Effects of Trifolium pratense on the climacteric and sexual symptoms in postmenopause

Abstracts

OBJECTIVE: To evaluate effects of treatment with Trifolium pratense on climacteric symptoms and sexual satisfaction in postmenopausal women. METHODS: This study was prospective, randomized, double-blind and placebo-controlled. We selected 120 women, aged between 45 and 65 years with climacteric symptoms, with absence of menstruation (amenorrhea) for more then one year and without any treatment in the last six months. After selection, women were divided into two groups: GT received 40 mg of Trifolium pratense (one capsule per day); GP received placebo (control, one capsule of lactose per day). Treatment lasted 12 months and women were evaluated before and after four, eight and twelve months of treatment by clinical (Kupperman Menopausal Index -KMI and the Golombok Rust Inventory of Sexual Satisfaction) and laboratory exams. At study end, each group had 50 patients. RESULTS: There was a significant decrease of symptoms after four months of treatment according to the KMI, mainly of hot flashes in relation to baseline data for both groups, but not between both groups. Evaluation of sexual satisfaction did not disclose any difference in both groups before and after treatment. CONCLUSION: The 40mg/day Trifolium pratense treatment may not ameliorate menopausal symptoms or improve sexual satisfaction.

Menopause; Sexual satisfaction; Trifolium pratense; Hot Flashes

OBJETIVO: Avaliar os efeitos do tratamento com Trifolium pratense nos sintomas climatéricos e na satisfação sexual de mulheres na pós-menopausa. MÉTODOS: Este estudo foi prospectivo, randomizado, duplo-cego e controlado com placebo. Foram selecionadas 120 mulheres na faixa etária de 45 anos a 65 anos com sintomas climatéricos, amenorreia superior a um ano e sem tratamento nos últimos seis meses. Após a seleção, foram divididas em dois grupos: GT -receberam Trifolium pratense na dose de 40 mg, 1 capsula/dia; GP -receberam placebo (controle), contendo lactose, 1 cápsula/dia. A duração do tratamento foi de 12 meses. As pacientes foram avaliadas clinica e laboratorialmente antes do tratamento e com quatro, oito e 12 meses de tratamento. Foi empregado também o Índice Menopausal de Kupperman (IMK) e o Inventário de Satisfação Sexual Golombok Rust. No final do estudo, cada grupo tinha 50 pacientes. RESULTADOS: Houve melhora significante dos sintomas menopausais após quatro meses de tratamento pelo IMK, principalmente em relação aos fogachos, comparando os dados antes do tratamento nos dois grupos, porém, não houve diferença significante entre os grupos. Não houve melhora na sexualidade antes e após o tratamento. CONCLUSÃO: O tratamento por 12 meses com Trifolium pratense, na dose de 40mg/dia, não promoveu melhora significante dos sintomas menopausais e na satisfação sexual.

Menopausa; Sexualidade; Trifolium pretense; Fogachos

ORIGINAL ARTICLE

Effects of trifolium pratense on climacteric and sexual symptoms in postmenopausal women

Cecília Del Giorno^I; Angela Maggio da Fonseca^II; Vicente Renato Bagnoli^III; Joserita Serrano de Assis^IV; José Maria Soares Jr^V; Edmund Chada Baracat^VI

^IMestre em Ciência e Saúde; fisioterapeuta; departamento de Obstetrícia e Ginecologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP

^IILivre-docente em Ginecologia; professor associado da disciplina de Ginecologia do departamento de Obstetrícia e Ginecologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP

^IIILivre-docente em Ginecologia; professor associado da disciplina de Ginecologia do departamento de Obstetrícia e Ginecologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP

^IVDoutora da disciplina de Ginecologia do departamento de Obstetrícia e Ginecologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP

^VLivre-docente em Ginecologia e assistente do departamento de Obstetrícia e Ginecologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP

^VIProfessor titular da disciplina de Ginecologia do departamento de Obstetrícia e Ginecologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP

Correspondence

ABSTRACT

OBJECTIVE: To evaluate the effects of treatment with Trifolium pratense on climacteric symptoms and sexual satisfaction in postmenopausal women.

