DISCUSSION
Sexual dysfunction in women has a multifactorial etiology, including psychosocial factors and the difficulty of marital relationships, but the relationship between sexual function and obesity remains unclear.18 Female sexual dysfunction is reported in 40% of women in the United States.19 However, the prevalence of FSD in women of reproductive age may vary due to different geographical and cultural factors. In Turkey, previous studies reported the FSD prevalence between 46.9% and 53.2%.20
Consistent with these reports, a slightly higher rate of FSD with 56.9% was reported in this study. Obesity is generally assessed using anthropometric measurements such as WC and BMI. Considering the WC, only several reports investigated the impact of increased WC levels on female sexual function. We recently showed that WC was not a reliable marker for erectile dysfunction in sexually active men. In that report, the WC failed to show the real burden of body fat because it only measures the subcutaneous adipose tissue.21 Unlike many studies in men, only a few conflicting reports have been reported investigating the relationship between WC and FSD in women. The present study showed that the WC was not a good predictor for all the subdomains of FSD in women with a sensitivity of 53.3% and specificity of 54.4%, as shown in Fig. 1 and Table 5 (OR=1.019, p=0.318). Data provided by Paningbatan et al. similarly showed that greater WC than 35 inches was not associated with FSD.22
Contrary to these reports, Trompeter et al. stated that women with high WC were more sexually inactive than those with low WC.23 In another report, the WC was shown to decrease vaginal orgasm.24
In our opinion, only a few studies with limited data have been conducted in the literature showing the relationship between WC and FSD. Therefore, further studies are needed to reach satisfactory results in this regard.
BMI’s sensitivity and specificity are low due to individual differences such as age, gender, race, muscle mass, and fluid intake habits.25 Our results showed that BMI did not affect the female sexual function index (OR=0.983, p=0.742). Conflicting data have been published regarding the BMI and FSD. Some authors reported significant relationships between the BMI and the FSD.26
Besides, some authors stated that the BMI affected some of the subdomains of female sexual function. Rabeipoor et al. stated that BMI only affected sexual satisfaction but did not impair sexual function in overweight or obese women.27 Another study showed that the BMI impaired arousal, lubrication, orgasm and satisfaction, whereas the desire and pain scores remained stable28. However, some authors reported similar FSFI scores between the obese women and an age-matched control group.29
When interpreting data on BMI and FSD, one should keep in mind that BMI, as an anthropometric measure, may cause different results in different individuals for various reasons.
Recent reports showed a significant correlation between visceral adiposity index and male sexual function.13 Although many disciplines other than andrology carried out numerous studies on VAI, as far as we know, the current study is the first in the English literature investigating the relationship between the FSD and VAI. Studies previously conducted in our clinic showed that each integer increase of VAI in men increased the likelihood of erectile dysfunction by 1.4 times. The VAI, especially in those with metabolic syndrome, was two-fold higher than those without metabolic syndrome.21
Considering the VAI level of less than or greater than 4.45; our results showed that arousal, satisfaction and pain scores remained stable, whereas desire, lubrication and orgasm scores were lower (Table 5). Although the VAI scores were similar in both groups, a significant decrease in the arousal, satisfaction and pain scores did not reach a statistical significance in the logistic regression analysis in individuals with higher VAI values ​​regardless of the groups. This study was conducted based on anthropometric (such as WC, BMI, VAI) and biochemical parameters. Besides the low number of participants, one of the reasons the logistic regression analysis could not show the VAI as a risk factor can be attributed to its anthropometric basis. In this context and the psychogenic situation, the lack of consideration of various factors such as parity, number of births, birth type, partner characteristics, comfort during the sexual relationship, and privacy issues can be perceived as limiting factors. Although it may be considered a limiting factor, providing the parameters mentioned above is challenging, especially in populations where sexual privacy is at the forefront. Multiparity was associated with less orgasmic and pain problems compared to nulliparity.30 With psychological and biological aspects, childbirth has an essential impact on female sexual function.31
Female sexual dysfunctions related to MeTS may be a messenger of severe conditions such as cardiovascular and cerebrovascular diseases.32 The relationship between the MeTS and FSD has been studied in several studies. Di Francesco et al. showed that MeTS was associated with a higher prevalence of low sexual desire, orgasm and satisfaction than those without MeTS.33Metabolic syndrome has been reported to cause reduced vaginal engorgement via neuropathy and pelvic vascular injury.34 Excessive adipose tissue accumulation is strongly associated with MeTS. As a continuous process, adipogenesis works not only for energy storage but also for immune and endocrine functions. Therefore increased adipogenesis may result in inflammatory, immune and cardiovascular disorders secondary to MeTS.33
Based on this, it is thought that MeTS may affect female sexual function by disrupting oxygenation by reducing pelvic blood flow through chronic vascular inflammation, oxidative stress and atherosclerosis that can explain the higher rate of FSD in postmenopausal and premenopausal relatively older women.35
In the present study, logistic regression analysis showed that the Odds ratio between MeTS and FSD was 2.27, which could not reach statistical significance (p = 0.153). This finding can be explained by the relatively young patients in this study and the relatively low number of participants (six were in Group 1 group (8.8% and 19 were in Group 2 (17.8%). Unlike other anthropometric variables such as BMI and WC, our opinion is that the significant decrease in desire, lubrication and orgasm scores is remarkable considering the VAI> 4.45. Nevertheless, although the presence of MetS was not reached statistical significance in this study, it may have a higher impact on FSD compared to other possible risk factors in a higher cohort of participants.