Type 2 Diabetes

In one clinic based study of White and African American children the prevalence of type 2 diabetes increased tenfold from 0.7 per 100,000 to 7.2 per 100,000 from 1982-1994.  In this clinical practice the percentage of children and adolescents with Non-Insulin Dependent Diabetes Mellitus (NIDDM)  increased from 2%-4% of all newly diagnosed diabetes in 1992 to 16% in 1994.¹³⁹ 

The prevalence of type 2 diabetes among Pima Indian children is the highest reported to date and has increased significantly from 1967 to 1996.¹⁴⁰

NHANES III data provide an estimated prevalence of type 2 diabetes of 4.1 per 1,000 among US children.¹³⁴  For comparison, the prevalence of type 1 diabetes in youth under age 20 is 1.7 per 1,000.¹³⁸  Although undiagnosed type 2 diabetes is common in adults, it is unknown how many cases of type 2 diabetes in children are undiagnosed.^134,138  Also, African American and Hispanic children with type 2 diabetes may be diagnosed as having type 1.¹³⁸

Ethnic Disparities

Black, Hispanic and Native American adolescents are at higher risk for type 2 diabetes, as 94% of youth with type 2 diabetes are a member of a minority group.^138,141

Additionally, the prevalence of type 2 diabetes among minority youth is a concern, as the minority youth population is rapidly growing. 

An earlier age of onset means an earlier onset of complications.¹³⁸  When the impact of multiple morbidities is considered, type 2 diabetes can be more devastating than type 1 diabetes.¹³⁸   Several studies have estimated the prevalence of type 2 diabetes in different racial/ethnic groups.

• Native American
  
• A population based study of Pima Indians in Arizona found a prevalence of 22.3 cases per 1,000 among 10-14 year olds and 50.9 per 100,000 among 15-19 year olds.¹³⁸ 
• A population based study of Navajo Indians in New Mexico noted a prevalence of both type 1 and type 2 diabetes of 22.3 per 1,000 among 12-19 year olds.¹³⁸
• The Indian Health Service reports a prevalence of 1.3 per 1,000 of both type 1 and type 2 diabetes among 0-14 year olds and 4.5 per 1,000 among 15-19 year olds.¹³⁸
  
• Between 1988 and 1996, the Indian Health Service noted a 54% increase in diabetes among adolescents aged 15-19.¹³⁴ The prevalence of diabetes among Native Americans in the Southwest increased 61% to 4.6 per 1,000 from 1988 to 1997.¹³⁷
  
• African American
  • Reports from clinical practices note that 69%-75% of type 2 diabetes patients are Black.^135,139
  • Fewer African American children with type 2 diabetes presented with weight loss than white children.
  • Blood pressure was higher in African American children than White children with 32% classified as hypertensive compared to 4% of White children.
  • Children with non-insulin dependent diabetes were less knowledgeable about their disease and its management than those with insulin dependent diabetes.^142,143
    
    
• Hispanic
  • A study of cases of non insulin dependent diabetes in San Antonio, Texas found that 83% of the cases were Hispanic while 52% of population is Hispanic.¹⁴⁴

Factors Contributing to the Increasing Prevalence

Factors contributing to the increased prevalence of type 2 diabetes are a sedentary lifestyle; high calorie/high fat diet; and obesity.^134,139,141 

As many as 85% of children and adolescents with type 2 diabetes are obese.^{134,139,141,142,143,144} 

Although type 2 diabetes is usually diagnosed during middle or late puberty, younger prepubertal children may be diagnosed with type 2 diabetes as obesity continues to increase among children. Glycosylated hemoglobin levels, a measure of long term blood sugar levels, were higher in black and Mexican American girls and boys than White girls and boys.¹⁴⁵ 

Glycosylated hemoglobin levels are related to atherosclerosis in youth and may indicate a preclinical stage of diabetes.¹⁴⁵

A study in Alabama reported that insulin sensitivity among Black children was 40% lower and the insulin response two times greater than White children.¹⁴⁶ 

Studies of African American, Mexican American, and Pima Indian youth have documented higher insulin levels suggestive of compensated insulin resistance.  This may indicate a genetic predisposition to insulin resistance which when combined with the insulin resistance that occurs during puberty and obesity, could result in type 2 diabetes.^{134,135,136,141,147} 

Insulin resistance/hyperinsulinemia is associated with the risk of developing hypertension and dyslipidemia.  The Bogalusa Heart study noted correlations between fasting insulin levels and blood pressure as well as adverse lipid profiles in children and young adults.¹⁴⁷  Insulin resistance at age 21, as measured by glucose utilization, was greater among those who were obese at age 13.¹⁴⁸

Family history of diabetes also is a risk factor as 45%-80% of children with type 2 diabetes have a parent with diabetes, and 74%-100% have a first or second degree relative with type 2 diabetes.^134,136  In Pima Indians diabetes occurs more often in those who were low birth weight, who were high birth weight (>4.5 kg), and who were exposed to diabetes in utero.^135,140,149

Compliance with Treatment

Compliance with treatment of type 2 diabetes among Native American, Mexican American, and African American youth is poor, as indicated by high mean glycosylated hemoglobin values.^136,138

A follow-up study of Pima Indians as young adults found indication of kidney disease in 60% and severe kidney disease in 17%, hypercholesterolemia in 30%, hypertriglyceridemia in 55%, and hypertension in 14%.¹³⁷  Adults diagnosed with type 2 diabetes as children are at higher risk for complications as diabetes complications are related to disease duration.¹³⁷ 

Diabetes complications tend to occur earlier in Hispanic patients than non-Hispanic patients.¹³⁶

Culturally appropriate prevention programs require an understanding of health beliefs and behaviors of the target group.¹³⁷ 

American native youth with a family member with diabetes did not relate the complications of diabetes such as retinopathy or amputations to the disease. 

Additionally many believed that diabetes was contagious or was caused by "bad blood" or "weakness."¹³⁵