Type 1 diabetes is an autoimmune disease in which the immune system destroys the insulin-producing beta cells of the pancreas. This results in a deficiency of insulin, causing chronic hyperglycemia.
A report from the SEARCH for Diabetes in Youth study, a national multicenter study sponsored by the CDC and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), found that between 2002 and 2005, 15,600 new cases of type 1 diabetes were diagnosed in the US37. The incidence and prevalence of type 1 diabetes are summarized in Tables 14-15.
|SEARCH for Diabetes in Youth, 2002-2005||US children under 10 years||19.7 per 100,000|
|US children 10-20 years||18.6 per 100,000|
Source: Mayer-Davis et al. 200937
|SEARCH for Diabetes in Youth||Age <20 years||0.148% (2001)||Dabelea et al. 20141|
|NHANES 1999-2000||Age 20-39 years||0.34-0.42%||Menke et al. 201338|
|Age 40-59 years||0.31-0.49%|
|Age 60+ years||0.08-0.12%|
Type 1 diabetes incidence rates appear to be rising; assuming increases over time, the prevalence of type 1 diabetes may increase by as much as 144% by the year 2050 (Table 16).
|SEARCH DATA Model Scenarios||Prevalence Projection for 2010-2050|
|Scenario 1: constant incidence over time||0.197% to 0.18% decrease/stable|
|Scenario 2: increases over time by age group||144% increase|
Source: Imperatore et al. 201239
Most recent studies place the prevalence of type 1 diabetes among US youth between 0.15% and 0.2%.
Data from the SEARCH study indicated that the prevalence of type 1 diabetes among youth increased 21.1% between 2001 and 2009, with similar increases for boys and girls and in most racial/ethnic and age groups.1 The increase in prevalence in Scenario 2 was expected to occur especially among youths of minority race/ethnicity.39
In the SEARCH for Diabetes in Youth Study (2009), where the population was drawn from five geographic areas of the US, the prevalence of type 1 diabetes differed somewhat from a study that represented nearly 253,000 schoolchildren in Philadelphia, Pennsylvania.40 In the SEARCH study, the prevalence was based on youths younger than 20 years; the Philadelphia study (2005) found that the prevalence of type 1 diabetes varied only slightly by ethnicity (Table 17).
|Race/Ethnicity||Prevalence of type 1 diabetes|
|SEARCH for Diabetes in Youth (0-19 years)||Lipman et al. 2013 (4-18 years)|
Source: 0–19 years, Dabelea et al. 20141; 4–18 years, Lipman et al. 201340
In a US study that compared two cohorts of type 1 diabetes patients based on year of diagnosis, the life expectancy at birth for those diagnosed between 1965 and 1980 was 15 years greater than participants diagnosed between 1950 and 1985 (68.8 years vs 53.4 years). The reasons for this increase in life expectancy was presumed to be due to earlier recognition and improved treatment; better glucose monitoring and insulin administration; reduction of renal disease resulting from improved diabetes care; and possibly, the increase in statin use.41 In addition, mortality of adult diabetes patients due to hyperglycemic crisis (including diabetic ketoacidosis and hyperglycemic hyperosmolar state) decreased by 64% between 1990-201014, in part due to the near-universal adoption of protocols to treat these conditions.
Overall, life expectancy is decreased among individuals living with type 1 diabetes compared to those living without. In a recent study of Scottish type 1 diabetes patients, males lost 11.1 years of life expectancy, and females lost 12.9 years when compared to persons living without type 1 diabetes. Even among patients with preserved renal function, males lost 8.3 years of life expectancy and females lost 7.9 years. The overall largest percentage of loss in life expectancy resulted from ischemic heart disease: men lost 36% and females lost 31% of life expectancy compared with persons without type 1 diabetes. Death from diabetic coma or ketoacidosis was associated with the largest percentage of estimated life expectancy loss occurring before age 50 (29.4% in males, 21.7% in females).42
Intensive therapy and glycemic control appears to lower the mortality rate among type 1 diabetes patients. In the multisite Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study, after a mean of 27 years’ follow-up of patients with type 1 diabetes, 6.5 years of initial intensive diabetes therapy was associated with a modestly lower all-cause mortality rate when compared with conventional therapy (64 versus 43 deaths).43
Insulin is an integral part of the treatment for type 1 diabetes. Insulin (regular) or modified versions of insulin (analogs) are given subcutaneously either by injection or an infusion device. An analysis of 2007 MarketScan commercial claims data found that among youth aged 19 and younger with diabetes, 92% took insulin.17 This likely reflects the relatively higher prevalence of type 1 diabetes in the younger age groups, as insulin is required for survival in type 1 diabetes. However, insulin therapy is sometimes used in youth with type 2 diabetes.
An analysis of over 3,000 children and adolescents (6-17 years of age) enrolled in the type 1 diabetes Exchange Clinic Registry showed that those with “excellent” glycemic control (A1C < 7%) tended to use insulin pumps and performed self-monitoring of blood glucose more frequently than those who had “poor” glycemic control (A1C ≥ 9%).44 Similar results were found in a study of the type 1 diabetes Exchange registry’s adult cohort (greater than 26 years of age), in which the “excellent” control group was more likely to be using an insulin pump than those in the “poor” control group.45
Among patients with type 1 diabetes, levels of glucose control have been linked to mortality. One study reported 2- to 3-fold greater risks of all-cause and cardiovascular mortality in the highest compared to the lowest quartiles of glycosylated hemoglobin.46
In a recent Cochrane review of 12 studies, intensive glucose control was more effective than conventional glucose control at reducing microvascular complications of diabetes such as retinopathy, nephropathy, and neuropathy, as shown in Table 18. 47
|Complication||Intensive glucose control||Conventional glucose control|
|Retinopathy||63 per 1000||232 per 1000|
|Nephropathy||159 per 1000||284 per 1000|
49 per 1000
139 per 1000
Overall, the incidence of major diabetes complications appears to be declining. The Pittsburgh Epidemiology of Diabetes Complications (EDC) Study showed that the estimated incidence of coronary artery disease, end-stage renal disease, and blindness among type 1 diabetes patients was lower among the cohort of patients diagnosed in the 1970s compared to those diagnosed in the 1960s. The authors of this study noted a concurrent decline in microalbuminuria, which may explain the improvements between the two cohorts.41