High Prolactin May Lower Metabolism

A recent doctoral thesis by Louise Nilsson of the University of Gothenburg in Sweden explores the function of the hormone Prolactin, which is naturally high in women who are pregnant or breast feeding. Prolactin is what stimulates the mammary glands right before lactation. It is also present in men at lower levels.

This hormone aids in the function of the nervous system and helps provide humans with sexual pleasure. When present in normal levels, prolactin helps regulate the body.

However, the new thesis proposes that prolactin levels can be raised too high by some prescription drugs, by stress or by hypothyroidism. When this happens, the body responds badly.

Fatty tissue in both genders may respond by reducing the amount of another hormone called adiponectin, which aids in fat metabolism. Prolactin can also reduce the ability that human fatty tissue has to store sugar and fat, thus causing the tissue to release those elements into the bloodstream. This alone can raise a person’s risk of cardiovascular disease.

Nilsson’s thesis stated more than 30,000 men and women in Sweden may have raised levels of prolactin. And a study from our National Endocrine and Metabolic Diseases Information Service explains that too much of it can be symptomatic of having a tumor in the pituitary gland. Such tumors, however, are almost always benign.

Obesity May Cause Infertility

There may be more to your fertility problems than just stress and reproductive issues.

According to a new study scheduled to appear in the May issue of Journal of Clinical Endocrinology and Metabolism, obesity may be the cause of infertility. The study was conducted in Australia and focused on 96 women of varying body types, from normal to overweight and obese, based on their BMI. This new evidence showed that excess abdominal fat might have an effect on fertility because women that are suffering from obesity experience changes in the tissue surrounding their ovaries, and even in the fluid surrounding their eggs.

Since the development of the egg in the ovary is influenced by the environment in which it develops, and particularly by the follicular fluid which surrounds the developing egg, it follows that these changes could impact an egg’s potential for fertilization. Analysis of the follicular fluid samples revealed that the levels of insulin, lactate, triglycerides, and inflammation-related proteins, also known as CRPs, increased as the subject’s body mass index rose.

The samples also revealed the amount of sex hormone-binding globulin, or SHBG, decreased. This decrease is significant because high SHBG levels are associated with fertilization and pregnancy, and low levels are associated with Polycystic Ovarian Syndrome, diabetes, and hypothyroidism—all diseases linked to infertility issues.

Researchers in the study stress the preliminary nature of these findings. However, for obese women who have had fertility problems, this study represents a significant first step towards understanding the relationship between abdominal fat and ovarian function. And with female waistlines, on average, two inches bigger than they were a decade ago, continuation of this research will be more important than ever.