The global prevalence of sexual dysfunction in men with thyroid gland disorders: a systematic review and meta-analysis

Abstract

Introduction

fluctuation in serum levels of thyroid hormones or thyroid-associated dysfunction can negatively affect the sexual behaviors or performance, and disruption in couples` relationship or satisfaction. Thus, this systematic review and meta-analysis study was aimed to investigate the global prevalence of sexual dysfunction in men with thyroid gland disorders (TGD).

Methods

this systematic review and meta-analysis study conducted based on PRISMA statement criteria regarding the available evidences representing the prevalence of sexual dysfunction in men with TGD. The initial searching process was applied on July, 2023. In this era, the main keywords of “Prevalence”, “Sexual disorders”, “Sexual disorder”, “Sexual dysfunction”, “Male sexual dysfunction”, “Erectile dysfunction”, “Males”, “Men”, “Thyroid disorders”, “Thyroid diseases”, “Hyperthyroidism”, “Thyroid”, and “Thyroiditis” were hired. Also, “AND” and “OR” operators were used for keywords combination. All intended studies were searched using the databases of Web of Science, Google Scholar, Scopus, ScienceDirect, PubMed, and Embase. Random effects model was used to perform the analysis and the heterogeneity of the studies was assessed through I² index. Data analysis was applied with CMA software (v.2).

Results

following the assessment of 17 eligible studies with a sample size of 501 individuals, the global prevalence of male sexual dysfunction with TGD was found 51.5% (95% CI:38.7–64). Also, the prevalence of male sexual dysfunction in hypothyroidism and hyperthyroidism cases was 59.1% (95% CI:37.2–77.8) and 41.5% (95% CI:25.9–59.1), respectively. The meta-regression analysis showed that following incremental trend in sample size, the global prevalence of male sexual dysfunction with TGD decreases. This assessment also revealed that the prevalence of male sexual dysfunction increases with the year of study conduction, significantly (p < 0.05).

Conclusion

the global prevalence of sexual dysfunction in men with TGD was found relatively high. also, the highest prevalence of sexual disorders was reported in hypothyroid cases. Thus, health policymakers are suggested to inform the individuals prone to this pathology regarding the negative effects of TGD on sexual dysfunction. Besides, TGD-affected cases can prevent sexual disorders and unpleasant consequences through timely medical treatments.

Background

Thyroid is one of the largest endocrine glands with critical functions in regulation of homeostatic state of body [1]. Thyroid gland influences the growth, development, organ-associated metabolism, and energy consumption. Thus, interfering factors which negatively affects the physiological functions of thyroid can potentially lead to acute or chronic TGD [1]. The occurrence of TGD increases by the age [2]. There are various types of TGD including goiter, thyroid malignancies, autoimmune disorders (Hashimoto’s thyroiditis and graves’ disease), hypothyroidism, and hyperthyroidism [2, 3]. Among these, the hypothyroidism and hyperthyroidism can be converted to each other, in some cases [4].

Although the occurrence of hypothyroidism is more common in Hashimoto’s patients, this pathology was also reported in cases with no morphological or serological abnormalities [5]. Hypothyroidism can increase the risk of serological irregularities like dyslipidemia, atherosclerosis, and cardiovascular disorders. Since the occurrence of hypothyroidism is symptomless in some cases, these patients are exposed to more complications prior to diagnosis [6].

Hypothyroidism causes variety ranges of pathologic symptoms in adults (such as cold intolerance, weight gain, and paresthesia) and neuro-psychological symptoms in elderly (such as fatigue and sleepiness, memory loss, cognitive decline, and constipation) [3]. On the other hand, mild hyperthyroidism increases the risk of cardiovascular diseases and osteoporosis [6]. Besides, hyperthyroidism symptoms include resting tachycardia, palpitations, diarrhea, heat intolerance, eyelid delay, and ophthalmopathy in young adults and atrial fibrillation, heart failure, weight loss, failure to thrive, and osteoporosis in elderly [3].

In population-based studies, the prevalence of TGD was calculated 2–6% [6]. Also, the rate of TGD in european and the USA adults was 6.6% (more prevalent in women than men) [7]. Also, the global prevalence of Hashimoto’s thyroiditis, as the most common form of TGD, was 10–12% [8]. Studies have reported the prevalence of overt hypothyroidism as 1–2%, while subclinical hypothyroidism is more common than overt type with the prevalence of 4–10% (9. 10). Also, the prevalence of subclinical hyperthyroidism was reported 0.5–6.3% [9, 10]. Since the prevalence of these types of diseases is strictly associated to the age, hypothyroidism and hyperthyroidism comprise 30% and 10% of the elderly population > 65 years, respectively [11].

