{
  "id": "prediabetes",
  "title": "Prediabetes",
  "lang": "en",
  "source_lang": "en",
  "summary": "A metabolic state in which blood glucose or HbA1c is raised above normal but below the diagnostic threshold for diabetes.",
  "category": "health",
  "subcategory": "diseases",
  "type": "concept",
  "aliases": [
    "impaired glucose regulation",
    "borderline diabetes",
    "intermediate hyperglycemia"
  ],
  "generated_at": "2026-10-15",
  "model": "pro/claude-haiku-5-5",
  "url": "https://aiwiki.page/en/prediabetes/",
  "translations": {
    "zh-Hans": {
      "url": "https://aiwiki.page/zh/prediabetes/",
      "json": "https://aiwiki.page/zh/prediabetes.json"
    }
  },
  "sections": [
    {
      "heading": "",
      "text": "Prediabetes is a state of abnormal carbohydrate metabolism in which blood glucose or glycated hemoglobin is higher than normal but not high enough to meet the criteria for diabetes. It is a risk state rather than a disease in its own right: people with prediabetes have a substantially higher chance of developing type 2 diabetes and of experiencing cardiovascular disease, and many revert to normal glucose levels or never progress. The condition is closely linked to excess body weight, insulin resistance, and the wider cluster of abnormalities sometimes called metabolic syndrome."
    },
    {
      "heading": "Definition and diagnostic criteria",
      "text": "Prediabetes is defined by three measurements, any one of which can place a person in the category:\n\n- Impaired fasting glucose (IFG): a fasting plasma glucose of 100–125 mg/dL (5.6–6.9 mmol/L) after at least eight hours without caloric intake.\n- Impaired glucose tolerance (IGT): a plasma glucose of 140–199 mg/dL (7.8–11.0 mmol/L) two hours after a 75-gram oral glucose tolerance test.\n- Elevated HbA1c: a glycated hemoglobin (HbA1c) of 5.7–6.4% (39–47 mmol/mol).\n\nThe American Diabetes Association (ADA) uses these thresholds in its annual Standards of Care. The ADA's 2026 guidance states that fasting plasma glucose, the two-hour OGTT, and HbA1c are each appropriate for screening, and that the same tests can be used to establish a diagnosis. The World Health Organization historically applied a higher lower limit for IFG (110 mg/dL, or 6.1 mmol/L), so the category's boundaries differ somewhat between guidelines. Diagnostic thresholds for diabetes itself are a fasting glucose of 126 mg/dL or higher, a two-hour value of 200 mg/dL or higher, or an HbA1c of 6.5% or higher.\n\nBecause prediabetes is defined by continuous risk rather than a sharp biological cut-off, risk of progression rises gradually as values approach the diabetes threshold. Experts therefore generally regard the thresholds as conventions for practical decision-making rather than natural boundaries."
    },
    {
      "heading": "Epidemiology",
      "text": "Prediabetes is very common. CDC estimates from the National Health and Nutrition Examination Survey (NHANES) indicate that about 115 million American adults, more than two in five, have prediabetes, and roughly 8 in 10 of them do not know it. Earlier CDC estimates for 2017–2020 were lower (about 97.6 million, or 38% of adults), and the difference largely reflects changes in survey methods and the use of newer data, so comparisons across editions should be made cautiously.\n\nPrevalence rises with age. CDC figures cited in recent public summaries show a prevalence of roughly 36% among adults aged 18–44, about 49% among those aged 45–64, and about 52% among those 65 and older. Prevalence also varies by ethnicity, with some groups, including Hispanic and Asian American adults, showing higher rates than non-Hispanic White adults in certain analyses. The condition is no longer confined to older adults: a 2025 CDC report based on NHANES data from 2023 estimated that about 32.7% of adolescents aged 12–17 had blood glucose or HbA1c values in the prediabetes range.\n\nAwareness remains low. Surveys since the mid-2000s have consistently found that most people with prediabetes are unaware of their status, which is a central reason for the emphasis on screening."
    },
    {
      "heading": "Risk factors",
      "text": "Established risk factors include overweight or obesity (particularly abdominal or visceral fat), physical inactivity, a family history of type 2 diabetes in a first-degree relative, age (risk increases from middle age), and membership in certain racial or ethnic groups with higher diabetes prevalence. Other associations include a history of gestational diabetes, polycystic ovary syndrome, hypertension, low HDL cholesterol, elevated triglycerides, a history of cardiovascular disease, and conditions characterized by insulin resistance. The ADA recommends screening adults who have overweight or obesity and at least one of these risk factors, and suggests that screening for everyone else begin at age 35.\n\nGenetic predisposition contributes substantially, but the strongest modifiable drivers are body weight, diet, and activity levels. Sleep disruption, chronic stress, and certain medications, such as some glucocorticoids, are also recognized as contributors to elevated glucose."
    },
    {
      "heading": "Pathophysiology",
      "text": "In most people, prediabetes reflects a combination of insulin resistance in muscle, liver, and adipose tissue and a gradual decline in the capacity of the pancreatic beta cells to compensate by secreting more insulin. Early in the process, the pancreas produces elevated insulin levels that keep glucose near normal; as beta-cell function falls, fasting and postprandial glucose begin to rise. IFG and IGT tend to reflect different relative contributions of hepatic glucose output and muscle glucose uptake, which is one reason the two categories are not interchangeable."