METHODS: This is a prospective, randomized, double-blind, placebo-controlled study. Initially, 120 women aged 45-65 years with menopausal symptoms, more than 12-month amenorrhea and no treatment in the past six months were selected. The participants were then divided into two groups: TG – receiving 40 mg Trifolium pratense, 1 capsule/day; PG – receiving placebo capsules containing lactose (control), 1 capsule/day. The duration of treatment was 12 months. The patients underwent clinical and laboratory evaluation before treatment and at four, eight and 12 months of treatment. The Kupperman Menopausal Index and the Golombok Rust Inventory of Sexual Satisfaction (GRISS) were used. At the end of the study, each group comprised 50 patients.

RESULTS: According to the Kupperman Menopausal Index, there was significant improvement in menopausal symptoms after four months of treatment, especially in relation to hot flashes, when compared to baseline data in both groups. However, no significant differences were observed between groups. There was no improvement in sexual satisfaction after treatment.

CONCLUSION: A 12-month treatment with a daily dose of 40 mg Trifolium pratense did not yield a significant improvement in menopausal symptoms and sexual satisfaction.

Key words: Menopause. Sexuality. Trifolium pratense. Hot flashes.

INTRODUCTION

Climacteric corresponds to the period of life during which women gradually loose their reproductive capacity as a result of aging. This period, according to the World Health Organization, commonly occurs between the ages of 40 and 65. It is closely related to loss of activity of ovarian follicles, with consequent estrogen deficiency^1,2.

Approximately 70% of women report some type of symptom during the climacteric period. In general, these symptoms are attributed to estrogen deprivation. The most common complaints are vasomotor symptoms and night sweats. In addition, vaginal dryness, dyspareunia and urinary urgency, which are associated with urogenital atrophy, may interfere with the sex life and quality of life of postmenopausal women^2,3_. Some women also experience cognitive impairment, insomnia, depression, irritability, fatigue, psychological symptoms, and increased risk for osteoporosis and cardiovascular disease^{3, 4}.

To minimize the impact of ovarian failure on women's health, hormone therapy is often recommended. However, the results of several studies, including the Women's Health Initiative (WHI)⁵ and the Million Women Study⁶, have raised serious concerns regarding the use and safety of hormone replacement therapy (HRT) in relation to cardiovascular events and breast cancer in long treatment⁷. These studies have significantly influenced the decline in the prescription of HRT in the United States, which dropped from 91 million users in 2001 to 57 million in 2003⁸. For this reason, many researchers have sought alternative therapies, such as the use of phytoestrogens to relieve menopausal symptoms^{9, 10}.

Phytohormones comprise several compounds that can be extracted from plants and, when purified, can enhance their activity in the body as well as improve their bioavailability⁹. Phytoestrogens are substances with chemical structure and function similar to that of estrogens and have been shown to bind to estrogen receptors due to the presence of a phenolic ring^{9,10, 11}.

Phytoestrogens are classified into four main groups: sterols, terpenoids, saponins, and phenols. The last group consists of isoflavones, lignans, coumestans, flavanols, flavones, and chalcones^11,12.Phytoestrogens are classified into four main groups: sterols, terpenoids, saponins, and phenols. The last group consists of isoflavones, lignans, coumestans, flavanols, flavones, and chalcones¹³. Among isoflavones, the main biologically active compounds are genistein, daidzein, biochanin A, and formononetin^11,12.

A source of isoflavones is red clover (Trifolium pratense)^14,15_, which has been used as a therapeutic agent in various diseases and also for menopausal symptoms¹⁶_. In addition to isoflavones, this drug contains cyanogenic glycosides and coumarin derivatives which may reduce blood clotting^16,17. Trifolium pratense has been used mainly in the treatment of vasomotor symptoms, but data in the literature on its actual effects are still scarce.

