Approximately 29 million Americans have diabetes, although a quarter of them are unaware of it.
Approximately 29 million Americans have diabetes, although a quarter of them are unaware of it.1Notably, the prevalence of diabetes is expected to double or triple by the year 2050.2
Diabetes currently accounts for 8% of legal blindness in the United States, and it is the leading cause of end-stage renal disease and nontraumatic lower extremity amputation.3,4It is also an independent risk factor for cardiovascular disease and is the seventh-leading cause of death.5Identifying and treating diabetes early is essential to prevent long-term complications.
What Is Diabetes?
It is a group of metabolic disorders, with a key feature being hyperglycemia, that can be broadly categorized as type 1 (T1D) and type 2 diabetes (T2D).3,4This article does not discuss diabetes secondary to other factors, such as genetic syndromes, gestational diabetes, drugs, infections, or pancreatic disease.
What Is the Difference Between T1D and T2D?
T2D accounts for approximately 90% to 95% of all diabetes cases and is a multifactorial disease with a genetic predisposition; however, it is largely preventable with behavior modification. It is characterized by decreased peripheral tissue response to insulin and B-cell dysfunction.4The average age of onset is over 40, but T2D can occur at any age and is strongly associated with obesity and a sedentary lifestyle.
Meanwhile, T1D only accounts for about 5% to 10% of cases and is an autoimmune disease that typically manifests before age 20.4It results from autoimmune-induced pancreatic beta cell destruction that leads to absolute insulin deficiency.4This means that patients will always be insulin-dependent.
What Are the Symptoms of T1D and T2D?
The symptoms reflect the pathophysiologic process. T1D typically has much more pronounced sudden symptoms than T2D. Due to the altered metabolism, a patient with T1D will have glycosuria-induced osmotic diuresis. This leads to polyuria, polydipsia, and polyphagia. The unopposed counterregulatory hormones—glucogon and growth hormone—can lead to weight loss and weakness.4
Patients with T1D may also present with diabetic ketoacidosis (DKA), which results from severe insulin deficiency and excessive release of free fatty acids and hepatic oxidation, which makes ketone bodies.4DKA may present with polydipsia, polyuria, malaise, weakness, nausea, vomiting, decreased appetite, kussamaul breathing, altered level of consciousness, and signs of severe dehydration.6It is a life-threatening condition.
In contrast, T2D symptoms are often lacking or insidious. Patients are typically older and overweight, and may have sedentary lifestyles and poor diets. Symptoms typically do not present until the condition has been present for some time or is very uncontrolled. Patients may have frequent infections, such as vaginal yeast infections, acanthosis nigricans, blurred vision, obesity, neuropathy, nephropathy, and foot ulcers.3
DKA is uncommon in T2D because these patients are still able to produce insulin, which limits ketone body production; however, patients may still present with hyperosmolar hyperglycemic state (HHS) on rare occasion.4This is usually associated with states of acute stress, infection, or dehydration, and it is more likely to occur in elderly patients.7Most patients with HHS present with severe dehydration, neurologic deficits, hyperglycemia, and hyperosmolarity.4This life-threatening condition has a mortality rate of 10% to 20%.7
What Are Some Microvascular and Macrovascular Changes Associated With Diabetes?
Diabetes can cause vascular alterations that lead to multiorgan dysfunction. Microvascular changes include retinopathy, nephropathy, and neuropathy, while macrovascular changes are ischemic heart disease, peripheral vascular disease, and cerebrovascular disease. Risk factors for macrovascular changes are obesity, hyperglycemia, insulin resistance, dyslipidemia, hypertension, and tobacco use.8
How Is Diabetes Diagnosed?
By 1 of 4 methods: fasting blood glucose, random blood glucose, a 2-hour oral glucose tolerance test (OGTT), or hemoglobin A1C measurement (average blood sugar). The following values are diagnostic of diabetes3,9:
What Are the Normal Variations in Blood Sugar in Nondiabetics?