According to recent studies, overt hypothyroidism ranges from 0.2 to 5.3% in Europe and 0.3–3.7% in the USA [10]. Thyroid gland secretions provide a wide range of impacts on various organs such as reproductive system disrupting normal sexual behaviors [12]. Sexual dysfunction is explained as the inability of couples to achieve normal sexual intercourse [13]. Sexual performance is one of the public health indicators affecting the quality of life. Also, preservation of correct sexual function depends on coordination and proper communication among the nervous system, cardiovascular, endocrine and reproductive organs. Since the reproductive system is more sensitive in males, the TGD can be occurred by many risk factors such as pollutants, drugs, and lifestyle [14]. Male sexual performance includes sexual arousal, penile erection, penetration and ejaculation. Thus, each factor disturbing the sexual process can potentially cause sexual dysfunction [14].

These pathologies can be examined in five areas (called the current gold standard for evaluating male sexual performance) including erectile function, orgasm function, sexual desire, relationship satisfaction, and overall satisfaction [15]. One of the most common male sexual disorders is premature ejaculation, which is often misdiagnosed or neglected [12]. Sexual disorders are reported in 33–60% in women and 8–52% in men with two forms of erectile dysfunction or premature ejaculation. In these cases, the TGD have received much attention, recently [15]. In Romania, the prevalence of female sexual disorders with autoimmune TGD was reported as 33.2%, while the prevalence of erectile dysfunction in Dutch men with hyperthyroidism and Graves’ diseases was found 85% (in which, 62% represented toxic adenoma and hyperthyroidism) [16, 17]. According to published reports, 52% of men aged 40–70 show various levels of sexual disorders, and 15% of couples suffer from these types of pathologies (40–50% of which are male-associated factors) [14]. Sexual dysfunction has unpleasant consequences on person’s life such as marital relations [18, 19]. Sexual dysfunction also affects self-esteem for establishment of a relationship, frequency of sexual life, sexual satisfaction, sexual relations, infertility, anxiety, and depression [18, 19].

Considering the high prevalence of TGD and its associated negative effects on men’s sexual performance, as well as the fact that reported prevalence’s around the world show heterogeneous data, the aim of this systematic review and meta-analysis is the global prevalence of sexual dysfunction in men with thyroid gland disorders.

Methods

This systematic review and meta-analysis study conducted based on PRISMA statement criteria regarding the available evidences representing the prevalence of sexual dysfunction in men with TGD. The initial searching process was applied on July, 2023. In this era, the main keywords of “Prevalence”, “Outbreak”, “Sexual disorders”, “Sexual disorder”, “Sexual dysfunction”, “Male sexual dysfunction”, “Erectile dysfunction”, “ED”, “Peyronie’s disease”, “PD”, “Premature ejaculation”, “PE”, “Males”, “Men”, “Thyroid disorders”, “Thyroid diseases”, “Hyperthyroidism”, “Thyroid”, “Hypothyroidism”, and “Thyroiditis” were hired. Also, “AND” and “OR” operators were used for keywords combination. All intended studies were searched using the databases of Web of Science, Google Scholar, Scopus, ScienceDirect, PubMed, and Embase. For deep screening, all citations of the selected articles were transferred to the Endnote Citation Manager software (v.8x) based on the inclusion/exclusion criteria. In primary process of paper selection, all studies reporting the prevalence of sexual disorders in men with TGD were considered for further assessment and screening.

PubMed search strategy:

(((((((((Prevalence[Title/Abstract]) OR (Outbreak[Title/Abstract])) AND (Sexual disorders[Title/Abstract])) OR (Sexual disorder[Title/Abstract])) OR (Sexual dysfunction[Title/Abstract])) OR (Male sexual dysfunction[Title/Abstract])) OR (Erectile dysfunction[Title/Abstract])) AND (Thyroid disorders[Title/Abstract])) OR (Thyroid diseases[Title/Abstract])) OR (Hyperthyroidism[Title/Abstract])))))))))

Inclusion and exclusion criteria

All observational studies and cross-sectional studies reporting the prevalence of sexual disorders in men with TGD, available full texts, English studies, and case-control, and cohort investigations were included for data extraction. Besides, case studies, intervention studies, investigations with no available full text, duplicate papers, and non-English texts were also excluded from the investigation.

