Puberty occurs when areas within the brain awaken beginning a cascade of hormone signals which conclude with the gonads (ovaries and testicles) increasing their production of the female and male sex hormones estrogen and testosterone. Under the influence of these hormones a child begins the transition from childhood to sexual maturity. In boys puberty is associated with a growth spurt, the appearance of facial, axillary (arm pit) and pubic hair, acne, deepening of the voice, growth of the testicles and penis while girls undergo a growth spurt, develop breasts, acne, pubic and axillary hair, and growth of the clitoris.
Historical data shows the average age of puberty today is many years sooner than in previous generations. Most experts attribute earlier puberty to better nutrition. A recent article in metabolism.com reviewed how “over-nutrition” accelerates obese children into puberty sooner (referred to as precocious puberty) than normal weight children. The latest studies on causes of precocious puberty suggests that a child’s social environment also exerts an important influence on the timing of puberty. Researchers in Madrid publishing in The Journal of Clinical Endocrinology and Metabolism 95:4305 2010 analyzed the age of puberty in normal children, adopted children and children whose families immigrated (children not adopted but subject to high levels of personal stress) to Spain. Adopted children were 25 times more likely than other groups of children to undergo precocious puberty (breast development before the age of 8 years in girls, and boys under 9 years of age with testicular growth). Over-all girls were 11 times more likely than boys to demonstrate precocious puberty.
Researchers speculate that socio-emotional stresses early in life of children who are later adopted result in changes in the brain that cause premature maturation of vital nerve pathways. This early brain maturation later results in stimulation of the pituitary gland, turning on the hormone pathways that cause puberty. This seems strange to me because various forms of deprivation in childhood can also delay puberty. For example, girls who have anorexia remain child-like in their body development and may fail to menstruate even into their late teens. A decade ago I studied hormone levels in adults during the stress of illness and surgery and found this lowered the sex hormone levels in their blood. This makes sense from an evolutionary point of view because during stressful conditions nature wisely cuts off the reproductive hormones. Why make babies if the environment is hostile in some way? Why the opposite occurs in children under stress of adoption is an interesting but unanswered question.
Gary Pepper, M.D.,
It seems obvious that cutting away part of the stomach and intestine should cause weight loss. With a smaller stomach and less intestine fewer calories can be absorbed per day causing weight loss. Surgeons who perform gastric by-pass were puzzled however, by how fast their patients showed metabolic improvement after undergoing this procedure. They noticed many of their diabetic patients could be taken off diabetic medication immediately after surgery before weight had been lost. Scientists looking into this phenomena discovered unsuspected ways gastric by-pass improved metabolism.
The intestines produce hormones which regulate blood sugar and appetite. GLP-1 is among the best known of these intestinal hormones. GLP-1 is the basis of a whole new generation of medications used to treat diabetes such as Byetta, Victoza, Januvia and Onglyza. GLP-1 lowers blood sugar, stimulates the pancreas and reduces appetite. After gastric by-pass increased amounts of GLP-1 are produced by the remaining intestine. In a study published in the Journal of Clinical Endocrinology and Metabolism (95:4072-4076, 2010), researchers at St. Lukeâ€™s Hospital in New York discovered that levels of oxyntomodulin, another intestinal hormone that suppresses appetite and acts like GLP-1 on blood sugar levels, is doubled after gastric by-pass.
These exciting discoveries help explain why obese diabetics can often be sent home without any medication to control blood sugar immediately after undergoing gastric by-pass surgery. Although most insurance plans do not cover gastric by-pass surgery, dramatic improvements in patients after the procedure with greatly reduced medication costs may convince insurance companies that paying for the procedure will result in better outcomes and save them money in the long run.
Gary Pepper, M.D.
Due to the potential for abuse and high cost, growth hormone treatment in adults is the subject of much controversy. I believe that treating adults with growth hormone deficiency is many times an appropriate and beneficial choice. Firming up my conviction for treating adult growth hormone deficiency is a recent study conducted in the Netherlands and UK published in the Journal of Endocrinology and Metabolism (JCEM 95:3664-3674, 2010). The researchers compared Body Mass Index (BMI), waist circumference, triglycerides, and HDL (good cholesterol), between normal adults and those with low growth hormone levels due to deficient pituitary function (hypopituitarism). All measurements of obesity and lipid metabolism were significantly worse in the young adults (younger than 57 years) with growth hormone deficiency compared to normal adults of a similar age.
