Epidemiology and Pathophysiology

Epidemiology 

  • 30.3 million Americans, or 9.4% of the US population, have diabetes.1
  • 7.2 million people with diabetes are undiagnosed.1

Reference 2.

Diabetes affects people of all races and ethnicities, but disparities exist.3

  • American Indians/Alaskan Natives comprise the largest age-adjusted racial/ethnic group of people diagnosed with diabetes.
  • The proportion of African-American, Hispanic, and Asian American populations who have diabetes is higher than in the non-Hispanic white population.

Reference 3.

 

1.5 million new cases of diabetes were diagnosed in adults in the United States in 2015. An estimated 355,000 new cases of diabetes occurred in patients age 18-44 years, 809,000 new cases in patients age 45-64 years, and 366,000 new cases in patients 65 years or older.1

Estimated incidence of diabetes among adults aged ≥18 years, United States, 2015

Characteristic No. in thousands (95% CI)a Rate per 1,000 (95% CI)b
Total 1,530 (1,402–1,658) 6.7 (6.2–7.3)
Age in years
18–44 355 (289–420) 3.1 (2.6–3.8)
45–64 809 (714–905) 10.9 (9.6–12.2)
≥65 366 (310–422) 9.4 (8.0–10.9)
Sex
Women 787 (694–880) 6.8 (6.0–7.6)
Men 743 (645–840) 6.7 (5.9–7.7)

CI = confidence interval.

a Numbers for subgroups may not add up to the total because of rounding.

b Rates are crude, not age-adjusted.

Data source: 2013–2015 National Health Interview Survey, 2011–2014 National Health and Nutrition Examination Survey, and 2015 U.S. Census Bureau data.

Reference 1

Approximately 5,300 people younger than 20 years were diagnosed with type 2 diabetes annually during 2008-2011.1

  • The proportion of newly diagnosed cases in people under 20 years of age was higher among US minority populations than in non-Hispanic whites.1
  • Between 2001 and 2009, the overall prevalence of type 2 diabetes among children and adolescents increased by 30.5% when adjusted for differences in completeness of ascertainment.4

 

Trends in type 2 diabetes prevalence among children and adolescents, 2001-2009, by sex and age and race/ethnicity 4

NHW=non-Hispanic white; AA=African American; HISP=Hispanic; API=Asian Pacific Islander; AI=American Indian.

  • In 2015, 84 million Americans age 20 and older had prediabetesan increase from 79 million in 2010.1

 

  • In 2015, based on fasting glucose or A1C levels, 34% of U.S. adults aged 18years or older, or an estimated 84 million Americans, hadprediabetes.1
    • 48% of those adults 65 years or older had prediabetes.
  • On the basis of fasting glucose or A1C levels, and after adjusting for population age differences, thepercentage of U.S. adults aged 20 years or older with prediabetes in 2009−2012 was similar for non-Hispanicwhites (32%), non-Hispanic blacks (37%), non-Hispanic Asians (36%) and Hispanics (32%).1

 

  • Diabetes was the seventh leading cause of death in the United States in 2017.5
    • The death rate due to diabetes may be underreported.6
    • Studies have reported that only about 35% to 40% of people with diabetes who died had diabetes listed anywhere on the death certificate.6
    • Approximately 10% to 15% had it listed as the underlying cause of death.6

 

Pathophysiology

Diabetes is characterized by the dysfunction of insulin-producing pancreatic beta cells, insulin hormone resistance in cells of the body, or a combination of both.8,9

  • Genetic predispositions and environmental factors that affect beta-cell function and insulin sensitivity have both been implicated in the development of type 2 diabetes.8,9
  • Type 2 diabetes begins with a resistance to insulin that worsens over time.7
  • When the pancreatic beta-cell can no longer produce enough insulin to compensate for a diminished insulin response, glucose concentrations rise and B cell functions are impaired.8
  • The progressive failure of beta cells is responsible for the transition from impaired glucose tolerance to type 2 diabetes.9

Reference 9.

References

  1. Centers for Disease Control and Prevention. National Diabetes Statistics Report, 2017. Atlanta, GA: Centers for Disease Control and Prevention, U.S. Dept of Health and Human Services; 2017. https://www.cdc.gov/diabetes/data/statistics/statistics-report.html. Accessed May 9, 2019.
  2. https://www.cdc.gov/diabetes/library/socialmedia/infocards.html. Accessed May 13, 2019.
  3. https://www.cdc.gov/diabetes/disparities.html. Accessed May 13, 2019.
  4. Dabelea D, Mayer-Davis EJ, PhD, Saydah S, et al; SEARCH for Diabetes in Youth Study. Prevalence of type 1 and type 2 diabetes among children and adolescents from 2001 to 2009. JAMA. 2014; 311:1778-1786.
  5. Murphy SL, Xu JQ, Kochanek KD, Arias E. Mortality in the United States, 2017. NCHS Data Brief, no 328. Hyattsville, MD: National Center for Health Statistics. 2018.
  6. American Diabetes Association. Statistics about diabetes. www.diabetes.org/diabetes-basics/statistics/?loc=db-slabnav. Accessed May 14, 2019.
  7. Levin PA. Practical combination therapy based on pathophysiology of type 2 diabetes. Diabetes Metab Syndr Obes. 2016;9:355-369.
  8. Kahn SE, Cooper ME, Del Prato S. Pathophysiology and treatment of type 2 diabetes: perspectives on the past, present, and future. Lancet. 2014;383:1068-1083.
  9. DeFronzo RA, Bonadonna RC, Ferrannini E. Pathogenesis of NIDDM. A balanced overview. Diabetes Care. 1992;15:318-368.