In a systematic review and meta-analysis including 17 clinical trials involving Trifolium pratense, only five studies were randomized and placebo-controlled. The authors reported that Trifolium pratense would be effective for treating hot flashes, over a six-month to one-year period, in a dose ranging from 40 to 80 mg/day¹⁸. The other studies were excluded due to methodological problems, incomplete results or because they did not use a control group^{19, 20, 21, 22, 23}.

In relation to sexual dysfunction, the effect of estrogen is well defined, especially concerning improvement in atrophy of the female genital tract²⁴. Chedraui et al., in a randomized, double-blind, placebo-controlled study, observed an improvement in the vaginal epithelium with 80 mg/day of Trifolium pratense compared to placebo. In addition, participants reported reduced dyspareunia and vaginal dryness and increased libido²⁵.

The objective of this study was to evaluate the effects of treatment with Trifolium pratense on climacteric and sexual symptoms in postmenopausal women.

METHODS

The study was conducted at the Division of Endocrine Gynecology and Climacteric, Discipline of Gynecology, Department of Obstetrics and Gynecology, School of Medicine of Universidade de São Paulo (FMUSP), Brazil. The treatment consisted of a daily dose of 40 mg Trifolium pratense, which is considered the minimum effective dose to control vasomotor symptoms in postmenopausal women¹⁸.

Of the 500 women recruited in our climacteric outpatient clinic, 120 participants aged 45 to 65 years with menopausal symptoms were selected. All participants were informed about the study protocol before agreeing to participate.

During an interview, the participants were informed about the procedures, risks and benefits involved in the study and provided written informed consent.

This study was approved by the Research Ethics Committee of FMUSP Hospital das Clínicas (no. 153/4), Brazil. Inclusion criteria were: more than 12-month amenorrhea; menopausal symptoms; follicle-stimulating hormone (FSH) > 30 mIU/mL; estradiol < 30 pg/mL.

Exclusion criteria were: diabetes mellitus; cardiovascular disease; hypersensitivity to drugs used in the study; estrogen-dependent cancer; liver failure; nephropathy; systemic lupus erythematosus; porphyria; altered cervicovaginal cytology; osteoporosis (standard deviation > -2.5); endometrial thickness > 6 mm; uterine volume > 200 cm³; BI-RADS category 3, 4 or 5 mammograms; hormone treatment with sex steroids or phytoestrogens in the past six months.

This is a prospective, randomized, double-blind, placebo-controlled study. The duration of treatment was 12 months. Four visits were performed: before treatment (randomization) and at four, eight and 12 months of treatment. The study was conducted from December 2005 to December 2008.

BLINDING OF DRUGS

The bottles were identified as four-digit numbers separated by a slash, as follows: 01/01, where the first number indicates the patient and the second indicates the month. Example: patient 01 should always receive samples identified with these numbers: 01/01; 01/02; 01/12.

RANDOMIZATION

Women included in the study (n = 120) were randomized into two groups using a computer program. Sample blinding codes were disclosed after completion of treatment for all patients.

END OF STUDY

Of the 120 participants, 20 failed to complete the study due to personal reasons (n = 12) or because they did not take more than 80% of the drug (n = 8). Thus, the final sample was composed of 100 women, who were equally divided into the following groups: Trifolium group (TG) – receiving 40 mg Trifolium pratense, 1 capsule/day (n = 50); placebo group (PG) – receiving placebo capsules containing lactose, 1 capsule/day (n = 50).

KUPPERMAN MENOPAUSAL INDEX

This index measures the sum of symptoms reported by women during the climacteric period, which is classified as mild, moderate and severe according to each item evaluated. Symptoms are classified as mild when the cumulative score is up to 19, moderate from 20 to 35, and severe above 35. Vasomotor symptoms followed the patterns described by Kuppermann²⁶. This index was assessed at each visit, i.e., before treatment and at four, eight and 12 months of treatment.

HORMONE MEASUREMENTS

During selection, 12-hour fasting blood samples were withdrawn by venipuncture. Levels of FSH and estradiol were also assessed before patients were included in the study.

