Over the years that we have been writing this web site, we have shared many articles in this spot about the effects of diabetes on our bodies. Also, over the years we have received many questions about these effects on both the sexuality of men and women with diabetes. When we came across an excellent research on menopause in type 1 diabetes, we felt it was important to share the information with you, our readers. Why do this type of research? It is known that women with type 1 diabetes have a delayed menarche and a greater prevalence of menstrual disorders than women without diabetes. However, before this research, little was known about the menopausal transition among type 1 diabetic women. The Familial Autoimmune and Diabetes (FAD) Study recruited both adult individuals who were identified from the Children's Hospital of Pittsburgh Type 1 registry for the years 1950-1964 and their family members. Unrelated non-diabetic control probands and their relatives were also evaluated. The study appears in Diabetes 50(8):1857-1862,2000 by Janice S. Dorman, Ph.D. et al.
The Familial Autoimmune and Diabetes Study (FAD), recruited a cohort of both men and women (n=656) who were retrospectively defined in 1981 for a study of type 1 diabetes mortality. During 1990, registered patients were recontacted to update the data collected in 1981 and information was collected for 86% of the registered patients. No significant difference in sex, age, duration of diabetes, or smoking at baseline between the respondents and non-respondents was noted. Women with diabetes (n=143) compared with non-diabetic sisters (n=186) or unrelated control subjects (n=160) were more likely to have an older age of menarche 913.5, 12.5, and 12.6 years respectively), more menstrual irregularities before age 30 years (45.7, 33.3, and 33.1% respectively). This resulted in a 6 years reduction in the number of reproductive years (30.0, 37.0, and 35.2 years respectively) for women with type 1 diabetes. Risk factors univariately associated with earlier menopause included type 1 diabetes, menstrual irregularities before age 30, nulliparity, and unilateral oophorectomy. Of women with type 1 diabetes >30% reported these problems, which is more than double the prevalence of those women without diabetes. Type 1 diabetic women are also more likely to have adverse pregnancy outcomes than non-diabetic women. Spontaneous adotionism stillbirths, and congenital abnormalities characterize diabetic women with poor glycemic control. The researchers knew that with better control women with type 1 diabetes have successful pregnancies and healthy children, however, little is known about late reproductive events such as menopausal transition. There is little knowledge about this process.
The results of this study indicate that 98% of the FAD Study cohort was Caucasian with a mean diagnosis of type 1 diabetes which was 8.1 plus or minus 5.1 years, and their mean diabetes duration at the time of exam was 34.5 plus or minus 5.5 years. The results indicated that women with type 1 diabetes were statistically significantly more likely to have Hashimoto's thyroiditis than non-diabetic sisters or control subjects. No differences in the prevalence of Graves' disease or definite RA was observed. The incidence of possible RA was significantly higher among type 1 diabetic women compared with their non-diabetic sisters or control subjects.
In the Discussion section, the researchers suggest that menopause for type 1 women can have a great clinical significance. First, it dramatically reduces the number of childbearing years among women whose reproductive experience is already compromised. It has been well established that women with type 1 diabetes, particularly, those with poor glycemic control, are at high risk for prenatal morbidity and mortality. Thus the observed 6-year reduction in childbearing years, caused by late menarche and early menopause, clearly illustrates the significant decrease in the reproductive potential of type 1 diabetic women.
Secondly, premenopausal type 1 diabetic women are already at high risk of developing cardiovascular disease. Therefore, an earlier menopause transition may exacerbate their likelihood of developing complications during their postmenopausal years. Among non-diabetic women, menopause is associated with more atherogenic lipid profiles, lower bone mineral densities, increased risks for cardiovascular disease, osteoporosis, and early mortality. Such conditions appear to improve with hormone replacement therapy in the general population. To the researchers' knowledge, there is no comparable data for type 1 diabetic women. This confirms the importance of future prospective studies of menopause transition among this population.
In addition to type 1 diabetes, menstrual irregularities before age 30 and unilateral oophorectomy were independently associated with earlier menopause in the cohort. The association with unilateral oophorectomy was particularly strong. It has been reported that a subgroup of hysterectomized women without bilateral oophorectomy have a significantly earlier age of failure than women who experience natural menopause. Hysterectomy with the removal of one rather than two ovaries may have similar but less dramatic effects. Whether this is the same for type 1 diabetic women who frequently suffer from microvascular complications remains to be examined, but is an important subject area for future research.
Among women with type 1 diabetes, those with early menopause were somewhat younger at type 1 diabetes onset ( 8.6 vs.12.6 years of age), however the mean HbA1c were virtually the same (8.5 vs. 8.4%). Also similar was the amount of insulin taken per day. There was no statistical difference in reported macrovascular complications, microvascular complications, hypertension, or lipid levels.
The researchers explained an early menopause among type 1 diabetic women may be related to prolonged hyperglycemia and/or other long-term complications of the disease. In addition, peripheral hyperinsulinemia and insulin resistance occurs among approximately one-half of persons with type 1 diabetes. Hyperinsulinemia is associated with polycystic ovarian syndrome (PCOS) and is characterized by hyperandrogenemia and amenorrhea. Because insulin and androgen levels are highly correlated in women with PCOS, one may speculate that the young age of menopause in women with type 1 diabetes may be mediated, in part, through peripheral hyperinsulinemia and/or hyperandrogenemia. However, the occurrence of PCOS in women with type 1 diabetes has rarely been reported. This, factors unrelated to long-term diabetes may be important determinants of the menopause transition. One such variable may be autoimmunity.
Several reports have suggested that early menopause has an autoimmune etiology. Approximately 20-40% of women with premature ovarian failure also have autoimmune disorders, particularly autoimmune thyroid disease. In addition, circulating anti-ovarian autoantibodies have been observed with greater frequency among people who have experienced premature ovarian failure compared with healthy control subjects, even though they had no evidence of overt autoimmune disease. There appears to be a strong positive association between autoimmunity and premature menopause. It remains for researchers to determine whether a the clustering of autoimmune diseases within individuals is an independent risk factor for earlier menopause.
The researchers suggest that given the well-documented associations between the HLA region of chromosome 6 and type 1 diabetes risk, the genetic factors that increase the risk of autoimmune disorders may also influence age of menopause. It has been shown that HLA-linked genes contribute to the levels of sex hormones in men and age of menarche in women. In addition, associations between premature ovarian failure and HLA-DR3 and HLA-DR4, which confer susceptibility to type 1 diabetes, have been observed. The FAD Study follow-up is currently under way and will provide researchers with a unique opportunity to prospectively evaluate the menopause transition among type 1 diabetic women. It will reveal critical information about premature aging, autoimmunity, and early menopause among women with type 1 diabetes. We'll keep our eyes open for you and report any further information.
BSP
