Belly Fat During Menopause Linked Low Testosterone
The dreaded belly fat that many middle-aged women develop appears to be associated with an increase in the level of active testosterone, and not a decline in estradiol (the primary form of estrogen) as once thought. Accumulation of belly fat, also known as visceral fat, is a concern because it is a significant risk factor for cardiovascular disease.
The dramatic changes in hormonal balance that occur during the menopause transition are responsible for a number of physical and psychological signs and symptoms, including hot flushes, night sweats, mood swings, loss of libido, and vaginal dryness. For many women, the weight gain and increase in waist circumference and fat deposits in the abdominal area are not only disturbing for the sake of appearance but because it is one of the factors in metabolic syndrome, a collection of risk factors for cardiovascular disease.
Visceral fat forms deep within the abdominal cavity and collects in the spaces between the abdominal organs. It differs metabolically from subcutaneous fat, which is located under the skin. Scientists have found that visceral fat releases chemicals called cytokines, which promote chronic inflammation and insulin resistance and thus the reason why belly fat is associated with an increased risk for type 2 diabetes and cardiovascular disease. It also heightens the risk for breast cancer and gallbladder problems.
In the current study, which was published in the journal Obesity, researchers evaluated 359 women ages 42 to 60 who were going through menopause. Computed tomography scans were used to measure belly fat, and blood tests were done to measure levels of testosterone and estradiol. The results showed that active testosterone (also called bioavailable testosterone) was the strongest predictor of visceral fat formation.
This study is important because it shifts the focus away from estrogen which was thought to protect premenopausal women against cardiovascular disease and to subsequently increase the risk after menopause once estrogen levels declined. Attention can now be given to active testosterone and its role in belly fat and greater risk of disease.
In a related study also published this year (Psychosomatic Medicine, May 2009), researchers reported that depression is associated with the accumulation of belly fat. This study, which was also done with women in menopausal transition, highlights how depression contributes to the risk for cardiovascular disease and diabetes in menopausal and postmenopausal women.
Everson-Rose SA et al. Psychosomatic Medicine 2009 May; 71(4): 410-16
Harvard Women’s Health Watch, December 2006
Janssen I et al. Obesity (Silver Spring) 2009 Aug 20 (Epub ahead of print)