GOLOMBOK RUST INVENTORY OF SEXUAL SATISFACTION – FEMALE VERSION (GRISS)

Subjective evaluation of the sexuality of sexually active women was performed using the GRISS²⁷, a reproducible questionnaire already validated in Brazil²⁸.

This inventory consists of a questionnaire with 28 questions that evaluate how women relate to their own body and to their partner's, the level of interest in sexual activity, quality of communication with the partner, sexual frequency, and the ability to achieve orgasm.

The answers vary according to intensity, from none to the highest intensity observed or experienced by women in relation to the questions under each topic of the assessment instrument²⁸.

For data analysis, among the five response options, "always" and "usually" were considered affirmative; "never", "almost never" and "occasionally" were considered negative answers.

STATISTICAL ANALYSIS

The initial sample size calculation was based on hot flashes (beta = 10%, power = 80%) for 38 patients per group (76). Bartlett's test was used to assess sample homogeneity. Student's t test was used to compare TG and PG results at different time points. To assess the influence of time (before and after four, eight and 12 months), two-way ANOVA was applied to each group. Significance level was set at 5% (p < 0.05).

RESULTS

After analyzing the clinical data, no significant differences were observed between TG and PG in the following parameters: age at menopause, time since menopause, initial weight, and body mass index (BMI) before treatment (Table 1).

Overall results of the Kupperman Menopausal Index were similar between groups at the following time points: before treatment (TG = 25.34±10.17 and PG = 25.12±9.02, p = 0.65); four months (TG = 16.96±9.16 and PG = 17.22±8.34, p =0.45); eight months (TG = 13.16±9.55 and PG = 13.3±7.06, p = 0.39); 12 months (TG = 11.12±8.68 and PG = 12.01±9.01, p = 0.87). Throughout treatment, symptoms improved after four, eight and 12 months of treatment (p < 0.01) in both groups according to two-way ANOVA.

Table 2 describes the status of vasomotor symptoms during treatment, revealing similar behavior in both groups.

Table 3 provides the mean and standard deviation of GRISS scores in both study groups. There were no significant differences before and after treatment in both groups.

No side effects were observed during treatment.

DISCUSSION

It is estimated that approximately 75% of postmenopausal women have some symptoms related to estrogen deficiency, and an average of 40% will seek medical attention to relieve menopausal symptoms, especially hot flashes, night sweats, vaginal dryness, and sleep disturbances^{3, 6}. Such symptoms can negatively affect daily activities and the quality of life of these women¹¹. For this reason, therapy to ameliorate these symptoms is an important factor in this phase.

Traditionally, HRT is the main form of treatment for symptoms associated with postmenopausal hypoestrogenism. However, some studies report negative effects of this therapy, including the Heart and Estrogen-progestin Replacement Study (HERS II)²⁹, the Women's Health Initiative (WHI)⁵, and the Million Women Study⁶_. In those studies, a greater risk of cardiovascular disease and breast cancer was observed with the traditional estrogen-progestin replacement therapy. For this reason, several authors have sought alternatives to reduce menopausal symptoms, especially vasomotor symptoms^{16, 17, 18, 22}.

In recent years, there has been a growing interest in the use of phytoestrogens for the relief of vasomotor symptoms in postmenopausal women^7,8. Therefore, we chose to study Trifolium pratense in this population. However, our study revealed no significant differences in the effects of Trifolium pratense on menopausal symptoms, as assessed by the Kupperman Menopausal Index, and on sexual satisfaction, as assessed by the GRISS, compared to patients receiving placebo after one year of treatment. At first glance, these findings seem to conflict with data from the literature. We point out that this is a randomized, double-blind, placebo-controlled study, which is different from most publications on the subject^16-22.

