Testosterone Loss and Estradiol Administration Modify Memory in Men:

Mild cognitive impairment and dementia: the importance of modifiable risk factors

BACKGROUND

Mild cognitive impairment (MCI), a common condition among the elderly, is defined as a deterioration of memory, attention, and cognitive function that exceeds what would be expected for the individual's age and level of education, yet does not interfere significantly with the activities of daily living. MCI may be a precursor of dementia; the rate of transition from MCI to dementia is 10% to 20% per year. The role of somatic diseases and modifiable risk factors in MCI and dementia needs further study.

METHODS

We analyzed pertinent original articles and reviews published 1990 up to December 2010 that were retrieved by a selective search in PubMed and the Cochrane Library.

RESULTS

MCI and dementia are associated with many somatic disorders and modifiable risk factors. MCI has biologically plausible associations with hypertension, diabetes mellitus, and hyperlipidemia, although the interventional trials performed to date have yielded negative results. Recently, chronic renal failure has also been recognized as a risk factor. Insufficient evidence supports a putative benefit on MCI from the substitution of vitamin B12, vitamin D, or testosterone (when these substances are deficient), the treatment of hyperhomocysteinemia or subclinical thyroid dysfunction, or hormone replacement therapy after menopause. Epidemiological data suggest that a Mediterranean diet, physical activity, and moderate alcohol consumption protect against MCI, while cigarette smoking promotes it and should be stopped.

CONCLUSION

Modifiable risk factors for MCI should be sought (at the very latest) in persons who already have MCI, as their optimal treatment may improve these patients' cognitive performance or keep the existing deficits from progressing.

Hormonal therapy in the elderly prostate cancer patient

BACKGROUND

Prostatic cancer (PCa) is the most common cancer in men in Germany. The goal of this review is to define the indication for hormonal treatment in patients over age 70.

METHODS

A selective search of the literature up to 2008 for the terms "prostate cancer", "androgen suppression and deprivation", "hormone therapy", "LHRH analogs", "antiandrogens", "active surveillance", and "watchful waiting" was performed in the Medline and Cochrane databases. The guidelines of the American Society of Clinical Oncology (ASCO, 2007) and the European Society of Urology (EAU, 2008) were also taken into account.

RESULTS

Hormonal therapy is not indicated for patients with organ-confined, well-differentiated or moderately differentiated tumors who are otherwise in good health. It is beneficial in the treatment of locally advanced cancer with an unfavorable Gleason score. For patients with organ-confined cancers who are in poor general condition, hormonal therapy is deferred until symptoms arise. The guidelines recommend hormonal therapy in case of PSA elevations greater than 1.5 ng/mL after attempted curative treatment. Symptomatic metastases require immediate hormonal therapy. Intermittent androgen deprivation is an attractive alternative.

CONCLUSIONS

In patients over age 70, an attempt at curative treatment is only reasonable if the life expectancy exceeds 10 years. Hormonal therapy is the treatment of choice for patients with undifferentiated, locally advanced prostate cancer, recurrences as defined by PSA elevation, and symptomatic metastases.

The role of androgens in cognition and brain aging in men

Losses of working and long-term memory are hallmarks of human aging and may signal impending neurodegenerative disease. The maintenance of neural elements in brain systems that support memory, such as synapse formation in prefrontal cortex and hippocampus, are critical for cognitive health in aging. This paper reviews the biological basis for androgens as neuroprotectants or neuromodulators in aging and the importance of androgens on the brain systems important for memory. We relate biological effects to cognitive outcomes in elderly men under a variety of androgen conditions. In brief, androgen deprivation causes significant loss of synapses in the hippocampus in rodent and nonhuman primates, increases amyloid deposition in human and rodent models and causes changes in neurotransmission in prefrontal cortex in rodent models. Recent work suggests that these changes modify age-related cognitive loss, particularly to memory in men. In addition, the conversion of testosterone to its androgen metabolites or to estradiol may play a special role in the preservation of memory in aging. This paper reviews discrepancies between studies using animal models and studies of human cognition, and suggests new directions that are likely to be fruitful in the future for understanding the role of androgens in brain aging. This review suggests that studies of low androgen levels in older men may not index the same biological mechanisms and behavioral effects as the studies of gonadectomy in animal models.