Many men and women with chronic kidney disease (CKD) have low levels of sex hormones. Low estradiol and testosterone concentrations are generally accompanied by normal or high gonadotropin levels, and evidence indicates both hypothalamic and pituitary dysfunction in this population. However, the exact cause of the hypothalamic-pituitary-gonadal axis is not clear.
Sexual and reproductive dysfunction are also common among patients with CKD and appear to be related to abnormalities in the hypothalamic-pituitary-gonadal axis. These abnormalities include infertility in both sexes and erectile dysfunction in men, as well as amenorrhea or dysfunctional uterine bleeding in women. These problems likely have a substantial effect on quality of life among patients with CKD, but this relationship has been understudied and deserves greater attention.
Despite these long-known problems with sexual and hormonal function among patients with CKD, few controlled studies of the effects of hormone replacement therapy in these patients have been done. Available data do not strongly support an improvement in sexual function with hormone replacement in either sex.
Hormone replacement therapy can also affect nonreproductive organ systems, an area that has recently received increasing attention in both men and women in the general population. In particular, osteoporosis and heart disease have been targets of estrogen replacement among women, and muscle wasting (sarcopenia) and bone loss have been targets of testosterone replacement among men. Unfortunately, as with sexual function, few studies have been done on the nonreproductive effects of hormone replacement therapy in patients with CKD.
This issue of Advances in Chronic Kidney Disease summarizes the literature on this topic in men and women with CKD. The defects in the hypothalamic-pituitary-gonadal axis are summarized, as well as the potential consequences of hypogonadism among men and women. Effects of hormone replacement therapy on sexual and reproductive function, as well as on nonreproductive outcomes, are also reviewed. The reports on treatment rely heavily on data from other populations because of the paucity of data available to directly address the CKD population, but emphasis is placed on data from this population when it is available.
We hope that presentation of this information will be of use to providers who care for patients with CKD. However, this collection of articles should also serve to highlight the inadequacies in available information and the need for further exploration of this important topic. Specifically, more work is needed to understand the basis for hormonal and sexual dysfunction in this population. In this way, more effective treatments could be designed and evaluated. Patients with CKD who do not yet require dialysis have been less studied than those who receive dialysis. Delineating the time course of development of abnormalities in hypothalamic-pituitary-gonadal function and the effects of such dysfunction on quality of life among patients with various stages of CKD will be important. The effects of hormone replacement therapy on bone disease, cardiovascular disease, and muscle function must be better defined within this population. Effects of other promising treatments, such as bisphosphonates and selective estrogen receptor modifiers (SERMs), must be more extensively tested in these patients as well. Without such investigations, nephrologists will be forced to continue to rely on data from other populations when faced with treatment decisions that affect quality of life, and possibly survival, among our patients.
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