Two of the primary measures physicians use to aid in their physical diagnosis of low testosterone are:  1) the presence/absence of substantial muscle mass; and 2) the recent significant gain of body fat.  These two characteristics combine with other primary variables such as gender, height, weight, lifestyle (i.e., sedentary, occasional exercise, routine exercising non-athlete, competitive athlete, elite athlete), body type (i.e., underweight, healthy weight, overweight, obese, morbidly obese) to comprise the measures used in computing general physical health.  Such measures include body fat percentage, body mass index (BMI), waist-to-height ratio (WHtR), the basal metabolic rate (BMR), surface area, Willoughby athlete weight calculation, etc.  Thus, a variety of internal, external, and habitual factors are involved in what is generally seen as physical appearance, and low testosterone can be one of the key hidden factors to subpar aesthetics.

Low Testosterone

Low testosterone rates are commonly reported among today’s middle-aged men to elderly men, and are considered to be testosterone levels near the lower limit of 300 ng/dl (nanograms per deciliter) and below.  Generally speaking, testosterone levels rise rapidly throughout adolescence, reach their peak in the early to mid-twenties, and gradually decline around age 30 at a rate of approximately one percent per year, until they reach a substantial deficit sometime after age 60 (earlier for some, later for others).  Consensus estimates cite the incidences of andropause (male menopause, i.e., the significant reduction in the primary male sex hormone testosterone) in the United States as follows:  ages 40 to 49 at least 2% to 5% of men could be clinically diagnosed with the condition; ages 50 to 59 anywhere from 6% to 30%; ages 60 to 69 between 20% and 45%; ages 70 to 79 from 34% to 70% and; 80+ is at approximately 91%.  Although the widespread normal ranges are often attributed to the different ways to measure androgens, and the various ways to define andropause, they are far more likely attributable to the many variables cited in the introduction and individual sensitivities to hormonal shifts resulting in hypogonadic (low testosterone) symptoms.

Low Testosterone and Health

Surprisingly, there’s only a relatively small body of research concerning the long-term health effects of low testosterone, supposedly due to the fact that scientists, researchers, epidemiologists, etc. view this problem as a normal and natural part of the aging process that simply doesn’t warrant significant attention.  However there is a well known correlation between low testosterone and several chronic medical conditions, including depression, diabetes, obesity, and possibly even cardiovascular disease.

Actually, there could be an inverse relationship.  For example, the same processes which lead to high blood pressure or diabetes could potentially also be the root of a patient’s low testosterone.  In this respect, low testosterone levels could serve as a marker for health decline.  After all, it is a clinically proven fact that low testosterone impacts several bodily systems, and numerous areas of life.  This simply means that just as the separate and different parts of the body come together to make a single unit, the various symptoms can work together to adversely affect a specific segment of life.  Here are some of the negatively affected areas and their respective primary symptoms:

• Changes in sexual function.  This may include erectile dysfunction – the inability to become sexually aroused, reduced quality and/or duration of erections, fewer spontaneous erections (awake or asleep); reduced libido/sexual desire; decreased sperm count or motility, and ultimately infertility.

• Emotional changes.  An increase in moodiness and seemingly bipolar (rapid or extreme) mood swings; decreased motivation and/or self-confidence; reduced mental clarity, including problems like trouble concentrating, recalling facts, or remembering things; unwarranted feelings of sadness, loneliness or depression and; a general decreased sense of well-being.

• Changes in sleep patterns.  Easily disturbed or light sleeping; a decreased ability to achieve latter stages of sleep (3, 4, and REM); insomnia – a reduced ability to readily fall asleep and; other sleep sensitivities and disturbances including an inability to sleep through the night.

• Physical changes.  Breast tenderness, swelling, or nodules/lumps (gynecomastia – female breast tissue in men); reduced lean body mass and muscular strength; decreased bone density; an increase in body fat; hair loss (both thinning and falling out); hot flashes and; a general lack of energy.

Physical Appearance Measures

BODY FAT

According to the National Heart, Lung, and Blood Institute (NIH), housed within the U.S. Department of Health and Human Services, the body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women.  The factors used to compute BMI are weight and height using standard or metric measures.  Its results are equivalent to the following BMI categories:

• Underweight = <18.5
• Normal weight = 18.5–24.9
• Overweight = 25–29.9
• Obesity = BMI of 30 or greater

Specifically, the BMI is calculated by dividing weight (in kg) by the square of height (in meters).  A BMI of greater than 25 indicates overweight status, while a BMI greater than 30 usually (according to most national boards) indicates obesity.  The National Health and Nutrition Examination Survey (NHANES II) uses a BMI cutoff point for obesity in men of 27.8, a cutoff point in women of 27.3.  Based primarily on data provided at the Department of Health and Human Services Consensus Conference on Obesity, April,1 1992, the National Academy of Sciences’ diet and health report suggests the following normal BMI ranges:

