When a Family Has Multiple Diabetic Patients: How Should We Understand Family Clustering, and What Can We Do Now?

1. Article Background: A Real Family Case

This is a typical Chinese family’s health record: Grandma has a history of diabetes and passed away from diabetes-related complications; Dad was recently found to have HbA1c as high as 15.16%, C-peptide 1.1200 (note: the unit of C-peptide (commonly ng/mL or nmol/L), laboratory reference range, blood glucose level at the time, and whether fasting must all be determined based on the lab report before further interpretation), elevated ketones, and significant unintentional weight loss over the past few months—down by dozens of jin; Mom’s HbA1c is 8.19%, with no elevated ketones; Grandpa’s HbA1c is 6.96%.

Let’s clearly distinguish four layers of information:

① Known Facts (objective statements, uninterpreted)

• Grandma has a history of diabetes and died from diabetes-related issues
• Dad’s HbA1c: 15.16%
• Dad’s C-peptide: 1.1200 (unit, reference range, blood glucose level at testing, and fasting status are all unknown; must refer to the lab report)
• Dad has elevated ketones
• Dad experienced significant unintentional weight loss of dozens of jin over recent months (not due to deliberate dieting)
• Mom’s HbA1c: 8.19%
• Mom’s ketones are not elevated
• Grandpa’s HbA1c: 6.96%

② Medical Diagnostic Criteria (Laboratory Thresholds)

• HbA1c ≥6.5%: Meets diagnostic criteria for diabetes [ADA Standards of Care]
• HbA1c 5.7–6.4%: Prediabetes [ADA/CDC/NIDDK]
• HbA1c <5.7%: Normal [ADA/NIDDK]
• Fasting plasma glucose ≥126 mg/dL (7.0 mmol/L): Diagnostic criterion for diabetes [ADA/WHO]
• 75g OGTT 2-hour glucose ≥200 mg/dL (11.1 mmol/L): Diagnostic criterion for diabetes [ADA/WHO]
• Random plasma glucose ≥200 mg/dL (11.1 mmol/L) + typical symptoms: Diagnostic criterion for diabetes [ADA]

③ Risk Speculation (Reasonable Inferences Based on Epidemiology)

• This family shows a clear pattern of familial clustering of glucose metabolism abnormalities
• Multiple family members have HbA1c exceeding the diabetes diagnostic threshold, suggesting that both genetic susceptibility and shared lifestyle factors may be at play
• Dad’s presentation (markedly elevated HbA1c + ketonuria + unintentional weight loss) suggests possible severe insulin deficiency, warranting urgent medical evaluation

④ Data Still Requiring Further Testing

• Dad’s fasting blood glucose, random blood glucose, and 2-hour postprandial glucose
• Dad’s simultaneous blood glucose level at the time of C-peptide testing
• Dad’s GAD antibodies, IA-2 antibodies, and ZnT8 antibodies (to assess pancreatic autoimmune status)
• Dad’s quantitative blood ketone/urine ketone testing
• Mom’s fasting blood glucose, 2-hour postprandial glucose, C-peptide, and other pancreatic function indicators
• Grandpa’s fasting blood glucose, 2-hour postprandial glucose, and C-peptide
• Basic metabolic indicators for the entire family: weight, height (to calculate BMI), waist circumference, blood pressure, blood lipids, etc.

Important Note: Laboratory data such as HbA1c alone cannot definitively diagnose the type of diabetes (type 1, type 2, LADA, etc.), nor can the presence of multiple affected family members alone confirm “genetic inheritance.” Diabetes is a multifactorial disease requiring comprehensive evaluation combining clinical presentation, laboratory tests, autoantibodies, and other assessments.

2. HbA1c: The “Blood Glucose Recorder” Reflecting Average Glucose Levels Over the Past 2–3 Months

HbA1c (glycated hemoglobin) is the product of glucose binding to hemoglobin, and its concentration reflects the average blood glucose level over approximately the past 2–3 months. This marker is important because it is unaffected by single-point glucose fluctuations and provides a more stable reflection of long-term glucose exposure.

HbA1c Reference Ranges and Clinical Significance

Figure: Comparison of family members’ HbA1c values with diabetes diagnostic ranges (normal / prediabetes / diabetes). Diagnostic thresholds sourced from: ADA / WHO / Chinese Guidelines for the Prevention and Treatment of Type 2 Diabetes (2020). This figure is for health education purposes only and does not constitute an individual diagnosis.