Lethaby et al.¹⁵, in a meta-analysis to assess vasomotor symptoms with Trifolium pratense, observed that more than 70% of studies could not be included due to methodological issues. The minimum effective dose was 40 mg daily (the same used in our study). However, other studies reported improvement with 80 mg per day. Therefore, the use of the minimum dose may be a possible explanation for the failure to identify greater effects of the drug over placebo in our study¹⁵. Nevertheless, it is worth noting that, during the preparation of this study protocol, other studies showed that the daily dose of 40 mg would be sufficient to control hot flashes^29-30.

We also highlight that treatment expectations, either positive or negative, are modulating factors that influence perception, behavior and even the biological process⁶. The findings justify a placebo effect in reducing symptoms during the study. This fact might explain the improvement in menopausal symptoms observed in both groups during the study. Furthermore, our group expected that any improvement in vasomotor symptoms would have an impact on sexuality, and for this reason we applied the GRISS²⁸. This questionnaire has been validated in Brazil²⁸ and other countries to assess the presence and severity of sexual problems. Some authors have demonstrated its reproducibility in the assessment of anorgasmia, vaginismus, and decreased sexual satisfaction²⁸. For these reasons, this instrument was used to assess participants in the present study. However, no significant differences were observed in the improvement in questionnaire scores compared to placebo.

CONCLUSION

A 12-month treatment with a daily dose of 40 mg Trifolium pratense did not yield a significant improvement in menopausal symptoms and sexual satisfaction.

Conflict of interest: No conflicts of interest declared concerning the publication of this article

