Name: ジェンダー分析01。ローT：二つのホルモンの物語 (Gender Analysis 01. Low T: A Tale of Two Hormones)
Uploaded: 2021-01-14T06:27:26.000Z
Duration: 22 min 10 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

Hi, welcome to Gender Analysis. In recent years, prescription testosterone has become

a booming industry around the world. From 2001 to 2011, the percentage of men over 40

in the US who were prescribed testosterone replacement grew from about 0.8% to 2.9% - more

than a threefold increase. And data from 41 nations shows that yearly testosterone sales

have increased from $150 million in 2000, to $1.8 billion in 2011. Meanwhile, chains

of "low T clinics" focusing on testosterone therapy have opened dozens of locations across

the country. So, what's behind this growth? Let's take a look at one commercial for prescription

"I have low testosterone. There, I said it. See, I knew testosterone could affect sex

drive, but not energy or even my mood. That's when I talked with my doctor. He gave me some

blood tests - showed it was low T. That's it. It was a number."

Companies selling these medications increased their spending on testosterone ads from $14

million in 2011, to $107 million in 2012, using a snappy new name like "low T" and the

promise of a quick and easy pick-me-up for older men. If your T is low, you feel bad;

if your T is higher, you feel good – right? This is the approach that's fueled an explosion

in testosterone usage. The problem is, it's not just a number. In reality, "low T" levels

are uncertain, the symptoms are vague, and the relationship between levels and symptoms

The concept of "low testosterone" implies there's a level that's considered low. Interestingly,

there isn't really a medical consensus on what that level is. A report by the American

Urological Association described hypogonadism as a total testosterone level lower than 300

nanograms per deciliter. However, that same report also defined "true hypogonadism" as

less than 150 to 200, and later said that levels from 200 to 346 are in a "gray zone".

Other studies and sources have defined low testosterone as less than 230, 250, 280, 319,

325, or 350. One laboratory test considers levels as low as 132 to be normal. The Endocrine

Society actually acknowledged that their panelists couldn't agree on 200 or 300 as a lower limit

when deciding whether to treat older men who have low testosterone symptoms. According

to one article in the Cleveland Clinic Journal of Medicine: "There is no general agreement

on the acceptable normal range of testosterone". Another article adds: "There are no absolute

testosterone levels below which a man can unambiguously be stated to be hypogonadal."

This is not a merely theoretical dispute. As Dr. Lisa Schwartz pointed out, defining

low testosterone levels as below 230 nanograms per deciliter would classify 7% of men aged

50 or older as having low T. But moving the cutoff to below 350 would expand this to 26%

of that population. Meanwhile, there's a substantial gap between the testosterone levels that most

medical authorities aim for during treatment, and the levels that "low T clinics" aim for.

The Endocrine Society suggests that levels of 350 to 750 nanograms per deciliter are

best, while the Cleveland Clinic recommends levels of 400 to 600. However, Dr. Jeffrey

Life of Cenegenics Elite Health prefers to aim for 800 to 1000, the Apex Clinic in Oklahoma

City lists a goal of 800, the New Jersey Virility Center recommends 600 to 800, and the Total

Male Medical Center describes 800 to 1100 as "optimal levels". More T Clinics claims

that levels over 700 "can profoundly improve your quality of life by increasing your energy,

mental clarity, sex drive, sleep quality, muscle mass, and overall health." So, one

test might show that a man has low testosterone, while a different test indicates his levels

are normal. Another man might have levels that are firmly within all these "normal"

ranges, but a "low T clinic" would think he still needs more.

But low T levels are only half the story. What about the condition itself, and its symptoms?

Hypogonadism – the insufficient production of testosterone in men - is a real condition.

