Monthly Archives: March 2015

Tensile strain and articular cartilage

It may be possible to apply tensile strain to articular cartilage to induce endochondral ossification there thereby inducing height growth.

Effects of cyclic tensile strain on chondrocyte metabolism: a systematic review.

“Chondrocytes reorganize the extracellular matrix of articular cartilage in response to externally applied loads. Thereby, different loading characteristics lead to different biological responses. Despite of active research in this area, it is still unclear which parts of the extracellular matrix adapt in what ways, and how specific loading characteristics affect matrix changes. This review focuses on the influence of cyclic tensile strain on chondrocyte metabolism in vitro. It also aimed to identify anabolic or catabolic chondrocyte responses to different loading protocols. The key findings show that loading cells up to 3% strain, 0.17 Hz, and 2 h, resulted in weak or no biological responses. Loading between 3-10% strain, 0.17-0.5 Hz, and 2-12 h led to anabolic responses; and above 10% strain, 0.5 Hz, and 12 h catabolic events predominated{catabolic responses doesn’t necessarily mean bad for height growth}. However, this review also discusses that various other factors are involved in the remodeling of the extracellular matrix in response to loading, and that parameters like an inflammatory environment might influence the biological response.”<-3% strain is quite high but that’s for bone for cartilage it may be different.

“cartilage compression exposes the chondrocyte to compressive forces, to osmotic pressure, to fluid flows and also to tensile forces”<-lateral compression such as via lateral loading of the articular cartilage has potential to induce tensile forces.

“after loading with CTS, cells exhibited a more elongated cell shape and aligned perpendicular to the loading direction”

Collagen Type I was upregulated by CTS which could indicated endochondral ossification.

“Fibronectin connects collagen fibers and other ECM proteins. It is linked to the cell membrane through integrins and might transmit forces from the ECM to the chondrocyte. CTS at 7%, 0.33 Hz and 0.5 Hz, for 4, 12 and 24 h increased the fibronectin mRNA levels in comparison to non-loaded chondrocytes”

“7% CTS for 4 h at 0.33 Hz elevated the expression of IGF-1 and IGF-2. The mRNA expression of TGF-β1 was increased by several loading protocols ranging from strains of 5–12%, from 12–48 h and at frequencies of 0.05 and 0.5 Hz”

According to CYCLIC TENSILE STRAIN AND CYCLIC HYDROSTATIC PRESSURE DIFFERENTIALLY REGULATE EXPRESSION OF HYPERTROPHIC MARKERS IN PRIMARY CHONDROCYTES , tensile strain encourages endochondral ossification whereas hydrostatic pressure encourages chondrogenesis.

Study provides insight on how mechanical loading can affect growth

This study would only be relevant to people with existing growth plates as it only studies load effects on chondrocytes.  But, regardless, since we are studying mechanical loading methods to study height growth any mechanical loading study may be relevant.

Regional variations in growth plate chondrocyte deformation as predicted by three-dimensional multi-scale simulations.

“The physis, or growth plate, is a complex disc-shaped cartilage structure that is responsible for longitudinal bone growth. In this study, a multi-scale computational approach was undertaken to better understand how physiological loads are experienced by chondrocytes embedded inside chondrons when subjected to moderate strain under instantaneous compressive loading of the growth plate. Models of representative samples of compressed bone/growth-plate/bone from a 0.67 mm thick 4-month old bovine proximal tibial physis were subjected to a prescribed displacement equal to 20% of the growth plate thickness. At the macroscale level, the applied compressive deformation resulted in an overall compressive strain across the proliferative-hypertrophic zone of 17%. The microscale model predicted that chondrocytes sustained compressive height strains of 12% and 6% in the proliferative and hypertrophic zones, respectively, in the interior regions of the plate. This pattern was reversed within the outer 300 μm region at the free surface where cells were compressed by 10% in the proliferative and 26% in the hypertrophic zones, in agreement with experimental observations.  While the current model is relevant to fast dynamic events, such as heel strike in walking, we believe this approach provides new insight into the mechanical factors that regulate bone growth at the cell level and provides a basis for developing models to help interpret experimental results at varying time scales. ”