Other Methods for Diagnosing Diabetes

In addition to HbA1c, diabetes can also be diagnosed through the following blood glucose indicators, with general consensus across guidelines [ADA/WHO/Chinese Guidelines]:

Key Points of the Diagnostic Process

• Asymptomatic individuals: A single abnormal result is insufficient to diagnose diabetes; testing must be repeated on a different date or confirmed with an alternative standardized test [ADA/WHO]
• Individuals with typical symptoms (the classic “three Ps and one loss”: polydipsia, polyuria, polyphagia, and weight loss): A random glucose ≥200 mg/dL is highly suggestive
• HbA1c below 6.5%: Does not exclude diabetes; glucose testing must be combined for comprehensive assessment
• HbA1c results may be confounded: Anemia, hemoglobin variants, chronic kidney disease, liver disease, and other conditions can affect HbA1c accuracy

3. Focusing on Dad’s Situation: Why This Is a Medical Signal Requiring Immediate Attention

Dad’s test results show HbA1c of 15.16%, elevated ketones, and significant unintentional weight loss over recent months—this triad of three highly concerning warning signs suggests a possible state of severe insulin deficiency.

Pathophysiological Chain: From Hyperglycemia to Diabetic Ketoacidosis (DKA)

When the body severely lacks insulin, the following chain reaction occurs:

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Severe insulin deficiency
    ↓
Glucose cannot enter cells for utilization → Blood glucose persistently rises (hyperglycemia)
    ↓
Cells, "starved," switch to massive fat breakdown for energy
    ↓
Fat breakdown produces large amounts of ketone bodies (acetoacetate, β-hydroxybutyrate, acetone)
    ↓
Ketone bodies accumulate in the blood → Ketonemia / diabetic ketoacidosis
    ↓
The body attempts to expel acidic substances through deep, rapid breathing (Kussmaul respiration)
    ↓
In severe cases: confusion, shock, multi-organ failure

This pathological chain illustrates why the combination of hyperglycemia, elevated ketones, and unintentional weight loss is so dangerous. Father’s HbA1c of 15.16%, converted to estimated average glucose (eAG) using the formula eAG (mmol/L) = 1.59 × HbA1c − 2.59 [Nathan DM et al. Diabetes Care 2008], comes to approximately 21.5 mmol/L (~388 mg/dL). This represents an extremely severe state of chronic hyperglycemia.

Elevated Ketones ≠ Necessarily Type 1 Diabetes

Although diabetic ketoacidosis (DKA) is more common in type 1 diabetes, the following conditions should also be considered:

1. LADA (Latent Autoimmune Diabetes in Adults): A late-onset subtype of type 1 diabetes that presents in adulthood. It may not require insulin therapy initially but progresses slowly to insulin dependence.
2. Type 2 diabetes under extreme stress: Under severe stress such as serious infection, trauma, or acute pancreatitis, patients with type 2 diabetes can also develop DKA (known as ketosis-prone type 2 diabetes).
3. Special types of diabetes: Mitochondrial diabetes, pancreatic diabetes, and others.

Therefore, elevated ketones alone cannot confirm a diagnosis of type 1 diabetes; further testing is needed to determine the specific type.

Checklist of Tests Father Needs

Three Key Points for Interpreting C-peptide

C-peptide is a byproduct of insulin synthesis, and its concentration reflects pancreatic β-cell secretory function. However, C-peptide results must be interpreted in conjunction with three factors:

1. Concurrent blood glucose level:

   • High glucose + low C-peptide = absolute insulin deficiency (e.g., type 1 diabetes)
   • High glucose + normal/high C-peptide = predominantly insulin resistance (e.g., type 2 diabetes)
   • Low glucose + high C-peptide = endogenous hyperinsulinemia (e.g., insulinoma)

2. Fasting status:

   • Fasting C-peptide reference ranges vary by assay method and reported units (ng/mL or nmol/L). Always refer to the range printed on the lab report; do not compare across laboratories or units.
   • Postprandial C-peptide should rise significantly, reflecting pancreatic β-cell reserve function.

3. Laboratory reference ranges:

   • Different laboratories and testing methods may have different reference ranges.
   • You must check the reference interval on the report and cannot compare across laboratories.

