Female patients with CRF often suffer from sexual dysfunction[1, 4]. Sexual dysfunction in women with CRF is largely due to loss of sexual interest, difficulties with arousal and reaching orgasm, reduced libido and lubrication, and pain during intercourse[1, 12, 13].
Considering that there are no other treatment options except KT, maintaining HD is an important treatment strategy for patients with CRF. HD adequacy is directly related to a patient’s well–being, including physical activity, and is directly related to mortality and morbidity. Considering there is no standard protocol for treating sexual dysfunction in women with CRF on HD, one important motivation for this study arose from the need to investigate the impact of HD adequacy on female sexual dysfunction.
Kt/V, urea fractional clearance, is a standard method to assess HD adequacy. This kinetic model is a clear was of determining adequacy. There have been few reports regarding the role of Kt/V in female sexual dysfunction in patients with CRF[14, 15]. Previous studies reported that HD adequacy was not related to female sexual dysfunction. One of the limitations of those studies was the application of the Kt/V results. Recently, the recommended dose was increased to a target of 1.4. The KDOQI guidelines (2006) recommend a Kt/V dose target of 1.4 with a minimum of 1.2, and the Renal Association Clinical Practice guidelines recommend a single pool Kt/V of greater than 1.3. More importantly, HD adequacy cannot determined by a single Kt/V, but rather consecutive and consistent target doses of Kt/V are more important. In our study, adequate HD was defined as an average Kt/V of 1.3 over three consecutive months.
Although our study did not find an association between HD adequacy and female sexual dysfunction, this is the first study to assess the relation between sexual dysfunction and HD adequacy as measured using the consecutive method in women with CRF.
We reported in a previous study that the score of all domains of the FSFI questionnaire, ‘desire’, ‘arousal’, ‘lubrication’, ‘orgasm’, ‘satisfaction’ and ‘pain’, were significantly lower in the patient group than in the control group. However, it is not clear that HD adequacy is related to sexual dysfunction. Our results show that HD adequacy alone does not restore sexual dysfunction in women with CRF. This is in agreement with a report that sexual dysfunctions does not improve with dialysis treatment.
As the genesis of sexual dysfunction is multifactorial in CRF patients, one aspect of HD adequacy alone was insufficient for explaining sexual dysfunction. It is believed that the lack of estradiol-stimulated cyclic LH secretion in women on dialysis leads to ovarian failure, which is presumed to be the primary cause of infertility[13, 15, 18, 19]. Our results showed that levels of testosterone and estradiol were significantly decreased in the patient group. Moreover, estradiol showed a significant relationship with the scores in all domains of the FSFI. A previous study demonstrated that hormone replacement therapy allows sustained physiological serum estradiol concentrations in women with estrogen deficiency undergoing HD, with an associated improvement in sexual function. It is suggested that adequate treatment of multiple factors, including emotional derangement and sex hormone change, is also necessary for improvement in sexual function in female CRF patients. Among them, hormonal replacement therapy (HRT) could be a promising treatment option. To date, only 17% of dialysis women had ever been treated with HRT and even less (6%) were currently on such therapy. The benefits of HRT in premenopausal women on dialysis with estrogen deficiency treated with transdermal HRT have been reported to show a sustained increase in estrogen and recovery of menstruation.
This study had some limitations. First, our patient population was quite small. Generally, the participation rate in sex research is very low and the degree of conservatism in sexual attitudes was very high in those who refused participation. Second, the patients represented only a small geographic area, which limits the generalization of our findings. Third, we did not investigate the depression quantification by questionnaire. Although we excluded those patients with depression, concurrent and subclinical depression could be determined through a questionnaire. However, the diagnostic cut-off values of the Beck depression inventory, which is one of most commonly used questionnaires to assess depression, is not consistent between the DSM-IV criteria and Korean validation form. Therefore, the Beck depression inventory was not applied in our study. Fourth, we have not investigated other factors such as vascular abnormalities, medications, family interactions, and personal and social characteristics. Lastly, this study was not a prospective study. A prospective study of CRF patients is difficult as symptom onset is diverse, and indication and the method of dialysis differ according to each patient’s medical condition. Further research, including a multi-center prospective study, is warranted for investigating sexual dysfunction in females with CRF who are undergoing HD.