“The physis, or growth plate, is a complex disc-shaped cartilage structure that is responsible for longitudinal bone growth. This growth is modulated by many systemic and local factors including those arising from mechanical loading”

“Potential tissue level signals for modulating endochondral bone formation [include] hydrostatic and octahedral shear stresses and principal stresses”

“chondrocytes, are the active agents of growth and contribute to bone growth through cell proliferation, hypertrophy and extracellular matrix secretion in highly specialized, highly cellular and organized anatomic structures known as chondrons. It is likely that tissue level strains and stresses are experienced differently by chondrocytes embedded within such structures, possibly providing signals of varying intensity and type depending on location.”

“Mechanotransduction is more readily related to cell deformation than to tissue level stresses. In the context of bone growth, there is evidence that cell proliferation and differentiation can be regulated through activation of stretch-activated ion channels in the cell membrane following changes in cellular shape and size”

“Recent observational studies of physeal samples under compression have revealed regional variations in cellular strains and suggest that global physeal strains may be amplified at the cellular level”<-This statement may be applicable to other cells like the enthesis of ligament attachments or mesenchymal stem cells.

“The prescribed compressive displacement which was equivalent to 20% of the initial uncompressed combined initial thicknesses (0.67 mm) of RZ and P/H zones resulted in a -14.8% growth plate engineering strain across the combined layers of the reserve, proliferative and hypertrophic zones, while the combined proliferative and hypertrophic zone received -17.2% strain. The reserve zone experienced -9.5% and the calcified cartilage zone -3.3% compressive strain.”<-Effects on the reserve zone are interesting to us because those contain stem cells so would show any interesting effects on non-growth plate cells.

“Chondrons, the primary functional and structural units of the growth plate, deformed by buckling near the free surfaces where the cartilage bulged outward while remaining straight in the interior regions”

“chondrocytes in the interior of the growth plate undergo about 50% less strain than the prescribed overall growth plate strain.”

“Younger growth plates that are thicker (3 mm) also had thicker reserve zones, which may affect the transverse outward bulging at the free surface differently.”

“During compression of cells at short times scales (~0.5 s) intracellular water is redistributed within the cell[but not necessarily more compression]”

” At long time scales constant external pressure induces cell shrinkage, but cell shrinkage takes an order of magnitude (~10 s,) longer than the transient impact of heel strike or even the 0.2 s duration of the stance phase of a gait cycle and as long as an hour to reach equilibrium”

“growth plate stresses reached values of 0.1 to 0.6 MPa in compression during activities such as sitting. From the stress relaxation experiments on explants it may be estimated that 0.2 MPa corresponds to the stress levels attained after stress relaxation for displacements of the epiphysis equal to 20% of the initial growth plate thickness (defined as the combined thicknesses of the reserve, proliferative and hypertrophic zones).”

“Chondrons appear to be oriented along the minimum principal strain directions, becoming roughly perpendicular to the epiphyseal bone plate, whereas the hypertrophic portion along with the calcified cartilage bars and primary spongiosa align more with the primary compressive load direction along the tibial long axis”

Some interesting info but the significance is unclear yet.

To Dwell on Height-Healthy or Unhealthy?

To focus on the disadvantages of height is an unhealthy psychological pursuit.  To focus on striving to grow taller is a healthy psychological pursuit.

Here’s a typical conversation to someone about height:

A:  Don’t worry about height.  It’s what’s on the inside that counts.

B:  Why is it acceptable for height to be descriminated against?  Why is male height so associated with a male’s value?  Why is it acceptable to laugh at people because of their height?

A: You should accept who you are.  Play with the cards your dealt.

B:  If you have a losing hand, do you accept that or do you throw the cards off the table and start a fist fight?  If you can’t beat the game change the rules.

