Spotted this one at another board.
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Testosterone improves cognitive function in older men
Short-term supplementation with testosterone could enhance cognitive function in healthy older men, researchers report in Neurology.

Monique Cherrier (University of Washington Medical School, Seattle) and colleagues randomly assigned 25 healthy men, aged 50 to 80 years, to receive a six-week course of weekly testosterone (100 mg) injections or placebo. Cognitive evaluations were conducted at baseline, week three, and week six, and were based on scores from a battery of neuropsychologic tests.

Among the participants receiving testosterone, levels of circulating testosterone increased by an average of 130% by week three and by 116% by week six. Nevertheless, the researchers note that because of aromatization of testosterone, levels of estradiol also increased by an average of 77% at week three and by 73% at week six.

Cherrier's team found that spatial ability and verbal memory were significantly improved among the testosterone group, compared with their baseline cognitive ability and that of the placebo group. However, they point out: 'Improvements were not evident for all cognitive domains, such as selective attention or language, suggesting that increases in serum testosterone or estradiol have selective or specific effects on memory and spatial abilities.'

The authors concede that their results do not explain whether the improvements in cognition are attributable to increased testosterone or estradiol levels, or both. They add that further studies are needed to examine the relative contribution of testosterone compared with estradiol on cognition in men.

Neurology 2001; 57: 80–88



Performance in spatial tasks sensitive to hormonal fluctuations
Women appear to perform better in spatial tasks during the menstrual phase of their cycle compared with the midluteal phase and German scientists believe that hormonal fluctuations are the reason why.

A group led by Dr Markus Hausmann (Ruhr-Universitat Bochum, Germany) studied eight women in their 20s and 30s. The women took part in 3 different tests of spatial abilities on the 2nd and 22nd days of their menstrual cycles. The researchers also took blood samples every three days in order to analyze concentrations of estradiol, progesterone, testosterone, lutenizing hormone, and follicle-stimulating hormone. For two of the tests, the women's scores did not differ significantly for day two and twenty-two. However, scores for the Mental Rotation Test – where they were asked to recognize rotated versions of a figure – were higher for day two of the cycle in all except one of the women. Dr Hausmann also noted that hormonal fluctuations indicated that estrogen and progesterone were related to the women's spatial scores; higher levels of estrogen were linked to lower scores, while higher concentrations of testosterone were linked to higher scores. The group commented that their findings could explain some of the differences between the way men think compared with women. The authors conclude that 'spatial performance is sensitive to hormonal fluctuations over the menstrual cycle and that different aspects of spatial abilities are related to different hormones or hormone combinations'.