Tag: sex hormones

Categories : Metabolic DisordersTags :

Considering Sex Hormones Led to Better Identification of Genes Linked to Type 2 Diabetes

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Genomic and hormone study of white Europeans finds 22 additional disease-related variants

Ball and stick 3D model of testosterone. Source: Wikimedia CC0

Researchers identified almost two dozen previously unknown genetic variants linked to type 2 diabetes by including participants’ hormone levels in their analysis. Yan V. Sun of Emory University, USA, and colleagues reports these findings in the open-access journal PLOS Genetics.

Type 2 diabetes affects an increasing number of people worldwide, and more often affects men than women. The disease is caused by a mix of genetic and lifestyle factors, but little is known about how someone’s environment – both inside and outside the body – interacts with their genes to impact a person’s risk of developing the disease.

In the new study, researchers performed genome-wide interaction studies to investigate whether a person’s hormone levels interact with their genetic variants to affect their risk of developing type 2 diabetes. They grouped males and females independently and considered measurements of three types of sex hormones – total testosterone, bioavailable testosterone and sex-hormone binding globulin. The information came from white European participants in the UK Biobank, which contains biological samples and health data from half a million people.

The researchers used statistical analyses to identify relevant variants in the genomes of individuals with and without type 2 diabetes. By taking into account hormone levels, the analysis was able to identify 22 spots on the genome that increased a person’s risk for type 2 diabetes. These variants had not been reported previously in the most recent genomic study for type 2 diabetes.

The new study suggests that a person’s hormone levels may be interacting with their genes to increase their odds of having type 2 diabetes. For future studies, the researchers recommended that additional hormone measurements for each participant and more diverse cohorts should be included. They conclude that this approach, which includes environmental factors in genomic studies, may help us to identify additional disease-related genes and gain a better understanding of the mechanisms behind complex diseases.

The authors add, “We found that sex hormone levels contribute to differences in genetic risk factors for type 2 diabetes in men and women. By analyzing data for men and women separately, we identified new genetic associations with type 2 diabetes.”

The lead analyst, Amonae Dabbs-Brown notes, “I actually used to work at the CDC developing methods to measure some of these sex hormones. It’s really exciting to see what happens downstream. Maybe one day I’ll even get to see how these analyses are used in the clinic!”

Provided by PLOS

In your coverage, please use this URL to provide access to the freely available paper in PLOS Genetics: https://plos.io/3ViXDKH

Contact: Rob Spahr [rob.spahr@emory.edu]

Citation: Dabbs-Brown A, Liu C, Hui Q, Wilson PW, Zhou JJ, Gwinn M, et al. (2025) Identification of gene-sex hormone interactions associated with type 2 diabetes among men and women. PLoS Genet 21(9): e1011470. https://doi.org/10.1371/journal.pgen.1011470

Author countries: United States

Funding: This work is supported in part by funding from the National Institutes of Health (HL154996 to YVS, DK139632 to YVS, and HL156991 to YVS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. YVS received salary support from the National Institutes of Health.

Competing interests: The authors have declared that no competing interests exist.

Categories : Substance UseTags :

Long Ring Fingers are Associated with a Preference for Alcohol

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Photo by Pavel Danilyuk on Pexels

People’s finger lengths may hold a vital clue to their drinking habits, a new study suggests. There is evidence that alcohol consumption is influenced by prenatal sex steroids – so experts from Swansea University and colleagues from the Medical University of Lodz decided to use a sample of students for their research into the subject.

Their findings, published in the American Journal of Human Biology, revealed relationships between high alcohol consumption and long 4th  digits (ring fingers) relative to 2nd  digits (index fingers). This showed that high prenatal testosterone relative to oestrogen is linked to high student alcohol consumption.

Professor John Manning said: “Alcohol consumption is a major social and economic problem. Therefore, it is important to understand why alcohol use shows considerable differences across individuals.”

The study used a sample of 258 participants – 169 of them female  –  and it revealed consumption rates varied between the sexes. In comparison to women, men show higher alcohol consumption and higher mortality from alcohol abuse.

He said: “A pattern like this suggests an involvement of sex hormones, such as testosterone and oestrogen. Digit ratio (2D:4D: the relative lengths of the 2nd and 4th fingers) is thought to be an index of early testosterone (long 4th digit) and oestrogen (long 2nd digit).

“It is known that alcohol-dependent patients have very long 4th digits relative to their 2nd digits, suggesting high testosterone relative to oestrogen exposure before birth. As expected, the associations were stronger for men than women.”

Now the researchers hope their conclusions will bring a better understanding of the factors underlying the pattern of alcohol consumption, from abstinence to occasional use to harmful dependence. 

This is the latest paper which has highlighted Professor Manning’s work in the field of digit ratios. Previous research  has examined how digit ratio may provide vital information concerning outcomes after contracting Covid-19, as well as oxygen consumption in footballers.