A: Life isn’t fair.  Sucks for you.

If you try to get into an argument with someone about height it usually begins with a lot of platitudes which are refuted until their opposing argument devolves into “too bad”.

The argument with the best reasoning often isn’t the argument that wins.  Short support sites shouldn’t exist.  Realistically, very little improvements can be made for the average or below against the tall.  And ultimately such sites serve as a means of perseverating on height.

You can try to forget your height.  You can play video games.  You can engage in an activity where height is of less importance such as a musical instrument.  Although even in those activities such as piano or guitar, finger length has an effect on playing.  You can get around it with techniques but it’s still a reminder that you’re just not as good.  Even playing pool, height can be an advantage in performing certain shots.

There’s acceptance but will you ever accept?  Ryan Seacrest complains about his height all the time.  There’s escapism but will you be satisfied with just escape?  Most forms of escapism lack the depth and complexity of real life.

The healthiest way to focus on height is to strive to find a way to grow taller.  Instead of dwelling on it.  Instead of comparing height with your friends.  Instead of realizing that you’re shorter than that other guy that you thought was really short.

The research I’ve done on entheses is intriguing and I’m trying to develop a new routine to explore it. What’s most intriguing about Entheses is that it resembles the Zone of Ranvier which contains the stem cells to contribute to the growth plate.  What if by pushing two bones together such as the fibula and the tibia on the epiphyseal region we can stimulate the entheses to form neo growth plates?

Don’t accept that there’s no way to grow taller.

Your height is mostly based on the length of your bones{The other determinants of height are opportunities to find new ways to grow taller}.  The length of the bones is determined mostly by your growth plate{The rest of the length is determined by other means but are difficult to get to contribute in significant ways but again is another way to pursue the quest for height}.  The growth plate goes away after puberty after the exhaustion of the stem cells that contribute to the growth plate.

To grow taller you could find:

1) Increase other minor determinants of height not involving growth plate growth

2) Induce the formation of neo growth plates

3) Induce plastic(permanent) deformation of the long bones.  Stretch the bones in such a way that they increase in length in a way that is instant and permanent(although this has never bone in done and the mechanisms of measurement are not accurate enough to best gauge the elastic and plastic range of a bone).

4) Other?  For you to determine.

Escapism and acceptance aren’t the only options for dealing with your height.  Don’t let people tell you that you should just accept your height.  Every time you think about dwelling on the negative effects of not being tall, focus instead on finding ways to grow taller.

You can get distraction osteogenesis surgery but it costs a lot of money and ideally you’d have multiple surgeries.

This field of science is entirely under researched(but most areas are due to how slowly science progresses).  And due to the complexity it is difficult for it to be Lorenzo’s Oiled(Homemade scientific discovery).  It’ll be hard to find a more efficient way of performing distraction osteogenesis but you could find a home made way of inducing new growth plate formation.  Cells do respond to mechanical and chemical stimulation after all.  And has every manner of mechanical stimulation already been performed?  No.  Especially methods that would appear counterintuitive like lateral joint loading(now adjusted to focus more on pushing two bones together near the entheses rather than clamping the synovial joint region).  And there are novel apparatus to create to generate forces that we couldn’t using our own muscular force.

Don’t dwell on how Dave France doesn’t get as good a roles as James Franco because he’s shorter.  Don’t dwell on how the third Hemsworth brother doesn’t get as many roles because he’s shorter.

Focus on researching methods to grow taller!  Even when I find a way to grow taller, it’s not going to be perfect right away.  I’m going to need your help.  You’re going to need my help.  The faster people stop dwelling on height and start growing taller the faster we can start getting taller.

