The objective of this research is to assess the efficacy of oral metformin in mitigating the aging process in middle-aged and elderly males, to pinpoint sensitive indicators of human senescence, and to offer innovative frameworks and scientific insights for pharmaceutical interventions in aging.

Subjects in both the metformin hydrochloride extended-release tablets treatment group and the placebo group received two tablets (500 mg each) once daily after dinner, continuing for a one-year period of drug intervention.

Inclusion Criteria：

1. Male
2. Age 55-65; 18-28;
3. Able to understand and execute instructions;
4. After reading the consent form, be able to answer questions about the study and demonstrate understanding of the protocol;
5. Be able to participate in regular follow-up visits.

Exclusion Criteria

1. Severe chronic or acute disease: cancer, clinically significant congestive heart failure, chronic obstructive pulmonary disease (COPD), previous or new-onset diabetes, inflammatory state, serum creatinine >1.5 mg/dl , active liver disease, History of metabolic acidosis, poorly controlled hypertension, epilepsy, recent (within 3 months) cardiovascular events (MI, PTCA, CABG, stroke), severe renal insufficiency, inflammatory bowel disease, persistent glucocorticoids Treatment; neurological diseases such as dementia, AD, PD, etc.; infectious diseases such as HIV, hepatitis, tuberculosis, etc.; severe autoimmune diseases;
2. BMI<18.5 or BMI>30;
3. Persistent alcohol or drug abuse;
4. Treatment with drugs known to affect glucose metabolism (other diabetes drugs, systemic glucocorticoids, niacin);
5. Hypersensitivity to metformin or any component of the preparation;
6. Have taken metformin, low-dose aspirin, acarbose, vitamin C in the recent (3 months);
7. Unable to provide informed consent;
8. Other circumstances in which the researcher believes that the physical factors of the participants may adversely affect the research process or results.