It can be caused by injuries, infections, certain medications, pituitary disorders,

cancer treatment, inflammation, autoimmune disease, genetic disorders, or just normal

aging. Its symptoms can include lowered sex drive, erectile dysfunction, infertility,

loss of muscle, decreased body hair, osteoporosis, tiredness, difficulty concentrating, and even

breast growth. For men with hypogonadism, this is a serious issue. But when low testosterone

is simply the result of aging, the symptoms are often nonspecific. For instance, fatigue,

loss of libido, and difficulty concentrating could be caused by low T, but this can also

be caused by depression. And companies selling prescription testosterone frequently offer

symptom-based screening online. Websites for AndroGel and Testopel ask questions like,

"Do you have a lack of energy?", "Have you noticed a decrease in your enjoyment of life?",

"Are you sad and/or grumpy?", "Are your erections less strong?", and "Are you falling asleep

after dinner?" These screeners are based on the Androgen Deficiency in Aging Males questionnaire,

designed to detect low testosterone levels in older men. But the ADAM questionnaire has

some performance issues of its own. In the first study of the ADAM screener's accuracy,

it was given to Canadian doctors aged 40 to 62, and it was found to have a sensitivity

of 88% and a specificity of 60%. A test's sensitivity refers to how likely it is that

someone with a condition will receive a positive result, and specificity refers to how likely

it is that someone without a condition will receive a negative result. So, this study

showed that out of 100 men who do have low testosterone levels, 88 will get a positive

result from the ADAM screener, and the other 12 will receive false negatives – they'll

be told that they don't have low testosterone, when they actually do. Meanwhile, because

the specificity in this study was 60%, this means that out of 100 men without low testosterone,

60 will get a negative result from the screener – but 40 of them will get a false positive.

The test is broad enough to encompass a lot of the men who do have low testosterone, but

also some who don't. This is not an isolated finding from one study. In seven studies from

2004 to 2013 using the ADAM questionnaire, its sensitivity ranged from 66.7% to 88%,

and its specificity ranged from 14.8% to 36.6%. When men without low testosterone take these

online screeners, it's possible that a majority will nevertheless be told that they do have

low T. As one article explained: "...the ADAM questionnaire will rarely miss the diagnosis

in hypogonadal individuals, but will also incorrectly identify many nonhypogonadal men.

The lack of specificity is not only due to the fact that many positive responses in the

questionnaire may be indicative of other conditions such as depression, but also because scores

derived from these questionnaires do not predict or correlate well with measured free and total

testosterone." A story in the New York Times briefly touched on the origin of the ADAM

questionnaire. Quote: "Dr. Morley recalls that he drafted the questionnaire in 20 minutes

in the bathroom, scribbling the questions on toilet paper and giving them to his secretary

the next day to type up. He agrees that it is hardly a perfect screening tool." Yet this

is the tool that sellers of prescription testosterone are using to encourage men to see a doctor

– a tool that could be telling up to 85 out of 100 healthy men that they might have

low T. Surprisingly, other screeners don't do much better. In various studies, the Aging

Males' Symptoms scale was shown to have a sensitivity ranging from 54% to 96%, and a

specificity ranging from 30% to 48.1%. A screener used by the Massachusetts Male Aging Study

had a sensitivity of 76% and a specificity of 49%. Ultimately, the symptoms of low T

don't seem to be so strongly associated with, well, low T. This is especially concerning

given that only 51% of men on testosterone therapy have actually been diagnosed with

hypogonadism, and only 75% have had a blood test to check their T levels within the past

But what about men who do have low testosterone? Oddly enough, low T levels can often be asymptomatic

– men with low T might not show any signs of it. For instance, in a study of hundreds

of elite athletes, 16.5% of men were found to have testosterone levels below normal.

Another study focused on 1,475 men in the Boston area aged 30 to 79. 24% of them had

total testosterone levels below 300 nanograms per deciliter, but only 5.6% had low T levels

along with symptoms. So, of all the men whose testosterone levels might be considered low,

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ジェンダー分析01。ローT：二つのホルモンの物語 (Gender Analysis 01. Low T: A Tale of Two Hormones)

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