The mean age of the study subjects was 30.3 (±5.7 SD) and the median duration of infertility was 3.0 (2.0 to 4.0 interquartile range). Respondents with tubal factors as the cause of infertility were most 48 (22.2%), followed by malefactors 36 (16.7%), other causes 34 (15.7%), hyperprolactinemia 30 (13.9%), unexplained causes 28 (13.0%) and polycystic ovarian syndrome 24 (11.1%). The mean BMI was 28.6 Kg/m2. The means of central obesity measures were respectively, 88.6 cm, 0.87 and 0.56 for WC, WHR, and WHtR [Supplementary Table 1].
Average BMI was significantly higher among with PCOS, Male factor and other causes of infertility compared women with unexplained causes of infertility (p-value =0.041). Also, mean BAI was significantly lower among women with PCOS associated infertility compared with others with other causes (p-value =0.007). Although not statistically significant (p-value =0.070), the mean fasting blood glucose level was high for women with Male factor (6.4 mmol/L) and PCOS (6.5 mmol/L) associated infertility. Total cholesterol levels were significantly higher for Male factor (6.9 mmol/L) and PCOS (6.7 mmol/L) associated infertility, compared with others (p-value <0.0001). Compared with Male factor and PCOS associated infertility (p-value <0.05), the levels of Triglycerides and LDL-C was lower for women with uterine and unexplained causes of infertility. Systolic blood pressure was significantly higher among women with male factor (131.8 mmHg), unexplained (131.5 mmHg) and other (132.6 mmHg) cause of infertility. The prevalence of hypertension was higher among women with other causes of infertility 14/34 (41.2%) and male factor 14/36 (38.9%). Also, hyperglycemia was high among male factor 18/36 (50.0%), PCOS 10/24 (41.7%), other cause 14/34 (41.2%) and tubal factor 16/48 (33.3%) associated infertile women. The highest prevalence of dyslipidemia was observed among women with Male factor associated infertile women 26/36 (72.2%), followed by PCOS 16/24 (66.7%) and tubal factor 22/48 (45.8%). No prevalence of MetS was observed among women with unexplained causes of infertility [Table 1]
Table 1: Characteristics of the study participants stratified by causes of infertility
Variables
|
Hyper-prolactinemia
(N=30)
|
Tubal factor
(N=48)
|
Male factor
(N=36)
|
PCOS
(N=24)
|
Uterine causes
(N=16)
|
Unexplained
Causes
(N=28)
|
Other causes
(N=34)
|
P-value
|
Anthropometric indices
|
|
|
|
|
|
|
|
|
Body mass index (Kg/m2)
|
28.8 (0.80)
|
28.5 (0.91)
|
29.7 (0.91)
|
29.8 (1.12)
|
27.5 (1.13)
|
25.9 (0.77)
|
29.6 (0.65)
|
0.041
|
Waist Circumference (cm)
|
84.9 (1.45)
|
90.5 (2.14)
|
88.1 (1.36)
|
88.6 (2.1)
|
86.4 (2.48)
|
88.1 (2.44)
|
90.8 (1.57)
|
0.342
|
Waist-to-hip ratio
|
0.85 (0.007)
|
0.88 (0.016)
|
0.87 (0.073)
|
0.89 (0.010)
|
0.88 (0.023)
|
0.86 (0.014)
|
0.87 (0.007)
|
0.422
|
Waist-to-height ratio)
|
0.54 (0.009)
|
0.56 (0.014)
|
0.56 (0.007)
|
0.54 (0.013)
