Women with gestational diabetes (diabetes during pregnancy) who breastfeed their infant have been found, over the long term, to have a 40 percent reduced risk of developing type 2 diabetes. This is the conclusion of scientists of the Institute of Diabetes Research, Helmholtz Zentrum München, which is a partner in the German Center for Diabetes Research (DZD). According to analyses of the German prospective study on gestational diabetes, in particular mothers who breastfeed their child longer than three months have a protective benefit. Gestational diabetes increases the risk of developing type 2 diabetes later on in life. One in two women with gestational diabetes develop type 2 diabetes within ten years after childbirth, although their blood glucose levels at first return to normal after pregnancy. In Germany gestational diabetes occurs in about four percent of all pregnancies.
Breastfeeding is healthy – not only for the baby, but apparently also for the mother: If gestational diabetes occurs during pregnancy, the mother can reduce her risk of developing type 2 diabetes by up to 40 percent through breastfeeding. Gestational diabetes is a metabolic disorder limited to pregnancy, but it increases the risk of developing type 2 diabetes later on after giving birth. In this chronic metabolic disease, various problems in the release of the hormone insulin and reduced insulin sensitivity (insulin resistance) lead to a lack of insulin and thus to increased blood glucose levels.
Insulin-dependent gestational diabetes leads to type 2 diabetes in 90 percent of the cases
Women who had to undergo insulin treatment during pregnancy were at highest risk of developing type 2 diabetes. Nearly two-thirds of this subset of participants of the prospective gestational diabetes study developed type 2 diabetes within three years after giving birth – within 15 years the total was even more than 90 percent. Researchers involved in the prospective gestational study have been analyzing the development of type 2 diabetes in women with gestational diabetes for 19 years.
It has been known for some time that breastfeeding has short-term positive effects on the metabolism of the mother. Evidence suggests that women during the breastfeeding period have a better glucose and lipid metabolism and also have lower levels of estrogen. Apparently, breastfeeding – during and after the three-month and longer lactation period and up to three years after childbirth – has an influence on the concentrations of two antagonistic hormones that regulate the feeling of hunger: the appetite-stimulating hormone ghrelin and the hormone PYY, which mediates a feeling of satiety.
The new finding, however, is that breastfeeding also prevents type 2 diabetes in the mother over the long term. This applies only to women with gestational diabetes in whom no autoantibodies associated with type 1 diabetes could be detected. This was true for most of the 304 participants in the study: Only 32 participants had formed these autoantibodies, and in this subset breastfeeding did not appear to have any influence on the development of diabetes postpartum.
Breastfeeding can delay the development of type 2 diabetes by ten years
According to the study, the decisive factor is the breastfeeding duration: Only those women who breastfed longer than three months had a 42 percent risk of developing type 2 diabetes within 15 years. The study participants were able to reduce their diabetes risk even more through exclusive breastfeeding during this period (15-year risk of 34.8 percent). Through breastfeeding, the autoantibody-negative participants delayed the development of type 2 diabetes by an average of ten years.
Women who during pregnancy could treat their gestational diabetes with diet alone achieved the most success in prevention through breastfeeding. This was not dependent on the body mass index (BMI) of the participants. However, obese women tended to stop breastfeeding earlier – on average when the infant was five weeks. In contrast, the average duration of breastfeeding for the entire set of participants was nine weeks.
“The results show that women from the risk group can significantly reduce their personal risk of developing type 2 diabetes if they breastfeed their infant,” said Professor Anette-Gabriele Ziegler, director of the Institute of Diabetes Research at Helmholtz Zentrum München. “Especially overweight women, according to the study, should breastfeed for at least three months.” Next, the research group wants to elucidate the mechanisms responsible for the long-term protective effect of breastfeeding.
PINGUIN Study: Preventing Type 2 Diabetes
Women diagnosed with insulin-dependent gestational diabetes as far back as nine months ago still have the opportunity to participate in a new preventive study conducted by the Institute of Diabetes Research called PINGUIN (Postpartum Intervention in Women with Gestational Diabetes Using Insulin). The aim of this study is to prevent the development of type 2 diabetes through diet and exercise and also by taking tablets that contain the active ingredient vildagliptin, which has been approved to treat type 2 diabetes. The participants are not only supported in the transition to a healthy lifestyle but also – if necessary – in weight reduction.
To obtain more information on the studies on gestational diabetes, please contact us without any obligation: Diabetes Research Group of TU München - Univ.-Prof. Dr. Anette-Gabriele Ziegler - Kölner Platz 1, 80804 Munich - Phone: 089 3068-2917, e-mail: pinguin(at)lrz.uni-muenchen.de
Additional information can be found at: www.pinguin-studie.de
Ziegler, A.-G. et al. (2012): Long-Term Protective Effect of Lactation on the Development of Type 2 Diabetes in Women With Recent Gestational Diabetes Mellitus, Diabetes DOI: 10.2337/db12-0393
Link to the publication [http://diabetes.diabetesjournals.org/content/early/2012/10/11/db12-0393.long]