Father’s C-peptide is 1.1200, but the units (ng/mL or nmol/L), the reference range, and the simultaneous blood glucose at the time of testing are currently unknown. A complete interpretation can only be made once the lab report is reviewed. The general principle is to assess whether C-peptide is appropriate for the corresponding blood glucose: if blood glucose is significantly elevated but C-peptide is low relative to the reference range, this suggests insufficient insulin secretion; if C-peptide is not low relative to the reference range yet blood glucose remains significantly elevated with ketosis, this suggests the primary problem is insulin resistance with relative deficiency. A single C-peptide value without units and without concurrent blood glucose makes it impossible to determine which scenario applies.

IV. Mother and Grandfather: Although HbA1c Is Only “Slightly Elevated,” It Still Deserves Serious Attention

Mother: HbA1c 8.19%, Ketones Not Elevated

• HbA1c of 8.19% is well above the diabetes diagnostic threshold (6.5%). Even without elevated ketones, diabetes cannot be ruled out.
• The absence of ketone elevation may suggest some remaining insulin secretory capacity, but further testing is needed for clarification.
• Recommended tests: fasting glucose, 2-hour postprandial glucose, C-peptide, pancreatic function assessment, BMI, waist circumference.

Grandfather: HbA1c 6.96%

• Although HbA1c of 6.96% is only slightly above the 6.5% threshold, it still meets the diagnostic criteria for diabetes.
• It should not be dismissed simply because it is “only a little high.” The 6.5–7.0% range still carries risk for microvascular complications.
• Recommendations: repeat HbA1c testing for confirmation, fasting glucose, 2-hour postprandial glucose assessment, lifestyle modification.

Pattern of Dysglycemia Distribution in the Family

From an epidemiological perspective, this family shows a clear pattern of familial aggregation:

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Grandmother's generation: History of diabetes (deceased; cause related to diabetes)
├── Father's generation: Father (HbA1c 15.16% severely elevated + ketones↑), Mother (HbA1c 8.19% elevated)
└── Grandfather's generation: Grandfather (HbA1c 6.96% slightly elevated)

This multi-generational, multi-member pattern of dysglycemia suggests the need to assess both genetic susceptibility and shared lifestyle factors.

V. Core Concept: Familial Aggregation ≠ Determined by a Single Genetic Gene

“Familial aggregation” is a core concept in epidemiology, referring to the phenomenon where a disease appears more frequently among family members than in the general population. However, multiple affected family members does not equal a single-gene cause, nor does it mean “it must be inherited.”

Multi-Factor Model of Familial Aggregation

Disease occurrence among family members results from the combined effect of multiple factors:

Important Clarifications

• ≠ Single-gene mutation: Common chronic diseases such as type 2 diabetes are polygenic, with each gene contributing a small effect, unlike single-gene disorders such as Huntington’s disease.
• ≠ Certain inheritance: Even with genetic susceptibility, environmental factors can significantly alter disease onset and progression [PMC2869073].
• ≠ Caused by white rice alone: Carbohydrate intake is one risk factor, but it cannot be attributed to a single food. Total energy intake, dietary structure, and physical activity must be considered together.
• ≠ Unchangeable: Although genetic susceptibility cannot be changed, lifestyle intervention has been proven to significantly reduce disease risk [CDC/ADA].

Suggested Accurate Wording

“This family shows a clear pattern of familial aggregation of dysglycemia, suggesting the combined effect of genetic susceptibility and shared lifestyle factors. While it is important to be aware of genetic risk, greater emphasis should be placed on modifiable lifestyle factors.”

VI. Why Family-Wide Lifestyle Change Is More Effective Than Individual Effort

In a shared household, asking one person to maintain a healthy diet is extraordinarily difficult—when the whole family eats white rice and drinks sugary beverages together, individual dietary restrictions create enormous social pressure and practical challenges.

Advantages of Family-Level Intervention

1. Reduce the difficulty of execution: No need for individual “special requests” or “special meals”—the whole family adjusts together, so kids don’t feel singled out, and spouses don’t feel isolated.
2. Build a healthy environment: With no sugary drinks or snacks at home, healthy eating becomes the default, reducing the frequency of “willpower vs. temptation” battles.
3. Behavioral modeling effect: Parents’ healthy habits set an example for children, building healthy eating patterns from an early age.
4. Long-term sustainability: Once a family consensus is established, there’s no need for constant resistance—healthy habits become natural.

