Introduction

Overview of frohlich syndrome (adiposogenital dystrophy)

Frohlich syndrome, which is known as adiposogenital dystrophy, Babinski-Frolich syndrome, dystrophia adiposogenitalis, hypothalamic infantilism (obesity), and Launois-Cleret syndrome. It is a condition that occurs due to the occurrence of an injury in the hypothalamus, which results in many endocrine disorders. The hypothalamus is a gland that connects the nervous system with that of the endocrine system through another gland, known as the pituitary gland.¹ The hypothalamus is present in the ventral region of the brain, and its main functions include coordination with the endocrine system and transmission of signals by releasing hormones that act on the pituitary gland, which in turn direct the functions of the thyroid gland, adrenal gland, and other reproductive glands.² Furthermore, it also has a role in controlling sleep cycles and regulating the body temperature. In comparison to other rare diseases, Froehlich syndrome is acquired. after the birth rather than being inherited before the birth. It primarily affects men and commonly arises due to lesions formed in the hypothalamus.³

Importance of understanding gonadal dysfunction and its impact on reproductive health

Glands that are involved in the reproductive processes in the human body are known as gonads, and they produce hormones such as testosterone, progesterone, and estrogen.⁴ These glands are present in both men and women. Gonal disorders affect the reproductive organs in both men and women. Ovaries are the female reproductive organs, which are in pairs and present on each side of the uterus and produce eggs and female hormones. Whereas the testis is the male reproductive organs that produce male hormones. An imbalance in hormonal production is the main cause of gonadal and menstrual disorders. The main function of the reproductive organs is the production of functional gametes for fertilization and also the secretion of gonadal hormones, which are important for sexual differentiation, maturation, and other functions. Any dysfunction in these gonads might result in a shortage of steroid hormones or infertility. In men, testicular failure may arise due to failure in spermatogenesis steroidogenesis, or both.⁵

Gonadal dysfunction in frohlich syndrome

Definition and causes

Hypothalamic dysfunction leading to hormonal imbalances

Growth retardation, obesity, and delayed genital organ development are the most common signs of Frohlich syndrome, a rare or uncommon metabolic disorder that primarily affects children. It is usually associated with decreased gonadotropin release and increased appetite, and it is usually associated with tumours. The illness bears Alfred Frohlich's name in recognition of the fact that he was the first Austrian neurologist to recognize this common pattern. Males are more likely than females to suffer from this particular condition. Because of its intimate connection to the hypothalamus, there is also a decline in pituitary function.⁶

The hypothalamus helps in maintaining the equilibrium of the body’s internal functions. It helps in the regulation of weight and appetite, body temperature, emotions, behaviours, growth, memory, childbirth, sex drive, electrolyte balances, etc. Additionally, it performs the important function of regulation of the gland, which is situated at the base of the brain region, the pituitary gland. The pituitary in turn regulates the testes on the ovaries and thyroid gland.⁷ 

Impact on the pituitary gland’s secretion of gonadotropins (LH and FSH)

One of the key components of the human hypothalamic-pituitary-gonadal (HPG) axis is gonadotropin-releasing hormone (GnRH). The gonads, i.e., testis and ovaries, produce sex hormones in response to the  GnRH release from the neurons of the hypothalamus. Overall,  GnRH aids in the onset of puberty, sexual maturation, and female ovulatory cycles.⁸  As it is well known, GnRH is produced by the hypothalamus. Follicular stimulating hormone (FSH) is released as a result of stimulation from GnRH. GnRH released from the hypothalamus causes the anterior pituitary gland to release FSH and luteinizing hormone (LH). FSH receptors are found in the granulosa cells of the ovaries in females, whereas in males, they are found in the testicular serial cells. The major functions of these gonadal hormones include the synthesis of estrogen and follicle formation in females and induction and spermatogenesis maintenance in males.⁹ Additionally, FSH helps in ovulation in women and stimulates the release of anti-mullerian factor and inhibin, which aid in spermatogenesis, and LH helps in the release of testosterone.¹⁰

Types of gonadal dysfunction

In males, hypogonadism is the term used to describe either a decrease in the sperm count or testosterone level. It may be the consequence of a default in the testis (primary hypogonadism) or due to any default in the hypothalamus ( secondary hypogonadism). If the patient's serum LH and/or FSH concentrations are above normal while their serum testosterone and/or sperm count are below normal, they are considered to have primary hypogonadism. If the patient's blood LH, FSH, and/or testosterone concentrations are normal or low, but their sperm count and/or serum testosterone concentration are below normal, they have secondary hypogonadism.¹¹

