Leading a sedentary lifestyle and spending many hours sitting, regardless of whether it is leisure time spent watching television, for example, or working hours in front of a computer, has a negative impact on health and In fact, the World Health Organization (WHO) considers that lack of physical activity is the fourth main risk factor for mortality.
And there is more and more scientific evidence to support it, such as a new study carried out by Chinese scientists that has revealed that women who sat for more than six hours during their daily leisure time were much more likely to develop uterine fibroids or myomas before birth. reach menopause.
Specifically, researchers led by Dr. Qiong Meng, from Kunming Medical University (China) found that more sedentary women had twice the risk of developing these types of tumors before menopause, which can cause symptoms such as pain, heavy menstrual bleeding or infertility. Their findings have been published in BMJ Open.
Uterine fibroids are the most common benign tumors in women of childbearing age, with a prevalence that varies from 4.5% to 69%, the researchers explained, adding that obesity linked to a sedentary lifestyle may be one of the factors. that contribute to their appearance: “Studies have shown that obesity is a risk factor for uterine fibroids.”
Sedentary lifestyle, obesity and vitamin D deficiency associated with fibroids
Obesity and a sedentary lifestyle have also been associated with increased levels of circulating estrogen and other hormones known to promote the development of fibroids, researchers have noted. In addition, a sedentary lifestyle contributes to producing vitamin D deficiency, which is also considered a risk factor for the development of these tumors.
In the new study, Meng and her colleagues analyzed data from 6,623 women across China between the ages of 30 and 55 who had not yet gone through menopause. 84% of the participants had had more than two children. Sedentary behavior included sitting or lying down and activities such as watching screens, knitting, reading, or playing board games. And the basic information collected included their height and weight, their menstrual and reproductive history, the number of children and the age they had when the first was born, their use of contraceptives, sedentary free time and time spent in physical activity and how It was their diet.
In perimenopausal women, the risk of fibroids was 5 times higher in those who dedicated 6 or more hours a day to sedentary leisure than in those who accumulated less than two hours.
Sedentary behavior was classified as 1.5 or fewer metabolic equivalent hours of task (MET)/day while sitting or lying down. METs indicate how much energy in calories is expended per hour of physical activity. Participants were asked to detail how much time they spent playing board games, watching screens, reading, knitting, or doing other similar activities, and were then divided into four groups of sedentary free time: less than 2 hours/day; 2 to 3.99 hours/day; 4 to 5.99 hours/day; and 6 or more hours/day.
61% of women dedicated between 2 and 3.99 hours of their free time per day to sedentary activities. 8.5% of women (562) had uterine fibroids, the prevalence of which increased with age. Rates were highest (2.5 times higher) among people aged 50 and older.
Factors that were associated with the development of uterine fibroids were weight (BMI), number of live births (more than two), menstrual status, time since last live birth (ages 13 to 17 and older), physical activity and sedentary free time. But the more sedentary the free time, the higher the risk of uterine fibroids appeared to be, and after taking potentially influential factors into account, sedentary free time of six or more hours a day was associated with a risk twice that of women. women who dedicated less than two to it.
Although sedentary leisure time was not associated with the prevalence of fibroids in premenopausal women, it was associated with the prevalence of fibroids in perimenopausal women: the risk was 5 times higher among those who reported 6 or more hours of sedentary leisure per day. day than in those who accumulated less than two hours.
As this is an observational study, it is not possible to establish a cause-and-effect relationship, but a possible explanation for the observed associations could be that sedentary behavior is related to obesity, which is a risk factor for uterine fibroids, say the researchers. researchers. Both a sedentary lifestyle and obesity increase the body’s estrogen level.
Other possible explanations include the known associations between sedentary behavior and metabolic disorders, chronic inflammation and vitamin D deficiency, they suggest. “This cross-sectional study, based on the natural population, demonstrated that [el tiempo libre sedentario] has a positive linear correlation with [los fibromas uterinos]Indicating that [puede] be an independent risk factor,” they conclude.