Age	Normal BMI Range
45 to 54 years	22 to 27
55 to 65 years	23 to 28
Over 65 years	24 to 29

Dr. Ben Z. Krentzman is an expert on the topic of weight control, obesity, and diet drug is a former family practitioner who became board certified in and switched exclusively to treating obesity patients in 1993.  Although the BMI uses a large chart for its scale, according to Dr. KrentzmanBMI ranges can be accurately interpreted thusly:

• A score of 20 to 26 is desirable for most middle-aged adults.  Additionally, nonsmokers with a consistent BMI in this range constitute those with the lowest risk of disease and premature death.  For individuals in the category, weight gain can be avoided through moderate eating habits and exercise.

• A score from 27 to 29 is characteristic of the moderately overweight, and carries a slightly increased risk of weight-related health problems, such as high blood pressure, high blood serum cholesterol levels, heart disease, and adult-onset diabetes. To prevent the development of weight-related health problems, members of this category should adopt a low-fat diet and a routine of regular exercise to avoid gaining additional weight.

• A score of 30 to 40 represents significant obesity, along with the risk of developing heart disease and other weight-related conditions, such as adult-onset diabetics.

• A BMI of 40 or higher tops the scale.  Members of this category are in danger of dying early, 80% of whom are frequent binge eaters, and the majority practice eating in secret.

Very similar, to the BMI is the Hamilton and Whitney’s Nutrition Concepts and Controversies Scale, which also accommodates gender and provides the following interpretation:

Men	Women	Risk Factor
<20.7	<19.1	Underweight. The lower the BMI the greater the risk
20.7 to 26.4	19.1 to 25.8	Normal, very low risk
26.4 to 27.8	25.8 to 27.3	Marginally overweight, some risk
27.8 to 31.1	27.3 to 32.2	Overweight, moderate risk
31.1 to 45.4	32.3 to 44.8	Severe overweight, high risk
> 45.4	> 44.8	Morbid obesity, very high risk

Very similar to NHANES II above, the National Institutes of Health (NIH) provided the following guidelines:

• Men:  Desirable body mass is 22 to 24. Obesity begins at 28.5, and serious obesity begins at 33. 

• Women:  Desirable body mass is 21-23. Obesity (20 percent above the desirable range) begins at 27.5. Serious obesity (40% above) begins at 31.5.

As exhibited by the both NHANES II and NIH, most measures have only modest differences in obesity criteria, usually within one point of each other.  This is true even when the measure itself is adjusted, for example in June of 1998 the National Institutes of Health changed to consider people with a BMI of 25 to 29.9 are overweight, while those with a BMI of 30 or above are obese.  In the year 2000 the Dietary Guidelines provided by both the US Department of Agriculture and the Department of Health and Human Services released this measure on weight and obesity:

• 18.5 – 25.0 kg/m²         Healthy Weight
• 25.0 – 29.9 kg/m²        Overweight
• > 30.0 kg/m²                   Obese

Another often used scale, the waist-to-height ratio (WHtR), is calculated by dividing waist size by height and measurement of under 50.0% is generally considered healthy.  The WHtR is believed to provide a more accurate assessment of health for serious athletes who fall outside the realm of normal bodily dimensions, especially bodybuilders, who have a higher percentage of muscle and a lower percentage of body fat.  It is also typically used to more accurately measure women who have a “pear” rather than an “apple” shaped body.  The waist-to-height ratio takes advantage of what’s called an anthropometric index, which evaluates the clustering of coronary risk factors among men and women who are not obese.  More specifically, as weight changes with regard to every 6-8 lbs, one can expect to lose about an inch from the waistline.

The Willoughby athlete weight and waist scale takes these calculations a step further.  In the early twentieth century champion body builder David P. Willoughby performed extensive anthropometrics measurements on highly-conditioned (male) athletes and discovered a directly proportional correlation between waist and height.  He determined the ideal form would have a WHtR of 45.8%.  Then by analyzing data on the morbidly obese, Willoughby found the same correlation between waist and height, but with a WHtR of 57.7%.  After much work cross referencing the Metropolitan Life Tables (the weight values on height in accordance with the calculation of Quetelet’s Index or BMI), with weight data proportional to the cube of the height (in accordance with Rohrer’s Index) he determined the average ideal weight for male athletes, which permits higher weight for strength-trainers and less weight for endurance athletes.  The Willoughby athlete waist is calculated by multiplying the height by 0.4584.

