Type 2 Diabetes

Symptoms

• Frequent urination (polyuria)
• Increased thirst (polydipsia)
• Increased hunger (polyphagia)
• Unexplained weight loss, despite normal or increased food intake
• Fatigue or lack of energy
• Blurred vision
• Slow-healing sores or cuts
• Frequent infections, such as skin, gum, or bladder infections
• Numbness or tingling in the hands or feet (neuropathy)
• Dark, velvety patches of skin, usually in body folds and creases (acanthosis nigricans)
• Signs of a hyperglycemic crisis, such as very high blood sugar (over 600 mg/dL), extreme thirst, confusion, or altered consciousness, which require immediate medical attention.
• Signs of diabetic ketoacidosis (DKA), including nausea, vomiting, stomach pain, or fruity-scented breath, especially during illness or stress.

Causes & Risk Factors

• Insulin resistance, where your body's cells (muscle, fat, and liver) do not respond efficiently to insulin, meaning the pancreas must produce higher amounts of insulin.
• Progressive beta-cell dysfunction, where the insulin-producing cells in the pancreas are unable to sustain the high output of insulin needed to overcome insulin resistance, leading to a relative insulin deficiency.
• Genetic factors, as a strong hereditary component exists, with multiple genes contributing to susceptibility.
• Obesity, particularly excess adipose tissue (visceral fat), which promotes insulin resistance through the release of inflammatory cytokines and other factors.
• Lifestyle factors, including physical inactivity and unhealthy dietary patterns, which contribute significantly to the development of insulin resistance.
• Age, with risk increasing particularly after 35-45 years.
• Family history, especially having a first-degree relative with type 2 diabetes.
• Race/Ethnicity, with higher prevalence in African American, Hispanic/Latino, American Indian, Asian American, and Pacific Islander populations.
• History of Gestational Diabetes Mellitus (GDM) during pregnancy.
• Genetic predisposition, with numerous genetic variants linked to increased risk.
• Overweight and obesity, particularly central or visceral adiposity (Body Mass Index (BMI) ≥25 kg/m² or ≥23 kg/m² in Asian Americans).
• Physical inactivity and a sedentary lifestyle.
• Prediabetes, indicated by impaired glucose tolerance (IGT) or impaired fasting glucose (IFG).
• High blood pressure (hypertension), defined as ≥140/90 mmHg or being on therapy for hypertension.
• Unhealthy cholesterol levels (dyslipidemia), specifically HDL cholesterol level <35 mg/dL and/or a triglyceride level >250 mg/dL.
• Diet high in processed foods, sugar-sweetened beverages, and saturated/trans fats.
• Smoking, as smokers are 30–40% more likely to develop type 2 diabetes than nonsmokers.
• Polycystic Ovary Syndrome (PCOS), due to its association with insulin resistance.
• Acanthosis Nigricans, a skin condition often signaling insulin resistance.
• History of Cardiovascular Disease (CVD).
• Non-alcoholic fatty liver disease (NAFLD).
• Obstructive Sleep Apnea.
• Certain medications, such as glucocorticoids, thiazide diuretics, or some atypical antipsychotics.

