What is the cause of menopause?

Physiological menopause is the result of the natural decline of ovarian function, which means the termination of ovarian reproductive function. Women's ovaries generally begin to age in the middle stage of their life course, and the termination of reproductive power is significantly earlier than that of humans, which is an obvious biological characteristic. So, what is the cause of menopause?

1. Age of menopause

The age of menopause reflects the reproductive lifespan of the ovaries, and cell aging is the result of menopause. Factors that affect the age of menopause include heredity, nutrition, weight, altitude of the living area, and smoking.

2. The impact of genetic factors on menopausal women

The DNA sequence and its variation in the human body reflect the evolution of human beings. Studying the variation of DNA sequences in different populations and individuals (i.e., polymorphisms) helps us understand human physiological changes, the occurrence and development of diseases, and the response to drug treatment.

DNA, which carries the genetic information of the human body, is composed of four different bases. The human genome has about 3.3 billion base pairs, and their arrangement order has been basically determined. The arrangement order of bases in the genomes of different people is mostly the same, but there are also very small differences, which are mainly reflected in the different arrangement of bases at individual positions of DNA. This genetic variation is called single nucleotide polymorphism (SNP). There are about 10 million SNPs in the human genome. The reason why different people have different susceptibility to the same disease and sometimes have different reactions to the same drug is related to the differences in SNPs. Similarly, SNPs also affect the differences in various physiological conditions and disease occurrence in menopausal women to varying degrees.

Many gene polymorphisms are associated with the timing of menopause and the onset of certain postmenopausal diseases.

Very early menopause is often accompanied by a decrease in estrogen levels, which has an important impact on postmenopausal health. Early menopause is a high risk factor for cardiovascular disease, osteoporosis and ovarian tumors, and increases mortality. Therefore, from a clinical point of view, it is very important to determine the factors that affect the age of menopause.

More and more studies have found that certain gene polymorphisms are associated with the occurrence of menopause and postmenopausal diseases.

(1) Estrogen receptor (ER) gene polymorphism:

① The structure and function of estrogen receptor (ER). ② Polymorphism of ER gene. ③ The relationship between ER gene polymorphism and menopause. ④ The relationship between ER gene polymorphism and postmenopausal bone density. ⑤ ER gene polymorphism and postmenopausal hormone replacement therapy (HRT).

For postmenopausal women receiving HRT, their ER gene polymorphism affects the level of high-density lipoprotein (HDL), thus affecting the dose-effect of HRT.

In summary, estrogen receptor gene polymorphism affects menopause time and bone metabolism at different levels and plays a role in HRT treatment. If clinicians can predict the risk of postmenopausal osteoporosis and the response to HRT treatment by testing ER genotype, it will play an important role in the early prevention and treatment of osteoporosis and the formulation of personalized HRT treatment plans.

(2) Vitamin D receptor gene polymorphism:

①The structure and function of vitamin D receptor. ②Polymorphism of VDR gene. ③The relationship between VDR polymorphism and postmenopausal bone mineral density and osteoporosis.

(3) Other gene polymorphisms:

① Calcitonin receptor (CTR) gene polymorphism. ② Type I collagen (COLIAI) gene polymorphism: COLIAI is associated with bone mass and osteoporotic fractures. ③ Interleukin-6 (IL-6) gene polymorphism. ④ Transforming growth factor β gene Transforming growth factor β (TGF-β) gene polymorphism. ⑤ CYP17 and CYP19 genes.

(4) Detection of gene polymorphism:

The study of gene polymorphism is inseparable from the detection of gene polymorphism sites.

① Restriction fragment length polymorphism (RFLP). ② Short tandem repeat sequence. ③ Amplified fragment length polymorphism. ④ Single strand conformation polymorphism (SSCP). ⑤ Gene chip and SNP map.