Practical Principles for Family Diet Adjustment

• Not “you shouldn’t eat white rice,” but rather “the whole family adjusts its staple food structure together”
• Not “you must lose weight,” but rather “the whole family takes a post-meal walk together”
• Not “you can’t eat dessert,” but rather “the family cuts back on buying sugary foods”

This kind of environmental-level change is more sustainable and less prone to failure than relying on individual willpower.

VII. Family Action Guide: A Specific, Actionable Checklist

The following recommendations are based on the ADA Standards of Care, CDC, WHO, and Chinese guidelines, aimed at helping families reduce the risk of glucose metabolism abnormalities. Individuals with severe hyperglycemia, elevated ketones, or significant weight loss must undergo medical evaluation before taking action.

1. Staple Food Adjustment: Gradually Reduce Refined Carbs, Increase Whole Grains and Legumes

Note: Whole grains and legumes are still sources of carbohydrates and will raise blood sugar—just more slowly〔Mayo Clinic〕. The key is not “eliminating carbs,” but rather controlling total amount + optimizing structure + pairing wisely.

2. Switch to Smaller Bowls: Reduce Unconscious Intake

• Replace large family bowls with smaller 200–300 ml bowls (or even the 150 ml soup bowls commonly used in restaurants)
• It’s not about “the smaller the better”—the goal is to make a reasonable portion of staple food fit easily, while an excessive portion clearly won’t fit
• After portioning staples into small bowls, add vegetables and protein to ensure a balanced plate

3. Plate Structure: Use the Universal Healthy Plate Method

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─────────────────────────────
|           │                 |
|  Non-     │   Fish / Shrimp / |
|  starchy   │   Egg / Chicken  |
|  veggies   │   / Meat / Tofu  |
|  (½)       │   (¼)           |
|           │                 |
─────────────────────────────
|     Whole-grain staple      |
|          (¼)                |
─────────────────────────────

• ½ non-starchy vegetables: leafy greens, broccoli, tomatoes, cucumbers, eggplant, mushrooms, etc.—low in energy, high in fiber
• ¼ protein: fish, shrimp, eggs, chicken breast, lean beef, tofu, dried tofu, etc.
• ¼ staples / whole grains: brown rice, oats, buckwheat, whole-wheat bread, sweet potato, etc.

Note: This is a general healthy eating framework; patients should adjust according to medical or dietitian recommendations.

4. Reduce Sugary Foods and Beverages

5. Skip Added White Sugar When Stir-frying

• Reduce the amount of added white sugar or brown sugar used in stir-frying, braising, sweet-and-sour cooking, and other methods
• Watch out for these common hidden sources of added sugar:
  • Braised pork, sweet-and-sour ribs, sweet-and-sour fish
  • Sweet-style braised snacks (braised chicken wings, braised duck necks, etc. with added sugar)
  • Sweet-flavored sauces (ketchup, salad dressing, teriyaki sauce, mapo sauce)
  • Doubanjiang (some brands add sugar)
• The goal is not to eliminate seasoning entirely, but to cut back on “unnecessary added sugars”

6. Post-Meal Activity: Light Exercise the Whole Family Can Do Together

• When physically able, take a light 10–20 minute walk after meals (e.g., a family stroll or brisk walking around the neighborhood)
• Accumulate at least 150 minutes of moderate-intensity physical activity per week〔CDC/WHO/ADA〕
• Activities include: brisk walking, cycling, swimming, square dancing, badminton, etc.
• Note: Individuals with severe hyperglycemia, elevated ketones, or significant weight loss should not engage in vigorous exercise on their own—medical evaluation is required first

7. Control Late-Night Snacks: Avoid High-Refined-Carb Night Snacks

• Cut back on late-night snacks like congee, steamed buns, noodles, cookies, cakes, and sweets
• Late-night snacking easily leads to extra calorie intake, and since activity levels are low at night, those calories are more likely to be stored as fat
• If genuinely hungry, opt for a small portion of protein or vegetables (e.g., an egg, tofu, or vegetable soup)

8. Build a Family Health Database: Long-Term Trend Tracking

Focus on trends: Long-term trends matter more than any single abnormal reading. For example:

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Dad's HbA1c: 2024 → 6.8% → 2025 → 7.2% → 2026 → 8.2% → mid-2026 → 15.16%
> This sustained upward trajectory is far more concerning than a single "8.2%" reading

