In the present study, the relationship between dietary ORAC index with lipid profile and fasting blood glucose in obese/overweight and normal weight population was examined. After calculating the sample size and simple random sampling, 220 adults, 110 overweight/obese and 110 with normal weight, were recruited based on the inclusion and exclusion criteria. Amongst these, 20 volunteers were excluded because of incomplete questionnaires (more than half of the items were not completed). Finally, the study was conducted with 100 normal weight and 100 overweight /obese subjects.
Basic information of two groups is presented in Table 1. As shown in Table 1, participants with normal weight had a lower visceral fat mass (five kilograms; P<0.01) and a lower body fat percentage (P<0.01). Waist to hip ratio (WHR) was significantly lower in the normal weight group as compared to overweight/obese group (P<0.01). As expected, fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL) were higher in overweight/obese volunteers than normal volunteers, whereas HDL was greater in the normal weight group; these differences were not significant.
Table 1. Basic information of two groups
Variable
|
Normal weight
|
Overweight/obese
|
P-Value
|
N
|
100
|
100
|
|
Sex (M/F)
|
70/30
|
65/35
|
0.824
|
Marital status (S/M)
|
25/75
|
45/55
|
0.762
|
Age (year)
|
40.50±8.97
|
40.60±7.35
|
0.915
|
Anthropometric indices, MEAN±SD
|
Weight (Kg)
|
70.13±9.33
|
95.05±12.32
|
0.0001*
|
Height (Cm)
|
172.86±4.58
|
170.20±4.38
|
0.856
|
BMI (Kg/m2)
|
23.58±1.52
|
31.28±4.16
|
0.0001*
|
WHR
|
0.88±0.04
|
1.05±0.06
|
0.0001*
|
Visceral fat
|
7.55±2.10
|
12.30±3.59
|
0.0001*
|
Body fat mass (Kg)
|
19.76±10.76
|
28.77±7.48
|
0.0001*
|
Body fat percentage (%)
|
2.14±0.78
|
3.14±2.77
|
0.004*
|
Biochemical parameters, MEAN±SD
|
FBG (mg/dl)
|
89.01±10.73
|
92.09±16.33
|
0.175
|
TG (mg/dl)
|
152.52±85.38
|
164.99±84.67
|
0.362
|
TC (mg/dl)
|
172.17±35.30
|
175.06±29.90
|
0.580
|
LDL (mg/dl)
|
98.44±29.71
|
100.22±25.75
|
0.687
|
HDL (mg/dl)
|
44.51±8.41
|
42.40±9.67
|
0.151
|
Abbreviations: BMI, Body mass index; WHR, Waist to hip ratio; F, Female; M, Male; S, Single; M, Married;
FBG, Fasting blood glucose; TG, Triglyceride; TC, Total Cholesterol; LDL, low-density lipoproteins; HDL, high-density lipoproteins.
* P<0.05
Dietary data analyses are presented in Table 2. The consumption of vegetable, fruits, vitamin C, and vitamin E was higher in the normal weight group than the other group; the difference was only significant in fruit consumption (P=0.026). Moreover, the dietary ORAC index was higher in normal weight volunteers than the overweight/obese group; the difference, though, was not significant (P=0.352).
Table 2. Comparison of dietary intake and ORAC index in two groups of normal weight and overweight/obese
Variable
|
Normal weight (n=100) MEAN±SD
|
Overweight/obese (n=100)
MEAN±SD
|
P-Value
|
Vegetable
|
15.116±1.713
|
12.426±1.284
|
0.918
|
Fruits
|
20.943±1.415
|
14.246±2.702
|
0.026*
|
Vitamin C
|
140.60±87.96
|
123.07±74.85
|
0.081
|
Vitamin E (alpha-tocopherol)
|
11.98±10.42
|
10.45±9.44
|
0.064
|
ORAC
|
48002.65±14651.20
|
14785.27±8149.51
|
0.352
|
Abbreviations: ORAC, Oxygen radical absorbance capacity.
*P<0.05
The correlation between the dietary ORAC index with anthropometric indices and biochemical parameters in the two groups are presented in Table 3. According to Table 3, ORAC index was inversely correlated with all anthropometric indices and biochemical parameters except for HDL. Despite significant correlation between ORAC index with BMI, WHR and HDL (P<0.05), weak relationship in normal group and all subjects, and fair relation among over weight/obese group was observed.
Table 3. Regression and Correlation coefficient between anthropometric indices and blood biochemical markers with dietary ORAC index
Variable
|
Normal weight
(n=100)
|
Overweight/obese
(n=100)
|
Total
(n=200)
|
CC
|
P-
Value
|
R2
|
CC
|
P-Value
|
R2
|
CC
|
P-Value
|
R2
|
BMI (Kg/m2)
|
-0.768
|
0.047*
|
0.258
|
-0.876
|
0.010*
|
0.558
|
-0.831
|
0.036*
|
0.246
|
WHR
|
-0.796
|
0.042*
|
0.312
|
-0.869
|
0.023*
|
0.581
|
-0.680
|
0.043*
|
0.353
|
Body fat mass (Kg)
|
-0.188
|
0.117
|
0.152
|
-0.196
|
0.068
|
0.421
|
-0.035
|
0.661
|
0.153
|
Body fat percentage (%)
|
-0.083
|
0.489
|
0.263
|
-0.201
|
0.062
|
0.436
|
-0.012
|
0.879
|
0.341
|
Visceral fat
|
-0.094
|
0.435
|
0.157
|
-0.172
|
0.111
|
0.341
|
-0.071
|
0.377
|
0.254
|
FBG (mg/dl)
|
-0.041
|
0.734
|
0.256
|
-0.008
|
0.938
|
0.314
|
-0.033
|
0.677
|
0.341
|
TG (mg/dl)
|
-0.031
|
0.796
|
0.247
|
-0.023
|
0.829
|
0.346
|
-0.020
|
0.802
|
0.232
|
TC (mg/dl)
|
-0.204
|
0.087
|
0.280
|
-0.066
|
0.544
|
0.365
|
-0.076
|
0.343
|
0.206
|
LDL (mg/dl)
|
-0.194
|
0.105
|
0.341
|
-0.008
|
0.944
|
0.412
|
-0.089
|
0.266
|
0.305
|
HDL (mg/dl)
|
0.773
|
0.049*
|
0.261
|
0.948
|
0.012*
|
0.499
|
0.890
|
0.034*
|
0.284
|
Abbreviations: BMI, Body mass index; WHR, Waist to hip ratio; FBG, Fasting blood glucose; TG, Triglyceride; TC, Total Cholesterol; LDL, low-density lipoproteins; HDL, high-density lipoproteins; CC, Correlation coefficient
*P<0.05