Impact of obesity on hypogonadism in the andropause

Obesity is an issue that is increasingly affecting ageing men. With ageing, there is a decline in androgens as well. There are implications for the health of ageing men as a result of hypogonadism. Overall, there seems to be an inverse relationship between body mass index and testosterone levels, as is also demonstrated in our cross-sectional study. Obesity seems to depress the production of testosterone. It has been hypothesized that there is increased aromatization of testosterone to oestradiol and alteration of the hypothalamic-pituitary-adrenal axis in obese older men. Some hormones can affect obesity in ageing men including leptin, insulin, dehydroepiandrostenedione and growth hormone. The relationship of obesity to these hormones in ageing men will be reviewed. Testosterone replacement in ageing men can alter body composition whereby fat is exchanged for muscle. These studies will also be reviewed. Further studies in this field are recommended to evaluate long-term benefits and risks.     

BARDET-BIEDL SYNDROME

The Bardet-Biedl syndrome is characterized by five main features: obesity, Polydactyly, pigmentary retinopathy, mental deficiency and hypogonadism; recently a sixth feature, renal disease, has been described. It was formerly known as the Laurence-Moon-Biedl syndrome, but Laurence and Moon described a different entity in which the main feature was paraplegia. Fourteen cases have been seen: all had pigmentary retinopathy which, in most cases, was severe and tended to affect central vision early in life. All had subnormal intelligence, twelve were obese, ten had Polydactyly, eight hypogonadism, and two had renal disease. The condition was thought to be rare, but this may have been due to the failure to diagnose incomplete or partial cases. It is suggested that the prevalence is 1:160 000 of the population.     

Age-associated endocrine deficiencies as potential determinants of femoral neck (type II) osteoporotic fracture occurrence in elderly men

Osteoporotic fractures, and especially hip fractures, are a leading cause of morbidity and mortality among elderly men. Among other factors, a decline in bone mass has been identified as the major determinant of the age-related reduction in bone strength and therefore of osteoporotic fracture risk. Recent evidence suggests that age-associated endocrine deficiencies may contribute to femoral bone loss and hip fracture occurrence in elderly men. The decline in circulating androgen levels and the decreased activity of the growth hormone–insulin-like growth factor-I axis may result in a reduction in bone formation that contributes to the age-related increase in bone fragility in men. Vitamin D deficiency-induced secondary hyperparathyroidism, on the other hand, may further enhance bone loss by activating bone turnover and so increasing the number of bone remodelling units with impaired bone formation. On the basis of these pathophysiological models, guidelines can be developed for the prevention of age-related bone loss in men, but these approaches lack validation. The results of controlled intervention trials will have to be awaited to answer the question of whether hormone replacement therapy attenuates bone loss and reduces fracture incidence in elderly men.     

Adult-onset idiopathic hypogonadotropic hypogonadism presented with erectile and ejaculatory disorder

A 37-year-old man who had fathered a child five years previously presented with erectile and ejaculatory disorder. Endocrinological examinations revealed isolated luteinizing hormone-releasing hormone (LHRH) deficiency of hypothalamus, resulting in hypogonadotropic hypogonadism, and no causative abnormality was detected in imaging studies, including magnetic resonance imaging (MRI). Having a diagnosis of adult-onset hypogonadotropic hypogonadism, the patient received pulsatile subcutaneous administration of gonadotropin-releasing hormone (GnRH). Sperm analysis and serum level of testosterone improved to normal in a few months. His wife became pregnant using artificial insemination with her husband's semen 15 months after the beginning of the treatment.     

Changes in hypothalamic-pituitary function following bone marrow transplantation in children

Patients who undergo bone marrow transplantation (BMT) frequently experience impaired pituitary function, but precise assessment using repeated provocative tests has not been described. We studied 32 children (16 boys) who had BMT after receiving preparative irradiation. Assessment of pituitary function was performed by infusing insulin, luteinizing hormone-releasing hormone (LHRH), and thyrotropin-releasing hormone (TRH) on several occasions at various intervals during the follow-up period. Serum free thyroxine (FT4) and thyrotropin (TSH) levels tended to be low during the early period following BMT. Serum FT4 concentrations reverted to the low-normal range 1 year after transplant, and eight of 29 patients had subnormal and delayed TSH response to TRH consecutively. No children showed overt hypothyroidism. Basal and peak serum gonadotropin levels in response to LHRH were elevated in the patients who had received transplant around the time of puberty. Leydig cell function assessed by human chorionic gonadotropin test was normal. Three girls experienced menarche, and one male patient fathered a normal boy 7 years after BMT. Pituitary-adrenal function and prolactin secretion were not affected. A high incidence of transient hypothyroidism which did not require replacement therapy and gonadal failure among pubertal children were observed. Shielding of gonads should be attempted, if possible, at the time of preparative irradiation to prevent resultant hypogonadism.     

Investigation of the Hormonal Axis Hypothalamus-Pituitary-Gonads in 20 Dialyzed Men

20 male patients suffering from end-stage chronic renal failure and maintained on hemodialysis were investigated for pituitary response to GnRH. The GnRH-Test was performed simultaneously with hemodialysis; however, hemodialysis was started 60 min. after the injection of GnRH. Basal values of LH and FSH were significantly higher (P less than 0.0001 and 0.005, respectively) than the normal range, while basal values of testosterone were in the subnormal range or depressed (P less than 0.0001). Poststimulatory values of LH were significantly lower (P less than 0.01) than normal and--other than normal--did not decline within 180 min. following injection of GnRH (P less than 0.001). The same pattern was seen for FSH, however, no statistical significance could be secured. Testosteron was elevated 30 min. after stimulation with GnRH (P less than 0.001).     

Intranasal trigeminal detection of chemical vapors by humans.

The majorityof 14 human observers lacking olfactory nerve function detected, by nasal inhalation, over one quarter of 31 chemicals commonly used in olfactory research. No major differences were noted between anosmic observers with and without documented anatomic, genetic, or physiologic etiology. Detected compounds differed significantly from nondetected ones on the basis of a number of chemical properties, including water solubility and molecular weight. Detection thresholds of the anosmics, established by a single staircase procedure, were approximately two log volume concentration steps above those of normals for two compounds examined. Exponents of power functions fitted to magnitude estimates of the anosmics did not differ significantly from those fitted to the estimates of matched normal controls. These data indicate the trigeminal nerve may play an important role in human nasal chemoreception and that effective trigeminal stimulants may be predictable on physicochemical grounds.     

Cataracts and testicular failure in three brothers

I report on three brothers with a syndrome of adolescent cataracts and infertility. Follicle-stimulating hormone (FSH) levels were elevated, suggesting testicular failure. Their parents were second cousins, suggesting autosomal recessive inheritance. Hypogonadism and cataracts occur in several syndromes, but with other findings. This association is probably more than fortuitous, and a common pathogenesis may be involved.     

二仙汤治疗迟发性性腺功能减退症验案举隅

迟发性性腺功能减退症,中医尚无确切病名,常归属于"心悸""郁证""阳痿""虚劳"等病的范畴,是临床难治病之一,西医主要以睾酮补充治疗为主,但其疗效及安全性均存在争议,而且在改善患者的心理、精神状态方面收效甚微。中医治疗该病辨证施治效果明显,二仙汤治疗该病有温肾阳、补肾精、泻肾火、阴阳并调之功,疗效卓著。