Impact on male reproductive health

Impaired spermatogenesis

Decreased testosterone levels leading to reduced sperm production: Sperm production may be reduced as a result of insufficient testosterone. Compared to the blood, the testicles where sperm are produced have substantially higher quantities of testosterone. One of the indirect effects of lower testosterone in fertility is the reduction in the sex drive, which leads to a reduction or even absence of indulging in sexual activity. It can also result in erectile dysfunction due to weaker or very less frequent erections. It could be very challenging to reach climax or to have enough intercourse to reproduce as a result.¹²

Testosterone helps in maintaining hormonal balance, which is required for optimum sperm production/ if the level of testosterone decreases, there is a high possibility of infertility.¹³

Delayed or absent puberty

Delayed puberty is basically defined as the absence of the development of secondary sexual characteristics (e.g., facial hair, deep voice). A functional delay in the hypothalamic neural networks that trigger the episodic or pulsatile release of gonadotropin-releasing hormone (GnRH) and activate the hypothalamic-pituitary-gonadal axis is the most common cause of delayed puberty. This delay could be mostly brought on by functional abnormalities like malnourishment, or it could be the result of unique genetic changes known as constitutional delay of growth and puberty (CDGP). There are numerous causes relating to hypothalamic, pituitary, and gonadal diseases that can lead towards delayed the puberty.¹⁴

Impact on female reproductive health

Anovulation

The primary cause of infertility in women is irregular or absent ovulation or anovulatory behaviour. It is identified by irregular menstrual cycles, and drugs that change endocrine profiles and encourage follicular maturation for ovulation and conception are frequently used in treatment.¹⁵

Delayed or absent puberty

In females, constitutional delays in growth and puberty are less common. Functional hypogonadotropic hypogonadism, on the other hand, is far more prevalent among women. It typically arises as a side effect of disorders that lower total body fat, which are frequently linked to anorexia nervosa or overexertion in females. Both entail cutting back on calories significantly, which lowers the body's leptin content and causes a gonadotropin shortage. Puberty is delayed due to the decrease in estrogen production and secretion, which is caused by decreased levels of FSH and LH secretion along with reduced body fat.¹⁶

Polycystic ovaries

The potential development of polycystic ovary syndrome (PCOS) is often due to hormonal imbalances. It has been discovered that many women who suffer from PCOS have been reported to have reduced amounts of even testosterone, which is believed to be a male hormone. Increased luteinizing hormone (LH) levels: these might cause aberrant effects on the ovaries if they are very high, even though LH encourages ovulation. Decreased blood levels of the blood protein sex hormone-binding globulin (SHBG), which binds to testosterone and lessens its effects, elevated prolactin levels, a hormone that encourages the breast glands to produce milk during pregnancy (only in some PCOS-afflicted women).

Treatment and management strategies

Hormone replacement therapy (HRT)

• Testosterone replacement in males: For men who believe that low testosterone levels are affecting their quality of life (sex drive, energy levels, etc.), there are clinical therapies available. Delivering testosterone to raise levels is part of the popular testosterone replacement therapy (TRT). There are various methods for doing this: injections administered into the muscle, gels, packets, and oral tablets; nasal sprays; and implants implanted under the skin¹²
• Estrogen and progesterone replacement in females

Fertility treatments

Assisted reproductive technologies (ART) for those seeking to conceive.

Conclusion

Frohlich syndrome is known by different names like adiposogenital dystrophy, Babinski-Frolich syndrome, dystrophia adiposogenitalis, hypothalamic infantilism (obesity), and Launois-Cleret syndrome. It is a condition that occurs due to the occurrence of an injury in the hypothalamus, which results in many endocrine disorders. The hypothalamus is a gland that connects the nervous system with that of the endocrine system through another gland, known as the pituitary gland. 1 Frohlich syndrome causes hypogonadism, delays puberty, and modifies sexual development because of the hormone imbalances and hypothalamic dysfunction it causes. These effects have a substantial influence on reproductive health. In order to control this particular condition and its implications on gonadal function, early identification and related therapy are crucial. Any damage to the hypothalamus, which is believed to control pituitary hormones that regulate growth, metabolism, and sexual development, results in the rare condition known as Frohlich syndrome. Among the main impacts on reproductive health are: delayed onset of puberty as a result of decreased release of pituitary gonadotropin Gonadal atrophy/hypoplasia and small testes (hypogonadism) Changes in secondary sex traits. The goal of treatment is to eliminate any hypothalamic tumours and replenish any missing hormones; however, controlling obesity is extremely difficult. In order to address the major effects that the hormonal imbalances in Frohlich syndrome have on gonadal function and sexual development, early identification and therapy are crucial.