Testosterone is a steroid hormone that falls under androgen group. The primary function of this group generally involves the maintenance of sexual functions, sperm conditions and secondary traits. This hormone is generally secreted by the testes in male body, though few traces of it are found in females. The secretion of testosterone begins during ones puberty and attains peak level, this level gradually depletes along with age. Recent developments have associated testosterone with major body functions which involves cardiovascular functions, locomotion activities, metabolism etc.. Here we will discuss the correlation between testosterone levels and obesity.
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Relation between Testosterone Levels and Obesity
Obesity is now becoming a raging concern for the health of people across the world, and the role of testosterone behind this epidemic has received the attention of the physicians and health researchers. Testosterone has turned out to be a key factor in metabolizing fat in cells and loss of fat in our body.
Testosterone is a major player in maintaining various regulatory functions including fat burning, body mass, muscle mass etc.. Loss of testosterone (hypogonadism) poses a major threat in disrupting the delicate balance that holds our bodily functions leading to the onset of obesity and many other health related problems. The 3 ways by which the testosterone plays its part are:
- Lipoprotein lipase is responsible for the uptake of fat in cells, thus aiding in the fat storage process, and testosterone happens to have an inhibiting effect on the role of lipoprotein lipase.
- Testosterone and dehydroepiandrosterone (DHEA) seems to play a major role in fat burning metabolism, mostly in visceral adipose tissues. Testosterone helps in inhibition of differentiation in the precursor adipose cells. These hormones amplify the receptor expressions of GLUT-1 and GLUT-4, present on the plasma membrane of fat cells, which stimulates the resting metabolic rate of the body (RMR) along with lipid oxidation, enhances the glucose oxidation, thus helping in fat reduction.
- A comparative study among eugonadal men and IHH (idiopathic hypogonadotropic hypogonadism) patients displayed higher levels of fasting plasma glucose, higher concentrations in the levels of fasting plasma insulin, elevated score of HOMA-IR (homeostasis model assessment of insulin resistance), and reduced QUICKI (quantitative insulin sensitivity check index) score. Administration of testosterone therapy, elevated insulin sensitivity and insulin metabolism, ameliorated metabolism of lipid resulting in decrease of fat deposits and enhancement in muscle fibers.
- Testosterone application also benefits the body composition with its potential to tweak and deplete the lean body mass and fat mass respectively.
Another noteworthy study conducted by researchers in Sweden in 1991 to observe the consequence of testosterone supplementation on the aggregate abdominal fat mass in obese men belonging to middle aged group. The volunteers were either given a single injection of 500 mg or moderate doses of 40 mg were given 4 times continuously for 6 weeks through oral administration. Abdominal lipoprotein lipase (LPL) activity tended to reduce after 1 week of administration, and after six weeks substantial decrease was observed in the abdominal and femoral regions. The effects were not limited to LPL values, visible results surfaced in forms of decrease in the circumferences of waist and hip. This study led authors to summarize that testosterone supplementation escalate fat metabolism in adipose tissues and reduces body fat mass. Additionally, a Neoteric review emphasized that multiple trials demonstrated increase in the values of lean body mass and consequential decrease in fat mass when subjected to varying degree of testosterone supplementation.
The regulatory aspects of correlation between testosterone secretion and maintenance of plasma level in men still remain controversial. The most intriguing side of this relationship depends on the relation between age and testosterone. Supranormal increase in SHBG (sex hormone binding globulin) after consumption of weight minimizing diet has also been observed. These observations formed the base of a study in which the researchers investigated the impact of BMI (body mass index), smoking habits, age, insulin levels in the level of testosterone and sex hormone binding globulin (SHBG) in 250 healthy non-obese people and 50 obese people throughout their weight variation. The analyzation of the observations led to the deduction of following results-
- In healthy, non-obese people, androgen levels share an inverse relation with age, while the sex hormone binding globulin (SHBG) shares a positive relation.
- Body Mass Index (BMI) of non-obese people elevated with age, even when BMI shared negative correlation with testosterone, serum testosterone, and SHBG SHBG (sex hormone binding globulin), but age related testosterone levels remained the same.