As I pointed out in previous articles at metabolism.com, growth hormone levels naturally decline as we get older. The authors of the present study note that growth hormone levels decline 14% per decade in adults. I conceive of this as one of the ways nature gets rid of us after we complete our biological/reproductive functions, since without growth hormone our muscles, immune and nervous systems, decline, leading to death. Itâ€™s planned obsolescence… what is typically referred to as aging. In the recent study senior citizens have equivalent levels of obesity and abnormal lipid metabolism as young adults with growth hormone deficiency. The authors note the effect on the body of growth hormone deficiency in young adults is equivalent to 40 years of aging. The theory that growth hormone functions to preserve our tissues during youth and aging results from its absence, appears confirmed by these results.
Most normal young adults arenâ€™t growth hormone deficient and the population that would qualify for growth hormone treatment from this group is small. What about older adults with low growth hormone who are troubled by the â€œnaturalâ€ decline in their body function? Should or could we treat this much larger population with growth hormone? It is my experience that private and federal insurers will not pay for this treatment regarded as â€œcosmeticâ€. On the other hand, there will be physicians who will comply with a request for growth hormone treatment from individuals who possess enough cash and motivation. Less affluent or determined individuals will have to contend with natural aging just as our ancestors have done for thousands of years.
This information is for educational purposes only and is not intended as medical advice or treatment.
Gary Pepper, M.D.
Large Neck Size Equals Big Metabolic Problems:
A bulging stomach is widely accepted as a sign of poor metabolic health. A recent study published in the August Clinical Endocrinology and Metabolism (95:3701, 2010), finds a chubby neck is likely to hold even a worse prognosis for metabolic health.
The research team evaluated the relationship between waist circumference and neck circumference with levels of blood sugar, good cholesterol (HDL), bad cholesterol (LDL), triglycerides, and insulin resistance, as well as blood pressure. What was found was that neck circumference was a better predictor than waist circumference of elevated blood pressure, LDL, triglycerides and insulin resistance, with lower levels of HDL. All this amounts to a greater risk of cardiovascular disease as neck size increases. As an example, an increase in neck circumference of about one inch is expected to result in a 2.5 point rise in blood pressure.
The authors point out that the neck circumference was a more accurate predictor of cardiovascular risk in women than men. The average neck size for men in this study was about 16 inches (40.5 cm) and about 13.7 inches for women (34 cm).
Alfred Hitchcock, the famous director of suspense movies, made a trademark of his corpulent silhouette with bulging chin and abdomen. Thanks to this research we know his silhouette can signify more than a movie that will thrill you but also a metabolism that will kill you.
Gary Pepper, M.D.
Good things can develop during a crisis situation. For me it was the eye opening experience I had this week by participating in The Thyroid Patient Community Call. The Thyroid Patient Community Call is a group internet telephone call hosted by Janie Bowthorpe, author of Stop The Thyroid Madness. During the 90 minute session I was able to interact with dozens of callers as well as Janie herself. Needless to say, Janie’s audience is mostly individuals who are deeply committed to maintaining Armour Thyroid as a treatment option and who are equally angry with the field of Endocrinology which backs the ban on dessicated thyroid hormone. I knew this audience wanted answers to some very tough and troubling questions. For a few days before the call I needed to review for myself just how this crisis developed, and how I became a lightning rod for the growing controversies. I believe this process was necessary and therapeutic.
Being a strong advocate of t4 plus t3 therapy and of Armour Thyroid, I was in sync with most of the topics being discussed on the call. What was hard for me was hearing the out pouring of stories describing how endocrinologists had alienated (infuriated) so many thyroid patients. How to explain but not excuse the inflexibility, wrong headedness and arrogance of a whole field of medicine on a topic central to its mission, my own field for the past 25 years? My head still hurts thinking about it. For those wanting to hear how this played out can visit Talkshoe.com which hosts these shows and follow the instructions for listening to past episodes of Janie’s show. Perhaps Janie can give more specific instructions by posting them here.
I came away from Janie’s session with a firm recognition that the field of Endocrinology is in serious need of a make-over. Imagine a Democrat walking into a room full of staunch Republicans and asking everyone to join him in a sensitivity training program. It is a lonely job.