Source: University of Swansea

Categories : CancerTags :

Scientists Figure out Paradoxical Effect of Testosterone in Prostate Cancer

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Ball and stick 3D model of testosterone. Source: Wikimedia CC0

A treatment paradox has recently come to light in prostate cancer: Blocking testosterone production halts tumour growth in early disease, while elevating the hormone can delay disease progression in patients whose disease has advanced.

The inability to understand how different levels of the same hormone can drive different effects in prostate tumours has been an impediment to the development of new therapeutics that exploit this biology.

Now, a Duke Cancer Institute-led study appearing in Nature Communications, provides the needed answers to this puzzle.

The researchers found that prostate cancer cells are hardwired with a system that allows them to proliferate when the levels of testosterone are very low. But when hormone levels are elevated to resemble those present in the normal prostate, the cancer cells differentiate.

“For decades, the goal of endocrine therapy in prostate cancer has been to achieve absolute inhibition of androgen receptor function, the protein that senses testosterone levels,” said lead investigator Rachid Safi, PhD, research assistant professor in the Department of Pharmacology and Cancer Biology, at Duke University School of Medicine.

“It’s been a highly effective strategy, leading to substantial improvements in overall survival,” he said. “Unfortunately, most patients with advanced, metastatic disease who are treated with drugs to inhibit androgen signaling will progress to an aggressive form of the disease for which there are limited therapeutic options.”

Using a combination of genetic, biochemical, and chemical approaches, the research team defined the mechanisms that enable prostate cancer cells to recognise and respond differently to varying levels of testosterone, the most common androgenic hormone.

It turned out to be rather simple. When androgen levels are low, the androgen receptor is encouraged to “go solo” in the cell. In doing so, it activates the pathways that cause cancer cells to grow and spread. However, as androgens rise, the androgen receptors are forced to “hang out as a couple,” creating a form of the receptor that halts tumour growth.

“Nature has designed a system where low doses of hormones stimulate cancer cell proliferation and high doses cause differentiation and suppress growth, enabling the same hormone to perform diverse functions,” McDonnell said.

In recent years, clinicians have begun treating patients with late-stage, therapy resistant prostate cancers using a monthly, high-dose injection of testosterone in a technique called bi-polar androgen therapy, or BAT. The inability to understand how this intervention works has hindered its widespread adoption as a mainstream therapeutic approach for prostate cancer patients.

“Our study describes how BAT and like approaches work and could help physicians select patients who are most likely to respond to this intervention,” McDonnell said. “We have already developed new drugs that exploit this new mechanism and are bringing these to the clinic for evaluation as prostate cancer therapeutics.”

Source: Duke University

Categories : Diet and NutritionTags :

Time to Debunk Four Persistent Myths about Intermittent Fasting

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Photo by Malvestida on Unsplash

In a new article published in Nature Reviews Endocrinology, researchers at the University of Illinois Chicago debunk four common myths about the safety of intermittent fasting. 

Intermittent fasting as a weight loss method has grown increasingly popular, with a large body of research demonstrating its safety. Despite this, several myths about fasting have spread among clinicians, journalists and the general public: that fasting can lead to a poor diet or loss of lean muscle mass, cause eating disorders, or decrease sex hormones. 

In a new commentary, UIC researchers debunk each of these. They base their conclusions on clinical studies, some of which they conducted and some done by others. 

“I’ve been studying intermittent fasting for 20 years, and I’m constantly asked if the diets are safe,” said lead author Krista Varady, professor of kinesiology and nutrition at UIC. “There is a lot of misinformation out there. However, those ideas are not based on science; they’re just based on personal opinion.”  

There are two main types of intermittent fasting. With alternate-day eating, people alternate between days of eating a very small number of calories and days of eating what they want. With time-restricted eating, people eat what they want during a four- to 10-hour window each day, then don’t eat during the rest of the day. The researchers conclude both types are safe despite the popular myths.

Their conclusions: 

Intermittent fasting does not lead to a poor diet: The researchers point to studies showing the intake of sugar, saturated fat, cholesterol, fibre, sodium and caffeine do not change during fasting compared with before a fast. And the percentage of energy consumed in carbohydrates, protein and fat doesn’t change, either.  

Intermittent fasting does not cause eating disorders: None of the studies show that fasting caused participants to develop an eating disorder. However, all the studies screened out participants who had a history of eating disorders, and the researchers say that those with a history of eating disorders should not try intermittent fasting. They also urge paediatricians to be cautious when monitoring obese adolescents if they start fasting, because this group has a high risk of developing eating disorders. 

Intermittent fasting does not cause excessive loss of lean muscle mass: The studies show that people lose the same amount of lean muscle mass whether they’re losing weight by fasting or with a different diet. In both cases, resistance training and increased protein intake can counteract the loss of lean muscle. 

Intermittent fasting does not affect sex hormones: Despite concerns about fertility and libido, neither oestrogen, testosterone nor other related hormones are affected by fasting, the researchers said. 

Source: University of Illinois Chicago