons (Table 2).
Table 2
The area under the curve, cut off, sensitivity and specificity of each anthropometric measures for the presence of vitamin D deficiency in both genders
|
Female
|
Male
|
Predictors
|
PCC
|
Cut off
|
sens
|
spec
|
AUC(95%CI)
|
PCC
|
Cut off
|
sens
|
Spec
|
AUC(95%CI)
|
WC
|
-0.277*
|
107.32
|
0.68
|
0.57
|
0.37(0.52–0.76)
|
-0.188*
|
113.86
|
0.61
|
0.74
|
0.47(0.34–0.67)
|
HC
|
-0.079
|
116.55
|
0.67
|
0.44
|
0.41(0.45–0.70)
|
0.105
|
115.69
|
0.65
|
0.51
|
0.59(0.47–0.72)
|
WHR
|
-0.102
|
0.92
|
0.51
|
0.63
|
0.44(0.47–0.71)
|
-0.175
|
0.94
|
0.72
|
0.62
|
0.28(0.19–0.54)
|
WHtR
|
-0.247*
|
0.74
|
0.72
|
0.60
|
0.41(0.55–0.79)
|
-0.171*
|
0.93
|
0.70
|
0.45
|
0.48(0.35–0.73)
|
LAP
|
-0.185*
|
67.43
|
0.60
|
0.52
|
0.44(0.57–0.78)
|
-0.165*
|
90.27
|
0.53
|
0.65
|
0.39(0.29–0.61)
|
VAI
|
-0.012
|
2.05
|
0.77
|
0.48
|
0.52(0.53–0.75)
|
-0.114
|
2.26
|
0.58
|
0.53
|
0.37(0.23–0.51)
|
BSI
|
0.050
|
0.08
|
0.35
|
0.67
|
0.56(0.52–0.76)
|
-0.085
|
0.08
|
0.50
|
0.61
|
0.63(0.47–0.88)
|
BRI
|
-0.246*
|
7.73
|
0.63
|
0.69
|
0.41(0.55–0.79)
|
-0.169*
|
6.51
|
0.68
|
0.65
|
0.48(0.33–0.81)
|
BAI
|
0.007
|
41.89
|
0.61
|
0.58
|
0.48(0.50–0.74)
|
0.058
|
38.66
|
0.51
|
0.70
|
0.59(0.41–0.76)
|
Abbreviations: PCC (Pearson Correlation Coefficient ), WC (waist circumstance), HC (hip circumstance), BMI(body mass index),WHR(Waist to hip ratio),WHtR (waist-to-height ratio ),BSI(body shape index), BRI (body roundness index), BAI (body adiposity inde). (*) means statistically significant (P<0.05).
After structuring a model to predict Vit. D deficiency considering age, triglyceride, FBS, SBP, and supplement intake as confounding factors, only WHtR predicted Vit. D deficiency independent of the mentioned variables with OR = 0.347(0.171–0.704) and P value = 0.003 in the women group but not in the men group (Table 3). Finally, the optimal cut point of Vit. D levels were calculated for differentiating patients with metabolic syndrome from those without MetS and was 4.55 ng/mL [Figure 2].
Table3: Odds ratio (95 % CI) of the presence of vitamin D deficiency for each anthropometric measure
|
Females
|
|
Males
|
|
Predictors
|
OR (95% CI)
|
P value
|
OR (95% CI)
|
P value
|
BMI
|
0.492(0.075-3.154)
|
0.864
|
0.069(-0.006-3.050)
|
0.955
|
WC
|
0.505(0.090-2.835)
|
0.125
|
0.687(0.337-1.400)
|
0.556
|
HC
|
0.453(0.013-0.763)
|
0.427
|
0.260(-0.086-5.029)
|
0.648
|
WHR
|
0.862(0.430-1.728)
|
0.437
|
0.074(-0.259-8.119)
|
0.301
|
WHtR
|
0.347(0.171-0.704)
|
0.003
|
0.715(0.205-2.487)
|
0.597
|
LAP
|
0.882(0.473-1.647)
|
0.372
|
0.701(0.320-1.530)
|
0.693
|
VAI
|
0.341(0.031-2.108)
|
0.715
|
0.322(0.112-1.673)
|
0.565
|
BSI
|
0.122 (0.006-1.024)
|
0.882
|
0.200(0.013-2.009)
|
0.701
|
BRI
|
0.564(0.223-1.429)
|
0.227
|
0.496(0.182-1.370)
|
0.176
|
BAI
|
0.365(0.036-1.872)
|
0.886
|
0.017(0.004-0.998)
|
0.762
|
MetS
|
0.766(0.486-1.208)
|
0.225
|
0.802(0.364-1.765)
|
0.586
|
Abbreviations: WC (waist circumstance),HC (hip circumstance), BMI(body mass index),WHR(Waist to hip ratio),WHtR (waist-to-height ratio ),BSI(body shape index), BRI (body roundness index), BAI (body adiposity index), LAP (lipid accumulation product), VAI (visceral adiposity index); Model: Adjusted for Age, Triglyceride, Fasting blood sugar, Systolic blood pressure and supplement intake.