What is statistics for diabetes type II
Diabetes is a serious disease that can have a significant impact on the health, quality of life, and life expectancy of individuals, as well as on the health-care system. Approximately 16 million men, women, and children in the United States have diabetes (10% have type I and 90% have type II diabetes), representing about 6% of the total population.
Eight million of these individuals have been diagnosed with diabetes; the other 8 million are undiagnosed and may be unaware that they have this disorder.[1,2] Many of these individuals are asymptomatic for years and often have developed diabetic complications before a diagnosis is made.
Prevalence of Type II Diabetes
The prevalence of diabetes increases with age. For the years 1991-1993, the mean percentage of people with diagnosed diabetes increased substantially from 0.8% in the under 45-year-old age group to 5.8% in the 45- to 64-year-old age group.
Another striking increase occurred in the 45- to 64-year-old age group compared with the 65- to 74-year-old age group (5.8% to 10.7%, respectively).
Gender differences in the prevalence of diagnosed diabetes also can be observed. Women have a slightly higher prevalence than men (55% vs 45%, respectively).
These differences are more readily observed at a national level and less apparent in smaller databases such as the community, in part because of variations in risk factors, such as obesity or genetic composition.
Racial and ethnic variations in the prevalence of diagnosed and undiagnosed diabetes in the United States: a disproportionate prevalence of diabetes exists among African Americans, Hispanic Americans, and American Indians.
The Pima Indians of Arizona have the highest rate of diabetes in the world. Approximately 50% of the population between ages 30 and 64 years of age have type II diabetes. A high prevalence of type II diabetes also exists among other Native American groups.
The overall prevalence of diabetes (type I and type II) has increased steadily over the last 35 years.
The 3% rate reported for the years 1991-1993 is more than three times the rate in 1960 (0.9%) and eight times the rate in 1935 (0.4%).
Several possible reasons for the substantial increases over time include:
- Increasing age of the US population (diabetes prevalence increases with age)
- Reduction in mortality rates of people with diabetes because of improved screening, detection, and health care
- Increase in risk factors such as:
- Degree of obesity
- Physical inactivity.
In the United States, the prevalence of undiagnosed type II diabetes is approximately equal to the rate of diagnosed type II diabetes.
Consequently, the actual prevalence of diabetes is twice the rate of diagnosed diabetes. In addition, 10% to 15% of people age 50 years and older are estimated to have undiagnosed type II diabetes. When age adjustments are taken into consideration, the rate of undiagnosed diabetes is 1.5 times higher in African Americans and 1.7 times higher in Mexican Americans than in Caucasians.
Undiagnosed type II diabetes threatens the health of many people, particularly because complications are likely to develop the longer that diabetes goes unrecognized and untreated. For example, retinopathy has been observed in 20% of individuals with undiagnosed type II diabetes at the time of their initial diagnosis.
Higher rates of macrovascular complications (stroke, angina, myocardial infarction) also are common at the time of diagnosis in people with previously undiagnosed type II diabetes.
Incidence of Type II Diabetes
Data for 1990 to 1992 suggest that approximately 625,000 people are diagnosed with diabetes each year.
Nearly half of the new cases are found in people age 55 years and older, and more women are diagnosed than men (58% vs 42%, respectively).
The average annual incidence rate in the United States in 1990 to 1992 was 2.4 per 1000 people.
Although incidence rates increased during the 1960s, they were more stable from 1968 through 1992. The 1990 to 1992 incidence rate of 2.4 per 1000 was 1.4 times the rate in 1964 (1.8 per 1000) and 6.4 times the rate in 1935 to 1936 (0.4 per 1000).
Ethnic/racial variations in incidence of diabetes are similar to the prevalence rates in these populations. African Americans, Hispanics, and Native Americans have a higher incidence rate than Caucasians.
Mortality in Type II Diabetes
A significant number of deaths in the United States each year can be attributed to diabetes. In 1993, approximately 400,000 deaths from all causes were reported in people with diabetes. This figure represents 18% of all deaths in the United States in people age 25 years and older.
According to the National Center for Health Statistics, diabetes was the seventh leading cause of death listed on US death certificates in 1993, and the sixth leading cause of death by disease type. Based on death certificate data, diabetes is the:
- Fourth leading cause of death in African American women
- Third leading cause of death in:
- Hispanic women ages 45 to 74 years
- Native American women ages 65 to 74 years.
Higher mortality rates in these racial/ethnic groups are partially related to the higher prevalance of diabetes in these populations.
Having type II diabetes reduces the life expectancy of middle-aged people by approximately 5 to 10 years, although this number decreases as a person ages.
Women tend to lose more years of life expectancy than men, particularly when they are diagnosed at a young age. Having complications of type II diabetes also reduces life expectancy.
The leading causes of death according to the death certificates of people with diabetes – cardiovascular diseases and multi-organ failure due to severe nerve and blood vessels damages.
People with diabetes are 2 to 4 times more likely to die from heart disease than people without diabetes. This risk exists regardless of age and the presence of other risk factors. Excess risk of cardiovascular mortality exists in younger people as well as:
- Older people with diabetes
- Those with younger onset and longer duration
- Those using insulin
The presence of complications in people with type II diabetes also increases their risk of death. Other factors that influence the risk of early death in type II diabetes, which are similar for people with type I diabetes, are:
- Duration of diabetes
- Lack of blood glucose control
- Cardiovascular risk factors such as:
- Abnormal lipid levels
- Physical inactivity
- Central obesity.