- The testosterone, serum testosterone, and SHBG SHBG (sex hormone binding globulin) levels of obese men were considerably lower than the levels of healthy, non-obese men, but the Body mass index (BMI) levels shared inverse correlation. The measurements of Dihydroepiandrsteroe (DHEAS) levels were marginally lower than the levels of healthy, non-obese men.
- A weight loss of about 15 kgs was observed in obese men after their consumption of protein rich, weight minimizing diet, even the sex hormone binding globulin (SHBG) levels attained optimal values and an increase in the insulin levels was observed, which was greater than the levels of non-obese people.
Another study was performed to investigate the correlation that exists between testosterone, elevated insulin levels, and process of fat distribution in obese males. For this study 52 obese people were considered, whose values were compared with 20 healthy, normal weight people taken as controls. The parameters that were associated with this study mainly comprised of circumference ratio of waist to hip (used to measure the fat distribution, testosterone (total and free) and sex hormone-binding globulin (SHBG) levels. The results obtained by evaluation of these parameters were-
- Fat distribution was abnormal in obese people than the controls.
- The levels of testosterone and sex hormone-binding globulin (SHBG) were significantly lower in obese men than compared to the levels of the non-obese.
- C-peptide levels and insulin levels (glucose and fasting) were higher in obese than in controls.
Levels of total testosterone (plasma) share an inverse relation to the degree of obesity, a study was performed to investigate the relationship that exists between free testosterone (plasma) and non SHBG (sex hormone binding globulin) bound testosterone. To obtain desired answers total plasma testosterone level in 48 volunteers were measured was measured. Free testosterone (plasma) and non SHBG (sex hormone binding globulin) bound testosterone was measured by the data from total testosterone (plasma). Dilution of the heavy-water isotope was utilized to measure the mean body fat mass. The results acquired from these methods were-
- Body Mass Index (BMI) shares a positive correlation with mean fat content in the body; thus, measurement of height and weight is sufficient for calculating the extent of obesity. The degree of obesity can also be measured by measuring the aggregate fat content.
- Total testosterone (plasma), non-SHBG-(sex hormone binding globulin) bound testosterone, and free testosterone (plasma) shared complimentary inverse correlation with Body Mass Index (BMI).
These observations led the researchers to conclude that, non-SHBG-(sex hormone binding globulin) bound testosterone and free testosterone (plasma) levels decrease with increase in degree of obesity, which is similar to that of total testosterone (plasma); however when calculated in percentage, the extent of declination for all the three parameters was identical.
An abnormality in body’s fat distribution is a primary consequence of a decrease in testosterone levels. The data for upper body fat content in women suggest it to be a result of decrease in sex hormone binding globulin levels. A population based study was organized to investigate the correlation between the levels of free testosterone, sex hormone binding globulin (SHBG), dihydroepiandrosterone sulfate (DHEAS), oestradiol and total body fat content by measuring the ratio of waist to hip and conicity index (used to measure the abdominal circumference) of 178 volunteers. The results that were obtained from the study was-
- An inverse correlation existed between the levels of free testosterone, sex hormone binding globulin (SHBG), dihydroepiandrosterone sulfate (DHEAS), oestradiol and total fat content.
This study demonstrated that in obese men the obesity is one of the key reasons behind the decline of levels of sex hormones.
How can one overcome obesity?
Obesity is regarded as the physical condition where a person suffers from excessive quantity of fat in the subcutaneous layer. Testosterone acts an inhibitor of factors related to obesity. Obese men, having age above 60 years, mostly suffer from testosterone deficiency (hypogonadism). It is often observed that with the decrease in testosterone level elevation occurs at the levels of fat deposits in adipose tissue cells leading to obesity. Furthermore, cell culture analysis exposed testosterone’s ability to express an elevated lipolytic potential and inhibit the activity of lipoprotein lipase activity (LPL).