Diagnosis

• A Hemoglobin A1c (A1C) test result of 6.5% (48 mmol/mol) or higher. Unless there is unequivocal hyperglycemia, the diagnosis requires two abnormal test results from the same sample or in two separate test samples.
• A Fasting Plasma Glucose (FPG) test result of 126 mg/dL (7.0 mmol/L) or higher, after not eating for at least 8 hours. Unless there is unequivocal hyperglycemia, the diagnosis requires two abnormal test results from the same sample or in two separate test samples.
• A 2-hour Plasma Glucose (2-h PG) test result of 200 mg/dL (11.1 mmol/L) or higher during an oral glucose tolerance test (OGTT) using 75 grams of glucose. Unless there is unequivocal hyperglycemia, the diagnosis requires two abnormal test results from the same sample or in two separate test samples.
• A Random Plasma Glucose test result of 200 mg/dL (11.1 mmol/L) or higher in a patient with classic symptoms of hyperglycemia or hyperglycemic crisis.
• For prediabetes, an A1C between 5.7–6.4% (39–47 mmol/mol), FPG between 100–125 mg/dL (5.6–6.9 mmol/L), or 2-h PG during OGTT between 140–199 mg/dL (7.8–11.0 mmol/L).
• A thorough review of your medical history, including symptoms, risk factors, family history, dietary patterns, physical activity level, and history of comorbidities (e.g., heart disease, high blood pressure, unhealthy cholesterol levels).
• A physical examination, including measurements of height, weight, BMI, waist circumference, blood pressure, and a comprehensive foot and skin examination (e.g., for acanthosis nigricans).
• Additional laboratory tests, such as a lipid panel, liver function tests, spot urinary albumin-to-creatinine ratio (UACR), and serum creatinine to estimate glomerular filtration rate (eGFR).
• In cases where the diagnosis is unclear (e.g., atypical presentation), tests like autoantibody testing (e.g., GAD65) and C-peptide levels may be considered to help distinguish type 2 diabetes from other forms, such as type 1 diabetes or monogenic diabetes syndromes.

Treatment Options

• Diabetes Self-Management Education and Support (DSMES) as a foundational part of your treatment plan.
• Medical Nutrition Therapy (MNT), focusing on a balanced diet rich in whole foods, portion control, and limiting processed carbohydrates and sugar, with weight management as a primary goal.
• Regular physical activity, aiming for at least 150 minutes per week of moderate-intensity aerobic activity spread over at least 3 days, with no more than 2 consecutive days without activity, plus 2-3 sessions per week of resistance exercise.
• Weight management, with a goal of at least 5% weight loss recommended for most individuals with overweight or obesity. More intensive goals (10-15%) can provide greater benefits, including potential for diabetes remission.
• Smoking cessation, if you smoke, as it is strongly advised.
• Metformin as the preferred initial medication, assuming no contraindications.
• Additional medications, such as GLP-1 receptor agonists (GLP-1 RAs) or SGLT2 inhibitors, especially if you have established or high risk of atherosclerotic cardiovascular disease (ASCVD), heart failure (HF), or chronic kidney disease (CKD), independently of your A1C.
• Medications chosen to minimize the risk of low blood sugar (hypoglycemia), such as GLP-1 RAs, SGLT2 inhibitors, DPP-4 inhibitors, or thiazolidinediones (TZDs), which are preferred over sulfonylureas or insulin.
• Medications that can help with weight loss, such as GLP-1 RAs or SGLT2 inhibitors, with dual GIP/GLP-1 receptor agonists (e.g., tirzepatide) showing superior efficacy for both blood sugar control and weight loss.
• Injectable therapies: If oral agents are insufficient, GLP-1 RAs are generally preferred over insulin. If insulin is needed, a basal insulin is typically initiated first.
• Metabolic (bariatric) surgery, recommended as a treatment option for adults with type 2 diabetes and a BMI of 40 kg/m² or higher (or 37.5 kg/m² or higher in Asian ancestry). It should be considered for those with a BMI of 35.0–39.9 kg/m² who do not achieve durable weight loss and improvement in comorbidities with nonsurgical methods.
• Regular monitoring of your A1C every 3-6 months, blood pressure at every routine visit, lipid profile annually or as needed, and kidney function (urine albumin-to-creatinine ratio and eGFR) annually.
• Annual comprehensive dilated eye examinations and annual comprehensive foot examinations.
• Referrals to specialists such as a registered dietitian for Medical Nutrition Therapy, an ophthalmologist for eye screening, a podiatrist for high-risk foot conditions, a nephrologist for advanced chronic kidney disease, a cardiologist for cardiovascular disease management, or an endocrinologist for complex management cases.

Frequently Asked Questions