Sons of women with polycystic ovary syndrome (PCOS) are three times more likely to develop obesity, a new study has shown. The study from Karolinska Institutet, Sweden, said that it highlighted a previously unknown risk of passing PCOS-related health problems across generations through the male side of a family. The study is published in the journal Cell Reports Medicine. Using registry data and mouse models, the researchers determined if and how PCOS-like traits are passed from mothers to their sons.
Just over 460,000 sons born in Sweden between July 2006 and December 2015 were included in the registry study. Of these, roughly 9,000 were sons of women with PCOS. The researchers then identified which of the children were obese.
“We discovered that sons of women with PCOS have a threefold risk of obesity and of having high levels of “bad” cholesterol, which increases the risk of developing insulin resistance and type 2 diabetes later in life,” said lead researcher Elisabet Stener-Victorin, professor at the Department of Physiology and Pharmacology, Karolinska Institutet.
Studies in mice confirmed these findings, where the researchers examined male offspring of female mice that before and during pregnancy were fed either a standard diet or a diet rich in fat and sugar, and were exposed to high levels of the male sex hormone dihydrotestosterone during pregnancy to mimic the pregnancy of normal weight individuals and obese women with PCOS.
The male mice were then fed a standard diet until adulthood when their fat distribution and metabolism were examined. “We could see that these male mice had more fat tissue, larger fat cells, and a disordered basal metabolism, despite eating a healthy diet,” said Stener-Victorin.
To investigate the reproductive function of the offspring and whether physiological characteristics could be passed on from generation to generation, the first-generation male mice were mated with healthy female mice that were not exposed to male sex hormones or a diet rich in fat and sugar.
The whole process was repeated in the second generation to reach the third generation which is the first generation not to be affected by the mother condition.
The experiments showed, the researchers said, that obesity and high levels of male hormones in the woman during pregnancy can cause long-term health problems in the male offspring because their fat tissue function, metabolism, and reproductive function deteriorate, which in turn affects future generations.
“These findings may help us in the future to find ways to identify, treat and prevent reproductive and metabolic diseases at an early stage,” said Stener-Victorin.