|
0.54 (0.013)
|
0.55 (0.014)
|
0.57 (0.009)
|
0.372
|
Body adiposity index
|
31.8 (0.97)
|
32.1 (0.87)
|
33.5 (0.79)
|
29.2 (0.80)
|
31.0 (0.92)
|
32.8 (0.96)
|
34.3 (0.78)
|
0.007
|
Abdominal volume index
|
14.7 (0.51)
|
17.0 (0.79)
|
15.8 (0.47)
|
16.0 (0.72)
|
15.3 (0.90)
|
16.0 (0.91)
|
16.8 (0.58)
|
0.243
|
Biochemical parameters
|
|
|
|
|
|
|
|
|
Fasting plasma sugar
|
5.3 (0.38)
|
5.7 (0.37)
|
6.4 (0.42)
|
6.5 (0.63)
|
5.0 (0.25)
|
5.1 (0.22)
|
5.8 (0.33)
|
0.070
|
Total Cholesterol
|
5.3 (0.27)
|
5.8 (0.23)
|
6.9 (0.51)
|
6.7 (0.58)
|
4.7 (0.17)
|
4.7 (0.24)
|
5.3 (0.22)
|
<0.0001
|
Triglyceride
|
1.6 (0.19)
|
1.3 (0.08)
|
1.6 (0.21)
|
1.7 (0.18)
|
1.2 (0.13)
|
1.0 (0.06)
|
1.5 (0.10)
|
0.028
|
HDL-C
|
1.48 (0.10)
|
1.59 (0.08)
|
1.57 (0.07)
|
1.85 (0.17)
|
1.58 (0.15)
|
1.58 (0.11)
|
1.60 (0.14)
|
0.556
|
LDL-C
|
3.45 (0.27)
|
3.91 (0.24)
|
5.04 (0.48)
|
4.46 (0.44)
|
2.85 (0.18)
|
2.88 (0.23)
|
3.38 (0.17)
|
<0.0001
|
Blood pressure indices
|
|
|
|
|
|
|
|
|
SBP (mmHg)
|
129.0 (2.80)
|
126.7 (1.52)
|
131.8 (2.52)
|
122.6 (2.22)
|
126.0 (3.64)
|
131.5 (1.68)
|
132.6 (2.57)
|
0.040
|
DBP (mmHg)
|
77.7 (1.60)
|
79.0 (1.13)
|
81.1 (1.24)
|
72.3 (2.00)
|
78.8 (1.26)
|
77.6 (1.27)
|
82.2 (0.67)
|
<0.0001
|
Cardiometabolic factors^
|
|
|
|
|
|
|
|
|
Hypertension
|
6 (20.0)
|
8 (16.7)
|
14 (38.9)
|
0
|
2 (12.5)
|
4 (14.3)
|
14 (41.2)
|
0.001
|
Hyperglycaemia
|
4 (13.3)
|
16 (33.3)
|
18 (50.0)
|
10 (41.7)
|
2 (12.5)
|
6 (21.4)
|
14 (41.2)
|
0.011
|
Dyslipidaemia
|
12 (40.0)
|
22 (45.8)
|
26 (72.2)
|
16 (66.7)
|
6 (37.5)
|
8 (28.6)
|
14 (41.2)
|
0.006
|
Metabolic syndrome
|
4 (13.3)
|
14 (29.2)
|
10 (27.8)
|
6 (25.0)
|
4 (25.0)
|
0
|
12 (35.3)
|
0.026
|
Other causes (at least two of ovulatory problems, endometriosis, hyperprolactinemia, tubal factors). Biochemical variables were measured in mmol/L. All values are presented as mean (standard error of the mean) unless otherwise stated; ^ represents values presented as frequency (percentage)
The prevalence of hypertension among the study participants was 22.2%. Metabolic syndrome, hyperglycemia and dyslipidemia were presents among 23.1%, 32.4% and 48.1%, respectively [Figure 1].
Figure 2 shows the correlation of anthropometric indices with cardiometabolic risk factors. A significant positive correlation was observed between adiposity indices and fasting plasma glucose except for BAI, which showed no significant correlation (p-value =0.337). A significant positive correlation was observed between TC and BMI (R=0.37, p-value <0.0001), WC (R=0.22, p-value =0.024), WHtR (R=0.19, p-value =0.044) and AVI (R=0.21, p-value =0.030). BMI showed a significant positive correlation with TG and LDL, but negative correlation with HDL-C. WC, WHtR and AVI showed a significant positive correlation with LDL-C. Also, all adiposity indices other than WHR showed a significantly positive correlation with systolic blood pressure measurements.
