According to data from the 2020 Prevention Diabetes Surveillance System and the Centers for Disease Control, it is estimated that diabetes affects approximately 10.5% (34.2 million people) of all U.S. adults, with 20% (7.3 million) of that population yet undiagnosed. As unmanaged diabetes can lead to serious health complications such as blindness, cardiovascular disease, limb amputation, and kidney failure, it is imperative for individuals at high risk for diabetes to be screened frequently.

CLINICAL RISK FACTORS

Obesity – Adults who are overweight or obese have the highest risk of developing prediabetes and type 2 diabetes (T2D). Excess body fat, assessed by body mass index (BMI), is associated with various metabolic abnormalities that lead to insulin resistance and is the strongest risk factor for T2D. Additionally, abdominal obesity, assessed by waist circumference, as well as visceral adiposity are independent predictors for T2D risk. In an analysis of 5 National Health and Nutrition Examination Surveys (NHANES) over 30 years, BMI accounted for approximately 50% and 100% of increase in diabetes prevalence in males and females, respectively.

Family History – Individuals with a first degree relative (ie, parents, siblings, or offspring) diagnosed with T2D have a two- to three-fold increased risk of developing diabetes. The risk increases to five- to six-fold in those with both maternal and paternal history of T2D.

LIFESTYLE RISK FACTORS

Even though clinical and genetic factors play a significant role in the development of T2D, multiple studies have found that lifestyle factors including physical activity, dietary patterns, and smoking can also significantly influence the risk of T2D.

Physical Inactivity – The American Diabetes Association (ADA) lists physical inactivity as one of the risk factors for developing T2D. Multiple prospective cohort studies have shown that a sedentary lifestyle promotes weight gain and increases the risk of T2D whereas physical activity, including both aerobic exercises and resistance training, significantly lowers the risk. Moreover, there is evidence that suggests that physical inactivity is a strong risk factor for T2D even without weight gain.

Poor Diet – Dietary patterns are known to affect the risk of T2D. The Canadian Task Force on Preventive Health Care considers diets with limited intake of vegetables and fruits as a risk factor for developing T2D. Additionally, multiple observational studies have found that a diet high in sugar sweetened beverages, red meat, and processed meat is associated with an increased risk of T2D, whereas a diet rich in vegetables, fruits, whole grains, and olive oil is linked with a decreased risk. A large prospective study (N=84,941) found that the incidence of diabetes in women who ate a diet high in cereal fiber and polyunsaturated fat and low in glycemic load and saturated and trans fats was 90% lower than those who did not.

Smoking – Cigarette smoking is likely associated with an increased risk of T2D. A 2007 meta-analysis of 25 prospective cohort studies (N=1.2 million) concluded that current smokers are at a greater risk of developing T2D than nonsmokers. The risk is found to increase with dosage and duration of cigarette use. The current ADA guidelines advise the cessation of all tobacco-related products.

DEMOGRAPHIC RISK FACTORS

Population data show disparities in the prevalence and incidence of T2D among different ethnic groups. There was an increased age-standardized prevalence of total diabetes in non-Hispanic Black (21.8%), non-Hispanic Asian (20.6%), and Hispanic (22.6%) individuals when compared to non-Hispanic White individuals in an analysis of 2011-2012 NHANES data. The ethnic disparities may primarily be associated with biological risk factors (eg, BMI, waist circumference, blood pressure) but also with modifiable risk factors (eg, socioeconomic, neighborhood, psychosocial, and behavioral) during young adulthood.