Characteristics and Management of Gestational Diabetes in Japan

Hirohito SoneJapan Speaker The Impact of Underweight in Young Women on GDM and the Next Generation In Japan and some neighboring East Asian countries, it is somewhat surprising given their socio-economic level that underweight, rather than obesity, is a significant health issue for young women. According to the National Health and Nutrition Survey in Japan, the proportion of underweight women in their 20s (BMI < 18.5) has remained above 20% for decades. Despite this, many young women overestimate their own body size, with numerous individuals attempting to lose weight even though they are actually within the normal range. This reveals a discrepancy between perceived and actual body size, alongside the existence of a desire to be thin. The ideal thin body shape is influenced by social trends and traditional values that posit thinness as more attractive, as well as the influence of mass media and social media. Entertainers and fashion models are often seen as being too thin. The health effects of being underweight in young women are known to include increased osteoporosis and mortality, but adverse effects on pregnancy and pregnancy outcomes have also been observed. Underweight women have a higher risk of gestational diabetes mellitus (GDM), a higher rate of low birth weight, and a lower birth rate compared to women of normal weight. Indeed, in Japan, the rate of low birth weight infants has been increasing in parallel with the proportion of thin women. Recent findings from DOHaD (Developmental Origins of Health and Disease) and fetal programming research have revealed that low birth weight infants face a higher future risk of developing metabolic diseases such as diabetes and hypertension. Consequently, maternal underweight before pregnancy and weight-control behaviors after pregnancy likely have adverse health effects on future generations. Based on this background, Japan has revised the standards for appropriate weight gain during pregnancy, and discussions are currently underway regarding GDM pregnant women. Furthermore, as part of preconception care, education on the importance of maintaining a healthy weight and body image is being promoted, starting from junior high and high school. The trend toward underweight among young Japanese women, even during pregnancy, is a major national health issue, as it affects not only the health of the women themselves but also the next generation. However, its causes are complex, and multifaceted measures involving society as a whole are required. These countermeasures are also expected to be useful for prevention of same issues in other East Asian countries as well in the future.