Insulin Resistance and Diabetes

May 25, 2022
Insulin Resistance and Diabetes

Type 2 diabetes, prediabetes, and insulin resistance are on a continuum.  Type 2 diabetes (DM2), previously referred to as “adult-onset” or “non-insulin-dependent diabetes, progresses from an often symptom-free insulin resistance to high blood sugar elevation after meals to a disease that has many medical complications associated with it when poorly controlled. The frequency of DM2 is rising at an alarming rate in the United States.  In the US, there are over 34 million Americans living with diagnosed diabetes (~ 1 out of 10) and 90% are type 2 (type 1 diabetes is a different medical condition where the pancreas stops making insulin; I will discuss in an upcoming blog post). Diabetes is the 6th leading cause of death in the world. What is more alarming is that approximately 1 out of 3 American adults have prediabetes and many more have insulin resistance, and many are unaware that they have the condition.

DM2 does not just appear overnight; it takes many years to develop.  The first step is insulin resistance.  Insulin is a hormone that helps to regulate blood sugar and store energy.  When someone is insulin resistant, this means that the cells do not respond properly to insulin and blood sugars.  This leads the pancreas to overproduce insulin to fix the issue.  When insulin is chronically elevated, it is harder for the body to efficiently burn body fat for energy.  And over time, the cells in the pancreas that produce insulin cannot continue to keep up the pace, which can lead to a diagnosis of prediabetes and then ultimately diabetes.

Insulin resistance can lead to:

  • Impaired fasting glucose, DM2, and increased insulin requirements in type 1 diabetes,
  • Increased risk for coronary artery disease,
  • Metabolic syndrome,
  • Polycystic ovary syndrome (PCOS),
  • Nonalcoholic fatty liver disease,
  • Increased risk for certain cancers,
  • Increased weight gain, especially visceral fat.

Often insulin resistance is not picked up until a diagnosis of prediabetes or DM2 is made.  If you are concerned that you might have insulin resistance, you should discuss it with your doctor; a fasting blood sugar alone or an A1C unfortunately does not always pick up insulin resistance; additional labs can be considered including a fasting insulin.  

Diabetes can be diagnosed:

Symptomatic: classic symptoms of hyperglycemia (thirst, frequent urination, weight loss, blurry vision) and random blood glucose values of 200 mg/dL or higher. 


  • Fasting Glucose ≥126 mg/dL, 
  • Two-hour plasma glucose values of ≥200 after glucose tolerance test,
  • A1C values ≥6.5%

Prediabetes can be diagnosed:

  • Fasting Glucose between 100-125 mg/dL,
  • Two-hour plasma glucose values of 140-199 after glucose tolerance test,
  • A1C value 5.7-6.4 %. 

Some long-term complications from DM2 include:

  • Vision-retinopathy, cataracts and glaucoma, 
  • Coronary Heart Disease,
  • Stroke,
  • Cognitive Impairment,
  • Kidney Disease,
  • Nerve Issues-leading to numbness, wounds, and sometimes amputation,
  • Erectile Dysfunction.

Insulin resistance can be treated and sometimes reversed with some changes including:

  • Avoiding processed flours and sugars,
  • Eating whole “real” foods,
  • Exercise,
  • Weight loss,
  • Time Restricted Eating (see blog).

There are also medications that can help lower insulin that you can discuss with your physician. If you have prediabetes or diabetes, the same lifestyle recommendations apply but you should discuss additional medical interventions if necessary.  As always, you should always discuss your treatment plan with your doctor. 


DISCLAIMER: Sarah Smith MD is a medical doctor, but she is not your doctor, and she is not offering medical advice on this website. If you are in need of professional advice or medical care, you must seek out the services of your own doctor or health care professional.