REFERENCES

• ¹
  Organização Mundial da Saúde. Report of a WHO Scientific Group. Research on the menopause. Geneva; 1981. (WHO Technical report series 670).
• 2. Speroff L. The menopause: a signal for the future. In: Lobo RA. Treatment of the postmenopausal woman. 2^nd ed. New York: Raven Press; 2005. p.1-7.
• 3. Dennerstein L, Lehert P, Guthrie J. The effects of the menopausal transition and biopsychosocial factors on well-being. Arch Women Ment Health. 2002;5:15-22
• 4. Wolff LPG, Martins MR, Bedone AJ, Monteiro IMU. Avaliação do endométrio em menopausadas após uso de isoflavonas. Rev Assoc Med Bras. 2006;52: 419-23.
• 5. WHI Writing Group for the Women's Health Initiative Investigators: risks and benefits of estrogen plus progestin in healthy postmenopausal women:principal results from the Women's Health Initiative Randomized Controlled Trial. JAMA. 2002;288:321-33.
• 6. Beral V, Bull D, Reeves G. Endometrial cancer and hormone-replacement therapy in the Million Women Study. Lancet. 2005;365:1543-51.
• 7. Han KK, Soares Junior JM, Haidar MA, Lima GR, Baracat EC. Benefits of soy isoflavone therapeutic regimen on menopausal synptoms. Obstet Gynecol. 2002;99:389-94.
• 8. Kaari C, Haidar MA, Soares Júnior JM, Nunes MG, Quadros LG, Kemp C, et al. Randomized clinical trial comparing conjugated equine estrogens and isoflavones in postmenopausal women: a pilot study. Maturitas. 2006;53:49-58.
• 9. Knight DC, Eden JA. A review of the clinical effects of phytoestrogens. Obstet Gynecol. 1996;87:897-904.
• 10. Setchell KD. Phytoestrogens: the biochemistry,physiology, and implications for human health of soy isoflavones. Am J Clin Nutr. 1998; 68:1333S-1346S.
• 11. Bachmann GA, Vasomotor Flushes in menopausal women. Obstet Gynecol. 1999;180:S312-S6.
• 12. Baber RJ, Templeman C, Morton T, Kelly GE, West L, Randomized placebo-controlled trial of an isoflavone supplement and menopausal symptoms in women. Climacteric.1999;2:85-92.
• 13. Dornstauder E, Jisa E, Unterrieder I, Krenn L, Kubelka W, Jungbauer A, Estrogenic activity of two standardized red clover extracts (Menoflavon^®) intended for large scale use in hormone replacement therapy. J Steroid Biochem Mol Biol. 2001;78:67-75.
• 14. Nachtigall LE. Isoflavones in the management of menopause. J Br Menopause Soc. 2001;(Suppl 1):8-11.
• 15. Lethaby AE, Brown J, Marjoribanks J, Kronenberg F, Roberts H, Eden J. Phytoestrogens for vasomotor menopausal symptoms. Cochrane Database Syst Rev. 2007;1-17.
• 16. Atkinson C, Compston JE., Day NE., Dowsett M, Bingham SA. The effects of phytoestrogen isoflavones on bone density in women: a double-blind, randomized, placebo-controlled trial. Am J Clin Nutr. 2004;79:326-33.
• 17. Atkinson C, Warren RML, Sala E, Dowsett M, Dunning A, Healey CS. Rede clover-derived isoflavonas and mammographic breast density: double-blind, randomized, placebo-controlled trial. Breast Cancer Res. 2004;8:170-9.
• 18. Coon JT, Pittler MH, Ernst E. Trifolium pratense isoflavones in the treatment of menopausal hot flushes: A systematic review and meta-analysis. Phytomedicine.2007;14:153-9.
• 19. Hale G, Hughes CL, Robboy SJ, Agarwal SK, Bievre M. A double blind randomised study on the effects of red clover isoflavones on the endometrium. Menopause. 2001;8: 338-46.
• 20. Howes JB, Sullivan D, Lai N, Nestel P, Pomeroy S, West L, et al. The effects of dietary supplementation with isoflavones on the lipoprotein profiles of post menopausal women with mild to moderate hypercholesterolemia. Atherosclerosis. 2000;152:143-7.
• 21. Tice JA., Ettinger B, Ensrud KE, Wallace RB, Blackwell T, Cummings SR. Phytoestrogen supplementsfor the treatment of hot flashes: the isoflavone clover extract (ICE) study. JAMA. 2003;290:207-14.
• 22. Ingram DM., Hickling C, West L, Mahe LJ, Dunbar PM. A double blind randomised controlled trial of isoflavones in the treatment of cyclical mastalgia. Breast. 2001;11:170-4.
• 23. Van de Weijer PHM., Barentsen R. Isoflavones from red clover (PromensilR) significantly reduce menopausal hot flush symptoms compared with placebo. Maturitas. 2000;42:187-93.
• 24. Penteado SR, Fonseca AM, Bagnoli VR, Abdo CH, Júnior JM, Baracat EC. Effects of the addition of methyltestosterone to combined hormone therapy with estrogens and progestogens on sexual energy and on orgasm in postmenopausal women. Climacteric. 2008;11:17-25.
• 25. Chedraui P., Hidalgo L., San Miguel G., Morocho N., Ross S. Red clover extract (MF 11 CE) supplementation and postmenopausal vaginal and sexual health. Obstet Gynecol. 2006;95:296-7.
• 26. Kupperman HS, Blatt MH, Wiesbader H, Filler W. Comparative clinical evaluation of estrogenic preparations by the menopausal and amenorrheal indices. J Clin Endocrinol Metab. 1953;13:688-703.
• 27. Golombok S, Rust J. The GRISS: a psychometric instrument for the assessment of sexual dysfunction. Arch Sex Behav. 1986;15:157-65.
• 28. Cavalcanti AL, Bagnoli VR, Fonseca RP, Cardoso E, Paixão J, Soares Jr J, et al. Effect of sildenafil on clitoral blood flow and sexual response in postmenopausal women with orgasmic dysfunction. Obstet Gynecol. 2008;102:115-9.
• 29. Knight DC, Howes JB, Eden JA. The effect of promensil, an isoflavone extract, on menopausal symptoms. Climateric. 1999;2:79-84.

*

Correspondência: Rua Martiniano de Carvalho, 880 Apto. 54 São Paulo - SP CEP: 01321-000 Tel: [phone]

Publication Dates

• Publication in this collection
  30 Nov 2010
• Date of issue
  2010

History

• Received
  10 Mar 2010
• Accepted
  07 June 2010