If You Feel Depressed Or Angry Over Your Short Height – For Reddit and Sluthate

I do track the websites which link to this website. Some of the most common sites that come to this website are from some of the most negative areas on the internet. The level of anger, bitterness, and spite on these strange internet discussion boards means that you can’t tell the difference between a genuine poster who just wants to vent and rant onto an internet discussion board and a troll. I’ll just say a few messages for those guys who feel depressed, angry, resentful, or just mentally stuck over their short height. This is directed mainly towards reddit/r/short and places like sluthate.com

Guys, take it down a little. You may be 5’6″ and have some level of asperger’s syndrome but that does not mean that you can’t enjoy your life. If you are thinking of killing yourself or hurting another person Rodger Eliot style, then read the following message.

I would assume that most people believe that they are above average in intelligence. Well, two of the principle traits of people who are truly intelligent exhibit are that 1) they can make decisions based on long term goals and 2) have the ability to control their emotional impulses and states. You can may be really good at mathematics but you still can’t control your own emotional state with the behavior of an immature child. For those of you who read this message, you know who you are. Emotional Intelligence has been shown to be often a much better indicator of eventual success in life than any traditional IQ test.

Start of my message

I don’t do much these days for this website since I run my own business which now takes up so much of my time. However, let me assure the regular readers that based on what I have seen from being on the cutting edge of the tissue engineering & biomedical fields, there will be something that will come out in the coming decades that will be much better than the limb lengthening surgeries you see today, which means less pain, less invasive, and less possibility for surgical complications. I am talking about lab grown growth plate implantations and healing intervertebral discs compression. I personally don’t think it is possible to “reopen the growth plates” which so many people hope for. Some little bit of surgical incision will be needed to cut the bone slightly (osteonomy). I do dare to dream big, but I am also a realist on what is possible, and what is pure science fiction. There are no magic pills or silver bullets.

You guys should not be worrying how tall you are and how much the world discriminate against you. You can’t change the world, unless you feel like it is your life’s mission to combat heightism similar to MLK to black/white conflict and put in maybe 20 years of hard work to make slight social changes. I suggest that you should not waste your time and energy on fighting an uphill battle against this hard-wired instinctual pre-programming which most humans have which creates prejudice towards shorter humans.

It is there, heightism exists, shorter guys get less dating and romantic opportunities (and maybe also less respect from other guys in their work), yada yada yada. You can cry about how unfair people are to you all day but at the end of this year, you would realize that all this venting of frustrating you post onto reddit/other doesn’t improve your life overall by much. You did not move that needle of your life gauge even a little bit. For now, just swallow the hard reality of this unfair world and existence we live in, accept that you did not win the genetic lottery like a channing tatum, and go in a different direction.

If you dwell on this fact, about your short stature and how no matter how much you go the gym you can’t change your height, you are going to get stuck psychologically, and maybe spiral down to a psychological state which you can’t get out of.

A lot of guys might tell you to go to the gym to lift weights, work out, build confidence, dress better, have a great social life, etc. and they are only half right. Improving on the areas of life of what you can control helps somewhat, but it won’t help all the time. Sometimes no matter what you do to try to make up for your short stature, that girl you like still won’t move towards you. The reality is that there is probably over 100 Mil other guys in the world out there. They have their own standards, and if they are not willing to lower their height requirement for you, there is nothing you can do. You already did everything else to improve yourself. You did everything you can to make you have a better advantage in this game we call life for success, and maybe sometimes that is still not good enough. Sometimes the only thing that matters is how long your bones are.

Some of you will be depressed. Go outside to the beach and get some sun. Take up long distance running to get the dopamine receptors firing again. Stay off the computer.

Work on yourself on the cognitive level is the best place to start. Take some nootropics, do tDCS, experiment with sleep cycles, learn acupressure and deep tissue massage for stress relief, yoga, fishing, etc. to get your mind away from this sub-reddit and other negative areas on the internet.

Get an education to increase your level of intelligence first (since being smart and short is much better than being tall and stupid in the long run), go into business for yourself to increase your net worth and build real assets, make your money, enjoy life, and come back when you are maybe 15-20 years older. You will have the funds to then spend on the latest cosmetic biomedical treatments. Most of you I would assume don’t have a lot in the wealth area of life. Money is not the be-all,end-all but it is a tool to help you get what you want out of life.

