Application of CGM in Precision Diabetes Management: Precise In-Hospital Glycemic Control & Evidence-Based Post-Discharge Follow-Up

Medical History and Basic Information

Chief Complaint:

A 46-year-old male patient was admitted to the hospital presented to the outpatient department due to "intermittent polyuria and polydipsia for 17 years, and burning sensation in both feet for 5 months."

Present History:

Before admission, the patient received subcutaneous insulin injection: insulin aspart 6IU-6IU-6IU, insulin glargine 14IU; acarbose (50mg, 3 times/day, before meals). In the past 5 months, he has felt a burning sensation in both feet, which was more prominent at night. He took mecobalamin (0.5mg, 3 times/day) and vitamin B1 (10mg, 3 times/day) orally, and the symptoms were slightly relieved. In the past half month, significant fatigue and increased nocturia. His usual fasting blood glucose was 7mmol/L-10mmol/L, and postprandial blood glucose was 17mmol/L-20mmol/L.

Past History:

The patient had a 30-year smoking history, smoking 20 cigarettes per day, and occasionally drank alcohol, 150g each time.

Physical Examination:

Temperature 36.1℃, pulse 82 beats/min, respiration 20 breaths/min, blood pressure 119/87mmHg, Body Mass Index (BMI) 27.6kg/m². Conscious and articulate,no crackles or rales. The cardiac border was not enlarged, heart rate was 82 beats/min, rhythm was regular, no extra heart sounds or murmurs. The abdomen was flat and soft, no tenderness or rebound tenderness, liver and spleen were not palpable, and bowel sounds were normal. No foot deformity, no local skin redness, swelling or ulceration, decreased superficial sensation in both feet, no edema of both lower extremities.

Auxiliary Examinations:

Abnormal indicators of auxiliary examinations after admission were: glycated hemoglobin 10.5%, total cholesterol 5.73mmol/L, low-density lipoprotein cholesterol 3.6mmol/L; arteriosclerosis of both lower extremities, arteriosclerosis of both carotid arteries with left plaque formation. Pancreatic islet function examination after admission showed:

Admission Diagnosis:

Type 2 diabetes mellitus (T2DM) with poor glycemic control, diabetic peripheral neuropathy.

Treatment Regimen Based on Continuous Glucose Monitoring (CGM) Interpretation

The patient had a 17-year course of diabetes, was treated with insulin combined with oral drugs, had poor glycemic control, and already had diabetic complications. After admission, oral glucose tolerance test and insulin release test were performed, and the fasting blood glucose was 2.57 mmol/L. Considering the patient's risk of hypoglycemia, CGM was worn after the test to monitor blood glucose.

On the 2nd day after admission, the patient was given intensive treatment with insulin pump (insulin aspart): basal dose 16IU, bolus dose 6IU-6IU-6IU, acarbose 50mg, 3 times/day, before meals. The treatment effect was obvious, and no hypoglycemia was found.

Note: TIR: Time in target blood glucose range (3.9~10.0mmol/L); TAR: Time above target blood glucose range (>10.0mmol/L); TBR: Time below target blood glucose range (<3.9mmol/L)

During the period of wearing the insulin pump, the patient was given diet and exercise guidance, and was advised to eat diabetic meals in the restaurant. During the wearing period, the patient had an intuitive understanding of diet, exercise and blood glucose changes, and had good compliance. Considering that the patient was a middle-aged male with complications and poor living habits, it was recommended that the patient's blood glucose should be strictly controlled, and the patient could understand.

The patient was discharged on February 10, 2025.

On February 12 (post-discharge day 2), follow-up showed glucose fluctuations related to increased food intake and higher fat content. The dose of insulin glargine/lixisenatide was increased to 18 IU. The patient was educated on the importance of sustained lifestyle management to prevent major cardiovascular and cerebrovascular events.

Blood glucose changes after discharge:

Note: TIR: Time in target blood glucose range (3.9~10.0mmol/L); TAR: Time above target blood glucose range (>10.0mmol/L); TBR: Time below target blood glucose range (<3.9mmol/L)

Case Summary

The patient was a middle-aged male with irregular and poor living habits. Long-term poor glycemic control would significantly increase the risk of cardio-cerebrovascular diseases (such as myocardial infarction, stroke) and microvascular complications (such as diabetic nephropathy, retinopathy). A large number of studies have confirmed that persistent hyperglycemia (HbA1c >7%) and blood glucose fluctuation (CV >36%) can accelerate the process of atherosclerosis and damage target organs through multiple mechanisms such as oxidative stress, inflammatory response and endothelial dysfunction. Therefore, the primary task is to make the patient fully recognize the harmfulness of diabetes subjectively, especially irreversible complications (such as myocardial infarction, renal failure, amputation, etc.). Once they occur, the prognosis is extremely poor and the treatment cost is high.

CGM improves self management and promotes "eating less and moving more." The real-time feedback effect of CGM can enhance patients' sensitivity to diet and exercise. CGM is not only a monitoring tool but also a "digital coach" for behavioral intervention, helping patients establish healthy habits. During the latest follow-up, the attending physician emphasized to the patient that once blood glucose is well controlled, if the drug dose remains unchanged, there may be a risk of hypoglycemia. The doctor specially reminded the patient to pay attention to the signs of hypoglycemia and test blood glucose levels in a timely manner. The doctor suggested that the patient continue to use CGM to ensure stable blood glucose during drug adjustment. The patient highly recognized the intelligent functions of CGM and decided to start using it immediately.

The real-time, continuous and intelligent characteristics of CGM have brought an intuitive experience to diabetes management, metabolic health and even sports performance optimization, and are highly recognized by patients. Firstly, CGM enables visualized dietary response and exercise effect evaluation, helping patients optimize lifestyle and reduce glucose variability. Secondly, CGM is also very helpful for medical staff to conduct health education and guidance, increasing the persuasiveness of daily guidance.

References：

[1]Diabetes Nursing Professional Committee of Chinese Nursing Association, National Center for High-Performance Medical Device Innovation. Expert Consensus on Nursing Application of Continuous Glucose Monitoring Report (2025 Edition). Chinese Journal of Diabetes Mellitus, 2025, 17(03):311-321. DOI:10.3760/cma.j.cn115791-20241220-00748

[2]Endocrinology Society of Chinese Medical Association, National Center for High-Performance Medical Device Innovation. Expert Consensus on Clinical Application of Continuous Glucose Monitoring Report (2023 Edition). Chinese Journal of Diabetes Mellitus, 2024, 16(02):190-201. DOI:10.3760/cma.j.cn115791-20231120-00325

[3] Cardiovascular Diabetology, 2022.

[4] Health Psychology, 2023.