Metformin mainly reduces blood sugar by reducing the output of hepatic glycogen (inhibiting the transformation of hepatic glycogen into glucose), reducing the absorption of glucose by small intestine, improving insulin resistance, activating adenosine-activated protein kinase and promoting the oxidative decomposition of glucose.
Metformin, as a first-line drug for diabetes treatment, has always been the first choice, especially for overweight and obese diabetic patients. The hypoglycemic effect is positive. Monotherapy can reduce fasting blood glucose and postprandial blood glucose, and reduce glycosylated hemoglobin 1%-2%. The initial minimum dose is 500mg/day, the optimal effective dose is 2000mg/day, and the maximum dose is 2550mg/day.
It is suggested that metformin should be used from the minimum dose and gradually increased to the best effective dose. If the blood sugar is still not up to standard after a single dose of treatment for 3 months, consider taking a second dose of oral hypoglycemic agents. It can also be combined with insulin to further reduce the dosage of insulin and reduce the risk of weight gain and hypoglycemia caused by insulin.
One of the reasons why metformin plays an important role in the treatment of diabetes is that it has other functions besides lowering blood sugar. For example, in reducing blood lipids, metformin can improve the synthesis and metabolism of fat. Many studies have shown that metformin can reduce the levels of total cholesterol, low-density lipoprotein cholesterol and triglyceride in patients with type 2 diabetes, but it has little effect on high-density lipoprotein cholesterol.
Metformin can lose weight. According to the research, after the newly diagnosed patients with type 2 diabetes were treated with metformin alone for 4 months, the weight of normal patients, overweight patients and obese patients decreased by 65438±0.47kg, 2.865438±0kg and 2.92kg respectively. The greater the body mass index and waist circumference, the more obvious the weight loss after using metformin.
When treated with sulfonylureas (gliclazide XX), rosiglitazone, pioglitazone and insulin, weight usually increases. Combined with metformin, the effects of these drugs on body weight can be minimized. Studies have shown that metformin combined with insulin can reduce body weight by 2.28-3.85kg compared with insulin alone.
Metformin can also improve nonalcoholic fatty liver, including reducing alanine aminotransferase and aspartate aminotransferase, improving insulin resistance, and significantly improving liver inflammation, steatosis and fibrosis. Metformin can be used as long as the transaminase does not exceed 3 times the normal upper limit and there is no serious liver dysfunction or decompensation of liver cirrhosis.
Metformin has obvious cardiovascular protection. It can protect the cardiovascular system by reducing the risk factors of cardiovascular diseases. Controlling risk factors is an important measure to reduce cardiovascular events, including dyslipidemia, obesity, insulin resistance, hypertension, nonalcoholic fatty liver and so on. Metformin can reduce blood sugar, blood lipid and body weight, improve insulin resistance (especially in liver and muscle) and improve nonalcoholic fatty liver.
The prospective study of diabetes in UK 10 shows that the use of metformin can reduce macrovascular complications and mortality, and this benefit is sustained, and its role in reducing myocardial infarction and death is obviously better than that of sulfonylureas (gliclazide XX) and insulin. Therefore, it is very suitable for patients with type 2 diabetes complicated with cardiovascular diseases such as coronary heart disease, atherosclerosis and arrhythmia.
In addition, metformin also has anti-tumor effect. Diabetes mellitus is a risk factor for breast cancer, pancreatic cancer, colorectal cancer and endometrial cancer. Many studies have shown that metformin can not only affect metabolism, but also inhibit the occurrence and development of tumors by activating AMP-activated protein kinase pathway. Metformin treatment can reduce the risk of lung cancer, prostate cancer, rectal cancer, breast cancer and other cancers.
In a word, metformin has conclusive evidence in the treatment and cardiovascular protection of type 2 diabetes, and its price is low. For most patients with type 2 diabetes, it should be used as an oral hypoglycemic agent throughout the course. In order to reduce fasting blood glucose, postprandial blood glucose, glycosylated hemoglobin and protect target organs such as heart and kidney, the more expensive the better.