Table 3 shows the criterion of anthropometric measurement for predicting hypertension. Among the indices considered, BMI, WC, WHR, WHtR, and AVI showed significant AUCs indicating their better suitability for predicting MetS, dyslipidemia and hyperglycemia. Also, BAI (AUC=0.721) and BMI (AUC= 0.641) better predict hypertension compared to other adiposity indices. BMI predictive cut-off values among women presenting with primary infertility proved to be the best anthropometric index, as it showed the largest AUC values for MetS (0.731), dyslipidemia (0.707) and hyperglycemia (0.759). Alternative measurements like AVI (AUC=0.749), WC (AUC=0.747) and WHtR (AUC=0.742) also proved to be better indices for predicting hyperglycemia. Moreover, central obesity indices (WC, WHR, and WHtR) and AVI proved a better alternative index for predicting MetS and dyslipidemia. The cut-off values for predicting MetS were as follows: WC = 90 cm; WHtR = 0.61 cm/cm; BMI = 28.0 kg/m2; WHR = 0.89 and AVI= 16.5 units.
Table 3: Criterion of anthropometric measurements for predicting cardiometabolic risk factors among primary infertility patients
Variable
|
BMI
|
WC
|
WHR
|
WHtR
|
BAI
|
AVI
|
Mets
|
|
|
|
|
|
|
AUC
|
0.731
|
0.690
|
0.653
|
0.669
|
0.595
|
0.688
|
Sensitivity
|
0.760
|
0.680
|
0.640
|
0.400
|
0.398
|
0.680
|
Specificity
|
0.614
|
0.675
|
0.687
|
0.928
|
0.840
|
0.675
|
Criterion
|
>28.0
|
>90.0
|
>0.89
|
>0.61
|
>29.9
|
>16.5
|
Dyslipidaemia
|
|
|
|
|
|
|
AUC
|
0.707
|
0.627
|
0.650
|
0.614
|
0.541
|
0.622
|
Sensitivity
|
0.654
|
0.692
|
0.712
|
0.750
|
0.788
|
0.712
|
Specificity
|
0.714
|
0.517
|
0.589
|
0.446
|
0.375
|
0.500
|
Criterion
|
>28.0
|
>84.0
|
>0.85
|
>0.52
|
>29.4
|
>14.3
|
Hyperglycaemia
|
|
|
|
|
|
|
AUC
|
0.759
|
0.747
|
0.675
|
0.742
|
0.666
|
0.749
|
Sensitivity
|
0.914
|
0.743
|
0.629
|
0.686
|
0.686
|
0.771
|
Specificity
|
0.534
|
0.671
|
0.726
|
0.726
|
0.630
|
0.671
|
Criterion
|
>25.8
|
>88.0
|
>0.89
|
>0.57
|
>32.1
|
>15.6
|
Hypertension
|
|
|
|
|
|
|
AUC
|
0.641
|
0.565
|
0.437
|
0.592
|
0.721
|
0.570
|
Sensitivity
|
0.500
|
0.417
|
0.333
|
0.583
|
0.875
|
0.417
|
Specificity
|
0.810
|
0.738
|
0.604
|
0.595
|
0.548
|
0.750
|
Criterion
|
>33.2
|
>95.0
|
>0.90
|
>0.56
|
>31.3
|
>18.4
|
AUC- area under the curve. All values highlighted represent statistically significant variables.
