Perhaps you were not aware of the fact that seasonal changes coincide with changes in blood testosterone concentrations. If so, then you are not alone. A report that was recently published in the Journal of Clinical Endocrinology and Metabolism examined free and total testosterone, luteinizing hormone (LH), which is a hormone in the brain that stimulates the testes for testosterone secretion), and sex hormone binding globulin (SHBG) , which is a protein that binds to estradiol, dihydrotestosterone and testosterone to carry it through your circulation; when its concentration is changed it significantly affects the ratio of estradiol in plasma to unbound (biologically active) testosterone. These effects were examined in 1,549 males residing in Norway.
The finds were very interesting. Total testosterone peaked in October and November. In February, there was a smaller peak. The lowest total T levels were in June. Free T was at its lowest level in August and peaked in December. The waist-to-hip ratio of the subjects following the same pattern that testosterone did. When T was at its lowest, they were at their highest. So during the colder winter months subjects were leaner. This was also when there were the least hours of sunlight. There were also very large hormone level variations (31 percent difference between the peak and low point).
Perhaps all of those Southern Californians should move to the Aleutian Islands. Then again, it may be an evolutionary adaptation for individuals living in areas that have extreme weather changes (for example, really bitter cold winters). At least the pattern is Norway is for testosterone to be at its highest levels during the winter months.
When it is 10 degrees outside, the idea of chilling in your lawn chair with your neighbors while you are grilling steaks does not sound very appealing. So man has been equipped by evolution with raised testosterone levels so that you are more fully for those nice indoor activities spent with your girlfriend or wife. You have to admit that it's a very enjoyable way to pass the time over those long and cold winter months.
It Bites To Get Old
Six young males (24 years old) and seven healthy middle-aged males (47 years old) had their testosterone levels measured at night to test whether or not there were any differences that related to age. The night hourly average testosterone level for the young men as 60.6 ng / ml, whereas for the middle-aged men it was 43.4 ng / ml. The middle-aged men had higher LH values also. The older guys also had 3.8 testosterone pulses a night compared to the young guys who averaged 6.7. So it looks like young guys have naturally high testosterone levels. I guess the middle-aged make more money. Maybe they can purchase some extra testosterone from their doctors.
The steroid DHEA is produced inside the adrenal glands. Some evidence suggests that a 50 to milligram daily dose may improve overall feelings of well-being and increase muscle mass in middle-aged and older individuals. After using DHEA supplementation for five months, older males also show improved immune function. Although it was touted originally as an anti-obesity steroid, in humans it is clearly not an anti-obesity hormone.