Treat each dollar you have as your soldiers. Each day you send your soldiers out to capture more soldiers which can work for you. That is called using money to make more money (aka investing)

I lived in Gangnam, Seoul for 2 years so that type of exposure made me very accepting of the idea of cosmetic surgery to improve one’s appearance. It is okay, as long as it is empowering and can really improve your quality of life. Some people are against cosmetic surgery since they think that it will change who they think they are to make other people like them, but this world is a very competitive place. You need every little bit of advantage you can get.

Plus, one’s concept of who they are as a person is fluid. It is not static. As we go through life, our “self” evolves over time. Even our core values and belief system changes over time. Don’t be so stuck in your beliefs/value which cause you to miss out on not taking a chance on something great. It is very rare that we regret later in life for doing something instead of not doing something.

For something besides just a nice pep talk which can hopefully get the regular readers out of their heads and negative emotional states, just see how close we already are with the 3D Printed nose which is made from fibrocartilage, not the hyaline cartilage you would need. (https://www.youtube.com/watch?v=FuGZ-G0UCCY). Implantation, transplantation, vascularization problems, people are working on that.

{Tyler’s Comments:  I tend to avoid looking at the validity of the desire to grow taller.

You may say: “You need to accept your height.”

I say: “You need to accept my desire to increase my height.”

Does climbing mount everest make any sense?  What about getting the high score in a video game?

Human height has value.  We as humans should strive to further our value.

“If you set your mind to it, you can accomplish anything.”

ANYTHING………

ANYTHING……

Including growing taller and we should accept nothing less.}

The Unhealthy Obsession Of Basketball Players Towards Height, Why I Am Giving Up Basketball and Football

As I recently got back into playing basketball at the local YMCA which I just gave up, I came to realize just how strange it is that so many basketball players have an unnatural obsession on their height.

Back in my college days, I would sometimes eat in the same dining hall as the college athletes and the one time I ever sat really close to a set of basketball players I could over hear their conversation. What struck me as really odd back then was that half of their conversation revolved around how tall they were, or how tall other people were. One guy would tell the other guy about this player from another school, and they would go into his height by picking at it. The strange thing was they they didn’t mention the skill level of that kid, but just how large the opposing athlete was.

To these guys, it seemed like the height of a person defined who they were as a person. It was not their GPA, or GMAT scores, or what they had done in their lives. It was just their height. Back then, I just didn’t understand.

Now that I have started to watch basketball again, professional basketball, the thing that is always brought up is the players height.

Just watch the old 90’s bulls intro. Why is it that the announcers have to list how tall their players are? How often do I need to be reminded that Michael Jordan is 6′ 6″? The LA Lakers announcers do it too. (refer to this link https://www.youtube.com/watch?v=ojHOO4qbE4s). Being tall is not a skill, but people in the basketball world treat it as a skill. Being bigger does not make the player better.

Here is a sick truth that I would need to reveal about the nature of the game today. For most black american guys who play this game today, like in the streets of the inner city, basketball is actually a game of posturing, and showing off. (Refer to here https://www.youtube.com/watch?v=OJixT7F-Vog) People don’t play the game for the fun, for the team effort, or for the personal skills that they develop. They play the game to exert their masculinity and express their dominance. In the African American community, the young males are told to be ultra-masculine in expression. The easiest way to exhibit their dominance and masculinity is being taller than other men. If they are taller than others, they are told to use their body to push through to the post. I can’t even begin to remember how many times I would be in a game where it felt like it was not 5-on-5 but 1-on-1. The ability to pass seems to have been lost on certain people.I personally love playing the game and hearing that swish as the ball goes through the hoop but I have decided to let go of playing this game, and stop all-together to get away from the game.

As I grow older, I realize just how many psychological hang-ups people have over their height when they are playing basketball.