VIII. Building a Family Health Tree: From Disease Records to Health Risk Maps

The ASCII diagram below illustrates the distribution of metabolic abnormalities within this family, which can serve as the foundation for a “Family Health Risk Map”:

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┌───────────────────────────────────────────────────────────────────────────────┐
│                            家族健康风险地图                                    │
│                            Family Health Tree                                 │
└───────────────────────────────────────────────────────────────────────────────┘

Grandparent Generation (Previous Generation)
┌─────────────────┐     ┌─────────────────┐
│      Grandfather       │     │      Grandmother       │
│  (Health records unavailable) │     │  History of Diabetes    │
│                 │     │  → Diabetes-related    │
└─────────────────┘     └────────┬────────┘
                                 │
                                 │ Grandmother (Father's Mother)
                                 ▼
┌───────────────────────────────────────────────────────────────────────────────┐
│                           Parent Generation (Middle Generation)                │
│                                                                               │
│         ┌─────────────────────┐     ┌─────────────────────┐                  │
│         │         Dad          │     │         Mom          │                  │
│         │  HbA1c 15.16%        │     │  HbA1c 8.19%         │                  │
│         │  Elevated ketones ↑          │     │  Normal ketone levels          │                  │
│         │  Unexplained weight loss, dozens of pounds    │     │                      │                  │
│         │  → Highly suggestive of severe insulin   │     │                      │                  │
│         │  deficiency state       │     │                      │                  │
│         └──────────┬──────────┘     └──────────┬──────────┘                  │
│                    │                           │                              │
│                    ▼                           ▼                              │
│         ┌─────────────────────────────────────────────────────┐               │
│         │                    Child Generation (Next Generation)                   │               │
│         │                                                       │               │
│         │   ▶ Genetic risk monitoring: Recommended periodic screening of HbA1c, fasting glucose    │               │
│         │   ▶ Lifestyle intervention: Healthy diet + regular exercise to reduce disease risk     │               │
│         │   ▶ Establish personal health records to track long-term trends                    │               │
│         └─────────────────────────────────────────────────────┘               │
└───────────────────────────────────────────────────────────────────────────────┘
                                 │
                                 │ Grandfather (Mother's Father)
                                 ▼
                    ┌─────────────────────┐
                    │         Maternal Grandfather       │
                    │  HbA1c 6.96%         │
                    │  → Slightly above diagnostic threshold      │
                    │  → Requires further evaluation       │
                    └─────────────────────┘

 Legend:
 ─────────────────────────────────────────────────────────────────────────────────
 ▶ HbA1c ≥6.5% meets diagnostic criteria for diabetes                  ▶ Elevated ketones  requires urgent attention
 ▶ Unexplained weight loss  serves as a warning sign for various conditions      ▶ Periodic screening  recommended every 1–3 years
 ─────────────────────────────────────────────────────────────────────────────────

Future Scalable Disease Dimensions (currently limited to glucose metabolism disorders): ───────────────────────────────────────────────────────────────────────────────── ▶ Family history of hypertension ▶ Cardiovascular events (MI/stroke) ▶ Hyperlipidemia / hyperuricemia ▶ Obesity (central obesity) ▶ Family history of cancer (specific types) ▶ Gout ▶ Fatty liver disease ▶ Osteoporosis ▶ Mental health (depression / anxiety) ▶ Autoimmune diseases ─────────────────────────────────────────────────────────────────────────────────

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**Usage tips**:
1. Use this tree as a template to record each family member's disease history and age of onset
2. Update every 2 years, noting new diagnoses and latest test results
3. Bring it to medical visits to help doctors assess genetic risk
4. Can be digitized in the future (Excel / online spreadsheets) for easier statistical analysis

## 9. Don't Create Panic: Increased Risk ≠ Inevitable Disease — It's Preventable and Manageable

### Phrases to Avoid (They Create Panic / False Certainty)

- "You will definitely get diabetes" → **Wrong.** Even with genetic susceptibility, lifestyle intervention can significantly reduce risk.
- "It's all genetics" → **Wrong.** Genetic susceptibility + adverse environmental factors together cause disease onset.
- "White rice causes diabetes" → **Inaccurate.** A single food doesn't cause disease; it depends on the overall dietary pattern.
- "Eating brown rice can cure diabetes" → **Wrong.** Diet is a management tool, not a cure.
- "A family history of diabetes can't be changed" → **Wrong.** A healthy environment can delay or even prevent onset.