Weight reducing diet is becoming much popular these days, people tend to lose weight much faster by dieting, but the lost weight tends to return within five years. The search for an effective and efficient way to deal with obesity and maintaining a toned body is the primary objective these days. Obesity is regarded as a chronic disease, its treatment will be directed similar to that of other chronic diseases like high blood pressure and diabetes. Treating obesity cannot be a quick fix; rather, it’s a long term treatment plan.
Even minimal weight loss in obesity treatment is considered beneficial. For example, a minimal weight reduction of (5-10) % of the preliminary weight, and constant maintenance of that reduced weight can bring noteworthy health gains, which also includes-
- Reduction in blood pressure;
- Cholesterol levels get reduced
- The risk of type 2 diabetes gets diminished.
- The probability of getting a massive or minor stroke, coronary disease reduces;
- Reduced onset of chronic heart disease;
- Overall mortality rates reduce.
Role of physical activity:
It is regarded that people who involve themselves in regular physical activities acquire fat at a slower rate than idle people. Physical activity and exercises are one of the usual ways by which one can reduce the fat content of the body by burning extra calories. Burning of calories also vary according to the type, intensity and duration of the physical activity. The weight of a person is also one factor in calorie loss, for example, a man weighing 300 pounds will lose calorie at a much faster rate than a 150 pound man even if they run the same distance. Physical activity cannot cure obesity all by itself, it needs the aid of proper dieting and routine maintenance. Regular exercise also helps people to maintain a sound and effective lifestyle. The weight loss is not the only forte of exercise, as it helps in toning one’s muscles, some other benefits are-
- Enhancement in insulin content and sensitivity, thus helping a diabetic patient.
- Triglyceride levels get lowered, while body gains good cholesterol.
- Reduction in blood pressure.
- Abdominal fat content gets lowered.
- The probability of getting a massive or minor stroke, coronary disease reduces,
- Endorphins are released into the blood stream, helping in mood improvement.
Proper diet is the key to maintain the weight loss. The primary goal of proper dieting is to halt gaining weight in the future. The next objective of dieting is to maintain the previous goal. A body Mass Index (BMI) of 20-25 is considered to be the ideal weight for healthy people. Thus, achieving success in weight reduction lies in fixing target on an incremental basis. Reduction of any magnitude is considered to be beneficial in weight reduction.
Consumption of few calories is effective in dieting. 3,500 calories is equal to 1 pound, thus to lose 1 pound one has to lose 3500 calories more than the total calorie consumed. The calorie requirements vary amongst the adults, depending on their work schedule and the amount of physical labour.
Let’s take the example of a bowl of an ice cream, skipping it will take someone one-seventh step towards losing 1 pound. A routine of losing 1 pound per week will help in achieving a stable weight loss. Initial weight acts as a determining factor for losing weight, as a person having higher initial weight will lose weight much faster than others. This is generally for every 2.2 pound loss in body weight, nearly 22 calories is essential to maintain that new weight. For example, in case of a woman weighing 220 pounds (100 kilos), 2200 calories are required to maintain her weight, whereas for a 132 pound woman (60 kilos), 1320 calories is required. If both of them consume a reduced diet of 1200 calories, the heavier woman loses weight faster than the lighter one. Age also becomes an essential factor, with reduction of metabolic rate fat burning reduces, thus aged people tends to lose weight at a much slower rate.
There is a dispute surrounding the carbohydrates and weight loss. With a restriction of carbohydrate rich diet, people tend to lose weight rapidly for the first two weeks. This rapid weight loss is considered to be loss of fluids. Addition of carbohydrates in the diet causes regaining of loss fluids and gaining of lost weight.
Regardless of the above mentioned ways to combat obesity, there are other ways too. The advancement of research has led to the development of many alternative ways to deal with weight loss, some of them are- meal substitute, artificial sweeteners, food products etc.
Testosterone deficiency escalates with aging. Loss of physical integrity, problems in fat metabolism leading to obesity, are general problems associated along with this gradual decrease. Various studies, including the ones described above has made us to acknowledge the repercussions of testosterone deficiency and the palliating capacities of testosterone replacement therapy.