In general, body fat percentage is calculated for males as 100*(-98.42 + 4.15*waist – 0.082*weight)/weight, and for females as 100*(-76.76 + 4.15*waist – 0.082*weight)/weight.  The benefit here is that body fat calculations are based on two measures, i.e., both on weight and waist size, while also providing a separate allowance for muscle mass.  Here each measure is sensitive to the other wherein a lowering the value for the weight without a change waist size is considered by the calculation as a loss of muscle mass, and an increase in the percent body fat.  However, due to the inability to accurately measure waist size, this calculation is not recommended for evaluating minor changes in body weight.  In such cases water displacement, calipers, and body weight scales are preferred.

The minimal percentage of body weight considered “essential fat” is approximately 4% for men and approximately 10% for women.  Although the American Dietetic Association recommends that men maintain 15-18% body fat and women maintain 20-25% body fat, healthy male athletes tend to hover around 5-12% body fat whereas healthy female athletes range from about 10-20%.  These measures are much more aligned with the American Council on Exercise’s body fat recommendation of 6-25% for men, and 14-31% for women.

How Low Testosterone Influences Physical Appearance

The body has a series of set points, i.e., homeostatic levels at which it is comfortable.  Included among such levels are measures like heart rate, blood pressure, respiration, hormone secretion (thyroid, testosterone, estrogen, etc.), and metabolism among others.  The latter, more popularly known as the basal metabolic rate (BMR)

is the energy expenditure without any contribution from exercise or digestion.  BMR is best taken in a darkened room upon waking after 8 hours of sleep; or following a fasting state of 12 hours to ensure an inactive digestive system; and while resting in a reclined position.  This same measure is sometimes erroneously referred to by the term resting energy expenditure (REE), which is quite different as it tends to include energy used in digesting food.  REE measurements are typically taken under less restricted conditions than BMR, and do not require that the subject spend the night.  The old BMR calculation was flawed, the latest generally accepted version is:

• Men, BMR = 66 + ( 6.23 x weight in lbs ) + ( 12.7 x height in inches ) – ( 6.8 x age in year )
• Women, BMR = 655 + ( 4.35 x weight in lbs ) + ( 4.7 x height in inches ) – ( 4.7 x age in years )

Numerous clinical studies have conclusively determined one of the bodily factors directly influenced by testosterone secretion to be metabolic rate.  Low serum testosterone levels are directly related to metabolic syndrome, characterized by central obesity, insulin resistance, dyslipidemia, hypertension, and late-onset hypogonadism has been highlighted by several epidemiologic studies.  According researcher A. Tsujimura’s (Department of Urology, Osaka University Graduate School of Medicine, Suita, Japan) study on ‘ The Relationship between Testosterone Deficiency and Men’s Health’ in the World Journal of Men’s Health published in August of 2013, numerous randomized clinical trials have demonstrated that testosterone replacement treatment significantly decreases insulin resistance in addition to its advantage for obesity.

A July 2013 study from the Journal of Sexual Medicine entitled ‘Metabolic Syndrome in Men with Low Testosterone Levels: Relationship with Cardiovascular Risk Factors and Comorbidities and with Erectile Dysfunction’ by E. Garcia-Cruz, et al (Department of Urology, Hospital Clinic de Barcelona, Barcelona, Spain) the expressed aim was to identify cardiovascular comorbidities and risk factors, including erectile dysfunction (ED), associated with metabolic syndrome in men 45 year of age and older with total testosterone (< 8 nmol/L, or <12 nmol/L) and to gain further insight into the relationship between both conditions.  Garcia-Cruz, et al collected data from a multi-center, cross-sectional, observational study conducted in Spain among healthcare office visiting men with a confirmed diagnosis of testosterone deficiency.  Although subject data for low testosterone levels was central to this analysis, other available data included metabolic syndrome statistics, toxic habits, cardiovascular comorbidities (two or more coexisting medical conditions or disease processes that are additional to an initial diagnosis), ED diagnosis, and anthropometrics – a measurement or description of the physical dimensions and properties of the body, typically used on upper and lower limbs, neck, and trunk.  The study measures used included the metabolic syndrome harmonized definition, a waist circumference threshold of 94 cm, and an ED diagnosis as classified by the International Index of Erectile Function-5 (IIEF-5) questionnaire.  The analysis analyses used to calculate odds ratios (ORs) for metabolic syndrome included both bivariate and multivariate logistic regression.  Bivariate analysis demonstrated that moderate or severe ED, obesity, and peripheral vascular disease (PVD) were the variables associated with the greatest odds of metabolic syndrome (OR = 2.672 and 2.514, respectively), followed by alcohol intake (OR = 1.911), and that elevated triglycerides and HDL-cholesterol were metabolic syndrome risk factors associated with a lower testosterone levels.  Garcia-Cruz, et al concluded that moderate to severe low testosterone values, ED, obesity, PVD, and alcohol intake all significantly increase the likelihood of metabolic syndrome – a condition of reduced metabolic function that promotes excessive body weight and body fat gain.