Blood sugar rises and falls throughout the day, depending on when an individual eats and how high the glycemic index is for the food or drink. Typical blood sugar in a healthy individual will be lower than 100 mg/dL before breakfast and lower than 110 mg/dL before lunch, dinner, or snack.9,10Two hours after meals, it should be lower than 140 mg/dL, and at bedtime, it should be lower than 120 mg/dL.10
The higher the glycemic index in a food, the greater impact that food will have on blood sugar. Diabetic patients should monitor their carbohydrate intake and minimize high-glycemic foods. For example, meats and fats do not have carbohydrates, so they do not have a glycemic index, but foods like candies, cookies, white bread, and pastries have very high glycemic indexes, which will negatively impact blood sugar. Both diabetic and nondiabetic individuals should minimize refined carbohydrate intake and eat more whole foods made of healthy proteins and fibers. Examples of good carbohydrates are steel-cut oatmeal, oatbran, pumpernickel, bulgar, barley, beans, peas, legumes, most fruits, and most nonstarchy vegetables.
What Is Prediabetes?
Impaired fasting glucose or impaired glucose tolerance is abnormal blood sugar that often progresses to diabetes, also called prediabetes. Each year, there is a 5% to 10% risk of prediabetes progressing to diabetes.4The condition is associated with obesity, dyslipidemia with high triglycerides, and hypertension.11Prediabetes has a fasting glucose range between 100 mg/dL and 125 mg/dL and an A1C value between 5.7% and 6.4%.3
Who Should Be Screened for Diabetes, and How Often?
The US Preventive Services Task Force recommends that adults with a sustained blood pressure of 135/80 mm Hg or more, treated or untreated, should be screened.12It also recommends others to be screened, on an individual basis, depending on risk factors.12The American Diabetes Association believes this screening should be repeated approximately every 3 years.11Any asymptomatic individuals with risk factors should be screened, as well as anyone over age 45. Individuals who have a body mass index of 25% or higher and have the following risk factors should also be screened3:
What Can a Convenient Care Clinician Do to Address Diabetes?
Typically, retail health is viewed as a primary care safety net. It is generally not meant to replace seeing the primary care provider, but often serves many of the same functions. Patients may choose a retail health clinic out of convenience, cost savings, personal preference, or inability to get an appointment with their primary care provider soon enough. The retail health provider has an excellent opportunity to combat the diabetes epidemic in various ways. These clinics often provide screening for diabetes, diabetic nephropathy, hypertension, and dyslipidemia, as well as weight-loss and smoking-cessation counseling, medication refills, surveillance of disease progression, referrals, and much more.
Because retail health clinics are stocked with vaccines, and many primary care offices are not, the retail health provider has a perfect opportunity to offer much-needed vaccines to diabetic patients that may be missed or delayed in other health care settings. These providers can give immunizations—such as the flu, Hepatitis B, pneumococcal, Tdap, and zoster vaccines—perform a physical exam, obtain immediate lab results, provide counseling, refill a medication, and initiate a referral, all in one visit. This can provide significant value for a patient’s present and future health.
What About Education and Counseling in the Retail Health Setting?
Diabetes is highly prevalent in the United States, and many patients seen by providers in urgent care, primary care, and retail health settings already have either diagnosed or undiagnosed diabetes. The retail health setting is an excellent place for initiating the wellness process and providing counseling. Weight loss, smoking cessation, hypertension management and monitoring, and immunizations are cornerstones of retail health, as well as of diabetes disease progression management.
Sara Marlow is a licensed and board-certified family nurse practitioner, public health nurse, and adjunct assistant professor of health policy. She was the spring 2015 health policy fellow at the American Association of Nurse Practitioners’ government affairs office in Washington, DC, and is the current co-chair of the Health Policy and Practice Committee of the California Association for Nurse Practitioners.