Sometimes I start to question my own motives for even still watching this game. Do I really find this game where abnormally tall guys running (and jumping) up and down the court that mesmerizing? Could it be that at some level in my mind, I have an unhealthy obsession with height just like the fellow basketball players? How many other people in the world also seem to find their primary source of identity through their height?

I had decided long ago that the sport of American Football is a huge waste of time and resources, but now I am adding the sport of Basketball on that list. No more playing the game, and no more watching the game, either in real life or on the internet. Watching one more sports game or event is not going to improve my overall life in any way. Having the local hometown sports team win a national championship does not make my life better or even bring any real prestige to the city.

(I live in the greater Seattle/Pacific Northwest area and I saw the whole Superbowl phenomena happen two months ago. People would make sure to revolve their jobs and business around the football games. The local Whole Foods would announce over the air whether the Seahawks would win or not, and people would crowd around the TV in the local Costco. I am not sorry that the Seattle located team lost. Imagine the type of pressure the team would have been in if they had won a 2nd year. People would be forcing the guys on the team to win again for a 3-peat. )

When people say things like “We Won!” after the local sports team win, I always want to correct them in saying that it is NOT that ‘we won’ but that the team won, they just watched while sitting on their couches and drinking bear and eating chips. Somehow they are trying to find some way to feel good about themselves from the glory of other people’s accomplishments, through association. Maybe not everyone can have the god-given talent to play at the highest professional level and win in athletics, but in the long term, nobody in a hundred years will care about who won the 2014 American Football Superbowl Championship. I am happy that at least the professional athletes today can make millions of dollars, but in the long term, I pity them since everyone knows that the human body is bound to fail, and father time always wins last.

Can your height growth be influenced by your community?

Can hanging out with tall people during development make you taller? One potential mechanism for how your communities genes may affect yours may be via biophotons.

The impact of physical connectedness on body height in Swiss conscripts.

“Human populations differ in height. Recent evidence suggests that social networks{who you hang out with} play an important role in the regulation of adolescent growth and adult height. We further investigated the effect of physical connectedness on height.
We considered Switzerland as a geographic network with 169 nodes (district capitals) and 335 edges (connecting roads) and studied effects of connectedness on height in Swiss conscript from 1884 – 1891, 1908 – 1910, and 2004 – 2009. We also created exponential-family random graph models to separate possible unspecific effects of geographic vicinity.
In 1884 – 1891, in 1908 – 1910, and in 2004 – 2009, 1(st), 2(nd) and 3(rd) order neighboring districts significantly correlate in height (p < 0.01). The correlations depend on the order of connectedness, they decline with increasing distance. Short stature districts tend to have short, tall stature districts tend to have tall neighbors. Random network analyses suggest direct road effects on height. Whereas in 1884 – 1891, direct road effects were only visible between 1(st) order neighbors, direct road effects extended to 2(nd) and 3(rd) in 1908 – 1910, and in 2004 – 2009, also to 4(th) order neighbors, and might reflect historic improvements in transportation. The spatial correlations did not significantly change when height was controlled for goiter (1884 – 1889) and for median per capita income (2006), suggesting direct road effects also in goiter-allowed-for height and income-allowed-for height.

Height in a district depends on height of physically connected neighboring districts. The association decreases with increasing distance in the net. The present data suggest that people can be short because their neighbors are short; or tall because their neighbors are tall (community effect on growth). Psycho-biological effects seem to control growth and development within communities that go far beyond our current understanding of growth regulation.”

Final height, target height and the community.