    },
    {
      "heading": "Progression and complications",
      "text": "Prediabetes does not inevitably lead to diabetes. Estimates of progression vary by population and by follow-up period. Some widely cited figures suggest that up to 70% of people with prediabetes eventually develop type 2 diabetes, while others, including longitudinal cohort data, report lower annual conversion rates, often around several percent per year in unselected populations, with a meaningful proportion reverting to normal glucose tolerance. Estimates are sensitive to which diagnostic criteria are used and to whether lifestyle or drug interventions were in place.\n\nEven before diabetes is diagnosed, elevated glucose is associated with increased cardiovascular risk. Many people with prediabetes already show signs of atherosclerotic changes, and the presence of prediabetes is often used as a prompt for broader cardiovascular risk assessment, including blood pressure, lipid levels, and kidney function."
    },
    {
      "heading": "Prevention and management",
      "text": "The best-supported interventions are lifestyle programs. The Diabetes Prevention Program trial, a randomized controlled trial conducted in the United States, found that intensive lifestyle modification reduced the incidence of diabetes by a substantially larger margin than placebo, and by more than the drug metformin in the same study. Core elements include modest weight loss (commonly around 5–7% of body weight), at least about 150 minutes per week of moderate physical activity, and dietary changes emphasizing fiber, reduced refined carbohydrates, and reduced energy intake. CDC describes these programs as capable of cutting the risk of type 2 diabetes roughly in half for participants who make sustained changes.\n\nPharmacological options, principally metformin, are used in selected patients, particularly those with high risk such as younger adults with obesity or a history of gestational diabetes. Other agents, including some newer glucose-lowering drugs, have been studied but are not routinely recommended for prediabetes alone. Bariatric surgery has been associated with diabetes remission and prevention in people with obesity, but its use for prediabetes is limited by surgical risk and cost.\n\nMonitoring is typically repeated at intervals. The ADA recommends annual testing for people with prediabetes, and periodic retesting for those with normal results depending on initial values and risk."
    },
    {
      "heading": "Controversies and limitations",
      "text": "Several issues remain debated. The first is whether the term itself is helpful. Critics argue that labelling a large fraction of the population as having a condition may lead to overdiagnosis, excess anxiety, or medicalization of a risk state; supporters respond that the label identifies people who can benefit from lifestyle intervention and that early detection is cost-effective when it leads to prevention.\n\nThe second concerns diagnostic variability. Fasting glucose, two-hour OGTT results, and HbA1c do not always agree in the same individual, and HbA1c can be affected by hemoglobin variants, anemia, and some ethnic-specific differences in red blood cell turnover, so single tests may misclassify some people.\n\nThe third concerns screening in children and adolescents. The epidemiological studies that underpin the adult thresholds were conducted in adult populations, and ADA guidance has extended their use to younger people while noting this evidence gap. The fourth concerns the threshold itself: because risk increases continuously, different thresholds between organizations shift the number of people counted as prediabetic, with implications for public health planning and for the reported prevalence.\n\nFinally, the magnitude of progression risk and the durability of lifestyle benefits after programs end remain active areas of research."
    }
  ],
  "links": [
    "diabetes-mellitus",
    "type-two-diabetes",
    "cardiovascular-disease",
    "glycated-hemoglobin",
    "pancreas",
    "insulin",
    "atherosclerosis",
    "randomized-controlled-trial",
    "metformin"
  ],
  "sources": [
    {
      "title": "2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes—2026",
      "url": "https://diabetesjournals.org/care/article/49/Supplement_1/S27/163926/2-Diagnosis-and-Classification-of-Diabetes"
    },
    {
      "title": "Diabetes Screening and Diagnosis: ADA 2026 Guideline Summary",
      "url": "https://reference.medscape.com/cc2/p10/guideline-essentials-2025-american-diabetes-association-2025a100074f"
    },
    {
      "title": "Prediabetes - Endotext - NCBI Bookshelf - NIH",
      "url": "https://www.ncbi.nlm.nih.gov/books/NBK538537/"
    },
    {
      "title": "Prediabetes Trends Among U.S. Adults",
      "url": "https://www.uspharmacist.com/article/prediabetes-trends-among-us-adults"
    },
    {
      "title": "Diabetes statistics: Read the facts",
      "url": "https://www.singlecare.com/blog/news/diabetes-statistics/"
    },
    {
      "title": "A U.S. Report Card",
      "url": "https://www.cdc.gov/diabetes/communication-resources/diabetes-statistics.html"
    },
    {
      "title": "Nearly a third of U.S. teens have prediabetes, CDC says",
      "url": "https://www.statnews.com/2025/07/09/prediabetes-in-teens-cdc-says-nearly-one-in-three-teenagers-at-risk-of-type-2-diabetes/"
    },
    {
      "title": "The Surprising Truth About Prediabetes",
      "url": "https://www.cdc.gov/diabetes/prevention-type-2/truth-about-prediabetes.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Ffeatures%2Fdiabetesprevention%2Findex.html"
    },
    {
      "title": "Restored CDC",
      "url": "https://www.restoredcdc.org/www.cdc.gov/diabetes/php/data-research/index.html"
    },
    {
      "title": "Prediabetes: Could It Be You?",
      "url": "https://www.cdc.gov/diabetes/communication-resources/prediabetes-statistics.html"
    },
    {
      "title": "Prediabetes",
      "url": "https://www.cdc.gov/diabetes/prevention-type-2/prediabetes-prevent-type-2.html"
    },
    {
      "title": "Awareness of Prediabetes — United States, 2005–2010",
      "url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604913/"
    },
    {
      "title": "2. Classification and Diagnosis of Diabetes: Standards of Medical Care in Diabetes—2022",
      "url": "https://diabetesjournals.org/care/article/45/Supplement_1/S17/138925/2-Classification-and-Diagnosis-of-Diabetes"
    }
  ],
  "license": "https://creativecommons.org/licenses/by/4.0/"
}