Table 4 shows the logistic regression analysis of various anthropometric cut-off values predictive of cardiometabolic factors. The odds ratios (95% confidence interval) for BMI, WC, WHR, WHtR and AVI were 4.96 (2.36-10.40), 4.56 (2.24-9.26), 5.35 (2.53-11.31), 7.45 (3.24-17.10) and 4.56 (2.24-9.26), respectively for predicting MetS. However, in the multivariate model, WC and AVI were no longer significant in predicting MetS. The odds ratios for predicting dyslipidemia was significant for BMI, WC, WHR, WHtR, and AVI in the univariate-adjusted model. However, in the multivariate model, only BMI and WHR were significant for predicting dyslipidemia. BMI (OR=7.52), WHR (OR=5.71) and BAI (OR=3.49) proved to be the most significant adiposity indices for predicting hyperglycemia.
Table 4: Logistic regression analysis of various anthropometric cut-off values predictive of cardiometabolic factors
Variable
|
Univariate-adjusted
OR (95% CI)
|
P-value
|
Multivariate
OR (95% CI)
|
P-value
|
Kappa
|
Mets
|
|
|
|
|
|
BMI
|
4.96 (2.36-10.40)
|
<0.0001
|
3.35 (1.41-7.93)
|
0.006
|
0.263
|
WC
|
4.56 (2.24-9.26)
|
<0.0001
|
0.95 (0.36-2.48)
|
0.917
|
0.280
|
WHR
|
5.35 (2.53-11.31)
|
<0.0001
|
2.77 (1.29-5.93)
|
0.009
|
0.264
|
WHtR
|
7.45 (3.24-17.10)
|
<0.0001
|
4.88 (1.81-13.21)
|
0.002
|
0.375
|
AVI
|
4.56 (2.24-9.26)
|
<0.0001
|
-
|
-
|
0.280
|
Dyslipidaemia
|
|
|
|
|
|
BMI
|
3.71 (2.00-6.86)
|
<0.0001
|
3.98 (2.03-7.79)
|
<0.0001
|
0.332
|
WC
|
2.66 (1.45-4.86)
|
0.002
|
0.23 (0.02-2.61)
|
0.237
|
0.209
|
WHR
|
2.77 (1.51-5.07)
|
0.001
|
3.47 (1.81-6.65)
|
<0.0001
|
0.299
|
WHtR
|
2.43 (1.30-4.52)
|
0.005
|
0.92 (0.26-3.29)
|
0.903
|
0.194
|
AVI
|
2.97 (1.61-5.47)
|
<0.0001
|
3.96 (0.51-30.75)
|
0.189
|
0.210
|
Hyperglycaemia
|
|
|
|
|
|
BMI
|
13.43 (5.26-34.30)
|
<0.0001
|
7.52 (2.69-21.02)
|
<0.0001
|
0.365
|
WC
|
5.61 (2.87-10.94)
|
<0.0001
|
0.19 (0.02-1.63)
|
0.129
|
0.373
|
WHR
|
4.05 (2.13-7.71)
|
<0.0001
|
5.71 (2.33-14.00)
|
<0.001
|
0.337
|
WHtR
|
5.72 (2.93-11.16)
|
<0.0001
|
1.28 (0.45-3.66)
|
0.650
|
0.386
|
BAI
|
4.32 (2.20-8.49)
|
<0.0001
|
3.49 (1.42-8.56)
|
0.006
|
0.258
|
AVI
|
5.67 (2.86-11.22)
|
<0.0001
|
4.34 (0.60-31.64)
|
0.147
|
0.366
|
Hypertension
|
|
|
|
|
|
BMI
|
4.15 (2.07-8.33)
|
<0.0001
|
2.47 (1.19-5.13)
|
0.016
|
0.292
|
BAI
|
8.52 (3.40-21.34)
|
<0.0001
|
6.35 (2.48-16.28)
|
<0.0001
|
0.278
|
Univariate-adjusted (adjusted for age, duration of infertility, causes of infertility). OR-odds ratios; CI-confidence interval. Values highlighted in back denotes statistically significant variables