Smoking marijuana may cause early puberty and stunts growth in boys
Boys who smoke marijuana go through puberty earlier but grow more slowly than those who have never smoked the drug according to a study presented today at the European Congress of Endocrinology in Dublin, Ireland. The findings will lead to a better understanding of the dangers of drug abuse on growth and development of children.
Scientists at the Pir Mehr Ali Shah Agriculture University Rawalpindi in Pakistan studied the levels of certain hormones involved in growth and puberty in the blood of 220 non-smoking and 217 marijuana-addicted boys. Levels of puberty-related hormones such as testosterone and luteinising hormone (LH) were increased in the marijuana smokers. In contrast, growth hormone levels were decreased in this group. It was also found that non-smoking boys were on average 4 kg heavier and 4.6 inches taller by the age of 20 than the marijuana smokers.
The research team, led by Dr. Syed Shakeel Raza Rizvi, also looked at the effect of smoking marijuana on levels of the stress hormone, cortisol, in 10 marijuana addicts; they found that marijuana smokers have significantly higher levels of cortisol than non-smokers. Dr Rizvi hypothesises that, ―marijuana use may provoke a stress response that stimulates onset of puberty but suppresses growth rate.
Marijuana is the most widely available illicit drug in Europe, it is estimated that it has been used by 80.5 million Europeans at least once in their life. The latest report from the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) reveals that the highest prevalence of marijuana use is in 15 — 24 year olds and is significantly higher among males than females. Previous studies have looked at the effect of smoking marijuana in adult rats and humans but this is the first time that the effects have been looked at in pubertal boys.
The research may have a wider impact than just health. ―Early puberty is associated with younger age of onset of drinking and smoking, and early matures have higher levels of substance abuse because they enter the risk period at an early level of emotional maturity,‖ explained Dr. Rizvi.
Boys who smoke marijuana go through puberty earlier but grow more slowly than those who have never smoked the drug according to a new study.
Heavy Pot Smoking Linked With Stunted Growth
— Study adds to evidence for developmental abnormalities with teen marijuana use
by Jeff Minerd, Contributing Writer, MedPage Today May 20, 2015
This article is a collaboration between MedPage Today and:
Boys who smoked marijuana heavily were significantly smaller than their peers by the end of their adolescent growth phase, according to a study conducted in Pakistan.
Study participants who were described as “marijuana addicts” during boyhood were on average 4.6 inches shorter and 4 kg lighter at age 20 than nonsmokers, reported lead investigator Syed Shakeel Raza Rizvi, PhD, and colleagues at the PMAS-Arid Agriculture University Rawalpindi, in a presentation at the European Congress of Endocrinology in Dublin.
The investigators compared height; weight; and levels of luteinizing hormone, testosterone, growth hormone, and cortisol in 220 marijuana-addicted and 217 nonpot-smoking boys.
Plasma concentrations of luteinizing hormone, testosterone, and cortisol were significantly higher in the marijuana addicted boys, but levels of growth hormone were significantly lower.
Chronic pot smoking may trigger a stress response that stimulates the onset of puberty but lowers growth hormone levels, the researchers suggested, on the basis of a separate set of laboratory experiments.
To determine the acute effect of smoking marijuana on cortisol levels, the researchers measured salivary cortisol in 10 “drug addict volunteers” of unstated age before, during, and after smoking a 0.25 g marijuana cigarette. “Acute administration of marijuana induced significant increases in the salivary concentrations of cortisol,” the researchers reported.
“The mechanism underlying the stimulation of reproductive function by marijuana in pubertal boys needs to be examined in detail. Furthermore, the suppressive effect of cortisol on growth directly through inhibition of growth at the cellular level by depletion of nutrients or indirectly through inhibition of growth hormone secretion needs to be further studied,” Rizvi said via email to MedPage Today.
“In addition, it is to be ascertained whether cortisol itself or some other factor like nutritional status is attributable to decline in growth rate in pubertal marijuana addicted boys. We are examining these aspects currently,” Rizvi said.
In the U.S., marijuana is the most popular drug among young people, with 11.7% of 8 th graders and 35.1% of 12 th graders reporting having used it within the past year, according to a 2014 survey from the National Institute on Drug Abuse (NIDA).
More than 6% of 8th graders and 21% of 12th graders reported using marijuana within the past month, the survey found, and about 1% and 6% of 8th and 12th graders, respectively, said they used the drug daily.
No funding sources were reported for this study.
Dr. Rizvi reported no relevant financial relationships with industry.
European Congress of Endocrinology
Proceedings of the National Academy of Sciences
Study adds to evidence for developmental abnormalities with teen marijuana use