Exposure of the fetus to famine increases the risk of diabetes in adulthood

HUnger killed an estimated four million people in Ukraine between 1932 and 1933 – the result of Holodomor, a famine caused by the Stalin-led Soviet regime. New research shows how the damage experienced during famines can extend even to people who have not yet been born.

The studypublished Thursday in Science, strengthens the link between fetal exposure to famine and an increased risk of type 2 diabetes later in life. It found that people exposed to the peak of the famine during early pregnancy (defined as the first three months) had double the risk of developing diabetes as adults compared to those who were not exposed. People born in areas hit harder by famine – Kiev, Cherkasy and Poltava – were also at greater risk.

The study looked at diabetes diagnoses between 2000 and 2008 among more than 10 million people born in Soviet Ukraine between 1930 and 1938. It marks an important step in answering questions about the long-term health effects of malnutrition and hunger, said L.H. Lumey. a professor of epidemiology at Columbia University and lead author of the study. This study is a more extensive follow-up to his 2015 study, which used more limited geographic and population data.

“Because of the unusual combination of factors, the high-quality demographic data, the sudden onset of the famine, the limited duration of the famine, the sheer numbers exposed – this makes it like a laboratory study from the medical community’s point of view. science, which will probably never be repeated,” Lumey said.

Type 2 diabetes occurs when the pancreas does not produce enough insulin, the hormone that controls blood sugar levels. The study does not identify the mechanism underlying the link between prenatal exposure to famine and the onset of type 2 diabetes in adulthood. But Simin Liu, a professor of epidemiology, medicine and surgery at Brown University, said epigenetics — how environmental factors influence gene expression — likely plays a role. He has the same phenomenon in the Chinese famine that began in 1959 and is widely considered the deadliest famine in human history.

“The short answer is that epigenetic modifications may link prenatal exposure to famine to an increased risk of cardiometabolic diseases later in life,” Liu, who was not involved in the study, wrote in an email to STAT. He added that additional experimental studies in animals, as the authors suggest, would be needed to further understand the reasons for the link.

The fetal programming hypothesis – which suggests that stimuli at a critical period of fetal development can influence metabolism into adulthood – could provide an explanation, said Peter Klimek, an associate professor at the Medical University of Vienna, who studies diseases in the context of complex socio-economic systems. . In the Ukrainian study, fetuses exposed to famine during early pregnancy saw an increase in diabetes risk as adults, while fetuses exposed during the later periods of pregnancy, as well as infants in the first years after birth, had no increased risk.

“The hypothesis is basically that metabolism is still malleable in early pregnancy, and that it will mainly respond to environmental influences,” says Klimek, who wrote a paper. guiding perspective on the study. The body prepares and adopts metabolism in accordance with a nutrient-poor environment. But if by the time the baby is born the famine is over, the metabolism has adapted to the wrong environment. However, exposure to famine does not always mean a higher risk of diabetes, Klimeck said, noting that there are many risk factors for diabetes.

One challenge the study authors faced was that the 1939 census was falsified by the Soviet government, said Oleh Wolowyna, co-author of the study and fellow at the Center for Slavic, Eurasian and East European Studies at the University of North Carolina.

“The population of Ukraine was inflated by almost 3% to hide the effect of the famine,” Wolowyna said. “In the case of births and deaths, especially in 1933 at the height of the famine, there was an extraordinary amount of under-registration – about 30% of births were unregistered, and more than half of all deaths were unregistered . .”

The study authors used a demographic equilibrium equation with data from the 1926, 1937 and 1939 censuses as input to obtain accurate annual population estimates, reporting births, deaths and net migration.

One in three Ukrainians is hungry today as a result of the ongoing war between Russia and Ukraine. 2023 United Nations Report. Before the war, Ukraine was one of the largest suppliers of agricultural products to parts of Africa and Asia. “Hunger in other countries has increased as a result of the war, and these consequences of the war are no longer limited to Ukraine alone,” Klimek said.

Liu said this research, among other famine studies, highlights the importance of prenatal and early childhood nutrition in shaping long-term health outcomes at both the individual and population levels.

“From a public policy perspective, priority should be given to targeting at-risk populations to ensure adequate nutritional support during critical developmental periods,” Liu wrote. He said this includes policies that ensure food security for pregnant women and young children in famine-vulnerable regions, as well as support in the detection and management of metabolic disorders for persons exposed to these conditions.