Study selection

All stages of paper selection were applied based on the PRISMA guideline. In the first stage, duplicate studies were merged using the Endnote software (v.8.1). Then, the titles and abstracts of the papers were assessed carefully according to the inclusion/exclusion criteria, and the irrelevant papers were excluded from the assessment. In the next step, full texts were prepared and evaluated for eligibility for data extraction. Finale-selected papers with extractable data were considered eligible studies for data extraction and meta-analysis applications. Independently, two authors conducted the process of study selection or screening to avoid any possible bias. In the case of disagreement between these two researchers, a third author was responsible for the final decision.

Quality control assessment

To validate and evaluate the quality of the articles, “The strengthening the reporting of observational studies in epidemiology” (STROBE) checklist was used. By the use of the STROBE checklist, six main parts of the eligible papers were assessed including the title, abstract, introduction, methods, results, and discussion using 32 items of title, problem statement, study objectives, study type, statistical population, sampling method, variables definition and procedures, data collection tools, statistical analysis methods, and results. Finally, the papers were scored and categorized methodologically as good and moderate papers (≥ 16) or Poor (< 16). All poor-quality articles were excluded from the study.

Data extraction

Data were extracted by two independent authors using a pre-prepared checklist including the name of first author, year of paper publication, study location, sample size, age groups, prevalence of sexual dysfunction in TGD men, and the Study tools.

Statistical analysis

Extracted data were analyzed using the Comprehensive Meta-Analysis software (CMA, v.2). I² index was used to evaluate the heterogeneity of the studies, and the Egger test and funnel plot were used to check the publication bias. All analysis was conducted based on the significantly level of p < 0.05.

Results

Search results and its steps

Since it was depicted in Fig. 1, following primary searching process in data bases and citations of published papers, 714 and 4 articles were respectively gathered and transferred to the Endnote software. In the next step, 112 duplicate articles were merged. Following article screening of Titles and Abstracts, 499 other remaining papers were also excluded. Full texts of eligible papers were assessed and 86 papers were removed. The quality of remaining papers was evaluated using the STROBE checklist and 4 poor papers were ignored. Finally, 17 eligible studies entered to the final evaluation and data extraction according to the Fig. 1; Table 1. All eligible included studies were categorized as cohort, case-control and cross-sectional investigations and most of which were conducted in the Europe. Krysiak et al. ([17], Poland) reported the highest prevalence (85%) of sexual dysfunction (erectile irregularity) in men with TGD (with hyperthyroidism and Graves’ disease) which employed the IIEF-15 questionnaire for the cases aged 20–60 years [17]. Also, the lowest (2.9%) prevalence of sexual disorder (with ejaculation delay) was reported by Karani et al. (2005, Italy) which employed the IIEF tool among the Italian individuals (with hyperthyroidism) in the age range of 22–62 years [20] (Table 1). In this meta-analysis study, the overall prevalence of sexual dysfunction in men with TGD was detected 51.5% (CI95%=38.7–64). In eligible studies, 5 investigations used the IIEF questionnaire and 3 ones used Spermogram, IELT and SHIM-5 tools (Table 1).

Fig. 1.

The flowchart on the stages of including the studies in the systematic review and meta-analysis (PRISMA 2009)

Table 1.

Summary of characteristics of included studies of prevalence of sexual dysfunction in men with thyroid disorders