### Appropriate Phrases (Scientific & Actionable)

| Scenario | ❌ Panic-Inducing Statement | ✅ Correct / Action-Oriented Statement |
|------|--------------|---------------|
| Multiple family members affected | "We have the diabetes gene in our family" | "This family shows a clustering pattern of glucose metabolism disorders. Genetic risk and lifestyle warrant attention." |
| Parents have diabetes, child is at risk | "The child is destined to get diabetes" | "The child has an increased genetic risk. Regular screening is needed, and a healthy lifestyle can significantly lower actual disease risk." |
| Slightly elevated HbA1c | "They already have diabetes" | "This meets the criteria for prediabetes — a warning signal from the body. Lifestyle intervention can reverse it." |
| Wanting to eat sweets | "I must cut out sweets completely" | "Reduce the frequency of sugary drinks and desserts, control portions, and learn to balance enjoyment with health management." |
| Family won't cooperate | "No one listens to me" | "Start with small changes the whole family can do together — like a post-meal walk or reducing the proportion of white rice." |

### Scientific Consensus on Diabetes Prevention

- **Prediabetes population**: Lifestyle intervention can reduce diabetes incidence by 58% [CDC National DPP]
- **High-risk population** (family history + overweight): A 5–7% weight loss significantly reduces disease risk
- **Already diagnosed**: Proper management (diet + exercise + medication) can prevent complications and support a normal lifespan and quality of life
- **Conclusion**: Increased risk ≠ inevitable disease; **it is preventable, manageable, and controllable**

## 10. Final Checklist for Everyday Families: "Family Blood Sugar Risk Action List"

The checklist below can be printed directly and used as a family health action guide:

□ Reduce the proportion of refined grains (gradually replace white rice with whole grains and mixed cereals) □ Replace white rice with brown rice, oat groats, buckwheat, corn, sweet potatoes, etc. □ Use smaller rice bowls (200–300 ml capacity) to reduce unconscious overconsumption □ Control portion sizes per meal (refer to the plate method: grains occupy 1/4 of the plate) □ Increase non-starchy vegetables at every meal (occupy 1/2 of the plate) □ Ensure adequate protein intake (fish, shrimp, eggs, chicken, lean meat, tofu, etc.) □ Reduce sugar-sweetened beverages (cola, fruit juice, bubble tea) □ Reduce fruit juices containing added sugar (even freshly squeezed juice) □ Reduce desserts, cakes, and candy □ Reduce added sugar in cooking (white sugar, brown sugar, honey, syrup) □ Be mindful of hidden sugars in braised pork, sweet-and-sour dishes, sweet marinades, and sweet sauces □ Take a walk after meals (10–20 minutes daily) □ Reduce prolonged sitting (stand and move for 2–3 minutes every hour) □ Maintain healthy weight and waist circumference (BMI 18.5–23.9; waist <90 cm for men, <85 cm for women) □ Regularly check fasting blood glucose (annually recommended) □ Regularly check HbA1c (annually recommended; every 6 months for high-risk individuals) □ Follow doctor’s orders for postprandial glucose or OGTT (if prediabetes is present) □ Establish long-term health records for all family members (age, height, weight, BMI, waist circumference, blood pressure, blood glucose, blood lipids, etc.) □ Record family disease history and age of onset (diabetes, hypertension, cardiovascular disease, etc.) □ Seek medical attention promptly if significant abnormalities are detected (HbA1c ≥6.5%, fasting glucose ≥7.0 mmol/L, etc.) □ Severe hyperglycemia + ketone elevation + noticeable weight loss → seek emergency care immediately (DKA warning signs)

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**Usage tips**: Review completion monthly. Parents should lead by example, with the whole family participating.

## 11. Medical Safety Disclaimer

This article is intended for health education and family risk management. It does not constitute a medical diagnosis or treatment advice. The content is based on epidemiological and public health perspectives, aimed at helping ordinary families understand familial clustering, recognize risk signals, and take preventive actions.

