Age at Start of Menstruation and Breastfeeding Duration Linked to Lupus Risk in Black Women
Beginning menstruation at age 15 or older and breastfeeding infants for six months or longer may be associated with increased risk for developing lupus in Black women. Other female reproductive factors, such as age at first birth, menopausal status, hysterectomy, age at menopause or history of endometriosis are not associated with the disease.
A group of 58,243 Black women were assessed twice a year for 20 years about reproductive and other health factors. Of the group, 125 women developed lupus at an average age of 43. Those women who started their menstruation cycle at a later age (15 vs. 12 years old) and breast fed for six months or more were associated with an increased risk of lupus.
Study Author and Lupus Foundation of America’s Medical-Scientific Advisory Council (MSAC) Chair, Karen Costenbader, MD, MPH, states, “Several years ago my team and I investigated reproductive factors in relation to the risk of developing lupus among the predominantly White women followed in the Nurses’ Health Study cohorts. (Costenbader KH, et al. Arthritis Rheum. 2007 Apr;56(4):1251-62.) We investigated a range of factors and found that early age at first period (age less than or equal to 10 years, compared to the average, age 12) was associated with a more than doubled risk of later developing lupus. Menstrual irregularity was also associated with risk of lupus. Age at first birth, having had babies, having breastfed babies and duration of breastfeeding were not associated. Here, we collaborated with the Black Women’s Health Study which enrolled 59,000 women in 1995 to investigate similar questions as Black women are at higher risk of developing lupus. Again, we identified new cases of lupus and examined whether a range of factors was associated with lupus. We found that later age at first period (at age 15 or older relative to age 12) was associated with a more than doubled risk of developing lupus and having breastfed one’s babies for 6 or more moths was also associated with a 70% increased risk. Other reproductive actors were again not associated with lupus risk. These findings were unanticipated, but may signal that abnormalities in the timing of puberty are related to the later development of lupus. More work needs to be done to figure out how the timing of sexual maturation and hormonal changes may be related to increased risk of later developing lupus.”
Further investigation into the biological mechanisms underlying reproductive factors and lupus is important. Lupus is three times more common in Black women than White women. The disease occurs at a younger age and is also more severe in Black women. Learn more about risk factors for developing lupus.