Author	Year	Country	Sample size	Prevalence	Age	Instrument	Type of disease	Type of sexual dysfunction
Krysiak et al. [17]	2019	Poland	20	85.00%	20–60	IIEF-15	hyperthyroidism and Graves’ disease	Erectile dysfunction
Krysiak et al. [17]	2019	Poland	21	62.00%	20–60	IIEF-15	hyperthyroidism and toxic multinodular goitre or toxic adenoma	Erectile dysfunction
Krysiak et al. [21]	2017	Poland	12	84.00%	18–50	IIEF-15	overt hypothyroidism	Erectile dysfunction
Krysiak et al. [21]	2017	Poland	12	41.00%	18–50	IIEF-15	subclinical hypothyroidism	Erectile dysfunction
Rezaeidanesh et al. [22]	2010	Iran	65	38.40%	44.9 ± 17.3	IIEF-5	Hyperthyroidism	Erectile dysfunction
Cihan et al. [23]	2009	Turkey	43	72%	----	IELT	Hyperthyroidism	Premature Ejaculation
Krassas et al. [24]	2008	United Kingdom	27	70.40%	52.6 ± 13.7	SHIM − 5	Hyperthyroidism	Erectile dysfunction
Krassas et al. [24]	2008	United Kingdom	44	84%	55.9 ± 15.3	SHIM − 5	Hypothyroidism	Erectile dysfunction
Veronelli et al. [25]	2006	Italy	55	54.54%	35–81	IIEF-5	Hypothyroidism	Erectile dysfunction
Veronelli et al. [25]	2006	Italy	13	76.92%	36–78	IIEF-5	Hyperthyroidism	Erectile dysfunction
Carani et al. [20]	2005	Italy	14	64.30%	22–62	IIEF	Hypothyroidism	hypoactive sexual desire & erectile dysfunction & delayed ejaculation
Carani et al. [20]	2005	Italy	14	7.10%	22–62	IIEF	Hypothyroidism	premature ejaculation
Carani et al. [20]	2005	Italy	34	17.60%	22–62	IIEF	Hyperthyroidism	hypoactive sexual desire
Carani et al. [20]	2005	Italy	34	14.70%	22–62	IIEF	Hyperthyroidism	erectile dysfunction
Carani et al. [20]	2005	Italy	34	50%	22–62	IIEF	Hyperthyroidism	premature ejaculation
Carani et al. [20]	2005	Italy	34	2.90%	22–62	IIEF	Hyperthyroidism	delayed ejaculation
Abalovich et al. [26]	1999	Argentina	25	48%	19–47	Spermogram	Hyperthyroidism	Erectile dysfunction

Global prevalence based on meta-analysis

After assessment of 17 studies with the sample size of 501 individuals, the high heterogeneity level (I²:82.6%) was calculated and the random effect model was used for data analysis. Thus, the global prevalence of sexual disorders in men with TGD was found 51.5% (95% CI: 38.7–64) (Fig. 2). publication bias was assessed through the Egger test and the absence of publication bias was detected in the studies (p:0.740) (Fig. 3).

Fig. 2.

Forest plot diagram representing the global prevalence of sexual disorders in men with thyroid disorders based on random effect model

Fig. 3.

Funnel plot of representing the distribution bias in included studies

Meta-regression and subgroup analysis

Following the assessment of probable factors influencing the heterogeneity value and the effect of the sample size on I² index, it was concluded that the global prevalence of sexual disorders in men with TGD decreases with the sample size (p < 0.05) (Fig. 4) and following the incremental trend in the year of paper publication, the global prevalence of sexual disorders increases (p < 0.05) (Fig. 5). Based on the results of the study, the highest prevalence of sexual disorders was reported 59.1% (95% CI: 37.2–77.8) in hypothyroid cases. Following subgrouping analysis, the prevalence of sexual disorders was found 59.1% and 41.5% in hypothyroidism and hyperthyroidism cases, respectively (Table 2).

Fig. 4.

Meta-regression analysis of the effect of sample size on the global prevalence of sexual disorders in men with thyroid disorders

Fig. 5.

Meta-regression of the effect of the study year on the global prevalence of sexual disorders in men with thyroid disorders

Table 2.

The global prevalence of sexual disorders in men with thyroid disorders by the type of thyroid disorders

Thyroid disorders	N	Sample size	I2	Egger test	Prevalence (95% CI)
Hyperthyroidism	9	309	85.09	0.466	41.5% (95%CI:25.9–59.1)
Hypothyroidism	6	151	77.4	0.725	59.1% (95%CI:37.2–77.8)

Discussion

In this systematic review and meta-analysis study, the global prevalence of sexual dysfunction in men with TGD was investigated and reported 51.5%. This value was also 59.1% and 41.5% in hypothyroidism and hyperthyroidism cases, respectively. Meta-regression analysis showed that the prevalence of sexual dysfunction in men with TGD increases with the year of paper publication, directly. In other words, the prevalence of sexual dysfunction in men with TGD increases over the time. Also, the overall prevalence of TGD decreases with the sample size. Studies showed that the incidence of sexual disorders in men with TGD is critically common representing the main side-effect of thyroid disorders in TGD cases [24].

As it was mentioned previously, TGD include two main types of hyperthyroidism and hypothyroidism. Hyperthyroidism causes major changes in gonadotropic-prolactin axis affecting the physiological function of spermatozoids. Hyperthyroidism leads to sexual irregularities, especially erectile dysfunction, by reduction of the total number of sperms, induction of progressive movement abnormalities, and linear movement defects. In addition, the TGD is one of the common causes of acquired premature ejaculation [21, 26].