### Important Medical Warnings

For the following situations, **medical evaluation should take priority — dietary adjustment alone is insufficient**:

1. **Severe hyperglycemia**: HbA1c >10% or fasting blood glucose >13.9 mmol/L (250 mg/dL)
2. **Elevated ketones**: Blood ketone >3.0 mmol/L or strong positive urine ketones
3. **Unintentional significant weight loss**: More than 5% or 5 kg (10 jin) body weight loss over several months (not from intentional dieting)
4. **DKA warning signs** (any one requires emergency care):
   - Worsening polydipsia, excessive thirst, and polyuria
   - Nausea, vomiting, abdominal pain
   - Deep, rapid breathing (Kussmaul respirations); breath with acetone odor
   - Confusion, lethargy
   - Severe dehydration (poor skin turgor, sunken eyes)

5. **Emergency indications for DKA**
   - Blood glucose persistently >250 mg/dL with elevated ketones
   - Vomiting ≥2 times or inability to eat or drink
   - Persistent, unrelenting abdominal pain
   - Difficulty breathing or altered consciousness

### Medical Advice Statement

- The examinations mentioned in this article should be decided by a doctor based on individual circumstances, including whether and in what sequence to perform them
- The dietary adjustment suggestions mentioned herein cannot replace individualized medical nutrition therapy (MNT)
- Patients already diagnosed with diabetes must follow their doctor's medication instructions and should not stop or adjust dosage on their own
- Exercise recommendations should be assessed based on individual health status (especially cardiovascular condition) before implementation
- Interpretation of laboratory markers such as HbA1c and blood glucose must be combined with clinical presentation and a physician's judgment

### Legal Statement

This article is for popular science and education purposes only and does not establish a doctor-patient relationship. Readers should consult a professional medical institution for individualized assessment and treatment based on their own circumstances.

---

## References

The medical content in this article is verified against the following authoritative medical guidelines and literature:

### Books and Guidelines

1. American Diabetes Association. **Standards of Medical Care in Diabetes—2024**. Diabetes Care 2024;47(Supplement 1). https://diabetesjournals.org/care/article/49/Supplement_1/S27/163926/2-Diagnosis-and-Classification-of-Diabetes

2. World Health Organization. **Diagnostic criteria for diabetes: Recommendation by WHO**. 2023. https://iris.who.int/bitstreams/db9b9d3d-f95e-4797-9d2b-c78dcef0133f/download

3. Chinese Diabetes Society. **Guidelines for the Prevention and Treatment of Type 2 Diabetes in China (2020 Edition)**. Chinese Journal of Diabetes 2021;13(4):315-409.

### Institutional Websites

4. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). **A1C Test**. https://www.niddk.nih.gov/health-information/diagnostic-tests/a1c-test

5. Centers for Disease Control and Prevention (CDC). **Prediabetes—Your Body Saying "Slow Down"**. https://www.cdc.gov/diabetes/diabetes-testing/prediabetes-a1c-test.html

6. American Diabetes Association. **Diabetes Tests and Diagnosis**. https://diabetes.org/about-diagnosis/diabetes-tests

7. CDC National Diabetes Prevention Program. **Lifestyle Change Program**. https://www.cdc.gov/diabetes/prevention/index.html

### Professional Literature

8. American Diabetes Association. **Physical Activity/Exercise and Diabetes**. Diabetes Care 2024;47(Supplement 1). https://diabetes.org/living-with-diabetes/ability-and-access/physical-activity

9. Review of Genetic and Environmental Risk Factors for Diabetes. PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC2869073 (2010)

10. Nathan DM, et al. **Translating the A1C assay into estimated average glucose values**. Diabetes Care 2008;31(8):1473-1478. (Source of the eAG conversion formula)

11. Pathophysiology of Diabetic Ketoacidosis (DKA). Medscape. https://emedicine.medscape.com/article/118361-overview

12. Lundholm M, Zhou K. **Latent Autoimmune Diabetes in Adults (LADA)**. Cleve Clin J Med 2025;92(12):757. https://www.ccjm.org/content/92/12/757

13. Review of Diabetes-Related Autoantibodies (GAD/IA-2/ZnT8). PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC2797953

14. C-Peptide Interpretation and Clinical Significance. PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC5446389/

15. Mayo Clinic. **Low-glycemic index diet**. https://www.mayoclinic.org/zh-hans/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/low-glycemic-index-diet/art-20048478

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*This article is compiled from authoritative medical guidelines and is intended for general family readers. It does not constitute medical advice; readers should consult qualified healthcare professionals for individualized assessment.*

*This article was completed on August 16, 2026. Medical guidelines may be updated; please consult professional medical institutions for the most current information.*