“Height varies with age, and it varies with historic time. Final height is determined by endocrine parameters and genetics, by nutrition and health, by environmental factors, by birth weight, early growth, BMI, and developmental tempo. European populations of the 19th century were short, but their shortness did not result from growth impairment at all ages. In those days, shortness was mainly due to a significantly blunted adolescent growth spurt. New modelling approaches suggest an independent regulation of adolescent growth and final height: the target for growth and final height appears to be set by the community{hanging around with probasketball players may make you taller?}. In order to test this hypothesis, we formed a geographic network of Switzerland consisting of 169 nodes (district capitals) and 335 connecting edges (roads), and investigated military conscript data obtained between 2004 and 2009. Average height of Swiss military conscripts was 178.2 cm (SD 6.5 cm). But conscripts from first order neighbouring districts were more similar in height than expected. Short stature districts have short, tall stature districts have tall neighbours. We found significant height correlations between 1st (r=0.58), 2nd (r=0.64), 3rd (r=0.45) and even 4th order neighbours (r=0.42). It appears that tall stature communities generate tall people, short stature communities generate short people, and migrants orientate towards the new height target of their host population (community effect on growth){So independent of genes from the community newborn migrants will be taller or shorter based on the community}. ”

Modeling determinants of growth: evidence for a community-based target in height?

“community-based target seeking in growth”

“adolescent height converges toward the average of the population. Height tends to cluster. The within-population variation of height is narrow.”

“Height differences are small throughout childhood but markedly increase during adolescence.”

“the smaller the adolescent is compared with past mean average height, the more the adolescent grows during puberty.”<-So according to this theory, if you are going through puberty and hang out with pro-basketball players you will grow taller than expected and at a faster rate.

“Short stature in cystic fibrosis results from tempo deceleration. Cystic fibrosis patients grow poorly at all ages (they have suboptimal peak height velocity and late pubertal growth, influenced by disease severity) but eventually achieve normal final height. ”

” tall communities generate tall people even in the presence of unfortunate living conditions”

According to Dose-dependent effect of growth hormone on final height in children with short stature without growth hormone deficiency.,exogenous administration of GH increased height by about 1 inch.  The authors of this study suggest that living around taller people could increase GH production as depression decreases GH production establishing a link between mental state and GH production.

Here’s a study that suggests that IGF-1 levels may play a role in the community effect on height.  Although it does not seem to be a strictly linear relationship between IGF-1 levels and height.  Height is more complex than that.

Sex, Sport, IGF-1 and the Community Effect in Height Hypothesis.

“We test the hypothesis that differences in social status between groups of people within a population may induce variation in insulin-like growth factor-1(IGF-1) levels and, by extension, growth in height{so “positive thinking” increases height via IGF-1 but again the relationship is more complex than IGF-1 increases height}. This is called the community effect in height hypothesis. The relationship between IGF-1, assessed via finger-prick dried blood spot, and elite level sport competition outcomes were analysed for a sample of 116 undergraduate men and women. There was a statistically significant difference between winners and losers of a competition. Winners, as a group, had higher average pre-game and post-game IGF-1 levels than losers. We proposed this type of difference as a proxy for social dominance. We found no evidence that winners increased in IGF-1 levels over losers or that members of the same team were more similar in IGF-1 levels than they were to players from other teams. These findings provide limited support toward the community effect in height hypothesis. The findings are discussed in relation to the action of the growth hormone/IGF-1 axis as a transducer of multiple bio-social influences into a coherent signal which allows the growing human to adjust and adapt to local ecological conditions.”

So it seems that the relationship as described here is that winners are more likely to have higher IGF-1 levels rather than winning increasing IGF-1 levels.

“Children and adolescents with pituitary gigantism have an excessive production of GH, and IGF-1 levels are elevated.”<-But again it seems as though there’s more to gigantism than excessive GH.

“the positive association between variation in IGF-1 levels and height, across the range from deficiency to excess, helps to explain differences in stature within and between human populations.”

” there is evidence for a new parameter that they define as ‘past relative height.’ This parameter operates during the adolescent growth period to adjust the growth rate of an individual toward the average height of her/his immediate community.”

“… the smaller the adolescent is compared with past mean average height [of the community], the more the adolescent grows during puberty”

Surprisingly the scientists found that women in sports tended to have higher IGF-1 levels than men in sports.

“Women, but not men, showed a significant association between their father’s social class and their own adult IGF-1 levels.”