For the first time, the Krysiak et al.‘s study showed that the hypothyroidism, especially with autoimmune origin, can potentially impact the normal function of hypothalamus-pituitary-thyroid axis leading to the negative effects on morphology, count, and motility of sperms. This study concluded that the hypothyroidism decreases sexual desire and delays ejaculation [21].

In the study of Veronelli et al., ([25], Italy) on 55 men with hypothyroidism and 13 men with hyperthyroidism, 54.54% and 76.92% of the individuals were diagnosed with the symptoms of sexual dysfunction, respectively [25]. Also, the prospective study of Karani et al. showed that 64.30% of patients (n = 14) with hypothyroidism and 50% of cases (n = 34) with hyperthyroidism suffered from sexual dysfunction, mainly early and late ejaculation and erectile dysfunction [20]. Also, in another study conducted in Poland, the prevalence of sexual dysfunction in men with subclinical hypothyroidism was calculated 41% [21] which were almost similar to the prevalence reported in this study. According to the study of Carani et al., [20] conducted on 34 hyperthyroid men aged 22–62 years, 2.9% of the individuals experienced sexual dysfunction such as premature ejaculation [20].

Since it was concluded that the prevalence of sexual dysfunction in males with TGD is directly associated to the time of paper publication, the low prevalence of sexual disorder in the study of Carani et al. could be associated to the old time of the research. Krysiak et al., ([17], Poland) reported the prevalence of sexual disorders (erectile dysfunction) as 85% among the patients (n = 20) with hyperthyroidism and Graves’ disease [17]. This report was nearly higher than our findings. It is approved that there are several interfering factor reducing the libido and low levels of seminal fluid secretion such as diabetes mellitus, cardiovascular diseases, chronic kidney diseases, cancer, obesity, smoking, alcohol, drugs, contact with heavy metals (such as Lead), and long-term exposure to poisons, chemicals, and agriculture agents [27].

In the study conducted by Gabrielson et al., it was reported that the prevalence of sexual dysfunction in patients with hypothyroidism included 59–63% and 22–46% in men and women, respectively and hyperthyroidism included 48–77% and 44–60% in men and women, respectively. Both hypothyroidism and hyperthyroidism were strongly associated with erectile and ejaculatory dysfunction. hypothyroidism with delayed ejaculation, and hyperthyroidism with premature ejaculation. Hypothyroidism and hyperthyroidism have been reported to impair libido in men and women; however, evidence of hypothyroidism’s impact on male libido is mixed [28].

based on a study by Kjaergaard et al., reported Hypothyroidism and hyperthyroidism are observationally associated with sex hormone concentrations and sexual dysfunction, but causality is unclear. this study reported, that the genetic risk score for TSH and hypothyroidism was associated with increased and the genetic risk score for hyperthyroidism with decreased free androgen index in men only. While genetically predicted thyroid function was associated with sex hormones, we found no association with sexual function [29].

According to the relatively high prevalence of sexual dysfunction in TGD patients, it is suggested to conduct more resemble studies in different regions of the world. Also, since the sexual dysfunction is affected by many factors, this concept needs more attention to achieve confirm overall conclusion. As one of limitation of this investigation, some studies were excluded due to the low quality, incomplete of presented data, and not reporting the total sample size.

Limitations and suggestions

The most important limitations of the current study are the unequal number of studies in the countries and the different age distribution of the participants. Also, included studies were limited to studies published in English, meaning that studies in other languages may have been overlooked. It is suggested that this study be repeated in the coming years for a better comparison of the results.

Conclusion

Since the overall prevalence of sexual dysfunction in men with TGD was reported at 51.5%, also, the highest prevalence of sexual disorders was reported in hypothyroid cases. according to the negative effects of sexual dysfunction on self-esteem and quality of life, it is suggested to the health policy makers for better management of the society and planning for wide application of preventive medicine for individuals with TGD. Based on the results of the study, the highest prevalence of sexual disorders was reported at 59.1% in hypothyroid cases.

Author contributions

NS and PH and NF and MM contributed to the design, MM statistical analysis, and participated in most of the study steps. MM and NF and PH and AA and SS prepared the manuscript. All authors have read and approved the content of the manuscript.

Funding

ByDeputy for Research and Technology, Kermanshah University of Medical Sciences (IR)(4020665). This deputy has no role in the study process.

Data availability

Datasets are available through the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

Ethics approval was received from the ethics committee of deputy of research and technology, Kermanshah University of Medical Sciences (IR.KUMS.REC.1402.373).

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no conflict of interest.