Chang Gung University College of Medicine, Taiwan researchers RT Liu, et al published a July 2013 study in the Journal of Urology entitled, ‘The prevalence and predictors of androgen deficiency in Taiwanese men with type 2 diabetes’.  The objective of this study was to evaluate the prevalence and predictors of androgen deficiency, i.e., low testosterone in Taiwanese men with type 2 diabetes.  RT Liu, et al found that of the 766 subjects attending out-patient diabetic clinics they possessed:  a mean age 62.2 years; a mean body mass index (BMI) of 26.0; and that 32.5% tested positive for low testosterone levels.  Furthermore, the low testosterone subgroup tended to be older, with a higher:  BMI; sensitivity C-reactive protein (hsCRP); proportion of metabolic syndrome and stroke; triglyceride levels; uric acid levels; and waist circumference.  This same subset also possessed poorer total cholesterol levels both low-density lipoprotein (LDL) and high-density lipoprotein (HDL), than the normal testosterone group.  After age adjustment, low testosterone was positively associated with metabolic syndrome in each of the aforementioned measurement categories using logistic regression analysis.  RT Liu, et al found of the nearly 800 test subjects, a full one third of Taiwanese men with type 2 diabetes also possessed low testosterone levels.  These researchers concluded that the major predictors of low testosterone are linked to obesity, which is a potentially modifiable risk factor, and may represent an important avenue for intervention.

In May of 2013 the European Journal of Endocrinology published a study by G. Corona, et al performed a meta-analytical study entitled, ‘Body weight loss reverts obesity-associated hypogonadotropic hypogonadism: a systematic review and meta-analysis’.  Calculated at the Sexual Medicine Andrology Unit, Department of Experimental, Clinical and Biomedical Sciences, University of Florence, Florence, Italy, G. Corona, et al analyzed the findings of 24 randomized clinical studies with the aim of discovering the effect of body weight loss on sex hormone levels.  Using extensive Medline data from January 1, 1969 to August 31, 2012 the found that both a low-calorie diet and bariatric surgery are associated with a significant (P<0.0001) increase in plasma sex hormone-binding globulin-bound and -unbound testosterone levels.  Using multiple regression analysis G. Corona, et al showed that the degree of body weight loss is the best determinant of total testosterone levels, and that androgen rise is greater in those patients who lose more weight as well as in younger, non-diabetic subjects with a greater degree of obesity.  G. Corona, et al concluded that weight loss is highly correlated with an increase in total testosterone levels (both bound and unbound).

This volume of contemporary, valid and reliable clinical and meta-analytical studies supports a genuine association between overweight conditions like obesity, diabetes, and other related factors that directly impact physical appearance and testosterone levels.  Study after study comparing low testosterone levels, hypogonadism, testosterone therapy effects, control and experimental groups, comorbidity (the presence of two or more concurrent disorders), and a multitude of other variables consistently and conclusively cite a direct relationship between low testosterone and physical appearance.

REFERENCE LIST

• Definition, categories, and computation of the body mass index (BMI)
• National Heart, Lung, and Blood Institute (NIH)
• U.S. Department of Health and Human Services
• http://www.nhlbi.nih.gov/guidelines/obesity/BMI/bmicalc.htm
• Am J Clin Nutr 2002 76 743. An interesting perspective on height-to-waist ratio is provided in Int J Obes Relat Metab Disord. 2003 May; 27(5): 610-6.
• Harris J, Benedict F. A biometric study of basal metabolism in man. Washington D.C. Carnegie Institute of Washington. 1919.
• The Relationship between Testosterone Deficiency and Men’s Health.
• Tsujimura A.
• World J Mens Health. 2013 Aug;31(2):126-135. Epub 2013 Aug 31. Review.
• Metabolic Syndrome in Men with Low Testosterone Levels: Relationship with Cardiovascular Risk Factors and Comorbidities and with Erectile Dysfunction.
• García-Cruz E, Leibar-Tamayo A, Romero J, Piqueras M, Luque P, Cardeñosa O, Alcaraz A.
• J Sex Med. 2013 Jul 30. doi: 10.1111/jsm.12265.
• The prevalence and predictors of androgen deficiency in Taiwanese men with type 2 diabetes.
• Liu RT, Chung MS, Wang PW, Chen CD, Lee JJ, Lee WC, Chancellor MB, Yang KD, Chuang YC.
• Urology. 2013 Jul;82(1):124-9. doi: 10.1016/j.urology.2013.03.023. Epub 2013 May 12.
• Body weight loss reverts obesity-associated hypogonadotropic hypogonadism: a systematic review and meta-analysis.
• Corona G, Rastrelli G, Monami M, Saad F, Luconi M, Lucchese M, Facchiano E, Sforza A, Forti G, Mannucci E, Maggi M.
• Eur J Endocrinol. 2013 May 2;168(6):829-43. doi: 10.1530/EJE-12-0955. Print 2013 Jun. Review.